Less hackish cross compilation support.

* Changed hardcoded gcc for build compiler to use
  m4_ax_prog_cc_for_build.m4 instead as suggested by Khaled.

3 files changed, 137 insertions, 30 deletions

diff --git a/configure.ac b/configure.ac
index 46634e1..363346d 100644
--- a/configure.ac
+++ b/configure.ac
@@ -111,6 +111,7 @@ AC_SUBST(SIZEOF_INT)
 AC_CHECK_SIZEOF(short)
 AC_CHECK_SIZEOF(void *)
 AC_CHECK_SIZEOF(wchar_t)
+AX_PROG_CC_FOR_BUILD
 
 # Checks for compiler characteristics.
 changequote(,)dnl
@@ -180,26 +181,7 @@ fi
 fi
 AM_CONDITIONAL(FRIBIDI_USE_GLIB, test x$FRIBIDI_USE_GLIB = x1)
 
-# A hack for supporting cross compilation
-if test $host != $build; then
-  BUILD_CC="gcc"
-  BUILD_CFLAGS="-O2 -g"
-  BUILD_LDFLAGS=""
-  BUILD_EXEEXT=""
-else
-  BUILD_CC="${CC}"
-  BUILD_CFLAGS="${CFLAGS}"
-  BUILD_LDFLAGS="${LDFLAGS}"
-  BUILD_EXEEXT="${EXEEXT}"
-fi
-
-# Continuation of hack to set up the proper include directories
-BUILD_CFLAGS="${BUILD_CFLAGS} -DHAVE_CONFIG_H -I.. -I../lib"
-
-AC_ARG_VAR([BUILD_CC])
-AC_ARG_VAR([BUILD_CFLAGS])
-AC_ARG_VAR([BUILD_LDFLAGS])
-AC_ARG_VAR([BUILD_EXEEXT])
+CFLAGS_FOR_BUILD="${CFLAGS_FOR_BUILD} -DHAVE_CONFIG_H -I.. -I../lib"
 
 # Generate output
 AC_CONFIG_FILES([fribidi.pc
diff --git a/gen.tab/Makefile.am b/gen.tab/Makefile.am
index 66f3573..8f00861 100644
--- a/gen.tab/Makefile.am
+++ b/gen.tab/Makefile.am
@@ -50,7 +50,7 @@ derived_bidi-type.tab.i: \
 		DerivedBidiClass.txt \
 		fribidi-unicode-version.h \
 		$(gen_bidi_type_tab_SOURCES)
-	$(BUILD_CC) $(BUILD_CFLAGS) -o $(gen_bidi_type_tab) $(gen_bidi_type_tab_SOURCES)
+	$(CC_FOR_BUILD) $(CFLAGS_FOR_BUILD) -o $(gen_bidi_type_tab) $(gen_bidi_type_tab_SOURCES)
 	./$(gen_bidi_type_tab) $(COMPRESSION) $^ > $@ \
 	|| ($(RM) $@ && false)
 
@@ -58,7 +58,7 @@ bidi-type.tab.i: \
 		UnicodeData.txt \
 		fribidi-unicode-version.h \
 		$(gen_bidi_type_tab_SOURCES)
-	$(BUILD_CC) $(BUILD_CFLAGS) -o $(gen_bidi_type_tab) $(gen_bidi_type_tab_SOURCES)
+	$(CC_FOR_BUILD) $(CFLAGS_FOR_BUILD) -o $(gen_bidi_type_tab) $(gen_bidi_type_tab_SOURCES)
 	./$(gen_bidi_type_tab) $(COMPRESSION) $^ > $@ \
 	|| ($(RM) $@ && false)
 
@@ -73,7 +73,7 @@ joining-type.tab.i: \
 		ArabicShaping.txt \
 		fribidi-unicode-version.h \
 		$(gen_joining_type_tab_SOURCES)
-	$(BUILD_CC) $(BUILD_CFLAGS) -o $(gen_joining_type_tab) $(gen_joining_type_tab_SOURCES)
+	$(CC_FOR_BUILD) $(CFLAGS_FOR_BUILD) -o $(gen_joining_type_tab) $(gen_joining_type_tab_SOURCES)
 	./$(gen_joining_type_tab) $(COMPRESSION) $^ > $@ \
 	|| ($(RM) $@ && false)
 
@@ -85,7 +85,7 @@ arabic-shaping.tab.i: \
 		UnicodeData.txt \
 		fribidi-unicode-version.h \
 		$(gen_arabic_shaping_tab_SOURCES)
-	$(BUILD_CC) $(BUILD_CFLAGS) -o $(gen_arabic_shaping_tab) $(gen_arabic_shaping_tab_SOURCES)
+	$(CC_FOR_BUILD) $(CFLAGS_FOR_BUILD) -o $(gen_arabic_shaping_tab) $(gen_arabic_shaping_tab_SOURCES)
 	./$(gen_arabic_shaping_tab) $(COMPRESSION) $^ > $@ \
 	|| ($(RM) $@ && false)
 
@@ -97,7 +97,7 @@ mirroring.tab.i: \
 		BidiMirroring.txt \
 		fribidi-unicode-version.h \
 		$(gen_mirroring_tab_SOURCES)
-	$(BUILD_CC) $(BUILD_CFLAGS) -o $(gen_mirroring_tab) $(gen_mirroring_tab_SOURCES)
+	$(CC_FOR_BUILD) $(CFLAGS_FOR_BUILD) -o $(gen_mirroring_tab) $(gen_mirroring_tab_SOURCES)
 	./$(gen_mirroring_tab) $(COMPRESSION) $^ > $@ \
 	|| ($(RM) $@ && false)
 
@@ -110,7 +110,7 @@ brackets.tab.i: \
 		UnicodeData.txt \
 		fribidi-unicode-version.h \
 		$(gen_brackets_tab_SOURCES)
-	$(BUILD_CC) $(BUILD_CFLAGS) -o $(gen_brackets_tab) $(gen_brackets_tab_SOURCES)
+	$(CC_FOR_BUILD) $(CFLAGS_FOR_BUILD) -o $(gen_brackets_tab) $(gen_brackets_tab_SOURCES)
 	./$(gen_brackets_tab) $(COMPRESSION) $^ > $@ \
 	|| ($(RM) $@ && false)
 
@@ -122,7 +122,7 @@ brackets-type.tab.i: \
 		BidiBrackets.txt \
 		fribidi-unicode-version.h \
 		$(gen_brackets_type_tab_SOURCES)
-	$(BUILD_CC) $(BUILD_CFLAGS) -o $(gen_brackets_type_tab) $(gen_brackets_type_tab_SOURCES)
+	$(CC_FOR_BUILD) $(CFLAGS_FOR_BUILD) -o $(gen_brackets_type_tab) $(gen_brackets_type_tab_SOURCES)
 	./$(gen_brackets_type_tab) $(COMPRESSION) $^ > $@ \
 	|| ($(RM) $@ && false)
 
@@ -134,7 +134,7 @@ fribidi-unicode-version.h: \
 		ReadMe.txt \
 		BidiMirroring.txt \
 		$(gen_unicode_version_SOURCES)
-	$(BUILD_CC) $(BUILD_CFLAGS) -o $(gen_unicode_version) $(gen_unicode_version_SOURCES)
+	$(CC_FOR_BUILD) $(CFLAGS_FOR_BUILD) -o $(gen_unicode_version) $(gen_unicode_version_SOURCES)
 	./$(gen_unicode_version) $^ > $@ \
 	|| ($(RM) $@ && false)
 
@@ -142,10 +142,10 @@ fribidi-unicode-version.h: \
 gen: $(EXTRA_PROGRAMS)
 
 $(top_builddir)/config.h: $(top_srcdir)/config.h.in
-	cd $(top_builddir) && $(BUILD_CC) $(BUILD_CFLAGS) -o config.h
+	cd $(top_builddir) && $(CC_FOR_BUILD) $(CFLAGS_FOR_BUILD) -o config.h
 
 $(top_builddir)/lib/fribidi-config.h: $(top_srcdir)/lib/fribidi-config.h.in
-	cd $(top_builddir)/lib && $(BUILD_CC) $(BUILD_CFLAGS) -o fribidi-config.h
+	cd $(top_builddir)/lib && $(CC_FOR_BUILD) $(CFLAGS_FOR_BUILD) -o fribidi-config.h
 
 .PHONY: gen
 
diff --git a/m4/m4_ax_prog_cc_for_build.m4 b/m4/m4_ax_prog_cc_for_build.m4
new file mode 100644
index 0000000..12cb005
--- /dev/null
+++ b/m4/m4_ax_prog_cc_for_build.m4
@@ -0,0 +1,125 @@
+# ===========================================================================
+#   https://www.gnu.org/software/autoconf-archive/ax_prog_cc_for_build.html
+# ===========================================================================
+#
+# SYNOPSIS
+#
+#   AX_PROG_CC_FOR_BUILD
+#
+# DESCRIPTION
+#
+#   This macro searches for a C compiler that generates native executables,
+#   that is a C compiler that surely is not a cross-compiler. This can be
+#   useful if you have to generate source code at compile-time like for
+#   example GCC does.
+#
+#   The macro sets the CC_FOR_BUILD and CPP_FOR_BUILD macros to anything
+#   needed to compile or link (CC_FOR_BUILD) and preprocess (CPP_FOR_BUILD).
+#   The value of these variables can be overridden by the user by specifying
+#   a compiler with an environment variable (like you do for standard CC).
+#
+#   It also sets BUILD_EXEEXT and BUILD_OBJEXT to the executable and object
+#   file extensions for the build platform, and GCC_FOR_BUILD to `yes' if
+#   the compiler we found is GCC. All these variables but GCC_FOR_BUILD are
+#   substituted in the Makefile.
+#
+# LICENSE
+#
+#   Copyright (c) 2008 Paolo Bonzini <bonzini@gnu.org>
+#
+#   Copying and distribution of this file, with or without modification, are
+#   permitted in any medium without royalty provided the copyright notice
+#   and this notice are preserved. This file is offered as-is, without any
+#   warranty.
+
+#serial 9
+
+AU_ALIAS([AC_PROG_CC_FOR_BUILD], [AX_PROG_CC_FOR_BUILD])
+AC_DEFUN([AX_PROG_CC_FOR_BUILD], [dnl
+AC_REQUIRE([AC_PROG_CC])dnl
+AC_REQUIRE([AC_PROG_CPP])dnl
+AC_REQUIRE([AC_EXEEXT])dnl
+AC_REQUIRE([AC_CANONICAL_HOST])dnl
+
+dnl Use the standard macros, but make them use other variable names
+dnl
+pushdef([ac_cv_prog_CPP], ac_cv_build_prog_CPP)dnl
+pushdef([ac_cv_prog_gcc], ac_cv_build_prog_gcc)dnl
+pushdef([ac_cv_prog_cc_works], ac_cv_build_prog_cc_works)dnl
+pushdef([ac_cv_prog_cc_cross], ac_cv_build_prog_cc_cross)dnl
+pushdef([ac_cv_prog_cc_g], ac_cv_build_prog_cc_g)dnl
+pushdef([ac_cv_exeext], ac_cv_build_exeext)dnl
+pushdef([ac_cv_objext], ac_cv_build_objext)dnl
+pushdef([ac_exeext], ac_build_exeext)dnl
+pushdef([ac_objext], ac_build_objext)dnl
+pushdef([CC], CC_FOR_BUILD)dnl
+pushdef([CPP], CPP_FOR_BUILD)dnl
+pushdef([CFLAGS], CFLAGS_FOR_BUILD)dnl
+pushdef([CPPFLAGS], CPPFLAGS_FOR_BUILD)dnl
+pushdef([LDFLAGS], LDFLAGS_FOR_BUILD)dnl
+pushdef([host], build)dnl
+pushdef([host_alias], build_alias)dnl
+pushdef([host_cpu], build_cpu)dnl
+pushdef([host_vendor], build_vendor)dnl
+pushdef([host_os], build_os)dnl
+pushdef([ac_cv_host], ac_cv_build)dnl
+pushdef([ac_cv_host_alias], ac_cv_build_alias)dnl
+pushdef([ac_cv_host_cpu], ac_cv_build_cpu)dnl
+pushdef([ac_cv_host_vendor], ac_cv_build_vendor)dnl
+pushdef([ac_cv_host_os], ac_cv_build_os)dnl
+pushdef([ac_cpp], ac_build_cpp)dnl
+pushdef([ac_compile], ac_build_compile)dnl
+pushdef([ac_link], ac_build_link)dnl
+
+save_cross_compiling=$cross_compiling
+save_ac_tool_prefix=$ac_tool_prefix
+cross_compiling=no
+ac_tool_prefix=
+
+AC_PROG_CC
+AC_PROG_CPP
+AC_EXEEXT
+
+ac_tool_prefix=$save_ac_tool_prefix
+cross_compiling=$save_cross_compiling
+
+dnl Restore the old definitions
+dnl
+popdef([ac_link])dnl
+popdef([ac_compile])dnl
+popdef([ac_cpp])dnl
+popdef([ac_cv_host_os])dnl
+popdef([ac_cv_host_vendor])dnl
+popdef([ac_cv_host_cpu])dnl
+popdef([ac_cv_host_alias])dnl
+popdef([ac_cv_host])dnl
+popdef([host_os])dnl
+popdef([host_vendor])dnl
+popdef([host_cpu])dnl
+popdef([host_alias])dnl
+popdef([host])dnl
+popdef([LDFLAGS])dnl
+popdef([CPPFLAGS])dnl
+popdef([CFLAGS])dnl
+popdef([CPP])dnl
+popdef([CC])dnl
+popdef([ac_objext])dnl
+popdef([ac_exeext])dnl
+popdef([ac_cv_objext])dnl
+popdef([ac_cv_exeext])dnl
+popdef([ac_cv_prog_cc_g])dnl
+popdef([ac_cv_prog_cc_cross])dnl
+popdef([ac_cv_prog_cc_works])dnl
+popdef([ac_cv_prog_gcc])dnl
+popdef([ac_cv_prog_CPP])dnl
+
+dnl Finally, set Makefile variables
+dnl
+BUILD_EXEEXT=$ac_build_exeext
+BUILD_OBJEXT=$ac_build_objext
+AC_SUBST(BUILD_EXEEXT)dnl
+AC_SUBST(BUILD_OBJEXT)dnl
+AC_SUBST([CFLAGS_FOR_BUILD])dnl
+AC_SUBST([CPPFLAGS_FOR_BUILD])dnl
+AC_SUBST([LDFLAGS_FOR_BUILD])dnl
+])