icmconf(7)

NAME
icmconf - Configuration file for the icmbuild(1) program maintenance script

DESCRIPTION

The icmconf configuration file is used to configure program maintenance performed by icmbuild(1). It uses various directives determining how the program or library maintenance is performed.

Icmconf’s directives are biased towards the construction of C++ programs, but program maintenance for other languages (e.g., C) can also easily be configured.

The icmbuild(1) script ignores empty lines and lines whose first non-blank characters are two consecutive forward slashes (//) or start with a hash-character (#). Long lines can be split over multiple lines by writing a final backslash character at lines continuing at the next line.

CLASS DEPENDENCIES

Traditional make-utilities recompile all dependent sources once header files are modified. When developing C++ programs this is hardly ever requird, as adding new member functions to classes does not require you to recompile already existing source files. Recompilation is required when the data member organization of classes is altered.

To handle class dependencies in a more sensible way, icmake(1) checks class dependencies using its support programs icm-dep, visiting the classes listed in the CLASSES file if icmconf’s USE_ALL directive was specified. If a directory mentioned in the CLASSES file contains a file having a name equal to the name specified at the USE_ALL parameter, then all sources of classes that depend on that particular class are also recompiled. In practice this means that when you change the data organization of a class you only need to touch it that directory the file whose name was specified by the USE_ALL directive. E.g., if your class is named Data, its sources are in the sub-directory ./data, and #define USE_ALL "a" was specified then after modifying the data organization of the class Data you only need to issue the command touch data/a. Subsequently, at the next icmbuild call all sources in ./data as well as all sources in directories whose (header) files include data.h are recompiled as well.

Likewise, if #define SPCH or (deprecated) #define PRECOMP was used, a similar action is performed for the precompiled headers: if a local file that’s (directly or indirectly) included by internal header files has changed, then the Single Pre-Compiled Header (SPCH) file is recompiled (or (deprecated), having specified PRECOMP the modified class headers are recompiled).

The icmbuild(1) script itself does not inspect these dependencies, but calls the support programs icm-spch and icm-dep to perform the requird tests. The usage summaries of these programs are written to the standard output stream when calling, respectively icmake -S and icmake -d.

DEFAULT DEFINE SPECIFICATIONS

The following #defines, except for those that are shown as commented (e.g., //#define REFRESH) are required.

o   //#define ADD_LIBRARIES ""
    when a program must be linked against additional libraries (other than the name of the program’s library itself (cf. LIBRARY, below) then those libraries should be specified here. E.g., when a program is linked against libbobcat then the specification is:
        #define ADD_LIBRARIES  "bobcat"

    If your program is linked against multiple libraries, then use a blank-separated list of libraries (like #define ADD_LIBRARIES "bobcat math");

o   //#define ADD_LIBRARY_PATHS ""
    this directtive must be specified if ADD_LIBRARIES is also specified, although it may be specified as an empty string. When additional libraries (specified at ADD_LIBRARIES) are located in non-standard library locations (e.g., not in /lib and /usr/lib) then these additional paths are (blank space separated) specified here. Specify only the paths, not the -L flags.

    It is stronly advised to specify full pathnames here. Relative path specifications can be used by specifying paths relative to the directory that is specified at the TMP_DIR directive (see below);

o   //#define CLS
    the clear screen directive. If defined tput clear is called to clear the terminal screen before starting compilations. By default it is not defined. Alternatively the -c option can be passed to icmbuild;

o   #define CXX "g++"
    the C++ compiler to use. For a C compiler specify, e.g., #define CC "gcc". Their settings are overruled by identically named environment variables. If only C files are compiled then #define CXX can be omitted.

    By specifying, e.g., #define CXX "ccache g++" compilations use caching facilities, which may impressively reduce recompilation times. Refer to the cccache(1) man-page for details.

o   #define CXXFLAGS "-Werror -Wall -O2"
    C++ compiler options to use (here showing the default options). When the C compiler is used, use #define CFLAGS rather than CXXFLAGS. Their settings are overruled by identically named environment variables. If only C files are compiled then #define CXXFLAGS can be omitted.

    Additional options can be defined by adding them to the CXXFLAGS definition. In addition, compilations use the environment variable ICMAKE_CPPSTD to set the C++ standard to use. E.g., after defining

        ICMAKE_CPPSTD=--std=c++26

    the compiler uses the options

        --std=c++26 -Werror -Wall -O2

o   //#define DEFCOM "..."
    a DEFCOM directive may be added to the icmconf file (the icmstart(1) script can do this for you). It can be specified as:
        #define DEFCOM  "program"

    in which case icmbuild does program maintenance, or as
        #define DEFCOM  "library"

    in which case icmbuild does library maintenance.;

o   //#define ICM_DEP "-V go"
    the existence and implied existence of USE_ALL files (see the description of the USE_ALL directive). When the (deprecated) PRECOMP directive is specified the recency of precompiled headers is ensured (see also the SPCH description, below). By default icm_dep is called with the shown default arguments. If icm_dep should not be called define ICM_DEP as an empty string (""). Icmake(1)’s man-page contains a separate section about the icm_dep support program;

o   #define IH ".ih"
    the extension used for internal header files. See #define SPCH below. If SPCH is specified the ttI#define H) directive must also be specified;

o   //#define LDFLAGS ""
    linker options to use. By default no options are passed to the linker. Its setting is overruled by an identically named environment variable;

o   //#define LIBRARY "ofiles"
    by defining this directive a local library (libofiles.a) is constructed. When a binary program is built it is linked against this library rather than to the individual object files.

    If a library instead of a program must be constructed (see also the DEFCOM directive), then the LIBRARY directive specifies the library’s base name (without the lib prefix and without the .a extension). In that case source files are expected in sub-directories of the project’s main directory (i.e., the directory containing icmconf). In that case avoid having source and header files in the project’s main directory. Instead, move such files to a separate sub-directory;

o   //#define MAIN "main.cc"
    the source file in which the int main function is defined. This directive is required when doing program (rather than library) maintenance.

    Note: if source files are located in the project’s main directory but library maintenance is intended (e.g., by specifying #define DEFCOM library) then define MAIN to specify a pseudo main source, whose base name is the base name of the header file in the project’s main directory. This, however, is considered a kludge, and should be avoided by moving those source and header files to a separate sub-directory;

o   //#define MULTICOMP "..."
    Example: #define MULTICOMP "jobs -q"

    This directive activates threaded compilation of source files. When used its first word specifies the name of a file to contain information about which files must be compiled. This must be a plain filename, not containing directory specifiers (like /). Refer to the icmake(1) man-page’s section ICM-MULTICOMP covering options, arguments, and usage of icm-multicomp which is called when #define MULTICOMP is specified;

o   //#define NO_PRECOMP_WARNING"
    when #define PRECOMP (now deprecated) is specified (see below) a warning is issued when a class-directory does not contain a IH file. Such warnings are suppressed by defining NO_PRECOMP_WARNING. This option is only considered when #define PRECOMP is specified;

o   #define OBJ_EXT ".o"
    this directive specifies the extension of object modules created by the compiler;

o   //#define PRECOMP "-x c++-header"
    (deprecated, consider declaring #define SPCH instead)
    define this directive to construct class-specific pre-compiled headers (in which case the IH) directive must also be specified. Dependencies between (precompiled) headers are automatically considered.
    Existing precompiled headers are removed by icmbuild cleangch (or icmbuild clean. When source files of other languages are compiled the PRECOMP’s -x argument must be adapted to those languages;

o   //#define REFRESH
    define REFRESH to relink the binary program when icmbuild program is called, even when no file was (re)compiled. This is useful when the program links to external libraries which were updated separately from the currrent project;

o   //#define SHARED
    this directive is only interpreted when LIBRARY is also specified. If defined a shared library (extension .so*) is built in addition to a static library (extension .a);
    The shared library receives VERSION as its version number while soft links using VERSION’s (see below) major version number an no version number are also made available. E.g., if VERSION is defined as 1.02.03 and #define LIBRARY "demo" then the shared library becomes libdemo.so.1.02.03, with libdemo.so.1 soft-linking to it, and libdemo.so soft-linking to libdemo.so.1;

o   //#define SHAREDREQ ""
    when creating a shared library SHAREDREQ specifies the names of libraries and library paths that are required by the constructed shared library itself. E.g., if a library is found in /usr/lib/special, assuming that the name of the required library is libspecial.so, then use the specification #define SHAREDREQ "-L/usr/lib/special -lspecial". The /lib and /usr/lib paths are usually automatically visited by the linker and do not have the be specified. This directive is required (possibly as an empty string) if SHARED is defined;

o   #define SOURCES "*.cc"
    the pattern to locate sources in directories;

o   //#define SPCH "..."
    Example: #define SPCH ""
    If #define SPCH is specified then #define IH must also be specified.
    This directive activates the construction of a Single Pre-Compiled Header (SPCH). Refer to the icmake(1) man-page, section ICM-SPCH for specific details and options when constructing a SPCH. The argument string can be empty, or it can contain specifications which are used when constructing a SPCH. The --internal (or -i) option should not be specified as it is used by default when calling icmake -S.
    By default the (g++) command constructing the SPCH is echoed to the standard output stream. This can be suppressed by specifying --quiet (or -q) in the SPCH string (e.g., #define SPCH "-q"). Additional options for the compiler can be specified using --option (or -o) specifications.

o   //#define SPCH_ARGS "..."
    Example: #define SPCH_ARGS "specs f:compiler"
    In practice the #define SPCH_ARGS specification is hardly ever required. It requires the specification of the #define SPCH directive. Refer to the icmake(1) man-page, section ICM-SPCH for specific details about this specification.
    The first word (specs) defines the name of the file (used by icmake -S) to contain the names of the headers used when constructing the SPCH. If SPCH_ARGS is not specified then icmake -S by default uses specs. When SPCH_ARGS is used the specified name must be a plain filename, not containing directory specifiers (like /) or an extension.
    The second word (here: f:compiler) is optional, but when provided defines the file containing the compiler-command to use when constructing the SPCH. By default the SPCH is constructed using the following command (all on one line):

    g++ -c -o $2 ${ICMAKE_CPPSTD} -Wall -Werror -O2 -x c++-header $1

    To the compiler-command options specified by -o specifications provided in the #define SPCH string are added. It is also possible (but probably less convenient) to specify the command directly as SPCH_ARGS’s second word. In that case surround the command by \\’ (two backslashes and a quote) characters to ensure that the multi-word specification is interpreted by icmake -S as a single argument.

o   #define TMP_DIR "tmp"
    the directory in which intermediate results are stored. To avoid cross-device communications it’s probably best to define TMP_DIR as a sub-directory of the project’s main directory;

o   //#define USE_ALL "a"
    when defining this directive icmbuild looks for directories containing files having the names defined by the USE_ALL specification. All source files in those directories as well as all source files in directories that (recursively) depend on the set of directories under consideration are recompiled, after which the USE_ALL files are removed;

o   //#define USE_ECHO ON
    when defined as ON (rather than OFF) (system) commands executed by icmbuild are echoed;

o   //#define USE_VERSION
    when defined (it is defined by default) a file VERSION is read by icmconf to determine the program’s or library’s version, and the project’s release years. The file VERSION must be available in the project’s main directory containing lines like:
        VERSION=1.02.03
        YEARS=2010-2025

    )

PARSER MAINTENANCE

The following directives are available in cases where a program uses a parser generator creating a parser class from a grammar specification. By default they’re all commented out, and can be removed if a parser generator is not used. See also the icmstart.rc(7) man-page (section(FINE-TUNING ICMCONF)) for an alternative way to specify the parser-related #defines.

o   //#define PARSER_DIR ""
    the sub-directory containing the parser’s specification file. If the PARSER_DIR directory is specified then all other directives in this section must also be specified;

o   //#define PARSFILES ""
    if the parser specification file named at PARSSPEC itself includes additional specification files, then patterns matching these additional grammar specification files should be specified here. The pattern is interpreted in the directory specified at PARSER_DIR and could contain a subdirectory name (e.g. specs/*). When files matching the pattern are modified then a new parser is created;

o   //#define PARSFLAGS "-V"
    the flags that are used when calling the program specified at PARSGEN;

o   //#define PARSGEN "bisonc++"
    the name of the program generating the parser;

o   //#define PARSOUT "parse.cc"
    the name of the file generated by the parser generator (used by icmbuild when checking the timestamps of parser specification s);

o   //#define PARSSPEC "grammar"
    the name of the parser specification file. This file is expected in the directory specified by the PARSER_DIR directive.

SCANNER MAINTENANCE

The following directives are available in cases where a program uses a scanner generator creating a lexical scanner class from a set of regular expressions. By default they’re all commented out, and can be removed if a scanner generator is not used. See also the icmstart.rc(7) man-page (section(FINE-TUNING ICMCONF)) for an alternative way to specify the scanner-related #defines.

o   #define SCANNER_DIR ""
    the subdirectory containing the scanner’s specification file. If the SCANNER_DIR directory is specified then all other directives in this section must also be specified;

o   #define SCANFILES ""
    if the lexical scanner specification file named at SCANSPEC itself includes additional specification files, then patterns matching these additional lexer specification files should be specified here. The pattern is interpreted in the directory specified at SCANNER_DIR and could contain a subdirectory name (e.g. specs/*). When files matching the pattern are modified then a new lexical scanner is created. By default no additional specification files are used;

o   #define SCANFLAGS ""
    the flags that are used when calling the program specified at SCANGEN;

o   #define SCANGEN "flexc++"
    the name of the program generating the lexical scanner;

o   #define SCANOUT "lex.cc"
    the name of the file generated by the lexical scanner (which is used by icmbuild when checking the timestamps of scanner specification s).

o   #define SCANSPEC "lexer"
    the name of the lexical scanner specification file. This file is expected in the directory specified by the SCANNER_DIR directive.

FILES
The mentioned paths are sugestive only and may be installation dependent:

o   /usr/share/icmake/CLASSES
    : example of an icmconf CLASSES file;

o   /usr/share/icmake/icmconf
    : default (skeleton) icmbuild resource files, like main.cc, usage.cc, etc.;

o   /etc/icmake
    : directory containing the default system-wide icmstart(1) configuration file;

o   $HOME/.icmake
    : optional user-defined directory containing user-defined specifications overruling the system-wide definitions. This directory is the proper location for a file AUTHOR defining the AUTHOR directive with the user’s name. E.g., my .icmake/AUTHOR file contains:
        #define AUTHOR  "Frank B. Brokken (f.b.brokken@rug.nl)";

SEE ALSO
ccache(1), icmake(1), icmbuild(1), icmstart(1), icmstart.rc(7).

BUGS
None reported.

COPYRIGHT
This is free software, distributed under the terms of the GNU General Public License (GPL).

AUTHOR
Frank B. Brokken (f.b.brokken@rug.nl).