build/tools/toolchain-patches/gcc/0002-gcc-prevent-crash-on-Eclair-and-older-platforms.patch

From 1fc21976be58987f036caa1103b821d51449af05 Mon Sep 17 00:00:00 2001
From: David 'Digit' Turner <digit@google.com>
Date: Fri, 17 Feb 2012 19:38:08 +0100
Subject: gcc: prevent crash on Eclair and older platforms.

The point of this patch is to work-around a bug in the Eclair
dynamic linker, which doesn't support weak symbols. By default,
libsupc++ and libstdc++ generate static C++ constructors that
reference weak symbols.

When they are statically linked into shared libraries, the
corresponding code is referenced in its .init_array section
and run when the shared library is loaded.

On Eclair and previous release, the weak symbol is not resolved
before the constructor are launched, resulting in a crash when
the PLT entry tries to jump to address 0.

By not generating weak symbol references, we avoid the problem
completely. And we don't need them because the pthread symbols
are all in the C library on Android, unlike legacy Linux systems
which put them in libpthread.so (and provide weak stubs in libc.so).
---
 gcc-4.4.3/gcc/gthr-posix.h |   13 +++++++++++++
 gcc-4.6/gcc/gthr-posix.h   |   13 +++++++++++++
 2 files changed, 26 insertions(+), 0 deletions(-)

diff --git a/gcc-4.4.3/gcc/gthr-posix.h b/gcc-4.4.3/gcc/gthr-posix.h
index 27652f9..a104d91 100644
--- a/gcc-4.4.3/gcc/gthr-posix.h
+++ b/gcc-4.4.3/gcc/gthr-posix.h
@@ -38,6 +38,19 @@ see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
 #define _REENTRANT 1
 #endif
 
+/* The following should normally be in a different header file,
+ * but I couldn't find the right location. The point of the macro
+ * definition below is to prevent libsupc++ and libstdc++ to reference
+ * weak symbols in their static C++ constructors. Such code crashes
+ * when a shared object linked statically to these libraries is
+ * loaded on Android 2.1 (Eclair) and older platform releases, due
+ * to a dynamic linker bug.
+ */
+#ifdef __ANDROID__
+#undef GTHREAD_USE_WEAK
+#define GTHREAD_USE_WEAK 0
+#endif
+
 #include <pthread.h>
 #include <unistd.h>
 
diff --git a/gcc-4.6/gcc/gthr-posix.h b/gcc-4.6/gcc/gthr-posix.h
index ecb06e2..8372c64 100644
--- a/gcc-4.6/gcc/gthr-posix.h
+++ b/gcc-4.6/gcc/gthr-posix.h
@@ -38,6 +38,19 @@ see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
 #define _REENTRANT 1
 #endif
 
+/* The following should normally be in a different header file,
+ * but I couldn't find the right location. The point of the macro
+ * definition below is to prevent libsupc++ and libstdc++ to reference
+ * weak symbols in their static C++ constructors. Such code crashes
+ * when a shared object linked statically to these libraries is
+ * loaded on Android 2.1 (Eclair) and older platform releases, due
+ * to a dynamic linker bug.
+ */
+#ifdef __ANDROID__
+#undef GTHREAD_USE_WEAK
+#define GTHREAD_USE_WEAK 0
+#endif
+
 #include <pthread.h>
 #include <unistd.h>
 
diff --git a/gcc-4.7/libgcc/gthr-posix.h b/gcc-4.7/libgcc/gthr-posix.h
index a935e92..08281b7 100644
--- a/gcc-4.7/libgcc/gthr-posix.h
+++ b/gcc-4.7/libgcc/gthr-posix.h
@@ -38,6 +38,19 @@ see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
 #define _REENTRANT 1
 #endif
 
+/* The following should normally be in a different header file,
+ * but I couldn't find the right location. The point of the macro
+ * definition below is to prevent libsupc++ and libstdc++ to reference
+ * weak symbols in their static C++ constructors. Such code crashes
+ * when a shared object linked statically to these libraries is
+ * loaded on Android 2.1 (Eclair) and older platform releases, due
+ * to a dynamic linker bug.
+ */
+#ifdef __ANDROID__
+#undef GTHREAD_USE_WEAK
+#define GTHREAD_USE_WEAK 0
+#endif
+
 #include <pthread.h>
 
 #if ((defined(_LIBOBJC) || defined(_LIBOBJC_WEAK)) \
-- 
1.7.6.rc0