xref: /netbsd-src/external/mit/isl/dist/m4/ax_prog_cc_for_build.m4 (revision 5971e316fdea024efff6be8f03536623db06833e)
1# ===========================================================================
2#   https://www.gnu.org/software/autoconf-archive/ax_prog_cc_for_build.html
3# ===========================================================================
4#
5# SYNOPSIS
6#
7#   AX_PROG_CC_FOR_BUILD
8#
9# DESCRIPTION
10#
11#   This macro searches for a C compiler that generates native executables,
12#   that is a C compiler that surely is not a cross-compiler. This can be
13#   useful if you have to generate source code at compile-time like for
14#   example GCC does.
15#
16#   The macro sets the CC_FOR_BUILD and CPP_FOR_BUILD macros to anything
17#   needed to compile or link (CC_FOR_BUILD) and preprocess (CPP_FOR_BUILD).
18#   The value of these variables can be overridden by the user by specifying
19#   a compiler with an environment variable (like you do for standard CC).
20#
21#   It also sets BUILD_EXEEXT and BUILD_OBJEXT to the executable and object
22#   file extensions for the build platform, and GCC_FOR_BUILD to `yes' if
23#   the compiler we found is GCC. All these variables but GCC_FOR_BUILD are
24#   substituted in the Makefile.
25#
26# LICENSE
27#
28#   Copyright (c) 2008 Paolo Bonzini <bonzini@gnu.org>
29#
30#   Copying and distribution of this file, with or without modification, are
31#   permitted in any medium without royalty provided the copyright notice
32#   and this notice are preserved. This file is offered as-is, without any
33#   warranty.
34
35#serial 21
36
37AU_ALIAS([AC_PROG_CC_FOR_BUILD], [AX_PROG_CC_FOR_BUILD])
38AC_DEFUN([AX_PROG_CC_FOR_BUILD], [dnl
39AC_REQUIRE([AC_PROG_CC])dnl
40AC_REQUIRE([AC_PROG_CPP])dnl
41AC_REQUIRE([AC_CANONICAL_BUILD])dnl
42
43dnl Use the standard macros, but make them use other variable names
44dnl
45pushdef([ac_cv_prog_CPP], ac_cv_build_prog_CPP)dnl
46pushdef([ac_cv_prog_cc_c89], ac_cv_build_prog_cc_c89)dnl
47pushdef([ac_cv_prog_cc_c99], ac_cv_build_prog_cc_c99)dnl
48pushdef([ac_cv_prog_cc_c11], ac_cv_build_prog_cc_c11)dnl
49pushdef([ac_cv_prog_gcc], ac_cv_build_prog_gcc)dnl
50pushdef([ac_cv_prog_cc_works], ac_cv_build_prog_cc_works)dnl
51pushdef([ac_cv_prog_cc_cross], ac_cv_build_prog_cc_cross)dnl
52pushdef([ac_cv_prog_cc_g], ac_cv_build_prog_cc_g)dnl
53pushdef([ac_cv_c_compiler_gnu], ac_cv_build_c_compiler_gnu)dnl
54pushdef([ac_cv_exeext], ac_cv_build_exeext)dnl
55pushdef([ac_cv_objext], ac_cv_build_objext)dnl
56pushdef([ac_exeext], ac_build_exeext)dnl
57pushdef([ac_objext], ac_build_objext)dnl
58pushdef([CC], CC_FOR_BUILD)dnl
59pushdef([CCDEPMODE], CCDEPMODE_FOR_BUILD)dnl
60pushdef([CPP], CPP_FOR_BUILD)dnl
61pushdef([GCC], GCC_FOR_BUILD)dnl
62pushdef([CFLAGS], CFLAGS_FOR_BUILD)dnl
63pushdef([CPPFLAGS], CPPFLAGS_FOR_BUILD)dnl
64pushdef([EXEEXT], BUILD_EXEEXT)dnl
65pushdef([LDFLAGS], LDFLAGS_FOR_BUILD)dnl
66pushdef([OBJEXT], BUILD_OBJEXT)dnl
67pushdef([host], build)dnl
68pushdef([host_alias], build_alias)dnl
69pushdef([host_cpu], build_cpu)dnl
70pushdef([host_vendor], build_vendor)dnl
71pushdef([host_os], build_os)dnl
72pushdef([ac_cv_host], ac_cv_build)dnl
73pushdef([ac_cv_host_alias], ac_cv_build_alias)dnl
74pushdef([ac_cv_host_cpu], ac_cv_build_cpu)dnl
75pushdef([ac_cv_host_vendor], ac_cv_build_vendor)dnl
76pushdef([ac_cv_host_os], ac_cv_build_os)dnl
77pushdef([ac_tool_prefix], ac_build_tool_prefix)dnl
78pushdef([am_cv_CC_dependencies_compiler_type], am_cv_build_CC_dependencies_compiler_type)dnl
79pushdef([am__fastdepCC_FALSE], am__fastdepCC_build_FALSE)dnl
80pushdef([am__fastdepCC_TRUE], am__fastdepCC_build_TRUE)dnl
81pushdef([am_cv_prog_cc_c_o], am_cv_build_prog_cc_c_o)dnl
82pushdef([cross_compiling], cross_compiling_build)dnl
83
84cross_compiling_build=no
85
86ac_build_tool_prefix=
87AS_IF([test -n "$build"],      [ac_build_tool_prefix="$build-"],
88      [test -n "$build_alias"],[ac_build_tool_prefix="$build_alias-"])
89
90AC_LANG_PUSH([C])
91
92dnl The pushdef([ac_cv_c_compiler_gnu], ...) currently does not cover
93dnl the use of this variable in _AC_LANG_COMPILER_GNU called by
94dnl AC_PROG_CC. Unset this cache variable temporarily as a workaround.
95was_set_c_compiler_gnu=${[ac_cv_c_compiler_gnu]+y}
96AS_IF([test ${was_set_c_compiler_gnu}],
97    [saved_c_compiler_gnu=$[ac_cv_c_compiler_gnu]
98    AS_UNSET([[ac_cv_c_compiler_gnu]])])
99
100AC_PROG_CC
101
102dnl Restore ac_cv_c_compiler_gnu
103AS_IF([test ${was_set_c_compiler_gnu}],
104  [[ac_cv_c_compiler_gnu]=$[saved_c_compiler_gnu]])
105
106_AC_COMPILER_EXEEXT
107_AC_COMPILER_OBJEXT
108AC_PROG_CPP
109
110dnl Restore the old definitions
111dnl
112popdef([cross_compiling])dnl
113popdef([am_cv_prog_cc_c_o])dnl
114popdef([am__fastdepCC_TRUE])dnl
115popdef([am__fastdepCC_FALSE])dnl
116popdef([am_cv_CC_dependencies_compiler_type])dnl
117popdef([ac_tool_prefix])dnl
118popdef([ac_cv_host_os])dnl
119popdef([ac_cv_host_vendor])dnl
120popdef([ac_cv_host_cpu])dnl
121popdef([ac_cv_host_alias])dnl
122popdef([ac_cv_host])dnl
123popdef([host_os])dnl
124popdef([host_vendor])dnl
125popdef([host_cpu])dnl
126popdef([host_alias])dnl
127popdef([host])dnl
128popdef([OBJEXT])dnl
129popdef([LDFLAGS])dnl
130popdef([EXEEXT])dnl
131popdef([CPPFLAGS])dnl
132popdef([CFLAGS])dnl
133popdef([GCC])dnl
134popdef([CPP])dnl
135popdef([CCDEPMODE])dnl
136popdef([CC])dnl
137popdef([ac_objext])dnl
138popdef([ac_exeext])dnl
139popdef([ac_cv_objext])dnl
140popdef([ac_cv_exeext])dnl
141popdef([ac_cv_c_compiler_gnu])dnl
142popdef([ac_cv_prog_cc_g])dnl
143popdef([ac_cv_prog_cc_cross])dnl
144popdef([ac_cv_prog_cc_works])dnl
145popdef([ac_cv_prog_cc_c89])dnl
146popdef([ac_cv_prog_gcc])dnl
147popdef([ac_cv_prog_CPP])dnl
148
149dnl restore global variables ac_ext, ac_cpp, ac_compile,
150dnl ac_link, ac_compiler_gnu (dependant on the current
151dnl language after popping):
152AC_LANG_POP([C])
153
154dnl Finally, set Makefile variables using the ac_cv_build_* variables
155dnl
156AC_SUBST(BUILD_EXEEXT)dnl
157AC_SUBST(BUILD_OBJEXT)dnl
158dnl Since autoconf 2.70, the call to AC_SUBST in the following lines
159dnl of _AC_COMPILER_EXEEXT
160dnl     AC_SUBST([EXEEXT], [$ac_cv_exeext])dnl
161dnl     ac_exeext=$EXEEXT
162dnl no longer sets BUILD_EXEEXT, but EXEEXT instead.
163dnl This means not only that BUILD_EXEEXT is not getting set,
164dnl but also that the original EXEEXT is overwritten
165dnl by a possibly different value.  Furthermore, ac_build_exeext
166dnl is assigned an undefined value.
167dnl Restore EXEEXT to the original value and
168dnl set BUILD_EXEEXT and ac_build_exeext.
169dnl Similarly for _AC_COMPILER_OBJEXT and OBJEXT.
170m4_version_prereq([2.70],[dnl
171EXEEXT=$ac_cv_exeext
172BUILD_EXEEXT=$ac_cv_build_exeext; ac_build_exeext=$ac_cv_build_exeext
173OBJEXT=$ac_cv_objext
174BUILD_OBJEXT=$ac_cv_build_objext; ac_build_objext=$ac_cv_build_objext],[[]])
175dnl Similarly to _AC_COMPILER_EXEEXT and _AC_COMPILER_OBJEXT,
176dnl the line
177dnl	AC_SUBST([$1DEPMODE], [depmode=$am_cv_$1_dependencies_compiler_type])
178dnl of _AM_DEPENDENCIES no longer sets CCDEPMODE_FOR_BUILD,
179dnl but overrides CCDEPMODE.
180dnl Restore CCDEPMODE and set CCDEPMODE_FOR_BUILD.
181AC_SUBST(CCDEPMODE_FOR_BUILD)dnl
182CCDEPMODE=depmode=$am_cv_CC_dependencies_compiler_type
183CCDEPMODE_FOR_BUILD=depmode=$am_cv_build_CC_dependencies_compiler_type
184AC_SUBST([CFLAGS_FOR_BUILD])dnl
185AC_SUBST([CPPFLAGS_FOR_BUILD])dnl
186AC_SUBST([LDFLAGS_FOR_BUILD])dnl
187])
188