Update GCC to 4.9.2

Update the GCC compiler to the 4.9.2 version.  It turns out that a C++
compiler is required to build the latest GCC releases, so build one in
stages 1 and 2 as well.

The updated list of GCC configuration options that either don't work in
a cross compiler or are not needed in a temporary compiler, were based
on the latest instructions from Linux From Scratch.

The inclusion of /lib64 in the lib path for the stage 1 linker is an
attempt to turn things more robust rather than to just symlink in /lib
stuff that ends up installed in /lib64 (as it is already being done for
libgcc_s.so).  Ideally, we should configure every chunk to install to
/lib, however GCC seems to not honour the `--with-libdir` configuration
flag.

With this version of GCC, it looks like a sysroot needs to be given at
configure time so that `--with-native-system-header-dir` does what it
claims to do.  Unfortunately, this has the side effect of making GCC not
passing to the linker the linker sysroot flag: `-Wl,--sysroot=$SYSROOT`.
The workaround is to modify LDFLAGS to give a sysroot directly to GCC,
`--sysroot=$SYSROOT`, which will then be further passed down to the
linker.

As the newest version of GCC finds more warnings than the previous one,
`-Werror` was disabled for the coreutils, GDB and Syslinux projects.
Syslinux's Makefile had to be patched, as it is not possible to disable
`-Werror` for all targets through the NO_WERROR variable.

The hack to handle libgcc_eh being required during eglibc's build was
removed, as it doesn't seem to be the case anymore.

1 files changed, 40 insertions, 30 deletions

diff --git a/strata/build-essential/stage1-gcc.morph b/strata/build-essential/stage1-gcc.morph
index 0574749b..1bf6dfb2 100644
--- a/strata/build-essential/stage1-gcc.morph
+++ b/strata/build-essential/stage1-gcc.morph
@@ -2,16 +2,24 @@ name: stage1-gcc
 kind: chunk
 
 configure-commands:
+# Workaround from LFS due GCC not detecting stack protection correctly
+- sed -i '/k prot/agcc_cv_libc_provides_ssp=yes' gcc/configure
+
 - mkdir o
 
 # Configure flag notes:
 #  1. See gcc.morph.
-#  2. Disable searching /usr/local/include for headers
-#  3. The pass 1 compiler needs to find the libraries we build in pass
+#  2. Although we will be setting a sysroot at runtime, giving a
+#     temporary one at configuration time seems necessary so that
+#     `--with-native-system-header-dir` produces effect and
+#     /tools/include is in the include path for the newly built GCC. We
+#     set it by default to a non-existent directory to avoid GCC looking
+#     at the host dirs, in case we forget to give it at runtime.
+#  3. Disable searching /usr/local/include for headers
+#  4. The pass 1 compiler needs to find the libraries we build in pass
 #     2.  Include path must be set explicility, because it defaults to
-#     $SYSROOT/usr/include rather than $SYSROOT/include.  FIXME: this
-#     flag is not present until GCC 4.6.3!
-#  4. Disable stuff that doesn't work when building a cross compiler
+#     $SYSROOT/usr/include rather than $SYSROOT/include.
+#  5. Disable stuff that doesn't work when building a cross compiler
 #     without an existing libc, and generally try to keep this build as
 #     simple as possible.
 - |
@@ -22,38 +30,40 @@ configure-commands:
             --target=$TARGET_STAGE1                           \
             --prefix="$PREFIX"                                \
     `# [1]` --libdir="$PREFIX/lib"                            \
+    `# [2]` --with-sysroot=/nonexistentdir                    \
             --with-newlib                                     \
-    `# [2]` --with-local-prefix="$PREFIX"                     \
-    `# [3]` --with-native-system-header-dir="$PREFIX/include" \
-            --with-mpfr-include="$(pwd)/../mpfr/src"          \
-            --with-mpfr-lib="$(pwd)/mpfr/src/.libs"           \
-            --with-system-zlib                                \
+    `# [3]` --with-local-prefix="$PREFIX"                     \
+    `# [4]` --with-native-system-header-dir="$PREFIX/include" \
             --without-headers                                 \
-            --without-cloog                                   \
-            --without-ppl                                     \
-            --disable-bootstrap                               \
             --disable-nls                                     \
             --disable-shared                                  \
             --disable-multilib                                \
-    `# [4]` --disable-decimal-float                           \
-    `# [4]` --disable-threads                                 \
-    `# [4]` --disable-libgomp                                 \
-    `# [4]` --disable-libmudflap                              \
-    `# [4]` --disable-libquadmath                             \
-    `# [4]` --disable-libssp                                  \
-    `# [4]` --disable-target-libiberty                        \
-    `# [4]` --disable-target-zlib                             \
-            --enable-languages=c
+    `# [5]` --disable-decimal-float                           \
+    `# [5]` --disable-threads                                 \
+    `# [5]` --disable-libatomic                               \
+    `# [5]` --disable-libgomp                                 \
+    `# [5]` --disable-libitm                                  \
+    `# [5]` --disable-libquadmath                             \
+    `# [5]` --disable-libsanitizer                            \
+    `# [5]` --disable-libssp                                  \
+    `# [5]` --disable-libvtv                                  \
+    `# [5]` --disable-libcilkrts                              \
+    `# [5]` --disable-libstdc++-v3                            \
+            --enable-languages=c,c++
 
 build-commands:
-- cd o && make
+- |
+  # GCC is not passing the correct host/target flags to GMP's configure
+  # script, which causes it to not use the machine-dependent code for
+  # the platform and use the generic one instead.  However, the generic
+  # code results on an undefined reference to `__gmpn_invert_limb' in
+  # ARMv7.  Fix the invocation of GMP's configure script so that GMP can
+  # use the machine-dependent code.
+  case "$MORPH_ARCH" in
+      armv7*)   sed -i "s/--host=none/--host=armv7a/" o/Makefile
+                sed -i "s/--target=none/--target=armv7a/" o/Makefile ;;
+  esac
+  cd o && make
 
 install-commands:
 - cd o && make DESTDIR="$DESTDIR" install
-
-# The file libgcc_eh is required during eglibc's build, but is not created
-# because we built GCC with --disable-shared. This is a workaround for
-# eglibc's build system being slightly broken.
-- |
-  libgcc_filename=$($DESTDIR$PREFIX/bin/$TARGET_STAGE1-gcc -print-libgcc-file-name)
-  ln -sv libgcc.a $(echo $libgcc_filename | sed 's/libgcc/&_eh/')