9.8.1 Structure of configure script and build files

A configure script tests running system’s properties to determine values of substitution parameters, then read one or more template build files, and write out one output build file for each, replacing substitution parameters for the assigned values.

By convention, a template file has a suffix .in, and the corresponding output file is named without the suffix. For example, Makefile.in is a template that generates Makefile.

Templates may contain substitution parameters, noted @PARAMETER_NAME@. This is a fragment of a typical Makefile template:

GAUCHE_PACKAGE = "@GAUCHE_PACKAGE@"
SOEXT          = @SOEXT@
LOCAL_PATHS    = "@LOCAL_PATHS@"

foo.$(SOEXT): $(foo_SRCS)
        $(GAUCHE_PACKAGE) compile \
          --local=$(LOCAL_PATHS) --verbose foo $(foo_SRCS)

When processed by configure, @GAUCHE_PACKAGE@, @SOEXT@ and @LOCAL_PATHS@ are replaced with appropriate values. If you know autoconf, you are already familiar with this.

The Gauche configure script is structurally similar to autoconf’s configure.in, but you can use full power of Scheme. The following is the minimal configure script:

#!/usr/bin/env gosh
(use gauche.configure)
(cf-init-gauche-extension)
(cf-output-default)

This script does several common tasks. The cf-init-gauche-extension does the following:

• First, it handles command-line arguments given to configure. In the default settings, it recognizes standard configure arguments such as --prefix, and --with-local=PATH:PATH:... which adds PATH/includes and PATH/libs to the header and library search paths. You can handle more arguments by adding cf-arg-with and cf-arg-enable before cf-init-gauche-extension.
• Then it reads package.scm. Package name and version are taken from it. Dependencies are also checked.
• It sets up global environment to run other configure checks.
• It sets up default values for standard substitution parameters such as @prefix@.

And cf-output-default does the following:

• Generate gpd (Gauche package description) file.
• Writes package version to VERSION file.
• Scan Makefile.in’s in the source directory and its subdirectories, and process them to generate Makefiles. If config header files (typically config.h) are specified by cf-config-headers, process input files (e.g. config.h.in) to generate the header files.

In general, a configure script consists of the following parts:

1. Extra argument declarations (optional): Declare --with-PACKAGE and/or --enable-FEATURE options you want to handle, by cf-with-arg and cf-enable-arg, respectively.
2. Initialization. Call to cf-init or cf-init-gauche-extension sets up global context and parses command-line arguments passed to configure. It also process package metainformation in package.scm, if it exists.
3. Tests and other substitution parameter settings (optional): Check system characteristics and sets up substitution parameters and/or C preprocessor definitions.
4. Output generation. Call cf-output or cf-output-default to process template files.

Most cf-* API corresponds to autoconf’s AC_* or AS_* macros. We need argument declarations before cf-init so that it can generate help message including custom arguments in one pass.

9.8.2 Configure API

Initialization

Function: cf-init-gauche-extension ¶

{gauche.configure} This is a convenience API that packages several boilerplate cf-* function calls in one call. This must be called exactly once in a configure script.

Specifically, it calls cf-arg-with to process --with-local, then calls cf-init with no arguments to initialize, then sets the following substitution parameters:

GOSH

Path to gosh.

GAUCHE_CONFIG

Path to gauche-config.

GAUCHE_PACKAGE

Path to gauche-package.

GAUCHE_INSTALL

Path to gauche-install.

GAUCHE_CESCONV

Path to gauche-cesconv.

GAUCHE_PKGINCDIR

Result of gauche-config --pkgincdir

GAUCHE_PKGLIBDIR

Result of gauche-config --pkglibdir

GAUCHE_PKGARCHDIR

Result of gauche-config --pkgarchdir

The --with-local command-line argument should take a parameter, which is a colon-separated list of paths. It becomes a value of substitution parameter LOCAL_PATHS. The default Makefile.in template passes its value to gauche-package via the --local argument. When the C extension is compiled and linked, the include and lib subdirectories of the given paths are searched for headers and libraries, respectively. For example, if the extension requires a library foo and you install it under /opt/foo (that is, headers in /opt/foo/include and library objects in /opt/foo/lib), then you can pass --with-local=/opt/foo to configure the extension.

If you don’t like these default behavior, you can call individual cf-* functions instead. See cf-init below.

Function: cf-init :optional package-name package-version maintainer-email homepage-url ¶

{gauche.configure} Initialize the configure system. Corresponds to autoconf’s AC_INIT. This must be called once in the configure script, before any feature-test procedures. (If you call cf-init-gauche-extension, cf-init is called from it.)

First, it checks if a file named package.scm is in the same directory as the configure script, and reads the Gauche package description from it. The package description contains package name, version, dependencies, etc. See gauche.package - Package metainformation, for the details.

It then parses the command-line arguments, sets up the configure environment, and (if package.scm defines dependencies) check if the system has required packages.

The optional arguments are only supported for the backward compatibility if you don’t have package.scm. You need at least to provide package-name and package-version to tell what package you’re configuring. They are used as the value of substitution parameter PACKAGE_NAME and PACKAGE_VERSION. The other optional arguments, maintainer-email and homepage-url, are used to initialize PACKAGE_BUGREPORT and PACKAGE_URL. These arguments are compatible to autoconf’s AC_INIT macro.

We recommend to always use package.scm and omit all the optional arguments, because it allows you to maintain the package metainformation in one place. When package.scm is read, PACKAGE_BUGREPORT is initialized by the first entry of maintainers slot of the package description, and PACKAGE_URL is initialized by its homepage slot. See gauche.package - Package metainformation, for description of slots of the package description.

Note that if there’s package.scm and you provide the optional arguments, they must match, or cf-init raises an error. It is to catch errors during transition in which you forgot to update either one.

This procedure sets up a bunch of standard substitution parameters such as prefix, bindir or srcdir. To see what substitution parameters are set, you can call cf-show-substs after cf-init.

Command-line arguments

Function: cf-arg-enable feature help-string :optional proc-if-given proc-if-not-given ¶

Function: cf-arg-with package help-string :optional proc-if-given proc-if-not-given ¶

{gauche.configure} Make the configure script accept feature selection argument and package selection argument, respectively. The corresponding autoconf macros are AC_ARG_ENABLE and AC_ARG_WITH.

Those procedures must be called before calling cf-init or cf-init-gauche-extension.

The feature and package arguments must be a symbol.

A feature selection argument is in a form of either --enable-feature=val, --enable-feature, or --disable-feature. The latter two are equivalent to --enable-feature=yes and --enable-feature=no, respectively. It is to select an optional feature provided with the package itself.

A package selection argument is in a form of either --with-package=val, --with-package and --without-package. The latter two are equivalent to --with-package=yes and --with-package=no, respectively. It is to select an external software package to be used with this package.

When cf-init finds these arguments, it adds entry of feature or package to the global tables, with the value val. Those global tables can be accessed with cf-feature-ref and cf-package-ref procedures below.

The help-string argument must be a string and is used as is to list the help of the option in part of usage message displayed by configure --help. You can use cf-help-string below to create a help string that fits nicely in the usage message.

If optional proc-if-given argument is given, it must be a procedure that accepts one argument, val. It is called when cf-init finds one of those arguments.

If optional proc-if-not-given argument is given, it must be a procedure that accepts no arguments. It is called when cf-init doesn’t find any of those arguments.

The following is to accept --with-local=PATH:PATH:…. (This cf-arg-with call is included in cf-init-gauche-extension). Note that the help string (the second argument) is generated by cf-help-string call. The command-line parameter followed by --with-local is passed as the argument of the procedure in the third argument:

(cf-arg-with 'local
             (cf-help-string
              "--with-local=PATH:PATH..."
              "For each PATH, add PATH/include to the include search
  paths and PATH/lib to the library search paths.  Useful if you have some
  libraries installed in non-standard places. ")
             (^[with-local]
               (unless (member with-local '("yes" "no" ""))
                 (cf-subst 'LOCAL_PATHS with-local)))
             (^[] (cf-subst 'LOCAL_PATHS "")))

Function: cf-help-string item description ¶

{gauche.configure} Return a string formatted suitable to show as an option’s help message. The result can be passed to help-string argument of cf-arg-enable and cf-arg-with. This corresponds to autoconf’s AS_HELP_STRING.

Call it as follows, and it’ll indent and fill the description nicely.

(cf-help-string "--option=ARG" "Give ARG as the value of option")

Function: cf-feature-ref name ¶

Function: cf-package-ref name ¶

{gauche.configure} Lookup a symbol name from the global feature table and the global package table, respectively. These can be called after cf-init.

For example, if you’ve called cf-arg-enable with foofeature, and the user has invoked the configure script with --with-foofeature=full, then (cf-feature-ref 'foofeature) returns "full". If the user hasn’t given the command-line argument, #f is returned.

If you add or change the value of features or packages, you can use generalized set! as (set! (cf-feature-ref 'NAME) VALUE) etc.

Messages

The cf-init procedure opens the default log drain that goes to config.log, and you can use log-format to write to it (See gauche.logger - User-level logging, for the details of logging).

However, to have consistent message format conveniently, the following procedures are provided. They emits the message both to log files and the current output port (in slightly different formats so that the console messages align nicely visually.)

Function: cf-msg-checking fmt arg … ¶

{gauche.configure} Writes out “checking XXX...” message. The fmt and arg … arguments are passed to format to produce the “XXX” part (see Formatting output).

For the current output port, this does not emit the trailing newline, expecting cf-msg-result will be called subsequently.

Here’s an excerpt of the source that uses cf-msg-checking and cf-msg-result:

(define (compiler-can-produce-executable?)
  (cf-msg-checking "whether the ~a compiler works" (~ (cf-lang)'name))
  (rlet1 result ($ run-compiler-with-content
                   (cf-lang-link-m (cf-lang))
                   (cf-lang-null-program-m (cf-lang)))
    (cf-msg-result (if result "yes" "no"))))

This produces a console output like this:

checking whether the C compiler works... yes

while the log file records more info:

checking: whether the C compiler works
... whatever logging message from run-compiler-with-content ...
result: yes

This corresponds to autoconf’s AC_MSG_CHECKING.

Function: cf-msg-result fmt arg … ¶

{gauche.configure} The fmt and arg … are passed to format, and the formatted message and newline is written out (see Formatting output). For the log file, it records “result: XXX” where XXX is the formatted message. Supposed to be used with cf-msg-checking.

This corresponds to autoconf’s AC_MSG_RESULT.

Function: cf-msg-notice fmt arg … ¶

{gauche.configure} Produces formatted message to both console and log. Newline is added. This corresponds to autoconf’s AC_MSG_NOTICE.

Function: cf-msg-warn fmt arg … ¶

Function: cf-msg-error fmt arg … ¶

{gauche.configure} Produces “Warning: XXX” and “Error: XXX” messages, respectively. The fmt and arg … are passed to format to generate XXX part (see Formatting output). Then, cf-msg-error exits with exit code 1.

These corresponds to autoconf’s AC_MSG_WARN and AC_MSG_ERROR. NB: AC_MSG_ERROR can specify the exit code, but cf-msg-error uses fixed exit code (1) for now.

Function: cf-echo arg … [> file][>> file] ¶

{gauche.configure} Convenience routine to replace shell’s echo command.

If the argument list ends with > file or >> file, where file is a string file name, then this works just like shell’s echo; that is, args except the last two are written to file, space separated, newline terminated. Using > supersedes file, while >> appends to it.

If the argument list doesn’t end with those redirection message, it writes out the argument to both the current output port and the log file, space separated, newline terminated. For the log file, the message is prefixed with “Message:”.

Parameters and definitions

The configure script maintains two global tables, definition tables and parameter tables. Definition tables is used for C preprocessor definitions, and parameter tables are used for @PARAMETER@ substitutions. (Do not confuse substitution parameters with Scheme’s parameter objects (see Parameters)).

Function: cf-define symbol :optional value ¶

{gauche.configure} Registers C preprocessor definition of symbol with value. Value can be any Scheme objects, but it is emitted to a command line (in -DSYMBOL=VALUE form) or in config.h (in #define SYMBOL VALUE form) using display, so you want to avoid including funny characters. If value is omitted, 1 is assumed.

NB: To #define a string value, e.g. #define FOO "foo", you have to call as (cf-define 'FOO "\"foo\"").

This corresponds to autoconf’s AC_DEFINE.

Function: cf-defined? symbol ¶

{gauche.configure} Returns #t iff symbol is cf-defined.

Function: cf-subst symbol value ¶

{gauche.configure} Registers a substitution parameter symbol with value. Value can be any Scheme objects; its display representation is used to substitute @SYMBOL@ in the template.

This corresponds to autoconf’s AC_SUBST, but we require the value (while autoconf can refer to the shell variable value as default).

Function: cf-subst-prepend symbol value :optional delim default ¶

Function: cf-subst-append symbol value :optional delim default ¶

{gauche.configure} Prepend or append value to the substitution parameter symbol, using delimiter delim. If the substitution parameter isn’t defined, value becomes the sole value of the parameter, except when default is given and not an empty string. If delim is omitted, single whitespace is used.

Special Form: with-cf-subst ((symbol value) …) … ¶

{gauche.configure} Temporarily replace substitution parameters with new values. This could be useful for example to run some compilation tests with different parameters

(with-cf-subst ((LIBS "-L<path> -l<lib>"))
  (cf-try-compile-and-link …))

Function: cf-have-subst? symbol ¶

{gauche.configure} Returns true iff symbol is registered as a substitution parameter by cf-subst.

Function: cf-arg-var symbol ¶

{gauche.configure} Lookup the environment variable symbol and if it is found, use its value as the substitution value. For example, if you call (cf-arg-var 'MYCFLAGS), then the user can provide the value of @MYCFLAGS@ as MYCFLAGS=-g ./configure.

This corresponds to autoconf’s AC_ARG_VAR, but we lack the ability of setting the help string. That’s because cf-arg-var must be run after cf-init, but the help message is constructed within cf-init.

Function: cf-ref symbol :optional default ¶

{gauche.configure} This looks up the value of the substitution parameter symbol. If there’s no such substitution parameter registered, it returns default when it’s provided, otherwise throws an error.

Function: cf$ symbol ¶

{gauche.configure} Looks up the value of the substitution parameter cf-ref, but it returns empty string if it’s unregistered. Useful to use within string interpolation, e.g. #"gosh ~(cf$'GOSHFLAGS)".

Predefined tests

Function: cf-check-prog sym prog-or-progs :key value default paths filter ¶

Function: cf-path-prog sym prog-or-progs :key value default paths filter ¶

{gauche.configure} Check if a named executable program exists in search paths, and if it exists, sets the substitution parameter sym to the name of the found program. The name to search is specified by prog-or-progs, which is either a string or a list of strings.

The difference of cf-check-prog and cf-path-prog is that cf-check-prog uses the basename of the found program, while cf-path-prog uses its full path. These corresponds to autoconf’s AC_CHECK_PROG, AC_CHECK_PROGS, AC_PATH_PROG and AC_PATH_PROGS.

For example, the following feature test searches either one of cc, gcc, tcc or pcc in PATH and sets the substitution parameter MY_CC to the name of the found one.

(cf-check-prog 'MY_CC '("cc" "gcc" "tcc" "pcc"))

If multiple program names is given, the search is done in the following order: First, we search for the first item (cc, in the above example) for each of paths, then the second, etc. For example, if we have /usr/local/bin:/usr/bin:/bin in PATH and we have /usr/local/bin/tcc and /usr/bin/gcc, the above feature test sets MY_CC to "gcc". If you use cf-path-prog instead, MY_CC gets "/usr/bin/gcc".

If no program is found, sym is set to the keyword argument default if it is given, otherwise sym is left unset.

If the value keyword argument is given, its value is used instead of the found program name to be set to sym.

The list of search paths is taken from PATH environment variable. You can override the list by the paths keyword argument, which must be a list of directory names. It may contain nonexistent directory names, which are silently skipped.

The filter keyword argument, if given, must be a predicate that takes full pathname of the executable program. It is called when the procedure finds matching executable; the filter procedure may reject it by returning #f, in which case the procedure keeps searching.

Note: If the substitution parameter sym is already set at the time these procedure is called, these procedures do nothing. Combined with cf-arg-var, it allows the configure script caller to override the feature test. For example, suppose you have the following in the configure script:

(cf-arg-var 'GREP)
(cf-path-prog 'GREP '("egrep" "fgrep" "grep"))

A user can override the test by calling configure like this:

$ ./configure GREP=mygrep

Function: cf-prog-cxx ¶

{gauche.configure} A convenience feature test to find C++ compiler. This searches popular names of C++ compilers from the search paths, sets the substitution parameter CXX to the compiler’s name, then tries to compile a small program with it to see it can generate an executable.

This corresponds to autoconf’s AC_PROG_CXX.

CXX is cf-arg-var’ed in this procedure. If a user provide the value when he calls configure, the searching is skipped, but the check of generating an executable is still performed.

If the substitution parameter CXXFLAGS is set, its value is used to check if the compiler can generate an executable. CXXFLAGS is cf-arg-var’ed in this procedure.

This procedure also emulates autoconf’s AC_PROG_CXX behavior— if CXX is not set, but CCC is set, then we set CXX by the value of CCC and skip searching.

Function: cf-header-available? header :key includes ¶

Function: cf-check-header header :key includes ¶

{gauche.configure} Check if a header file header exists and usable, by compiling a source program of the current language that includes the named header file. Return #t if the header is usable, #f if not.

Both procedure does the same thing. The name cf-check-header corresponds to autoconf’s AC_CHECK_HEADER.

If header requires other headers being included or preprocessor symbols defined before it, you can pass a list of strings to be emitted before the check in the includes keyword arguments. The given strings are just concatenated and used as a C program fragment. The default value is provided by cf-includes-default.

The following example sets C preprocessor symbol HAVE_CRYPT_H to 1 if crypt.h is available. (Note: For this kind of common task, you can use cf-check-headers below. The advantage of using cf-check-header is that you can write other actions in Scheme depending on the result.)

(when (cf-check-header "crypt.h")
  (cf-define "HAVE_CRYPT_H" 1))

Function: cf-check-headers headers :key includes if-found if-not-found ¶

{gauche.configure} Codify a common pattern of checking the availability of headers and sets C preprocessor definitions. This corresponds to autoconf’s AC_CHECK_HEADERS. This procedure is invoked for the side effects, and returns an undefined vlaue.

See this example:

(cf-check-headers '("unistd.h" "stdint.h" "inttypes.h" "rpc/types.h"))

This checks availability of each of listed headers, and sets C preprocessor definition HAVE_UNISTD_H, HAVE_STDINT_H, HAVE_INTTYPES_H and HAVE_RPC_TYPES_H to 1 if the corresponding header file is available.

A list of strings given to includes are emitted to the C source file before the inclusion of the testing header. You can give necessary headers and/or C preprocessor definitions there; if omitted, cf-includes-default provides the default list of such headers.

The keyword argument if-found and if-not-found are procedures to be called when a header is found to be available or to be unavailable, respectively. The procedure receives the name of the header.

The name of the C preprocessor definition is derived from the header name by upcasing it and replacing non-alphanumeric characters for _. Note that this substitution is not injective: Both gdbm/ndbm.h and gdbm-ndbm.h yield GDBM_NDBM_H. If you need to distinguish such files you have to use cf-check-header.

Function: cf-includes-default ¶

{gauche.configure} Returns a list of strings that are included in the check program by default. It is actually a combination of C preprocessor #ifdefs and #includes, and would probably be better to be called cf-prologue-default or something, but the corresponding autoconf macro is AC_INCLUDES_DEFAULT so we stick to this name.

Usually you don’t need to call this explicitly. Not giving the includes argument to cf-check-header and cf-check-headers will make cf-includes-default called implicitly.

Function: cf-type-available? type :key includes ¶

Function: cf-check-type type :key includes ¶

{gauche.configure} Test if type is defined as a type name. Return #t if type is defined, #f otherwise.

Two procedures are the same. The name cf-check-type corresponds to AC_CHECK_TYPE.

A list of strings given to includes are emitted to the C source file before the inclusion of the testing header. You can give necessary headers and/or C preprocessor definitions there; if omitted, cf-includes-default provides the default list of such headers.

Function: cf-check-types types :key includes if-found if-not-found ¶

{gauche.configure} For each type in the list types, call cf-check-type to see it is defined as a type. If it is, defines HAVE_type, and calls if-found with the type as an argument if provide. If the type is not defined and if-not-found is provided, calls it with the type as an argument.

The argument includes is passed to cf-check-type.

This corresponds to autoconf’s AC_CHECK_TYPES.

Returns an undefiend value. This procedure is for side effects.

;; May define HAVE_PTRDIFF_T and/or HAVE_UNSIGNED_LONG_LONG_INT
;; depending on its availability:
(cf-check-types '("ptrdiff_t" "unsigned long long int"))

;; Example of using includes to add an extra header.
(cf-check-types '("float_t")
                :includes `(,@(cf-includes-default)
                            "#include <math.h>\n"))

Function: cf-decl-available? symbol :key includes ¶

Function: cf-check-decl symbol :key includes ¶

{gauche.configure} Test if symbol is declared as a cpp macro, a variable, a constant, or a function. Return #t if type is defined, #f otherwise.

Two procedures are the same. The name cf-check-decl corresponds to autoconf’s AC_CHECK_DECL.

A list of strings given to includes are emitted to the C source file before the inclusion of the testing header. You can give necessary headers and/or C preprocessor definitions there; if omitted, cf-includes-default provides the default list of such headers.

Function: cf-check-decls symbols :key includes if-found if-not-found ¶

{gauche.configure} For each symbol in symbols, call cf-check-decl to see if it is declared. If it is, define HAVE_DECL_symbol to 1, and calls if-found with the symbol if provided. If it is not declared, define HAVE_DECL_symbol to 0, and calls if-not-found with the symbol if provided. This corresponds to autoconf’s AC_CHECK_DECLS.

The argument includes is passed to cf-check-decl.

This procedure returns an undefined value. This procedure is for side effects.

Note that, unlike other cf-check-* routines which leave HAVE_* macro undefined when the item isn’t found, this one always defines the macro and differentiate the result with its value. This behavior is the same as AC_CHECK_DECLS.

Function: cf-member-available? aggregate.member :key includes ¶

Function: cf-check-member aggregate.member :key includes ¶

{gauche.configure} The aggregate.member argument is a string of aggregate type name and its member concatenated by a dot, e.g. "struct password.pw_gecos". It can also be a submember, e.g. "struct foo.bar.baz". The aggregate part can be any type name (typedef-ed name is ok).

This test checks if member is a member of aggregate, and returns #t if so, or returns #f if not.

Two procedures are the same. The name cf-check-member corresponds to autoconf’s AC_CHECK_MEMBER.

A list of strings given to includes are emitted to the C source file before the inclusion of the testing header. You can give necessary headers and/or C preprocessor definitions there; if omitted, cf-includes-default provides the default list of such headers.

Function: cf-check-members members :key includes if-found if-not-found ¶

{gauche.configure} For each aggregate.member in members, call cf-check-member. If the test passes, defines HAVE_aggregate_member, and calls if-found with aggregate.member if provided. If the test fails, calls if-not-found with aggregate.member if provided.

This corresponds to autoconf’s AC_CHECK_MEMBERS.

The include argument is passed to cf-check-member.

;; Defines HAVE_STRUCT_ST_RDEV and/or HAVE_STRUCT_ST_BLKSIZE
;; depending on their availability:
(cf-check-members '("struct stat.st_rdev"
                    "struct stat.st_blksize"))

This procedure is for side effects, and returns an undefined value.

Function: cf-func-available? func ¶

Function: cf-check-func func ¶

{gauche.configure} See if a function func is available. This emits C code to call func (with dummy declaration) and tries to compile and link, using current value of substitution parameter LIBS. The value of cf-includes-default is at the top of the emitted C code.

They return #t if func is available, #f otherwise.

Two procedures are the same. The name cf-check-func corresponds to autoconf’s AC_CHECK_FUNC.

Function: cf-check-funcs funcs :key if-found if-not-found ¶

{gauche.configure} For each function name func in funcs, call cf-check-func to determine availability. If it is available, define HAVE_func, and calls if-found with func if provided. If it is not available, calls if-not-found with func if provided.

This corresponds to autoconf’s AC_CHECK_FUNCS.

This procedure is for side effects, and returns an undefined value.

Function: cf-lib-available? lib fn :key other-libs if-found if-not-found ¶

Function: cf-check-lib lib fn :key other-libs if-found if-not-found ¶

{gauche.configure} See if a library lib can be linked and a function fn in it is callable. Return #t it is, #t if not.

Two procedures are the same. The name cf-check-lib corresponds to autoconf’s AC_CHECK_LIB.

Give the name you pass after -l option to lib; for example, if you want to check availability of libm, you can say as follows:

(cf-check-lib "m" "sin")

This generates a C source that calls fn and try to compile and link it to generate executable. If linking lib requires additional libraries, it should be listed in other-libs:

(cf-check-lib "Xt" "XtDisplay" :other-libs '("-lX11" "-lSM" "-lICE"))

If compilation and linking succeeds, if-found is called at the tail position with the library name ("m" and "Xt" in the above examples, respectively) as the argument. The default behavior is to add -llib in the left of substitution parameter LIBS, and set HAVE_LIBlib definition, then returns #t.

If compilation or linking fails, if-not-found is called at the tail position with the library name. The default behavior is to return #f.

The default behavior of if-found and if-not-found allows cf-check-lib to be used as predicate as well. If you merery want to take an action depending on whether the library is found or not, you can write like this:

(unless (cf-check-lib "foo" "foo_fn)
  ... do something if libfoo isn't available ...)

Use if-found and/or if-not-found only if you want to override the default behaviors.

Function: cf-search-libs fn libs :key other-libs if-found if-not-found ¶

{gauche.configure} Like cf-check-lib, but can be used if you’re not sure which library contains desired function. This corresponds to autoconf’s AC_SEARCH_LIBS. Note that this takes function name first, while cf-check-lib takes function name second—blame autoconf for this inconsistency.

First it tests if fn is available without any library in libs (that is, with the ones already in LIBS and specified in other-libs). If not, it tests each library in libs in turn.

If fn is found, if-found is called at the tail position, with the name of the library as an argument (if fn is available without any library, the argument is #f). If omitted, and a library is required, then the library is added to the substitution parameter LIBS. The default procedure returns #t.

If fn isn’t found in any of the libraries, if-not-found is called at the tail position with #f as the argument. The default procedure does nothing and just returns #f.

The default behavior of if-found and if-not-found allows cf-search-libs to be used as predicate as well. If you give alternative procedures, keep in mind that their return value will be returned to cf-search-libs.

Running compiler

The gauche.configure module provides a generic mechanism to construct a small test program, compile it, and run it. Currently we only support C and C++; we’ll add support for other languages as needed.

Parameter: cf-lang ¶

{gauche.configure}

Function: cf-lang-program prologue body ¶

{gauche.configure} Returns a string tree that consists a stand-alone program for the current language. Prologue and body must be a string tree. Prologue comes at the beginning of the source, and body is included in the part of the program that’s executed. If the current language is C, the code fragment:

(use text.tree)
(write-tree (cf-lang-program "#include <stdio.h>\n" "printf(\"()\");\n"))

would produce something like this:

#include <stdio.h>

int main(){
printf("()");

; return 0;
}

Function: cf-lang-io-program ¶

{gauche.configure} This is a convenience routine. It returns a string tree of a program in the current language, that creates a file named conftest.out, then exits with zero status on success, or nonzero status on failure.

Function: cf-lang-call prologue func-name ¶

{gauche.configure}

Function: cf-try-compile prologue body ¶

{gauche.configure}

Function: cf-try-compile-and-link prologue body ¶

{gauche.configure}

Output

Function: cf-output-default file … ¶

{gauche.configure} A convenience routine to produce typical output. It does the following:

• Generate gpd (Gauche package description) file using cf-make-gpd.
• Generate VERSION file that contains the value of PACKAGE_VERSION substitution parameter.
• Search Makefile.in’s under the source directory (the value of substitution parameter srcdir), and process them to produce Makefile’s. If file … are given, file.in are also processed as well to produce file.

  See cf-output below for the details.

• If config header is registered by cf-config-headers, process them as well.

Function: cf-output file … ¶

{gauche.configure} Generates file’s from the input templates. This corresponds to autoconf’s AC_OUTPUT.

For each file, a file named file.in is read as a template. Within the file, @PARAMETER@ is substituted with the value of (cf$ 'PARAMETER). If the named parameter isn’t registered, a warning is issued and the parameter is left unsubstituted.

If config headers are not registered via cf-config-headers, a substitution parameter DEFS is replaced with all the definitions in the form of -D.... For example, if you have checked header files foo/bar.h and foo/baz.h, DEFS gets the value -DHAVE_FOO_BAR_H -DHAVE_FOO_BAZ_H.

If config header is registered by cf-config-headers, they are processed as well. In such case, the substitution parameter DEFS gets the value -DHAVE_CONFIG_H.

Function: cf-config-headers header-or-headers ¶

{gauche.configure} Sets up config header files to be processed. Usually a config header file is named config.h, and contains definitions determined by feature tests.

The header-or-headers argument may be a string header-spec or a list of string header-specs, where each header spec is a header file name (e.g. "config.h") or a header name and a input file name concatenated with a colon (e.g. "config.h:config.h.templ"). If it’s just a header name, input file name is assumed to be the header file name with ".in" appended.

The input template of config header file contains a bunch of #undef directives, such as the following:

/* Gauche ABI version string */
#undef GAUCHE_ABI_VERSION

/* Define if Gauche handles multi-byte character as EUC-JP */
#undef GAUCHE_CHAR_ENCODING_EUC_JP

/* Define if Gauche handles multi-byte character as Shift JIS */
#undef GAUCHE_CHAR_ENCODING_SJIS

/* Define if Gauche handles multi-byte character as UTF-8 */
#undef GAUCHE_CHAR_ENCODING_UTF_8

Once processed, the generated header file has either #undef line is replaced with #define, or commented out, depending on the definitions determined by feature tests.

/* Gauche ABI version string */
#define GAUCHE_ABI_VERSION "0.97"

/* Define if Gauche handles multi-byte character as EUC-JP */
/* #undef GAUCHE_CHAR_ENCODING_EUC_JP */

/* Define if Gauche handles multi-byte character as Shift JIS */
/* #undef GAUCHE_CHAR_ENCODING_SJIS */

/* Define if Gauche handles multi-byte character as UTF-8 */
#define GAUCHE_CHAR_ENCODING_UTF_8 /**/

Note that the lines other than #undef are copied as they are.

The substitution parameter DEFS behaves differently whether config header is specified or not. If no config header is registered, The value of DEFS is a C command-line arguments for definitions, e.g. -DGAUCHE_ABI_VERSION=0.97 -DGAUCHE_CHAR_ENCODING_UTF8. If config header files are registered, the value of DEFS becomes simply -DHAVE_CONFIG_H.

Function: cf-show-substs :key formatter ¶

{gauche.configure} Print all substitution parameters; this is for debugging.

For each substitution parameter name and value, formatter is called with them; the default is (^[k v] (format #t "~16s ~s" k v)).

Function: cf-make-gpd ¶

{gauche.configure} Generate gpd (Gauche package description) file, PACKAGE_NAME.gpd, where PACKAGE_NAME is the package’s name either taken form package.scm or the argument to cf-init. See gauche.package - Package metainformation, for the package description file format.