# HG changeset patch
# User "Yann E. MORIN" <yann.morin.1998@anciens.enib.fr>
# Date 1254514238 -7200
# Node ID 8c40b842e798312e17f1143301d6de024da5f7b9
# Parent  2e84b052ed5f283b0327730fb66236075e0fab94
libc/glibc: fix building for seemingly native toolchains

Build glibc with -O2 as a fix/workaround to building
seemingly-native toolchains.

See:
- docs/overview.txt
- docs/known-issues.txt
- http://sourceware.org/ml/crossgcc/2009-09/msg00055.html

diff -r 2e84b052ed5f -r 8c40b842e798 docs/known-issues.txt
--- a/docs/known-issues.txt	Thu Oct 01 22:14:45 2009 +0200
+++ b/docs/known-issues.txt	Fri Oct 02 22:10:38 2009 +0200
@@ -51,8 +51,10 @@
   None known.
 
 Workaround:
-  If this happens for you, stick with glibc-2.6.1 for now.
-  Or investigate! :-)
+  It seems that using -O2 in the CFLAGS fixes the problem. It has been
+  confirmed in the following threads:
+    http://sourceware.org/ml/crossgcc/2009-09/msg00055.html (for glibc)
+    http://sourceware.org/ml/crossgcc/2009-10/msg00001.html (for eglibc)
 
 --------------------------------
 Symptoms:
diff -r 2e84b052ed5f -r 8c40b842e798 docs/overview.txt
--- a/docs/overview.txt	Thu Oct 01 22:14:45 2009 +0200
+++ b/docs/overview.txt	Fri Oct 02 22:10:38 2009 +0200
@@ -28,6 +28,7 @@
   Tools wrapper
 Using the toolchain
 Toolchain types
+  Seemingly-native toolchains
 Internals
   Makefile front-end
   Kconfig parser
@@ -590,6 +591,21 @@
     were all being hashed out, Canada had three national political parties.
     http://en.wikipedia.org/wiki/Cross_compiler
 
+Seemingly-native toolchains |
+----------------------------+
+
+Seemingly-native toolchains are toolchains that target the same architecture
+as the one it is built on, and on which it will run, but the machine tuple
+may be different (eg i686 vs. i386, or x86_64-unknown-linux-gnu vs.
+x86_64-pc-linux-gnu). This also applies if the target architecture is of the
+same kind (eg. x86 vs. x86_64, or ppc vs. ppc64).
+
+Such toolchain is tricky to build, as the configure scripts may incorrectly
+assume that files (headers and libs) from the build (or host) machine can be
+used by the cross-compiler it is going to build. The problem seems to arise
+only with glibc (and eglibc?) starting with version 2.7.
+
+
 _____________
             /
 Internals  /
diff -r 2e84b052ed5f -r 8c40b842e798 scripts/build/libc/glibc.sh
--- a/scripts/build/libc/glibc.sh	Thu Oct 01 22:14:45 2009 +0200
+++ b/scripts/build/libc/glibc.sh	Fri Oct 02 22:10:38 2009 +0200
@@ -180,7 +180,7 @@
 
         libc_cv_ppc_machine=yes                         \
         CT_DoExecLog ALL                                \
-        make CFLAGS="-O -DBOOTSTRAP_GCC"                \
+        make CFLAGS="-O2 -DBOOTSTRAP_GCC"               \
              OBJDUMP_FOR_HOST="${CT_TARGET}-objdump"    \
              PARALLELMFLAGS="${PARALLELMFLAGS}"         \
              sysdeps/gnu/errlist.c
@@ -197,7 +197,7 @@
     CT_DoExecLog ALL                                \
     make cross-compiling=yes                        \
          install_root=${CT_SYSROOT_DIR}             \
-         CFLAGS="-O -DBOOTSTRAP_GCC"                \
+         CFLAGS="-O2 -DBOOTSTRAP_GCC"               \
          ${LIBC_SYSROOT_ARG}                        \
          OBJDUMP_FOR_HOST="${CT_TARGET}-objdump"    \
          PARALLELMFLAGS="${PARALLELMFLAGS}"         \
@@ -325,7 +325,7 @@
     # Please see the comment for the configure step in do_libc().
 
     BUILD_CC="${CT_BUILD}-gcc"                                      \
-    CFLAGS="${CT_TARGET_CFLAGS} ${CT_LIBC_GLIBC_EXTRA_CFLAGS} -O "  \
+    CFLAGS="${CT_TARGET_CFLAGS} ${CT_LIBC_GLIBC_EXTRA_CFLAGS} -O2"  \
     CC="${cross_cc} ${CT_LIBC_EXTRA_CC_ARGS} ${extra_cc_args}"      \
     AR=${CT_TARGET}-ar                                              \
     RANLIB=${CT_TARGET}-ranlib                                      \
@@ -457,7 +457,7 @@
     # silly messages. GNU folks again, he?
 
     BUILD_CC="${CT_BUILD}-gcc"                                      \
-    CFLAGS="${CT_TARGET_CFLAGS} ${CT_LIBC_GLIBC_EXTRA_CFLAGS} -O"   \
+    CFLAGS="${CT_TARGET_CFLAGS} ${CT_LIBC_GLIBC_EXTRA_CFLAGS} -O2"  \
     CC="${CT_TARGET}-gcc ${CT_LIBC_EXTRA_CC_ARGS} ${extra_cc_args}" \
     AR=${CT_TARGET}-ar                                              \
     RANLIB=${CT_TARGET}-ranlib                                      \