compiler building blocks: add support for custom build variables.

feature detection: set a fallback value of 'yes' to modern assembler
presence, PE dward support, libc-provided stack protector, and
dynamic-loader header iteration.

signed-off by Z. Gilboa; see copying.midipix (9cd0746c) for additional information.

3 files changed, 31 insertions, 9 deletions

diff --git a/gcc/Makefile.in b/gcc/Makefile.in
index e0b952ffd..c5ac57225 100644
--- a/gcc/Makefile.in
+++ b/gcc/Makefile.in
@@ -373,6 +373,22 @@ UNWIND_H = $(srcdir)/unwind-generic.h
 # Don't use this as a dependency--use $(GCC_PASSES).
 GCC_FOR_TARGET = $(STAGE_CC_WRAPPER) ./xgcc -B./ -B$(build_tooldir)/bin/ -isystem $(build_tooldir)/include -isystem $(build_tooldir)/sys-include -L$(objdir)/../ld
 
+# cbb: cbb_xgcc_for_specs (aka the key to paradise)
+# if the CC compiler or its flags involve a custom specs file,
+# then that specs file will become part of STAGE_CC_WRAPPER,
+# which will then interfere with the bootstrapping process.
+# we sidestep the problem by using a designated variable for
+# the -dumpspecs step. this variable (cbb_xgcc_for_specs)
+# is optional; to use it, set it prior to calling the
+# top-level configure.
+
+cbb_xgcc_for_specs = @cbb_xgcc_for_specs@
+
+ifeq ($(cbb_xgcc_for_specs),)
+cbb_xgcc_for_specs = $(STAGE_CC_WRAPPER)
+endif
+
+
 # This is used instead of ALL_CFLAGS when compiling with GCC_FOR_TARGET.
 # It specifies -B./.
 # It also specifies -isystem ./include to find, e.g., stddef.h.
@@ -1083,7 +1099,7 @@ BUILD_ERRORS = build/errors.o
 # libintl.h will be found in ../intl if we are using the included libintl.
 INCLUDES = -I. -I$(@D) -I$(srcdir) -I$(srcdir)/$(@D) \
 	   -I$(srcdir)/../include @INCINTL@ \
-	   $(CPPINC) $(GMPINC) $(DECNUMINC) \
+	   $(CPPINC) $(DECNUMINC) \
 	   $(PPLINC) $(CLOOGINC)
 
 .c.o:
@@ -1843,7 +1859,7 @@ cpp$(exeext): $(GCC_OBJS) cppspec.o version.o intl.o prefix.o \
 
 # Dump a specs file to make -B./ read these specs over installed ones.
 $(SPECS): xgcc$(exeext)
-	$(GCC_FOR_TARGET) -dumpspecs > tmp-specs
+	$(cbb_xgcc_for_specs) -dumpspecs > tmp-specs
 	mv tmp-specs $(SPECS)
 
 # We do want to create an executable named `xgcc', so we can use it to
diff --git a/gcc/configure b/gcc/configure
index c8caff252..278554119 100755
--- a/gcc/configure
+++ b/gcc/configure
@@ -22101,7 +22101,7 @@ $as_echo_n "checking assembler for cfi sections directive... " >&6; }
 if test "${gcc_cv_as_cfi_sections_directive+set}" = set; then :
   $as_echo_n "(cached) " >&6
 else
-  gcc_cv_as_cfi_sections_directive=no
+  gcc_cv_as_cfi_sections_directive=yes
   if test x$gcc_cv_as != x; then
     echo '	.text
 	.cfi_sections .debug_frame, .eh_frame
@@ -23609,7 +23609,7 @@ $as_echo_n "checking assembler for .secrel32 relocs... " >&6; }
 if test "${gcc_cv_as_ix86_pe_secrel32+set}" = set; then :
   $as_echo_n "(cached) " >&6
 else
-  gcc_cv_as_ix86_pe_secrel32=no
+  gcc_cv_as_ix86_pe_secrel32=yes
     if test $in_tree_gas = yes; then
     if test $gcc_cv_gas_vers -ge `expr \( \( 2 \* 1000 \) + 15 \) \* 1000 + 91`
   then gcc_cv_as_ix86_pe_secrel32=yes
@@ -25774,7 +25774,7 @@ $as_echo_n "checking __stack_chk_fail in target C library... " >&6; }
 if test "${gcc_cv_libc_provides_ssp+set}" = set; then :
   $as_echo_n "(cached) " >&6
 else
-  gcc_cv_libc_provides_ssp=no
+  gcc_cv_libc_provides_ssp=yes
     case "$target" in
        *-*-linux* | *-*-kfreebsd*-gnu | *-*-knetbsd*-gnu)
       # glibc 2.4 and later provides __stack_chk_fail and
@@ -25857,7 +25857,7 @@ fi
 
 { $as_echo "$as_me:${as_lineno-$LINENO}: checking dl_iterate_phdr in target C library" >&5
 $as_echo_n "checking dl_iterate_phdr in target C library... " >&6; }
-gcc_cv_target_dl_iterate_phdr=unknown
+if [ "$gcc_cv_target_dl_iterate_phdr"x = x ]; then gcc_cv_target_dl_iterate_phdr=yes; fi
 case "$target" in
   *-*-solaris2*)
     # <link.h> needs both a dl_iterate_phdr declaration and support for
@@ -27792,3 +27792,9 @@ $as_echo "$as_me: WARNING: unrecognized options: $ac_unrecognized_opts" >&2;}
 fi
 
 
+# Compiler Building Blocks variables
+sed -i  -e 's#@cbb_xgcc_for_specs@#'"$cbb_xgcc_for_specs"'#g' \
+	-e 's#@cbb_ldflags_for_target@#'"$cbb_ldflags_for_target"'#g' \
+	-e 's#@cbb_sysroot_for_libgcc@#'"$cbb_sysroot_for_libgcc"'#g' \
+		Makefile || exit 2
+
diff --git a/gcc/configure.ac b/gcc/configure.ac
index 48605c851..07a0c7837 100644
--- a/gcc/configure.ac
+++ b/gcc/configure.ac
@@ -2465,7 +2465,7 @@ gcc_GAS_CHECK_FEATURE([cfi sections directive],
   win32 | pe | cygwin* | mingw32* | uwin*)
     # Need to check that we generated the correct relocation for the
     # .debug_frame section.  This was fixed for binutils 2.21.
-    gcc_cv_as_cfi_sections_directive=no
+    gcc_cv_as_cfi_sections_directive=yes
     if test "x$gcc_cv_objdump" != x; then
      if $gcc_cv_objdump -j .debug_frame -r conftest.o 2>/dev/null | \
 	grep secrel > /dev/null; then
@@ -4362,7 +4362,7 @@ fi
 # Test for stack protector support in target C library.
 AC_CACHE_CHECK(__stack_chk_fail in target C library,
       gcc_cv_libc_provides_ssp,
-      [gcc_cv_libc_provides_ssp=no
+      [gcc_cv_libc_provides_ssp=yes
     case "$target" in
        *-*-linux* | *-*-kfreebsd*-gnu | *-*-knetbsd*-gnu)
       [# glibc 2.4 and later provides __stack_chk_fail and
@@ -4430,7 +4430,7 @@ if test x$gcc_cv_target_ldbl128 = xyes; then
 fi
 
 AC_MSG_CHECKING(dl_iterate_phdr in target C library)
-gcc_cv_target_dl_iterate_phdr=unknown
+gcc_cv_target_dl_iterate_phdr=yes
 case "$target" in
   *-*-solaris2*)
     # <link.h> needs both a dl_iterate_phdr declaration and support for