patches/gcc/4.3.2/110-trampolinewarn.patch
author "Yann E. MORIN" <yann.morin.1998@free.fr>
Sat Jan 04 01:02:57 2014 +0100 (2014-01-04)
changeset 3271 c65dc9b98841
parent 747 d3e603e7c17c
permissions -rw-r--r--
cc/gcc: diable libsanitizer without NPTL

gcc-4.8 comes with a new library to sanitise memory access:
- heap-, stack-, and global-buffer overflow, use-after-free
- data-races between threads

This library requires some _np parts of the API, which are not
implemented in the (old) LinuxThreads, which is still available
in uClibc.

Since NPTL requires a i486 or above, i386 are stuck with using LT,
which precludes building the libsanitizer.

Disable libsanitizer, a bit like libatomic is.

Signed-off-by: "Yann E. MORIN" <yann.morin.1998@free.fr>
Cc: Niels Penneman <niels@penneman.org>
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Original patch from gentoo: gentoo/src/patchsets/gcc/4.3.1/gentoo/00_all_gcc-trampolinewarn.patch
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	This trivial patch causes gcc to emit a warning whenever
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	it generates a trampoline.  These are otherwise hard to
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	locate.  It is rigged to default ON - to have it default
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	to OFF remove the text 'Init(1)' from the common.opt
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	patch, leaving just 'Common Var(warn_trampolines)'.
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	Kevin F. Quinn <kevquinn@gentoo.org> 17 Jan 2006
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diff -durN gcc-4.3.1.orig/gcc/builtins.c gcc-4.3.1/gcc/builtins.c
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--- gcc-4.3.1.orig/gcc/builtins.c	2008-04-23 00:36:27.000000000 +0200
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+++ gcc-4.3.1/gcc/builtins.c	2008-06-10 14:56:54.000000000 +0200
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@@ -5662,6 +5662,9 @@
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   trampolines_created = 1;
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   INITIALIZE_TRAMPOLINE (r_tramp, r_func, r_chain);
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+  if (warn_trampolines)
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+    warning (OPT_Wtrampolines, "generating trampoline in object (requires executable stack)");
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+
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   return const0_rtx;
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 }
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diff -durN gcc-4.3.1.orig/gcc/common.opt gcc-4.3.1/gcc/common.opt
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--- gcc-4.3.1.orig/gcc/common.opt	2008-01-22 15:11:44.000000000 +0100
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+++ gcc-4.3.1/gcc/common.opt	2008-06-10 14:56:54.000000000 +0200
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@@ -182,6 +182,10 @@
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 Common Var(warn_system_headers) Warning
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 Do not suppress warnings from system headers
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+Wtrampolines
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+Common Var(warn_trampolines) Init(1)
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+Warn whenever a trampoline is generated
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+
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 Wuninitialized
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 Common Var(warn_uninitialized) Warning
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 Warn about uninitialized automatic variables