Provided by: critcl_3.1.9-1build1_all 
NAME
critcl - Critcl - Package Reference
SYNOPSIS
package require Tcl 8.4
package require critcl ?3.1.8?
package require platform ?1.0.2?
package require md5 ?2?
::critcl::ccode text
::critcl::ccommand tclname cfunname
::critcl::ccommand tclname arguments body ?option value...?
::critcl::cdata tclname data
::critcl::cdefines definitions ?namespace?
::critcl::cproc name arguments resulttype body ?option value...?
::critcl::cproc name arguments resulttype
::critcl::cinit text externals
::critcl::api import name version
::critcl::api function resulttype name arguments
::critcl::api header ?pattern...?
::critcl::api extheader ?file...?
::critcl::license author ?text...?
::critcl::summary text
::critcl::description text
::critcl::subject ?key...?
::critcl::meta key ?word...?
::critcl::meta? key
::critcl::buildrequirement script
::critcl::cheaders ?arg...?
::critcl::csources ?pattern...?
::critcl::clibraries ?arg...?
::critcl::source path
::critcl::tsources pattern...
::critcl::owns pattern...
::critcl::cflags ?arg...?
::critcl::ldflags ?arg...?
::critcl::framework ?arg...?
::critcl::tcl version
::critcl::tk
::critcl::preload lib...
::critcl::debug area...
::critcl::check ?label? text
::critcl::checklink ?label? text
::critcl::msg ?-nonewline? msg
::critcl::print ?-nonewline? ?chan? msg
::critcl::compiled
::critcl::compiling
::critcl::done
::critcl::failed
::critcl::load
::critcl::config option ?val?
::critcl::cache ?path?
::critcl::clean_cache ?pattern...?
::critcl::readconfig path
::critcl::showconfig ?chan?
::critcl::showallconfig ?chan?
::critcl::chooseconfig target ?nomatcherr?
::critcl::setconfig target
::critcl::actualtarget
::critcl::buildforpackage ?flag?
::critcl::cnothingtodo file
::critcl::cresults ?file?
::critcl::crosscheck
::critcl::error msg
::critcl::knowntargets
::critcl::sharedlibext
::critcl::targetconfig
::critcl::buildplatform
::critcl::targetplatform
::critcl::cobjects ?arg...?
::critcl::scan path
::critcl::name2c name
::critcl::argnames arguments
::critcl::argcnames arguments
::critcl::argcsignature arguments
::critcl::argvardecls arguments
::critcl::argconversion arguments ?n?
::critcl::argoptional arguments
::critcl::argdefaults arguments
::critcl::argsupport arguments
::critcl::userconfig define name description type ?default?
::critcl::userconfig query name
::critcl::userconfig set name value
::critcl::at::caller
::critcl::at::caller offset
::critcl::at::caller offset level
::critcl::at::here
::critcl::at::get*
::critcl::at::get
::critcl::at::= file line
::critcl::at::incr n...
::critcl::at::incrt str...
::critcl::at::caller!
::critcl::at::caller! offset
::critcl::at::caller! offset level
::critcl::at::here!
::critcl::collect_begin
::critcl::collect_end
::critcl::collect script
::critcl::resulttype name body ?ctype?
::critcl::resulttype name = origname
::critcl::argtype name body ?ctype? ?ctypefun?
::critcl::argtype name = origname
::critcl::argtypesupport name code
::preload library
_________________________________________________________________________________________________
DESCRIPTION
Welcome to the C Runtime In Tcl, CriTcl for short, a system to build C extension packages
for Tcl on the fly, from C code embedded within Tcl scripts, for all who wish to make
their code go faster.
This document is the reference manpage for the critcl package. This package is the
system's core, i.e. it provides the essential functionality on top of which everything
else is built. Its intended audience are mainly developers wishing to write Tcl packages
with embedded C code. Some of its sections are however for developers wishing to
understand the package internals, and the API it provides to the CriTcl Application. These
sections will be marked, allowing package writers to skip them. Users of critcl on the
other hand are hereby refered to the applications' manpage, i.e. CriTcl Application. If
you are in need of an overview of the whole system instead, please go and read the
Introduction To CriTcl.
This package resides in the Core Package Layer of CriTcl.
+----------------+
|Applications |
| critcl |
| critcl::app |
+----------------+
*================*
|Core Packages |
| critcl |
| critcl::util |
*================*
+----------------+
|Support Packages|
| stubs::* |
| md5, platform |
| ... |
+----------------+
API
A short note ahead of the documentation: Instead of repeatedly talking about "a ".tcl"
with embbedded C code", or "a ".tcl" containing critcl commands", etc. we use a shorthand
and simply call them ".critcl" files, regardless of their file extension.
EMBEDDED C CODE
The package provides five commands to declare various types of C code fragments. These
are:
::critcl::ccode text
This command compiles the C code in text and makes the contained definitions
(variables, functions, macros, etc.) available to all C code fragments specified
after it. It itself can assume to have access to all definitions which were
specified before it. See section Runtime Behaviour for more details.
The result of the command is the empty string.
::critcl::ccommand tclname cfunname
This command creates a new Tcl command named tclname which is implemented by the C
function cfunname. It is expected that cfunname has the proper signature for a Tcl
command function, and was declared already.
The result of ::critcl::ccommand itself is the empty string.
::critcl::ccommand tclname arguments body ?option value...?
This form of critcl::ccommand creates a new Tcl command named tclname which is
implemented by the C code in body.
The command wraps the body in an invisible C function, compiles it and makes the
resulting definition available to all C code fragments declared later on. It itself
can assume to have access to all definitions which came before it. See section
Runtime Behaviour for more details.
The result of critcl::ccommand itself is the empty string.
The list of arguments contain the names for the four parameters required by a Tcl
command function. Superfluous list elements (i.e. beyond the fourth) are ignored.
Missing elements (parameters), and empty parameter names are handled by replacing
them with standard names. These are, in order of usage
[1] clientdata
[2] interp
[3] objc
[4] objv
The only options accepted by this command are:
-clientdata c-expression
The value of this option is the text of a single C expression. The value of
expression is used in the generated C statement registering tclname to
initialize the client data of the new Tcl command. If not specified the
expression defaults to NULL, i.e. no client data.
-delproc c-expression
The value of this option is the text of a single C expression. The value of
this expression has to be a function pointer of type "Tcl_CmdDeleteProc",
which is used in the generated C statement registering tclname to initialize
a deletion function for the new Tcl command, i.e. a function which is run by
Tcl when the Tcl command is deleted again. If not specified the expression
defaults to NULL, i.e. no deletion function.
-cname boolean
The value of this option is a boolean flag. If true the name of the command
is the C identifier of the command function. Namespaces, etc. are in that
case not relevant at all. The default value of this option is false, causing
the system to derive a name from the Tcl level command name, including its
namespace.
A ccommand is, in comparison to functions defined via critcl::cproc, more lower
level. Its advantage is that the developer can do their own argument processing,
enabling things like variable number of arguments, options, etc., i.e. much higher
flexibility. Their disadvantage is that you have to do your own argument
processing. Where a critcl::cproc generates the code to convert from Tcl values to
C values and back a critcl::ccommand forces the writer to do all of this on their
own. I.e. the cost of the aforementioned flexibility is a higher complexity seen by
the user.
::critcl::cdata tclname data
This command a new Tcl command named tclname which returns data as a ByteArray
result.
The result of critcl::cdata itself is the empty string.
::critcl::cdefines definitions ?namespace?
This command creates Tcl variables in the specified namespace which are linked to
the C enum values and #defines named as glob patterns in the list of definitions.
Each variable has the same name as the definition which gave rise to it, and its
value is the value of the corresponding enum value or #define. The namespace
defaults to the global namespace, i.e. "::", if it wasn't specified explicitly.
Please note that this command is only for the lifting of existing C definitions
into Tcl. The command does not create the definitions in C. It actually goes so far
to check for the presence of the named definitions and not performing the mapping
for any which do not exist. Which is sensible, given that non-existing defines have
no value which could be used in the mapping.
As these checks are run at the time the embedded C code of a ".critcl" file is
actually compiled they have access to and check all C fragments defined with
critcl::ccode, plus all the headers it has access to via critcl::cheaders, for that
file.
::critcl::cproc name arguments resulttype body ?option value...?
This command creates a new Tcl command named tclname which is implemented by the C
code in body. In contrast to the low-level critcl::ccommand here the arguments and
result are typed and critcl generates the code converting from Tcl_Obj's to C data
types, and vice versa. The command creates two invisible C functions, one wrapping
the body, the other a shim containing the necessary conversions, compiles them and
makes the resulting definitions available to all C code fragments declared later
on. It itself can assume to have access to all definitions which came before it.
See section Runtime Behaviour for more details.
The result of critcl::cproc itself is the empty string.
The only options accepted by this command are:
-cname boolean
The value of this option is a boolean flag. If true the name of the command
is the C identifier of the command function. Namespaces, etc. are in that
case not relevant at all. The default value of this option is false, causing
the system to derive a name from the Tcl level command name, including its
namespace.
-pass-cdata boolean
The value of this option is a boolean flag. If specified and set the shim
translating from Tcl to C level and back will pass the command's ClientData
to the function. If not specified the flag defaults to false, i.e. no
passing of client data.
-arg-offset int
The value of this option is a positive integer number specifying the number
of hidden arguments preceding the actual procedure arguments. If not
specified the flag defaults to 0. This is useful to higher-order code
generator using the command in settings with prefix arguments which are not
directly seen by the function, but influence argument counting and
extraction.
The list below shows the values which are legal for resulttype, and details their
semantics:
Tcl_Obj*
object The function returns a value of type "Tcl_Obj*". This value becomes the
interpreter result, if not 0. The Tcl status is TCL_ERROR when a 0 is
returned, and TCL_OK otherwise.
Attention: The conversion assumes that the value belonged to the function,
with an associated reference count, and decrements the reference count to
indicate the loss of ownership by the function. This means that it is an
error to return a value whose reference count is zero.
char*
vstring
The function returns a value of type "char*". This value becomes the
interpreter result, wrapped in a String. It is assumed that the string is
volatile in some way, with the wrapping in a String duplicating it before
making it the result, ensuring that we will not access a dangling pointer in
the future. The Tcl status is always TCL_OK.
const char*
Like type char* above, except that the returned string is const-qualified.
string
dstring
The function returns a value of type "char*". Contrary to the previous
string types here it is assumed that the value is dynamically allocated, via
Tcl_Alloc. This value becomes the interpreter result, as usual, but is not
copied. The Tcl status is always TCL_OK.
double The function returns a value of type "double". This value becomes the
interpreter result, properly wrapped (Int). The Tcl status is always
TCL_OK.
float The function returns a value of type "float". This value becomes the
interpreter result, properly wrapped (Double). The Tcl status is always
TCL_OK.
boolean
bool The function returns a value of type "int", interpreted as boolean. This
value becomes the interpreter result, properly wrapped (Int). The Tcl
status is always TCL_OK.
int The function returns a value of type "int". This value becomes the
interpreter result, properly wrapped (Int). The Tcl status is always
TCL_OK.
long The function returns a value of type "long int". This value becomes the
interpreter result, properly wrapped (Long). The Tcl status is always
TCL_OK.
ok The function returns a value of type "int". It is interpreted as the Tcl
status code. The interpreter result is left untouched (empty).
void The function does not return a value. The interpreter result is left
untouched (empty). The Tcl status is always TCL_OK.
Please note that it is possible to extend the above with custom types if these types are
not enough. See section Advanced: Extending cproc for details.
The arguments parameter has the overall syntax of a Tcl dictionary value, except that keys
(argument names) and values (argument types) are specified in reverse order. Consider the
example
int x int y
where mapped to type/value int.
The argument names must be valid C identifiers.
A limited form of variadic arguments is possible, through optional arguments with
default values. For these the argument name is a 2-element list containing the
actual name, and the default value. For example, in the declaration
int {x 1}
x optional argument of type int and default value 1.
One limitation, and one caveat!
First, the set of optional arguments must be a single contiguous segment in the
argument list. This limits them to a series of optional arguments at either the
beginning, end, or middle of the list. Multiple segments separated by non-optional
arguments are rejected, as the system cannot determine in these cases which
arguments are present and what to set where.
Second, the default value is assigned unconditionally. If a custom argument type
uses more complex validation, and the default may be invalid according to it, then
the relevant checks have to be done in the procedure body. The argument conversion
cannot do it as it is completely bypassed when the argument is not present.
Overcoming this requires the separation of argument conversion and validation code.
The list below shows the values which are legal for argument types, and details
their semantics:
Tcl_Obj*
object The function takes an argument of type "Tcl_Obj*". No argument checking is
done. The Tcl level word is passed to the argument as-is.
bytearray
rawchar*
rawchar
The function takes an argument of type "char*". The Tcl argument must be
convertible to ByteArray, an error is thrown otherwise. Note that the
length of the ByteArray is not passed to the function.
char* The function takes an argument of type "char*". The string representation
of the Tcl argument is passed in.
double The function takes an argument of type "double". The Tcl argument must be
convertible to Double, an error is thrown otherwise.
float The function takes an argument of type "float". The Tcl argument must be
convertible to Double, an error is thrown otherwise.
boolean
bool The function takes an argument of type "int". The Tcl argument must be
convertible to Boolean, an error is thrown otherwise.
int The function takes an argument of type "int". The Tcl argument must be
convertible to Int, an error is thrown otherwise.
long The function takes an argument of type "long int". The Tcl argument must be
convertible to Long, an error is thrown otherwise.
void*
double*
float*
int* The function takes an argument of the same-named C type. The Tcl argument
must be convertible to ByteArray, an error is thrown otherwise. The bytes
in the ByteArray are then re-interpreted as the raw representation of a C
pointer of the given type which is then passed as argument to the function.
In other words, this is for Tcl values somehow holding raw C pointers, i.e.
memory addresses.
Attention: These types are considered DEPRECATED. It is planned to remove
their documentation in release 3.2, and their implementation in release 3.3.
Their deprecation can be undone if good use cases are shown.
Note that optional arguments are not possible. This restriction is inherited from C.
Further note that the type of the first argument is allowed to be Tcl_Interp*. In that
case the argument in question is not counted as an argument of the new Tcl command.
::critcl::cproc name arguments resulttype
This variant of critcl::cproc assumes that the functionality to connect is
implemented by the C function name which has the signature described by the
arguments and resulttype.
It creates only the shim performing the conversions required by arguments and
result.
::critcl::cinit text externals
This command compiles the C code in text and externals.
Both have access to all definitions created by the previously listed commands,
regardless of their and its placement in the ".critcl" file. See section Runtime
Behaviour for more details.
The C code in text is put into the body of the initialization function of the
shared library backing the ".critcl" file, and is executed when this library is
loaded into the interpreter.
The code in externals on the other hand is placed outside and just before the
initialization function, making this is a good place for any external symbols
required by initialization function which should not be accessible by any other
parts of the C code.
The result of the command is the empty string.
STUBS TABLE MANAGEMENT
Newly introduced with critcl version 3 is the support for stubs tables, Tcl's dynamic
linking mechanism handling the resolution of symbols between C extensions. We won't go
into its details here. See http://wiki.tcl.tk/285 for an introduction in general, and
section Stubs Tables for the details of critcl's particular variant.
Critcl supports this via a single command, critcl::api, and its methods.
First, importing stubs tables, i.e. APIs, from another extension:
::critcl::api import name version
Critcl prepares the ".critcl" file and its companion ".c" files by including the
headers
[1] "name/nameDecls.h"
[2] "name/nameStubLib.h"
in the appropriate places. It is checked that the compiler will be able to find
these header files somewhere on the include search path, using the paths defined so
far (See critcl::cheaders, and the critcl application's -I and -includedir
options). Note how critcl expects the headers of package foo to reside in a sub-
directory "foo" of the known include search paths.
Important: If foo is a namespaced package name, like, for example "c::stack", then
the namespace separators "::" are converted into underscores ("_") in path names, C
code, etc.
The first header is expected to contain contains all the necessary stubs table type
declarations, mapping macros, etc., and may include package specific headers (See
critcl::api header below). This header is included at the beginning of the C code
backing the ".critcl" file, and at the beginning of all companion ".c" files. This
means that the writer of these files doesn't have to write the necessary #include
directory, critcl does it for them.
The second header is expected to contain the stubs table variable definition, and
the C code, i.e. definition, of the function to initialize it. This, and a call to
this initializer function are added to the ".critcl" file's initialization code.
If the directory containing the aforementioned headers also contains the file
"name/name.decls" then it is assumed that this file contains the external
representation of the stubs table used to generate the headers. The file is read
and the internal representation of the stubs table returned as result of the
command, for the importing package to use as it sees fit. If no such file is
present the command returns the empty string as its result.
One possible use would be the automatic generation of C code calling on the
functions listed in the imported API.
When generating a TEA wrapper the names of the imported APIs are used to declare
configure options with which the user can declare a non-standard location for the
headers of the API. Any API FOO is translated a single configure option --with-FOO-
include.
Second, declaration and export of a stubs table, i.e. API, for the current package, foo:
::critcl::api function resulttype name arguments
This method declares that the function name is in the public API of the package,
and its signature (type of the result, number, names and types of its arguments).
Using this method automatically causes critcl to generate both the code for a stubs
table in the package, the headers needed by packages using this API, and a ".decls"
file containing the stubs table implied by the exports, usable by critcl::api
import.
arguments is a list of C types and associated argument names. Like a dictionary,
except that keys (argument names) and values (argument types) are swapped. The
resulttype is a C type as well.
::critcl::api header ?pattern...?
This method notifies critcl of companion header files which have to be exported
together with the generated stubs headers.
All arguments are interpreted as glob pattern and the matching files are copied
into the directory containing the generated headers well. As an importing package
uses only "fooDecls.h" to access the API this generated header will contain the
necessary #include directives to make these companion header files and their
declarations available too. Patterns matching no file or non-existing files cause
the command to throw an error.
Note that patterns which are not beginning with an absolute path are interpreted
relative to the directory containing the current ".critcl" file.
::critcl::api extheader ?file...?
This method is similar ::critcl::api header, in that it notifies critcl of
companion header files which have to be exported together with the generated stubs
headers.
The difference is that these headers will be expected to exist in the external
development environment. As such they will be #included in the generated header
for the package, but not copied to the package header directory. Nor are they
allowed to be glob patterns, as critcl has no context, i.e directory, in which to
expand such patterns.
Note that the generated headers for an exported API are included in the package like it is
done when importing it somewhere else. To repeat:
The "fooDecls.h" header is included at the beginning of the C code backing the ".critcl"
file, and at the beginning of all companion ".c" files. This means that the writer of
these files doesn't have to write the necessary #include directory, critcl does it for
them.
In mode "compile & run" the generated header files, and their companion headers, if any,
are placed in the subdirectory "foo" of the Result Cache. As this location is implicitly
added to the include search path any other package importing this API and and build in
mode "compile & run" as well will find the these headers.
For mode "generate package" the application was extended with a new option -includedir
which specifies the location to place the generated headers in (again in subdirectory
"foo" of that path). This path is also be added to the include search paths, ensuring that
a package importing an API will find it if the package exporting that API used the same
setting for -includedir.
For mode "generate TEA" the static scanner was extended to recognize critcl::api header as
a source of companion files. It further uses data about critcl::api import commands to
put proper support for --with-foo-include options into the generate "configure(.in)" so
that a user may specify custom locations for the headers of any imported API.
PACKAGE META DATA
Newly introduced with critcl version 3 is support for TEApot meta-data.
While, from the package developer's perspective, some meta data support was already
present in critcl v2, through the command ::critcl::license, this was only used to
generate and place a file "license.txt" into the built package.
Now critcl supports the declaration of arbitrary meta data, which will be placed into a
file "teapot.txt" in a format suitable for use by the TEApot tools
[http://docs.activestate.com/activetcl/8.5/tpm/toc.html].
::critcl::license author ?text...?
This command provides information about the author of the package, and its license.
If no text is present the command expects to find a file "license.terms" in the
same directory as the ".critcl" file and reads the license from that. Otherwise the
license is the joined texts.
This information, the license, is ignored in mode "compile & run", only mode
"generate package" uses it. In that case the information is written to a file
"license.terms", a sibling to the "pkgIndex.tcl" file in the directory hierarchy of
the generated package.
This information is additionally placed into the meta data file "teapot.txt", under
the keys as::author and license.
The data specified by this command has priority over any information specified
through the generic API ::critcl::meta.
::critcl::summary text
Declares a short (one line is recommended) description of the package.
This information is ignored in mode "compile & run", only mode "generate package"
uses it. In that case the information is placed into the meta data file
"teapot.txt", under the key summary.
The data specified by this command has priority over any information specified
through the generic API ::critcl::meta.
::critcl::description text
Declares a longer description of the package.
This information is ignored in mode "compile & run", only mode "generate package"
uses it. In that case the information is placed into the meta data file
"teapot.txt", under the key description.
The data specified by this command has priority over any information specified
through the generic API ::critcl::meta.
::critcl::subject ?key...?
Declares one or more keywords and key-phrases describing the package, for an index.
Multiple calls of this command accumulate keywords and phrases.
This information is ignored in mode "compile & run", only mode "generate package"
uses it. In that case the information is placed into the meta data file
"teapot.txt", under the key subject.
The data specified by this command has priority over any information specified
through the generic API ::critcl::meta.
::critcl::meta key ?word...?
This command is for the declaration of arbitrary meta data outside of the reserved
keys as::author, as::build::date, description, license, name, platform, require
subject, summary, and version, Its behaviour is like ::critcl::subject, in that it
treats all keys as list of words, with each call declaring one or more words for
the key, and multiple calls extending the data for an existing key, if not
reserved.
While it is possible to declare information for one of the reserved keys with this
command such data is ignored when the final meta data is assembled and written.
Use the commands ::critcl::license, ::critcl::summary, ::critcl::description
::critcl::subject, package require, and package provide to declare data for the
reserved keys.
The information for the reserved keys as::build::date and platform is automatically
generated by critcl itself.
::critcl::meta? key
This command enables the retrieval of meta data information from with the code
defining a critcl based package. Given the key the associated value is returned as
the result of the command.
The envisioned main use is the retrieval of the package's name from within utility
packages having to adapt C code templates to their environment. An example of a
package using this command for exactly this purpose is critcl::class.
::critcl::buildrequirement script
This command provides control over the capturing of dependencies declared via
package require. It runs the script, and any dependencies declared within are
ignored, i.e. not recorded in the meta data.
CONTROL & INTERFACE
The package provides thirteen commands to control the details of compilation and linking,
enabling ".critcl" files to provide custom information about their environment and
dependencies.
In important thing to note about all these commands is that the package manages their
information on a per-file basis. I.e. information provided by and in a file "FOO.tcl" is
kept separate from the information provided by and in a file "BAR.tcl", preventing them
from interfering with each other.
The commands are:
::critcl::cheaders ?arg...?
This command provides the compile step with additional header files and header
locations.
All arguments matching the glob pattern -* are forwarded to the compiler's command
line when it is invoked for the current ".critcl" file.
All other arguments are interpreted as glob pattern and the matching files are made
available to the compiler when it is invoked for the current ".critcl" file.
Patterns matching no file or non-existing files cause the command to throw an
error.
Note that patterns which are not beginning with an absolute path are interpreted
relative to the directory containing the current ".critcl" file.
Note further that this declaration does not cause the specified header files to be
#include'd automatically. This still has to be done via critcl::ccode where
necessary. It does simply ensure that the compiler will be able to find these
files when invoked, by providing the necessary command line flags extending the
compiler's search paths.
Multiple invocations of this command accumulate their information.
::critcl::csources ?pattern...?
This command provides the compile step with additional C source files.
All arguments are intepreted as glob patterns. Patterns matching no file or non-
existing files cause the command to throw an error. The files matching the patterns
are made available to the compiler when it is invoked for the current ".critcl"
file. This means that the files in question are compiled together with the ".c"
file backing the ".critcl" file into a single object.
Note that patterns which are not beginning with an absolute path are interpreted
relative to the directory containing the current ".critcl" file.
Multiple invocations of this command accumulate their information.
::critcl::clibraries ?arg...?
This command provides the link step with additional libraries to link and library
locations.
All arguments matching the glob pattern -* are forwarded to the linkers's command
line when it is invoked for the current ".critcl" file.
All other arguments are interpreted glob patterns. Patterns matching no file or
non-existing files cause the command to throw an error. The files matching the
patterns are made available to the linker when it is invoked for the current
".critcl" file. This means that the files in question are linked together with the
object file backing the ".critcl" file into a single shared library.
Note that patterns which are not beginning with an absolute path are interpreted
relative to the directory containing the current ".critcl" file.
Multiple invocations of this command accumulate their information.
::critcl::source path
This command evaluates the critcl commands in the file specified by path in the
context of the current ".critcl" file.
The argument is actually considered as glob pattern and all matching files are
evaluated. A pattern matching no file or non-existing files cause the command to
throw an error.
Note that a pattern not beginning with an absolute path is interpreted relative to
the directory containing the current ".critcl" file.
::critcl::tsources pattern...
This command provides the critcl package with information about additional Tcl
script files to source when the shared library is loaded.
All arguments are considered as glob patterns and the matching files are made
available to generated shared library when it is loaded for the current ".critcl"
file. Patterns matching no file or non-existing files cause the command to throw an
error.
Note that patterns which are not beginning with an absolute path are interpreted
relative to the directory containing the current ".critcl" file.
Multiple invocations of this command accumulate their information.
The declared files are sourced after the shared library has been loaded, in the
same order they were provided to critcl::tsources.
::critcl::owns pattern...
This command is ignored by the regular build modes, i.e. both "compile and run",
and "generate package". It is present to support the static code scanner of critcl
v3's new mode to "generate TEA" packages.
In that situation it provides the critcl package with information about any files
which have to be wrapped and could not be figured out from the previous commands
(i.e. critcl::csources, critcl::tsources) because of getting specified dynamically,
or getting directly sourced and this not visible to critcl in any other way.
::critcl::cflags ?arg...?
This command provides the compile step with additional compiler flags.
All arguments are forwarded to the compiler's command line when it is invoked for
the current ".critcl" file.
Multiple invocations of this command accumulate their information.
::critcl::ldflags ?arg...?
This command provides the link step with additional linker flags.
All arguments are forwarded to the linkers's command line when it is invoked for
the current ".critcl" file.
Multiple invocations of this command accumulate their information.
::critcl::framework ?arg...?
This command provides the link step with the names of additional frameworks to link
on MacOS X. The command is ignored if we are not building for OS X. This means that
it is possible to declare the OS X specific frameworks unconditionally. The package
itself takes care to not use them when building for non-OS X platforms.
All arguments are forwarded to the linkers's command line when it is invoked for
the current ".critcl" file.
Multiple invocations of this command accumulate their information.
::critcl::tcl version
This command tells critcl for what minimum version of the Tcl runtime to compile
and link the package for. If not specified critcl falls back to the default of 8.4.
::critcl::tk
This command informs critcl that the package in question is based on Tk, and
therefore needs the Tk headers for compilation, and the Tk stubs for linking.
::critcl::preload lib...
This command arranges that the named dependent external shared library is loaded
before the generated package's shared library.
Multiple invocations of this command accumulate their information.
Each library FOO named for preload will be searched at the locations listed below,
in the order listed, and the search will stop on the first existing path.
Additional notes:
• platform is the placeholder for the target platform of the package.
• The extension ".so" is the placeholder for whatever actual extension is used
by the target platform for its shared libraries.
• Note how the search is relative to the current working directory.
And now the paths, depending on the exact form of the library name:
FOO
[1] FOO.so
[2] FOO/FOO.so
[3] FOO/platform/FOO.so
PATH/FOO
For this form the exact set searched depends on the existence of directory
"PATH/FOO". If it does not exist critcl searches
[1] FOO.so
[2] PATH/FOO.so
[3] PATH/platform/FOO.so
Otherwise it searches
[1] FOO.so
[2] PATH/FOO/FOO.so
[3] PATH/FOO/platform/FOO.so
instead.
/PATH/FOO
Even when specifying FOO with an absolute path the first path searched is
relative to the current working directory.
[1] FOO.so
[2] /PATH/FOO.so
[3] /PATH/platform/FOO.so
If you are a developer wishing to understand or modify the internals of the critcl
package then you possibly should read the section explaining how the Preloading
functionality is implemented.
::critcl::debug area...
This tells critcl if the package is to be compiled for debugging, and which areas
to activate. Internally each area is translated into area-specific flags for the
compiler which are then handed over to critcl::cflags.
memory Specification of this area activates Tcl memory debugging for the package
code.
symbols
Specification of this area activates compilation and linking with debugging
symbols, for use by a debugger or other tool.
all Specification of this area translates ino the activation of all other legal
areas.
INTROSPECTION
The package provides six commands to control compilation and linking. These are:
::critcl::check ?label? text
This command is useful to test if some functionality is available in the build
environment, and then select other C code fragments based on that information. It
immediately compiles the C code in text and returns a boolean value based on the
result of the compilation. The command returns true on success, and false
otherwise. If specified, the label is used to uniquely mark the check in the
generated log.
::critcl::checklink ?label? text
This command is an extenson of critcl::check above, useful to test if some
functionality is available in the build environment, and then select other C code
fragments based on that information. It immediately compiles and links the C code
in text and returns a boolean value based on the result of compilation and linking.
The command returns true on success, and false otherwise. If specified, the label
is used to uniquely mark the check in the generated log.
::critcl::msg ?-nonewline? msg
This command can be used by critc-based code to report results from critcl::check
and critcl::checklink. The default implementation used by mode compile & run
ignores any calls.
Tools like the CriTcl Application are allowed to redefine this procedure to perform
their own way of message reporting. The package critcl::app and the application on
top print such messages to stdout, for example.
::critcl::print ?-nonewline? ?chan? msg
This command is used by the critcl internals to report its activity. Its signature
is equivalent to the Tcl builtin command ::puts. The default implementation is
effectively ::puts.
Tools directly using either the critcl package, or the critcl application package
are allowed to redefine this procedure to perform their own way of printing.
An example of this is Kettle
[https://chiselapp.com/user/andreas_kupries/repository/Kettle/index] where the
newest revisions use this to highlight build warnings.
::critcl::compiled
This command returns a boolean value. It returns true if the C code of the current
".critcl" file is already compiled, and false otherwise.
This predicate effectively enables a ".critcl" file used as its own Tcl companion
file (see critcl::tsources) to distinguish between sourced by mode "compile & run"
for compilation and sourced from either the result of mode "generate package" or
during the load phase of "compile & run". In case of the two latter possibilities
the result is true, and false for the first.
::critcl::compiling
This command returns a boolean value. It returns true if C code can be compiled on
this platform in general, i.e. if a C compiler is available, and false otherwise.
::critcl::done
This command returns a boolean value. It returns true when critcl has built the
embedded C code, and false otherwise.
This enables the Tcl code of a critcl-based package to distinguish between it
getting used as a prebuilt package, versus dynamic compile & run, and take action
based on that.
Note that this command is only useful from within a ".critcl" file. The result is
managed on a per-file basis, like is done for the commands embedding C code and
controlling the behaviour of compiler and linker.
See also section Modes Of Operation/Use.
::critcl::failed
This command returns a boolean value. It returns true if critcl has failed to build
the package. As part of this it forces the building of the package, but not its
loading. Note that it will attempt to build the package only on the first call;
future calls for the same package will return a cached result.
This enables a critcl-based package to check itself for availability and throw an
error if it could not be built.
Note that this command is only useful from within in a ".critcl" file. The result
is managed on a per-file basis, like is done for the commands embedding C code and
controlling the behaviour of compiler and linker.
::critcl::load
This command is like critcl::failed, except that it also forces the loading of the
generated shared library, if it was built, and that its result has reversed sense.
It returns true if critcl succeeded in building and loading the package.
This enables a critcl-based package to to not only check itself for availability
and throw an error if it could not be built, but also force an immediate load,
circumventing the default behaviour, which is lazy. See also section Runtime
Behaviour.
Note that this command is only useful from within in a ".critcl" file. The result
is managed on a per-file basis, like is done for the commands embedding C code and
controlling the behaviour of compiler and linker.
BUILD MANAGEMENT
The package provides a single command for the management of global settings, i.e.
configuration options which are independent of any ".critcl" file.
It is expected that this command is irrelevant to anybody just wishing to write a
".critcl" file. It is a management command which is only useful to the CriTcl Application
or similar tools.
::critcl::config option ?val?
This command sets and returns critcl's global configuration options. These are
force bool
This flag tells the package whether it should force the building of C files
despite having a cached shared library (when true, or not. The default is
off.
lines bool
This flag tells the package whether to embed #line directives into the
generated C code (when true) or not. By default this is on.
Side note: This facility requires the use of a tclsh supporting the builtin
info frame command. If critcl is run by a tclsh not supporting this no #line
directives will be emitted. The command is supported by Tcl 8.5 and higher.
It is also supported by Tcl 8.4 provided that it was compiled with the
define -DTCL_TIP280. An example of such is ActiveState's ActiveTcl.
Developers of higher-level packages generating their own C code, either
directly, or indirectly, by using critcl commands, should also read section
Advanced: Location management to see how critcl helps them in generating
their directives. Examples of such packages come with critcl itself, see
the packages critcl::iassoc and critcl::class.
I path A single global include path to use for all files. Not set by default.
combine enum
dynamic
Object files have the suffix _pic.
static Object files have the suffix _stub.
standalone
Object files have no suffix, and the generated C files are compiled
without using Tcl/Tk stubs. The result are object files usable for
static linking into a big shell.
The default is dynamic.
language string
keepsrc bool
This flag tells the package whether to keep the generated ".c" files after
it has build their ".o" files (when true), or not. The default is off.
outdir path
The path where to place a generated shared library. Not set by default,
causing placement into the Result Cache.
RESULT CACHE MANAGEMENT
This package provides two commands for the management of the Result Cache. See that
section for background information.
NOTE that these commands are irrelevant to anybody just wishing to write a package using
critcl for the C parts. They are management commands which are only useful to the CriTcl
Application or similar tools.
::critcl::cache ?path?
This command sets and returns the path to the directory for the package's result
cache.
The default location is "~/.critcl/[platform::generic]" and usually does not
require any changes.
::critcl::clean_cache ?pattern...?
This command cleans the result cache, i.e. removes any and all files and
directories in it. If one or more patterns are specified then only the files and
directories matching them are removed.
BUILD CONFIGURATION
This package provides four commands for the management of the build configuration, i.e.
the per-platform information about compilers, linkers, and their commandline options.
NOTE that these commands are irrelevant to anybody just wishing to write a package using
critcl for the C parts. They are management commands which are only useful to the CriTcl
Application or similar tools.
::critcl::readconfig path
This command reads the build configuration file at path and configures the package
using the information for the currently set target platform.
::critcl::showconfig ?chan?
This command converts the currently active build configuration into a human-
readable string and prints the result to the channel chan. If chan is not present
the string is instead returned as the result of the command.
::critcl::showallconfig ?chan?
This command converts the set of all known build configurations (from the currently
active build configuration file last set with critcl::readconfig) into a string and
print the result to the channel chan. If chan is not present the string is instead
returned as the result of the command.
::critcl::chooseconfig target ?nomatcherr?
This command takes a target identifier and matches it against all known targets,
returning a list containing all the matching ones. This search is first done on an
exact basis, and then via glob matching. If no known target matches the argument
the default is to return an empty list. However, if the boolean nomatcherr is
specified and set, and error will be thrown instead, using critcl::error.
::critcl::setconfig target
This command takes a target identifier and configures the package to use all its
settings.
TOOL API
The twelve commands in this section provide tools like CriTcl Application or similar with
deeper access to the package's internals. These commands are irrelevant to anybody just
wishing to write a ".critcl" file.
::critcl::actualtarget
This command returns the platform identifier of the target platform, i.e. the
platform the generated code will be built for. In contrast to
::critcl::targetplatform this is the true target, with any cross-compilation
information resolved.
::critcl::buildforpackage ?flag?
This command signals whether the next file to be build is built for inclusion into
a package or not. If not specified the flag defaults to true, i.e. building for a
package. This disables a number of things in the backend, namely the linking of
that file into a shared library, and loading such. It is expected that the build
results are later wrapped into a larger collection.
::critcl::cnothingtodo file
This command checks whether there is anything to build for file.
::critcl::cresults ?file?
This command returns the build result information for the specified file. If no
file is specified the information is taken from info script. The result in
question is a Tcl dictionary with the following keys, and their meanings:
clibraries
The list of external shared libraries, and/or locations thereof to link the
file needs for successful linking.
ldflags
The list of linker flags needed by the file for successful linking.
license
The license the package in the file is under. A string.
mintcl The minimum version of Tcl required by the package in the file to run
successfully. A proper Tcl version number.
objects
The list of object files backing the file, to be linked.
preload
The list of libraries the generated package has to preload to allow the
package in the file to run successfully.
tk A boolean indicating whether the package in the file has to be linked
against Tk or not.
tsources
The list of companion ".tcl" files to source for the package in the
".critcl" file to run successfully.
log The build log in case of failure, and ::critcl::buildforpackage having
signaled the build of a package. Otherwise the empty string.
::critcl::crosscheck
This command checks if the package is configured for cross-compilation and prints a
message to the standard error channel if so.
::critcl::error msg
This command is used by the package to report internal errors. The default
implementation simply throws the error. Tools like the CriTcl Application are
allowed to redefine this procedure to perform their own way of error reporting.
There is one constraint they are not allowed to change: The procedure must not
return to the caller.
::critcl::knowntargets
This command returns a list containing the identifiers of all targets found during
the last invocation of critcl::readconfig.
::critcl::sharedlibext
This command returns the file extension used by shared libraries on the target
platform.
::critcl::targetconfig
This command returns the target identifier chosen to by either system or user to
build code for.
::critcl::buildplatform
This command returns the platform identifier of the build platform, i.e. where the
package is running on.
::critcl::targetplatform
This command returns the platform identifier of the target platform, i.e. the
platform the generated code will be built for. In contrast to
::critcl::actualtarget this may be the name of a cross-compilation target.
::critcl::cobjects ?arg...?
This command is like ::critcl::clibraries, provides the link step with additional
information. Instead of libraries the arguments are object files however. Despite
this similarity it is not listed in section Control & Interface because it is of no
use to package writers. Only tools like the CriTcl Application have need of it.
All arguments are interpreted glob patterns. Patterns matching no file or non-
existing files cause the command to throw an error. The files matching the patterns
are made available to the linker when it is invoked for the current ".critcl" file.
This means that the files in question are linked together with the object file
backing the ".critcl" file into a single shared library.
Note that patterns which are not beginning with an absolute path are interpreted
relative to the directory containing the current ".critcl" file.
Multiple invocations of this command accumulate their information.
::critcl::scan path
This command is the main entry point to critcl's static code scanner. Invoked for
a single ".critcl" file it returns a dictionary providing the following pieces
information about it:
version
Package version.
org Author(ing organization).
files List of the companion files. The paths in this list are all relative to the
location (directory) of the input file.
This command and the information it returns can be used by tools to implement
processing modes like the assembly of a directory hierarchy containing a TEA-
lookalike buildystem, etc.
::critcl::name2c name
This command exposes the conversion of a Tcl level identifier of commands into
various C-level pieces, i.e. Tcl namespace prefix, C namespace prefix, Tcl base
name, and C base name.
The result of the command is a list of 4 elements providing the above mentioned
information, in the named order.
The envisioned main use is from within utility packages providing Tcl commands
without going through the standard commands, i.e. critcl::ccommand, or
critcl::cproc. An example of a package using this command for exactly this purpose
is critcl::class.
ADVANCED: EMBEDDED C CODE
For the advanced user five commands used inside of critcl::cproc are exposed. These are:
::critcl::argnames arguments
This command takes an argument declaration as taken by critcl::cproc and returns a
list of the user visible arguments found in the declaration.
::critcl::argcnames arguments
This command takes an argument declaration as taken by critcl::cproc and returns a
list of the C side variable names for the user visible arguments found in the
declaration. The names returned here match the names used in the declarations and
code returned by ::critcl::argvardecls and ::critcl::argconversion.
::critcl::argcsignature arguments
This command takes an argument declaration as taken by critcl::cproc and returns a
list of C parameter declarations for all arguments found in the declaration.
::critcl::argvardecls arguments
This command takes an argument declaration as taken by critcl::cproc and returns a
list of C side variable declarations for the user visible arguments found in the
declaration. The names used in these declarations match the names returned by
::critcl::argcnames.
::critcl::argconversion arguments ?n?
This command takes an argument declaration as taken by critcl::cproc and returns a
list of C code fragments converting the user visible arguments found in the
declaration from Tcl_Obj* to C types. The names used in these statements match the
names returned by ::critcl::argcnames.
The generated code assumes that the procedure arguments start at index n of the
objv array. If this argument is not specified 1 will be assumed.
::critcl::argoptional arguments
This command takes an argument declaration as taken by critcl::cproc and returns a
list of boolean values indicating which arguments are optional (true) and not
(false).
::critcl::argdefaults arguments
This command takes an argument declaration as taken by critcl::cproc and returns a
list containing the default values for all optional arguments.
::critcl::argsupport arguments
This command takes an argument declaration as taken by critcl::cproc and returns a
list of C code fragments needed to define the necessary supporting types.
CUSTOM BUILD CONFIGURATION
This package provides one command for the management of package-specific, i.e. developer-
specified custom build configuration options.
::critcl::userconfig define name description type ?default?
This command defines custom build configuration option, with description, type and
optional default value.
The type can be either bool, or a list of values.
[1] For bool the default value, if specified, must be a boolean. If it is not
specified it defaults to true.
[2] For a list of values the default value, if specified, must be a value found
in this list. If it is not specified it defaults to the first value of the
list.
The description serves as in-code documentation of the meaning of the option and is
otherwise ignored. When generating a TEA wrapper the description is used for the configure
option derived from the option declared by the command.
A boolean option FOO are translated into a pair of configure options, --enable-FOO and
--disable-FOO, whereas an option whose type is a list of values is translated into a
single configure option --with-FOO.
::critcl::userconfig query name
This command queries the database of custom build configuration option for the
current ".critcl" file and returns the chosen value. This may be the default if no
value was set via ::critcl::userconfig set.
It is at this point that definitions and set values are brought together, with the
latter validated against the definition.
::critcl::userconfig set name value
This command is for use by a tool, like the critcl application, to specify values
for custom build configuration options.
At the time this command is used only the association between option name and value
is recorded, and nothing else is done. This behaviour is necessary as the system
may not know if an option of the specified name exists when the command is invoked,
nor its type.
Any and all validation is defered to when the value of an option is asked for via
::critcl::userconfig query.
This means that it is possible to set values for any option we like, and the value
will take effect only if such an option is both defined and used later on.
ADVANCED: LOCATION MANAGEMENT
First a small introduction for whose asking themselves ´what is location management' ?
By default critcl embeds #line directives into the generated C code so that any errors,
warnings and notes found by the C compiler during compilation will refer to the ".critcl"
file the faulty code comes from, instead of the generated ".c" file.
Side note: This facility requires the use of a tclsh supporting the builtin info frame
command. If critcl is run by a tclsh not supporting this no #line directives will be
emitted. The command is supported by Tcl 8.5 and higher. It is also supported by Tcl 8.4
provided that it was compiled with the define -DTCL_TIP280. An example of such is
ActiveState's ActiveTcl.
Most users will not care about this feature beyond simply wanting it to work and getting
proper code references when reading compiler output.
Developers of higher-level packages generating their own C code however should care about
this, to ensure that their generated code contains proper references as well. Especially
as this is key to separating bugs concerning code generated by the package itself and bug
in the user's code going into the package, if any.
Examples of such packages come with critcl itself, see the implementation of packages
critcl::iassoc and critcl::class.
To help such developers eight commands are provided to manage such location information.
These are listed below.
A main concept is that they all operate on a single stored location, setting, returning
and clearing it. Note that this location information is completely independent of the
generation of #line directives within critcl itself.
::critcl::at::caller
This command stores the location of the caller of the current procedure as a tuple
of file name and linenumber. Any previously stored location is overwritten. The
result of the command is the empty string.
::critcl::at::caller offset
As above, the stored line number is modified by the specified offset. In essence an
implicit call of critcl::at::incr.
::critcl::at::caller offset level
As above, but the level the location information is taken from is modified as well.
Level 0 is the caller, -1 its caller, etc.
::critcl::at::here
This command stores the current location in the current procedure as a tuple of
file name and linenumber. Any previously stored location is overwritten. The
result of the command is the empty string.
In terms of ::critcl::at::caller] this is equivalent to
critcl::at::caller 0 1
::critcl::at::get*
This command takes the stored location and returns a formatted #line directive
ready for embedding into some C code. The stored location is left untouched. Note
that the directive contains its own closing newline.
For proper nesting and use it is recommended that such directives are always added
to the beginning of a code fragment. This way, should deeper layers add their own
directives these will come before ours and thus be inactive. End result is that the
outermost layer generating a directive will 'win', i.e. have its directive used. As
it should be.
::critcl::at::get
This command is like the above, except that it also clears the stored location.
::critcl::at::= file line
This command allows the caller to set the stored location to anything they want,
outside of critcl's control. The result of the command is the empty string.
::critcl::at::incr n...
::critcl::at::incrt str...
These commands allow the user to modify the line number of the stored location,
changing it incrementally. The increment is specified as either a series of integer
numbers (incr), or a series of strings to consider (incrt). In case of the latter
the delta is the number of lines endings found in the strings.
::critcl::at::caller!
::critcl::at::caller! offset
::critcl::at::caller! offset level
::critcl::at::here!
These are convenience commands combining caller and here with get. I.e. they store
the location and immediately return it formatted as proper #line directive. Also
note that after their use the stored location is cleared.
ADVANCED: DIVERSIONS
Diversions are for higher-level packages generating their own C code, to make their use of
critcl's commands generating Embedded C Code easier.
These commands normally generate all of their C code for the current ".critcl" file, which
may not be what is wanted by a higher-level package.
With a diversion the generator output can be redirected into memory and from there on then
handled and processed as the caller desires before it is committed to an actual ".c" file.
An example of such a package comes with critcl itself, see the implementation of package
critcl::class.
To help such developers three commands are provided to manage diversions and the
collection of C code in memory. These are:
::critcl::collect_begin
This command starts the diversion of C code collection into memory.
The result of the command is the empty string.
Multiple calls are allowed, with each call opening a new nesting level of
diversion.
::critcl::collect_end
This command end the diversion of C code collection into memory and returns the
collected C code.
If multiple levels of diversion are open the call only closes and returns the data
from the last level.
The command will throw an error if no diversion is active, indicating a mismatch in
the pairing of collect_begin and collect_end.
::critcl::collect script
This is a convenience command which runs the script under diversion and returns the
collected C code, ensuring the correct pairing of collect_begin and collect_end.
ADVANCED: EXTENDING CPROC
While the critcl::cproc command understands the most common C types (see section Embedded
C Code), sometimes this is not enough.
To get around this limitation the commands in this section enable users of critcl to
extend the set of argument and result types understood by critcl::cproc. In other words,
to define their own custom types.
::critcl::resulttype name body ?ctype?
This command defines the result type name, and associates it with the C code doing
the conversion (body) from C to Tcl. The C return type of the associated function,
also the C type of the result variable, is ctype. This type defaults to name if it
is not specified.
If name is declared already an error will be thrown. Attention! The standard
result type void is special as it has no accompanying result variable. This cannot
be expressed by the this extension command.
The body's responsibility is the conversion of the functions result into a Tcl
result and a Tcl status. The first has to be set into the interpreter we are in,
and the second has to be returned.
The C code of body is guaranteed to be called last in the wrapper around the actual
implementation of the cproc in question and has access to the following
environment:
interp A Tcl_Interp* typed C variable referencing the interpreter the result has to
be stored into.
rv The C variable holding the result to convert, of type ctype.
As examples here are the definitions of two standard result types:
resulttype int {
Tcl_SetObjResult(interp, Tcl_NewIntObj(rv));
return TCL_OK;
}
resulttype ok {
/* interp result must be set by cproc body */
return rv;
} int
::critcl::resulttype name = origname
This form of the resulttype command declares name as an alias of result type
origname, which has to be defined already. If this is not the case an error is
thrown.
::critcl::argtype name body ?ctype? ?ctypefun?
This command defines the argument type name, and associates it with the C code
doing the conversion (body) from Tcl to C The C type of the variable to hold the
conversion result is ctype and the type of the function argument itself is
ctypefun. Both types default to name if they are not specified (or the empty
string).
If name is declared already an error will be thrown.
The body's responsibility is the conversion of a command's Tcl_Obj* argument into a
C value for the underlying function and its storage in a helper variable.
The C code of body is guaranteed to be called inside of a separate C code block
(thus allowing the use of local variables) which has access to the following
environment:
interp A Tcl_Interp* typed C variable referencing the interpreter the code is
running in.
@@ A placeholder for the Tcl_Obj*-valued C expression providing the value of
the argument to convert.
@A A placeholder for the name of the C variable to store the converted argument
into.
As examples here are the definitions of two standard argument types:
argtype int {
if (Tcl_GetIntFromObj(interp, @@, &@A) != TCL_OK) return TCL_ERROR;
}
argtype float {
double t;
if (Tcl_GetDoubleFromObj(interp, @@, &t) != TCL_OK) return TCL_ERROR;
@A = (float) t;
}
::critcl::argtype name = origname
This form of the argtype command declares name as an alias of argument type
origname, which has to be defined already. If this is not the case an error is
thrown.
::critcl::argtypesupport name code
This command defines a C code fragment for the already defined argument type name
which will be inserted before all functions using that type. Its purpose is the
definition of any supporting C types needed by the argument type. If the type is
used by many functions the system ensure that only the first of the multiple
insertions of the code fragment is active, and the others disabled.
CONCEPTS
MODES OF OPERATION/USE
CriTcl can be used in three different modes of operation, called
[1] Compile & Run, and
[2] Generate Package
[3] Generate TEA Package
Of these three Compile & Run came first and is the default when using the package
directly. In that case the package collects the C fragments, builds them as needed, and
caches the results for quick reuse when the same code is used in the future again.
The second mode, Generate Package, was introduced to enable the creation of (prebuilt)
deliverable packages which do not depend on the existence of a build system, i.e. C
compiler, on the target machine. This was originally done through the experimental
Critbind tool, and is now handled by the CriTcl Application, also named critcl.
Newly introduced with Critcl version 3 is Generate TEA Package. This mode constructs a
directory hierarchy from the package which can later be built like a regular TEA package,
i.e. using
.../configure --prefix ...
make all isntall
Regarding the caching of results please read the section about the Result Cache fore more
details.
RUNTIME BEHAVIOUR
The default behaviour of critcl, the package is to defer the compilation, linking, and
loading of any C code as much as possible, given that this is an expensive operation,
mainly in the time required. In other words, the C code embedded into a ".critcl" file is
built only when the first C command or procedure it provides is invoked. This part of the
system uses standard functionality built into the Tcl core, i.e. the auto_index variable
to map from commands to scripts providing them and the unknown command using this
information when the command is needed.
A limitation of this behaviour is that it is not possible to just use info commands check
for the existence of a critcl defined command. It is also necessary to search in the
auto_index array, in case it has not been build yet.
This behaviour can be changed by using the control command critcl::load. When invoked, the
building, including loading of the result, is forced. After this command has been invoked
for a ".critcl" file further definition of C code in this file is not allowed any longer.
FILE MAPPING
Each ".critcl" file is backed by a single private ".c" file containing that code, plus the
boilerplate necessary for its compilation and linking as a single shared library.
The Embedded C Code fragments appear in that file in the exact same order they were
defined in the ".critcl" file, with one exception. The C code provided via critcl::cinit
is put after all other fragments. In other words all fragments have access to the symbols
defined by earlier fragments, and the critcl::cinit fragment has access to all, regardless
of its placement in the ".critcl" file.
Note: A limitation of the current system is the near impossibility of C level access
between different critcl-based packages. The issue is not the necessity of writing and
sharing the proper extern statements, but that the management (export and import) of
package-specific stubs-tables is not supported. This means that dependent parts have to be
forcibly loaded before their user, with all that entails. See section Runtime Behaviour
for the relevant critcl limitation, and remember that many older platforms do not support
the necessary resolution of symbols, the reason why stubs were invented for Tcl in the
first place.
RESULT CACHE
The compilation of C code is time-consuming critcl not only defers it as much as possible,
as described in section Runtime Behaviour, but also caches the results.
This means that on the first use of a ".critcl" file "FOO.tcl" the resulting object file
and shared library are saved into the cache, and on future uses of the same file reused,
i.e. loaded directly without requiring compilation, provided that the contents of
"FOO.tcl" did not change.
The change detection is based MD5 hashes. A single hash is computed for each ".critcl"
file, based on hashes for all C code fragments and configuration options, i.e. everything
which affects the resulting binary.
As long as the input file doesn't change as per the hash a previously built shared library
found in the cache is reused, bypassing the compilation and link stages.
The command to manage the cache are found in section Result Cache Management. Note
however that they are useful only to tools based on the package, like the CriTcl
Application. Package writers have no need of them.
As a last note, the default directory for the cache is chosen based on the chosen build
target. This means that the cache can be put on a shared (network) filesystem without
having to fear interference between machines of different architectures.
PRELOADING FUNCTIONALITY
The audience of this section are developers wishing to understand and possibly modify the
internals of critcl package and application. Package writers can skip this section.
It explains how the preloading of external libraries is realized.
Whenever a package declares libraries for preloading critcl will build a supporting shared
library providing a Tcl package named "preload". This package is not distributed
separately, but as part of the package requiring the preload functionality. This support
package exports a single Tcl command
::preload library
which is invoked once per libraries to preload, with the absolute path of that
library. The command then loads the library.
On windows the command will further use the Tcl command ::critcl::runtime::precopy
to copy the library to the disk, should its path be in a virtual filesystem which
doesn't directly support the loading of a shared library from it.
The command ::critcl::runtime::precopy is provided by the file "critcl-rt.tcl" in the
generated package, as is the command ::critcl::runtime::loadlib which generates the
ifneeded script expected by Tcl's package management. This generated ifneeded script
contains the invocations of ::preload.
The C code for the supporting library is found in the file "critcl_c/preload.c", which is
part of the critcl package.
The Tcl code for the supporting runtime "critcl-rt.tcl" is found in the file
"runtime.tcl", which is part of the critcl::app package.
CONFIGURATION INTERNALS
The audience of this section are developers wishing to understand and possibly modify the
internals of critcl package and application. Package writers can skip this section.
It explains the syntax of configuration files and the configuration keys used by critcl to
configure its build backend, i.e. how this part of the system accesses compiler, linker,
etc.
It is recommended to open the file containing the standard configurations
("path/to/critcl/Config") in the editor of your choice when reading this section of the
documentation, using it as an extended set of examples going beyond the simple defaults
shown here.
First, the keys and the meaning of their values, plus examples drawn from the standard
configurations distributed with the package. Note that when writing a custom
configuration it is not necessary to specify all the keys listed below, but only those
whose default values are wrong or insufficient for the platform in question.
version
The command to print the compiler version number. Defaults to
gcc -v
compile
The command to compile a single C source file to an object file. Defaults to
gcc -c -fPIC
debug_memory
The list of flags for the compiler to enable memory debugging in Tcl. Defaults to
-DTCL_MEM_DEBUG
debug_symbols
The list of flags for the compiler to add symbols to the object files and the
resulting library. Defaults to
-g
include
The compiler flag to add an include directory. Defaults to
-I
tclstubs
The compiler flag to set USE_TCL_STUBS. Defaults to
-DUSE_TCL_STUBS
tkstubs
The compiler flag to set USE_TK_STUBS. Defaults to
-DUSE_TK_STUBS
threadflags
The list of compiler flags to enable a threaded build. Defaults to
-DUSE_THREAD_ALLOC=1 -D_REENTRANT=1 -D_THREAD_SAFE=1
-DHAVE_PTHREAD_ATTR_SETSTACKSIZE=1 -DHAVE_READDIR_R=1
-DTCL_THREADS=1
.
noassert
The compiler flag to turn off assertions in Tcl code. Defaults to
-DNDEBUG
optimize
The compiler flag to specify optimization level. Defaults to
-O2
output The compiler flags to set the output file of a compilation. Defaults to
-o [list $outfile]
NOTE the use of Tcl commands and variables here. At the time critcl uses the value of
this key the value of the referenced variable is substituted into it. The named variable
is the only variable whose value is defined for this substitution.
object The file extension for object files on the platform. Defaults to
.o
preproc_define
The command to preprocess a C source file without compiling it, but leaving
#define's in the output. Defaults to
gcc -E -dM
preproc_enum
See preproc_define, except that #define's are not left in the output. Defaults to
gcc -E
link The command to link one or more object files and create a shared library. Defaults
to
gcc -shared
link_preload
The list of linker flags to use when dependent libraries are pre-loaded. Defaults
to
--unresolved-symbols=ignore-in-shared-libs
strip The flag to tell the linker to strip symbols from the shared library. Defaults to
-Wl,-s
ldoutput
Like output, but for the linker. Defaults to the value of output.
link_debug
The list of linker flags needed to build a shared library with symbols. Defaults to
the empty string. One platform requiring this are all variants of Windows, which
uses
-debug:full -debugtype:cv
link_release
The list of linker flags needed to build a shared library without symbols, i.e. a
regular build. Defaults to the empty string. One platform requiring this are all
variants of Windows, which uses
-release -opt:ref -opt:icf,3 -ws:aggressive
sharedlibext
The file extension for shared library files on the platform. Defaults to
[info sharedlibextension]
platform
The identifier of the platform used in generated packages. Defaults to
[platform::generic]
target The presence of this key marks the configuration as a cross-compilation target and
the value is the actual platform identifier of the target. No default.
The syntax expected from configuration files is governed by the rules below. Again, it is
recommended to open the file containing the standard configurations
("path/to/critcl/Config") in the editor of your choice when reading this section of the
documentation, using it as an extended set of examples for the syntax>
[1] Each logical line of the configuration file consists of one or more physical lines.
In case of the latter the physical lines have to follow each other and all but the
first must be marked by a trailing backslash. This is the same marker for
continuation lines as used by Tcl itself.
[2] A (logical) line starting with the character "#" (modulo whitespace) is a comment
which runs until the end of the line, and is otherwise ignored.
[3] A (logical) line starting with the word "if" (modulo whitespace) is interpreted as
Tcl's if command and executed as such. I.e. this command has to follow Tcl's syntax
for the command, which may stretch across multiple logical lines. The command will
be run in a save interpreter.
[4] A (logical) line starting with the word "set" (modulo whitespace) is interpreted as
Tcl's set command and executed as such. I.e. this command has to follow Tcl's
syntax for the command, which may stretch across multiple logical lines. The
command will be run in a save interpreter.
[5] A line of the form "platform variable value" defines a platform specific
configuration variable and value. The variable has to be the name of one of the
configuration keys listed earlier in this section, and the platform string
identifies the platform the setting is for. All settings with the same
identification string form the configuration block for this platform.
[6] A line of the special form "platform when expression" marks the platform and all
the settings in its configuration block as conditional on the expression.
If the build platform is not a prefix of platform, nor vice versa the whole block
is ignored. Otherwise the expression is evaluated via expr, in the same safe
interpreter used to run any set and if commands found in the configuration file
(see above).
If the expression evaluates to true this configuration block is considered to be
the build platform fo the host and chosen as the default configuration. An large
example of of this feature is the handling of OS X found in the standard
configuration file, where it selects the architectures to build based on the
version of the operating system, the available SDK, etc. I.e. it chooses whether
the output is universal or not, and whether it is old-style (ix86 + ppc) versus
new-style (ix86 32+64) of universality.
[7] A line of the special form "platform copy sourceplatform" copies the configuration
variables and values currently defined in the configuration block for
sourceplatform to that of platform, overwriting existing values, and creating
missing ones. Variables of platform not defined by by sourceplatform are not
touched.
The copied values can be overridden later in the configuration file. Multiple copy
lines may exist for a platform and be intermixed with normal configuration
definitions. If a variable is defined multiple times, the last definition will be
used.
[8] At last, a line of the form "variable value" defines a default configuration
variable and value.
STUBS TABLES This section is for developers of extensions not based on critcl, yet
also wishing to interface with stubs as they are understood and used by critcl, either by
exporting their own stubs table to a critcl-based extension, or importing a stubs table of
a critcl-based extension into their own.
To this end we describe the stubs table information of a package foo.
[1] Note that the differences in the capitalization of "foo", "Foo", "FOO", etc. below
demonstrate how to capitalize the actual package name in each context.
[2] All relevant files must be available in a sub-directory "foo" which can be found on
the include search paths.
[3] The above directory may contain a file "foo.decls". If present it is assumed to
contain the external representation of the stubs table the headers mentioned in the
following items are based on.
critcl is able to use such a file to give the importing package programmatic access
to the imported API, for automatic code generation and the like.
[4] The above directory must contain a header file "fooDecls.h". This file declares the
exported API. It is used by both exporting and importing packages. It is usually
generated and must contain (in the order specified):
[1] the declarations of the exported, i.e. public, functions of foo,
[2] the declaration of structure "FooStubs" for the stub table,
[3] the C preprocessor macros which route the invocations of the public
functions through the stubs table.
These macros must be defined if, and only if, the C preprocessor macro
USE_FOO_STUBS is defined. Package foo does not define this macro, as it is
allowed to use the exported functions directly. All importing packages
however must define this macro, to ensure that they do not use any of the
exported functions directly, but only through the stubs table.
[4] If the exported functions need additional types for their proper declaration
then these types should be put into a separate header file (of arbitrary
name) and "fooDecls.h" should contain an #include directive to this header
at the top.
A very reduced, yet also complete example, from a package for low-level random number
generator functions can be found at the end of this section.
[5] The above directory must contain a header file "fooStubLib.h". This file defines
everything needed to use the API of foo. Consequently it is used only by importing
packages. It is usually generated and must contain (in the order specified):
[1] An #include directive for "tcl.h", with USE_TCL_STUBS surely defined.
[2] An #include directive for "fooDecls.h", with USE_FOO_STUBS surely defined.
[3] A definition of the stubs table variable, i.e.
const FooStubs* fooStubsPtr;
[4] A definition of the stubs initializer function, like
char *
Foo_InitStubs(Tcl_Interp *interp, CONST char *version, int exact)
{
/*
* Boiler plate C code initalizing the stubs table variable,
* i.e. "fooStubsPtr".
*/
CONST char *actualVersion;
actualVersion = Tcl_PkgRequireEx(interp, "foo", version,
exact, (ClientData *) &fooStubsPtr);
if (!actualVersion) {
return NULL;
}
if (!fooStubsPtr) {
Tcl_SetResult(interp,
"This implementation of Foo does not support stubs",
TCL_STATIC);
return NULL;
}
return (char*) actualVersion;
}
This header file must be included by an importing package exactly once, so that it
contains only one definition of both stubs table and stubs initializer function.
The importing package's initialization function must further contain a statement
like
if (!Foo_InitStubs (ip, "1", 0)) {
return TCL_ERROR;
}
which invokes foo's stubs initializer function to set the local stub table up.
For a complete example of such a header file see below, at the end of this section.
[6] The last item above, about "fooStubLib.h" differs from the regular stub stable
system used by Tcl. The regular system assumes that a static library "libfoostub.a"
was installed by package foo, and links it.
IMVHO critcl's approach is simpler, using only header files found in a single
location, vs. header files and static library found in multiple, different
locations.
A second simplification is that we avoid having to extend critcl's compiler backend
with settings for the creation of static libraries.
Below is a complete set of example header files, reduced, yet still complete, from a
package for low-level random number generator functions:
"rngDecls.h":
#ifndef rng_DECLS_H
#define rng_DECLS_H
#include <tcl.h>
/*
* Exported function declarations:
*/
/* 0 */
EXTERN void rng_bernoulli(double p, int*v);
typedef struct RngStubs {
int magic;
const struct RngStubHooks *hooks;
void (*rng_bernoulli) (double p, int*v); /* 0 */
} RngStubs;
#ifdef __cplusplus
extern "C" {
#endif
extern const RngStubs *rngStubsPtr;
#ifdef __cplusplus
}
#endif
#if defined(USE_RNG_STUBS)
/*
* Inline function declarations:
*/
#define rng_bernoulli (rngStubsPtr->rng_bernoulli) /* 0 */
#endif /* defined(USE_RNG_STUBS) */
#endif /* rng_DECLS_H */
"rngStubLib.h":
/*
* rngStubLib.c --
*
* Stub object that will be statically linked into extensions that wish
* to access rng.
*/
#ifndef USE_TCL_STUBS
#define USE_TCL_STUBS
#endif
#undef USE_TCL_STUB_PROCS
#include <tcl.h>
#ifndef USE_RNG_STUBS
#define USE_RNG_STUBS
#endif
#undef USE_RNG_STUB_PROCS
#include "rngDecls.h"
/*
* Ensure that Rng_InitStubs is built as an exported symbol. The other stub
* functions should be built as non-exported symbols.
*/
#undef TCL_STORAGE_CLASS
#define TCL_STORAGE_CLASS DLLEXPORT
const RngStubs* rngStubsPtr;
/*
*----------------------------------------------------------------------
*
* Rng_InitStubs --
*
* Checks that the correct version of Rng is loaded and that it
* supports stubs. It then initialises the stub table pointers.
*
* Results:
* The actual version of Rng that satisfies the request, or
* NULL to indicate that an error occurred.
*
* Side effects:
* Sets the stub table pointers.
*
*----------------------------------------------------------------------
*/
#ifdef Rng_InitStubs
#undef Rng_InitStubs
#endif
char *
Rng_InitStubs(Tcl_Interp *interp, CONST char *version, int exact)
{
CONST char *actualVersion;
actualVersion = Tcl_PkgRequireEx(interp, "rng", version,
exact, (ClientData *) &rngStubsPtr);
if (!actualVersion) {
return NULL;
}
if (!rngStubsPtr) {
Tcl_SetResult(interp,
"This implementation of Rng does not support stubs",
TCL_STATIC);
return NULL;
}
return (char*) actualVersion;
}
EXAMPLES
As the set of examples is a bit large, and growing, it has been put into a separate
document. Please see section "Embedding C" in the document about Using CriTcl.
CHANGES FOR VERSION 2.1
[1] Fixed bug where critcl::tsources interpreted relative paths as relative to the
current working directory instead of relative to the ".critcl" file using the
command, as all other commands of this type do.
[2] Fixed internals, preventing information collected for multiple ".critcl" files to
leak between them. Notably, critcl::tk is not a global configuration option
anymore.
[3] Fixed the command critcl::license to be a null-operation in mode "compile & run",
instead of throwing an error.
[4] Fixed the critcl application's interference with the "compile & run" result cache
in -pkg mode by having it use a wholly separate (and by default transient)
directory for that mode.
[5] Fixed bug where changes to a ".critcl" file did not result in a rebuild for mode
"compile & run". All relevant API commands now ensure UUID changes.
[6] Fixed bug in the backend handling of critcl::debug where the companion c-sources of
a ".critcl" file were not compiled with debug options, although the ".critcl" file
was.
[7] Fixed bug in critcl::debug which prevented recognition of mode "all" when it was
not the first argument to the command.
[8] Fixed bug in "preload.c" preventing its compilation on non-windows platforms.
[9] Fixed long-standing bug in the handling of namespace qualifiers in the command name
argument of critcl::cproc and critcl::ccommand. It is now possible to specify a
fully qualified command name without issues.
[10] Extended/reworked critcl::tsources to be the canonical way of declaring ".tcl"
companion files even for mode "compile & run".
[11] Extended/reworked critcl::tsources to allow the use of a ".critcl" file as its own
Tcl companion file.
[12] Extended critcl::framework to internally check for OS X build target, and to ignore
the declaration if its not.
[13] Extended critcl::failed to be callable more than once in a ".critcl" file. The
first call forces the build, if it was not done already, to get the result. Further
calls return the cached result of the first call.
[14] Extended the handling of environment variable CC in the code determining the
compiler to use to deal with (i.e. remove) paths to the compiler, compiler file
extensions, and compiler options specified after the compiler itself, leaving only
the bare name of the compiler.
[15] Extended the code handling the search for preloaded libraries to print the paths it
searched, making debugging of a search failure easier.
[16] A new command critcl::tcl can be used to declare the version of Tcl minimally
needed to build and run the ".critcl" file and package. Defaults to 8.4 if not
declared. Extended critcl to have the stubs and headers for all of Tcl 8.4, 8.5,
and 8.6.
[17] A new command critcl::load forces the build and load of a ".critcl" file. This is
the official way for overriding critcl's default lazy-build-&-load-on-demand scheme
for mode "compile & run".
Note that after using critcl::load / critcl::failed in a ".critcl" file it is not
possible to use critcl commands in that file anymore. Doing so will throw an error.
[18] Extended the generation of '#line' pragmas to use info frame (if available) to
provide the C compiler with exact line numbers into the ".critcl" file for the
reporting of warnings and errors.
[19] Extended critcl::check with logging to help with debugging build-time checks of the
environment, plus an additional optional argument to provide labeling.
[20] Added a new command critcl::checklink which not only tries to check the environment
via compiling the code, but also its linkability.
[21] Added a new command critcl::msg for messaging, like command critcl::error is for
error reporting. Likewise this is a hook a user of the package is allowed to
override. The default implementation, used by mode compile & run does nothing. The
implementation for mode generate package prints the message to stdout.
Envisioned use is for the reporting of results determined by critcl::check and
critcl::checklink during building, to help with debugging when something goes wrong
with a check.
[22] Exposed the argument processing internals of critcl::proc for use by advanced
users. The new commands are
[1] critcl::argnames
[2] critcl::argcnames
[3] critcl::argcsignature
[4] critcl::argvardecls
[5] critcl::argconversion
Please see section Advanced Embedded C Code of the critcl package documentation for
details.
[23] Extended the critcl package to intercept package provide and record the file ->
package name mapping. Plus other internal changes now allow the use of namespaced
package names while still using proper path names and init function.
[24] Dropped the unused commands critcl::optimize and critcl::include.
[25] Dropped -lib mode from the critcl application.
[26] Dropped remnants of support for Tcl 8.3 and before.
CHANGES FOR VERSION 3
[1] The command critcl::platform was deprecated in version 2.1, superceded by
critcl::targetplatform, yet kept for compatibility. Now it has been removed.
[2] The command critcl::compiled was kept with in version 2.1 with semantics in
contradiction to its, for compatibility. This contradiction has been removed,
changing the visible semantics of the command to be in line with its name.
[3] The change to version 3 became necessary because of the two incompatible visible
changes above.
[4] Extended the application package with code handling a new option -tea. Specifying
this option invokes a special mode where critcl generates a TEA package, i.e. wraps
the input into a directory hierarchy and support files which provide it TEA-
lookalike buildsystem.
This new option, and -pkg, exclude each other. If both are specified the last used
option takes precedence.
The generated package directory hierarchy is mostly self-contained, but not fully.
It requires not only a working installation of Tcl, but also working installations
of the packages md5 and cmdline. Both of these are provided by the Tcllib bundle.
Not required, but recommended to have installed are any of the packages which can
accelerate md5's operation, i.e. cryptkit, tcllibc, or Trf.
[5] Extended the critcl package with a new command critcl::scan taking the path to a
".critcl" file, statically scanning it, and returning license, version, a list of
its companion files, list of imported APIs, and list of developer-specified custom
configuration options. This data is the foundation for the TEA wrapping described
above.
Note that this is a static scan. While the other build modes can (must) execute the
".critcl" file and make platform-specific decisions regarding the assembled C code,
companion files, etc. the TEA wrap mode is not in a position to make platform-
specific decisions. It has to wrap everything which might conceivably be needed
when actually building. Hence the static scan. This has however its own set of
problems, namely the inability to figure out any dynamic construction of companion
file paths, at least on its own. Thus:
[6] Extended the API used by critcl-based packages with the command critcl::owns. While
this command is ignored by the regular build modes the static scanner described
above takes its arguments as the names of companion files which have to be wrapped
into the TEA package and could not be figured by the scanner otherwise, like
because of dynamic paths to critcl::tsources, critcl::csources, getting sourced
directly, or simply being adjunct datafiles.
[7] Extended the API used by critcl-based packages with the command critcl::api for the
management of stubs tables, be it their use, and/or declaration and export.
Please see section Stubs Table Management of the critcl package documentation for
details.
[8] Extended the API used by critcl-based packages with the command critcl::userconfig
for the management of developer-specified custom configuration options, be it their
use and/or declaration.
Please see section Custom Build Configuration of the critcl package documentation
for details.
[9] Extended the API used by critcl-based packages with the commands
critcl::description, critcl::summary, critcl::subject, critcl::meta, and
critcl::buildrequirement for the declaration of TEApot meta data for/about the
package.
Please see section Package Meta Data of the critcl package documentation for
details.
CHANGES FOR VERSION 3.0.1
[1] Bugfixes all around. In detail:
[2] Fixed recording of Tcl version requirements. Keep package name and version
together, unbreaking generated meta data and generated package load command.
[3] Fixed the build scripts: When installing, or wrapping for TEA, generate any missing
directories
[4] Modified the build scripts to properly exit the application when the window of
their GUI is closed through the (X) button.
[5] Removed an 8.5-ism (open wb) which had slipped into the main build script.
[6] Modified the example build scripts to separate the output for the different
examples (and packages) by adding empty lines.
[7] stack::c example bugfix: Include API declarations for use in the companion files.
[8] Extended the documentation: Noted the need for a working installation of a C
compiler.
[9] Extended the Windows target definitions and code to handle the manifest files used
by modern MS development environments. Note that this code handles both
possibilities, environment using manifests, and (old(er)) environments without.
[10] Extended the Windows 64bit target definitions and code to auto-detect the need for
the helper library "bufferoverflowU.lib" and reconfigure the compile and link
commands appropriately. We assume that the library must be linked when present.
This should be no harm if the library is present, yet not needed. Just superfluous.
We search for the library in the paths specified by the environment variable LIB.
CHANGES FOR VERSION 3.0.2
[1] Fixed issue in compile-and-run mode where commands put into the auto_index are not
found by Tcl's [unknown] command.
[2] Fixed an array key mismatch breaking usage of client data and delete function for
procedure. Reported by Jos DeCoster, with patch.
[3] Implemented a command line option -L, an equivalent of option -I, just for library
search paths.
[4] Fixed github issues 5 and 8. Working around a missing variable ::errorInfo. It
should always be present, however there seem to be revisions of Tcl around which
violate this assumption.
CHANGES FOR VERSION 3.0.3
[1] Fixed github issues 5 and 8, for the example build.tcl scripts. Working around a
missing variable ::errorInfo. It should always be present, however there seem to be
revisions of Tcl around which violate this assumption.
CHANGES FOR VERSION 3.0.4
[1] Fixed generation of the package's initname when the incoming code is read from
stdin and has no proper path.
[2] Fixed github issue 11. Now using /LIBPATH instead of -L on Windows (libinclude
configuration setting).
[3] Extended critcl to handle -l:path format of -l options. GNU ld 2.22+ handles this
by searching for the path as is. Good when specifying static libraries, as plain -l
looks for shared libraries in preference over static. critcl handles it now, as
older GNU ld's do not understand it, nor the various vendor-specific linkers.
[4] Fixed github issue #12. Critcl now determines the version of MSVC in use and uses
it to switch between various link debug options. Simplified the handling of
bufferoverflowU.lib also, making use of the same mechanism and collapsing the two
configurations sections we had back into one.
[5] Reworked the insertion of #line pragmas into the generated C code to avoid
limitations on the line number argument imposed by various compilers, and be more
accurate.
[6] Modified argument processing. Option -libdir now also implies -L for its argument.
[7] Extended handling of option -show (critcl::showconfig) to list the path of the
configuration file the data is coming from. Good for debugging configuration
processing.
[8] Extended the build script with targets to regenerate the embedded documentation,
and diagrams, and to generate a release.
CHANGES FOR VERSION 3.0.5
[1] Fixed bug in the new code for #line pragmas triggered when specifying C code
without leading whitespace.
[2] Extended the documentation to have manpages for the license, source retrieval,
installer, and developer's guides.
CHANGES FOR VERSION 3.0.6
[1] Fixed github issue 10. The critcl application now delivers a proper exit code (1)
on build failure, instead of always indicating success (status 0).
[2] Fixed github issue 13. Handling of bufferoverflowU.lib for release builds was
inconsistent with handling for debug builds. It is now identically handled
(conditional) by both cases.
[3] Documentation cleanup, mainly in the installation guide, and the README.md shown by
github
CHANGES FOR VERSION 3.0.7
[1] Fixed the code generated by critcl::c++command. The emitted code handed a non-
static string table to Tcl_GetIndexFromObj, in violation of the contract, which
requires the table to have a fixed address. This was a memory smash waiting to
happen. Thanks to Brian Griffin for alrerting us to the general problem.
CHANGES FOR VERSION 3.1
[1] Added a new higher-level package critcl::iassoc.
This package simplifies the creation of code associating data with an interpreter
via Tcl's Tcl_(Get|Set)AssocData() APIs. The user can concentrate on his data while
all the necessary boilerplate C code to support this is generated by the package.
This package uses several of the new features which were added to the core critcl
package, see below.
[2] Added the higher-level package critcl::class.
This package simplifies the creation of C level objects with class and instance
commands. The user can write a class definition with class- and instance-variables
and -methods similar to a TclOO class, with all the necessary boilerplate C code to
support this generated by the package.
This package uses several of the new features which were added to the core critcl
package, see below.
[3] Extended the API for handling TEApot metadata. Added the command critcl::meta? to
query the stored information. Main use currently envisioned is retrieval of the
current package's name by utility commands, for use in constructed names. This
particular information is always available due to the static scan of the package
file on execution of the first critcl command.
The new packages critcl::iassoc and critcl::class (see above) are users of this
command.
[4] Extended the API with a command, critcl::name2c, exposing the process of converting
a Tcl name into base name, namespace, and C namespace. This enables higher-level
code generators to generate the same type of C identifiers as critcl itself.
The new package critcl::class (see above) is a user of this command.
[5] Extended the API with a command, critcl::source, executing critcl commands found in
a separate file in the context of the current file. This enables easier management
of larger bodies of code as it allows the user to split such up into easier to
digest smaller chunks without causing the generation of multiple packages.
[6] Related to the previous item, extended the API with commands to divert collection
of generated C code into memory. This makes it easier to use the commands for
embedded C code in higher-level code generators.
See the section Advanced: Diversions for details of the provided commands.
The new package critcl::class (see above) is a user of these facilities.
[7] Extended the API with commands helping developers with the generation of proper C
#line directives. This allows higher-level code generators to generate and insert
their own directives, ensuring that compile errors in their code are properly
attributed.
See the section Advanced: Location management for details of the provided commands.
The new packages critcl::iassoc and critcl::class (see above) are users of these
facilities.
[8] Extended the API with commands giving users the ability to define custom argument
and result types for ::critcl::cproc.
See the section Advanced: Extending cproc for details of the provided commands.
CHANGES FOR VERSION 3.1.1
[1] Bugfixes all around. In detail:
[2] Fixed the generation of wrong#args errors for critcl::cproc and derived code
(critcl::class cproc-based methods). Use NULL if there are no arguments, and take
the offset into account.
[3] Fixed the handling of package names by critcl::class. Forgot that they may contain
namespace separators. Bumped to version 1.0.1.
[4] Extended a critcl::class generated error message in instance creation for clarity.
Bumped to version 1.0.2.
CHANGES FOR VERSION 3.1.2
[1] Enhancement. In detail:
[2] Extended critcl::cproc to be able to handle optional arguments, in a limited way.
This is automatically available to critcl::class cproc-based methods as well.
[3] Bugfix in lassign emulation for Tcl 8.4. Properly set unused variables to the
empty string. Bumped version of emulation package lassign84 to 1.0.1.
CHANGES FOR VERSION 3.1.3
[1] Enhancement. In detail:
[2] Added new argument type "pstring", for "Pascal String", a counted string, i.e. a
combination of string pointer and string length.
[3] Added new methods critcl::argtypesupport and ::critcl::argsupport to define and use
additional supporting code for an argument type, here used by "pstring" above to
define the necessary structure.
[4] Semi-bugfixes in the packages critcl::class and critcl::iassoc. Pragmas for the AS
meta data scanner to ensure that the template files are made part of the package.
Versions bumped to 1.0.4 and 1.0.1 respectively.
CHANGES FOR VERSION 3.1.4
[1] Bugfix in package critcl::class. Generate a dummy field in the class structure if
the class has no class variables. Without this change the structure would be empty,
and a number of compilers are not able to handle such a type.
[2] Fixed a typo which broke the win64 configuration.
[3] Fixed issue #16, a typo in the documentation of command critcl::class.
CHANGES FOR VERSION 3.1.5
[1] Fixed issue #19. Made the regular expression extracting the MSVC version number
more general to make it work on german language systems. This may have to be
revisited in the future, for other Windows locales.
[2] Fixed issue #20. Made option -tea work on windows, at least in a unix emulation
environment like msys/mingw.
CHANGES FOR VERSION 3.1.6
[1] Fixed issue #21. While the multi-definition of the stub-table pointer variables was
ok with for all the C linkers seen so far C++ linkers did not like this at all.
Reworked the code to ensure that this set of variables is generated only once, in
the wrapper around all the pieces to assemble.
[2] Fixed issue #22, the handling of the command identifier arguments of
critcl::ccommand, critcl::cproc, and critcl::cdata. We now properly allow any Tcl
identifier and generate proper internal C identifiers from them.
As part of this the signature of command critcl::name2c changed. The command now
delivers a list of four values instead of three. The new value was added at the
end.
Further adapted the implementation of package critcl::class, a user of
critcl::name2c. This package is now at version 1.0.6 and requires critcl 3.1.6
Lastly fixed the mis-handling of option -cname in critcl::ccommand, and
critcl::cproc.
[3] Fixed issue #23.
CHANGES FOR VERSION 3.1.7
[1] Fixed issue #24. Extract and unconditionally display compiler warnings found in the
build log. Prevents users from missing warnings which, while not causing the build
to fail, may still indicate problems.
[2] New feature. Output hook. All non-messaging user output is now routed through the
command critcl::print, and users are allowed to override it when using the critcl
application-as-package.
[3] New feature, by Ashok P. Nadkarni. Platform configurations can inherit values from
configurations defined before them.
CHANGES FOR VERSION 3.1.8
[1] Fixed issue with package indices generated for Tcl 8.4. Join the list of commands
with semi-colon, not newline.
[2] Fixed issue #26 which brought up use-cases I had forgotten to consider while fixing
bug #21 (see critcl 3.1.6).
CHANGES FOR VERSION 3.1.9
[1] Fixed issue #27. Added missing platform definitions for various alternate linux and
OS X targets.
[2] Fixed issue #28. Added missing -mXX flags for linking at the linux-{32,64}-*
targets.
[3] Fixed issue #29. Replaced the use of raw "cheaders" information in the processing
of "cdefines" with the proper include directives derived from it.
[4] Fixed the issue behind rejected pull request #30 by Andrew Shadura. Dynamically
extract the stubs variable declarations from the Tcl header files and generate
matching variable definitions for use in the package code. The generated code will
now be always consistent with the headers, even when critcl's own copy of them is
replaced by system headers.
[5] Fixed issue #31. Accepted patch by Andrew Shadura, with changes (comments), for
easier integration of critcl with OS package systems, replacing critcl's copies of
Tcl headers with their own.
[6] Fixed issue #32. Merged pull request by Andrew Shadura. Various typos in
documentation and comments.
[7] Fixed issue #33. Handle files starting with a dot better.
AUTHORS
Jean Claude Wippler, Steve Landers, Andreas Kupries
BUGS, IDEAS, FEEDBACK
This document, and the package it describes, will undoubtedly contain bugs and other
problems. Please report them at https://github.com/andreas-kupries/critcl/issues. Ideas
for enhancements you may have for either package, application, and/or the documentation
are also very welcome and should be reported at https://github.com/andreas-
kupries/critcl/issues as well.
KEYWORDS
C code, Embedded C Code, code generator, compile & run, compiler, dynamic code generation,
dynamic compilation, generate package, linker, on demand compilation, on-the-fly
compilation
CATEGORY
Glueing/Embedded C code
COPYRIGHT
Copyright (c) Jean-Claude Wippler
Copyright (c) Steve Landers
Copyright (c) 2011-2013 Andreas Kupries