build: Don't cross-compile GLSL builtin compiler

The builtin_compiler binary is used during the build process to generate
code for the builtin GLSL functions. Since this binary needs to be run
on the build host, it must not be cross-compiled.

This patch fixes the build system to compile a second version of the
source files and the builtin_compiler binary itself for the build
system. It does so by defining the CC_FOR_BUILD and CXX_FOR_BUILD
variables, which are searched for by the configure script and point to
the location of native C and C++ compilers.

In order for this to work properly, builtin_function.cpp is removed
from BUILT_SOURCES, otherwise the build system would try to generate it
before having had a chance to descend into the builtin_compiler
subdirectory. With the builtin_compiler and glsl_compiler now being
generated at different stages, the build instructions for glsl_compiler
can be simplified a bit.

Signed-off-by: Thierry Reding <thierry.reding@avionic-design.de>
Acked-by: Kenneth Graunke <kenneth@whitecape.org>

1 files changed, 140 insertions, 0 deletions

diff --git a/m4/ax_prog_cc_for_build.m4 b/m4/ax_prog_cc_for_build.m4
new file mode 100644
index 00000000000..08095a83dfc
--- /dev/null
+++ b/m4/ax_prog_cc_for_build.m4
@@ -0,0 +1,140 @@
+# ===========================================================================
+#   http://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 5
+
+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_SYSTEM])dnl
+dnl
+pushdef([AC_TRY_COMPILER], [
+cat > conftest.$ac_ext << EOF
+#line __oline__ "configure"
+#include "confdefs.h"
+[$1]
+EOF
+# If we can't run a trivial program, we are probably using a cross
+compiler.
+# Fail miserably.
+if AC_TRY_EVAL(ac_link) && test -s conftest${ac_exeext} && (./conftest;
+exit) 2>/dev/null; then
+  [$2]=yes
+else
+  echo "configure: failed program was:" >&AC_FD_CC
+  cat conftest.$ac_ext >&AC_FD_CC
+  [$2]=no
+fi
+[$3]=no
+rm -fr conftest*])dnl
+
+dnl Use the standard macros, but make them use other variable names
+dnl
+pushdef([cross_compiling], [#])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
+pushdef([ac_tool_prefix], [#])dnl
+
+AC_PROG_CC
+AC_PROG_CPP
+AC_EXEEXT
+
+dnl Restore the old definitions
+dnl
+popdef([AC_TRY_COMPILER])dnl
+popdef([ac_tool_prefix])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([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_works])dnl
+popdef([ac_cv_prog_cc_cross])dnl
+popdef([ac_cv_prog_gcc])dnl
+popdef([cross_compiling])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
+])