gcc/4.7: add patch to warn about unsafe header paths

From 160397ef3c3331099af028f1b8d3e085b07d88ad Mon Sep 17 00:00:00 2001

From: Khem Raj <raj.khem@gmail.com>

Date: Fri, 29 Mar 2013 08:59:00 +0400

Subject: [PATCH 16/35] gcc: poison-system-directories

Adapted to Buildroot and gcc 4.7.4 by Thomas Petazzoni, especially the

addition of the BR_COMPILER_PARANOID_UNSAFE_PATH environment variable.

Signed-off-by: Khem Raj <raj.khem@gmail.com>

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>

Upstream-Status: Inappropriate [distribution: codesourcery]

---

 gcc/Makefile.in     |    2 +-

 gcc/common.opt      |    4 ++++

 gcc/config.in       |    6 ++++++

 gcc/configure       |   20 ++++++++++++++++++--

 gcc/configure.ac    |   10 ++++++++++

 gcc/doc/invoke.texi |    9 +++++++++

 gcc/gcc.c           |    2 ++

 gcc/incpath.c       |   19 +++++++++++++++++++

 8 files changed, 69 insertions(+), 3 deletions(-)

Index: b/gcc/common.opt

===================================================================

--- a/gcc/common.opt

+++ b/gcc/common.opt

@@ -585,6 +585,10 @@

 Common Var(warn_padded) Warning

 Warn when padding is required to align structure members

+Wpoison-system-directories

+Common Var(flag_poison_system_directories) Init(1) Warning

+Warn for -I and -L options using system directories if cross compiling

+

 Wshadow

 Common Var(warn_shadow) Warning

 Warn when one local variable shadows another

Index: b/gcc/config.in

===================================================================

--- a/gcc/config.in

+++ b/gcc/config.in

@@ -144,6 +144,12 @@

 #endif

+/* Define to warn for use of native system header directories */

+#ifndef USED_FOR_TARGET

+#undef ENABLE_POISON_SYSTEM_DIRECTORIES

+#endif

+

+

 /* Define if you want all operations on RTL (the basic data structure of the

    optimizer and back end) to be checked for dynamic type safety at runtime.

    This is quite expensive. */

Index: b/gcc/configure

===================================================================

--- a/gcc/configure

+++ b/gcc/configure

@@ -918,6 +918,7 @@

 with_system_zlib

 enable_maintainer_mode

 enable_version_specific_runtime_libs

+enable_poison_system_directories

 enable_plugin

 enable_libquadmath_support

 with_linker_hash_style

@@ -1632,6 +1633,8 @@

   --enable-version-specific-runtime-libs

                           specify that runtime libraries should be installed

                           in a compiler-specific directory

+  --enable-poison-system-directories

+                          warn for use of native system header directories

   --enable-plugin         enable plugin support

   --disable-libquadmath-support

                           disable libquadmath support for Fortran

@@ -27186,6 +27189,19 @@

 fi

+# Check whether --enable-poison-system-directories was given.

+if test "${enable_poison_system_directories+set}" = set; then :

+  enableval=$enable_poison_system_directories;

+else

+  enable_poison_system_directories=no

+fi

+

+if test "x${enable_poison_system_directories}" = "xyes"; then

+

+$as_echo "#define ENABLE_POISON_SYSTEM_DIRECTORIES 1" >>confdefs.h

+

+fi

+

 # Substitute configuration variables

Index: b/gcc/configure.ac

===================================================================

--- a/gcc/configure.ac

+++ b/gcc/configure.ac

@@ -5037,6 +5037,16 @@

                 [specify that runtime libraries should be

                  installed in a compiler-specific directory])])

+AC_ARG_ENABLE([poison-system-directories],

+             AS_HELP_STRING([--enable-poison-system-directories],

+                            [warn for use of native system header directories]),,

+             [enable_poison_system_directories=no])

+if test "x${enable_poison_system_directories}" = "xyes"; then

+  AC_DEFINE([ENABLE_POISON_SYSTEM_DIRECTORIES],

+           [1],

+           [Define to warn for use of native system header directories])

+fi

+

 # Substitute configuration variables

 AC_SUBST(subdirs)

 AC_SUBST(srcdir)

Index: b/gcc/doc/invoke.texi

===================================================================

--- a/gcc/doc/invoke.texi

+++ b/gcc/doc/invoke.texi

@@ -260,6 +260,7 @@

 -Woverlength-strings  -Wpacked  -Wpacked-bitfield-compat  -Wpadded @gol

 -Wparentheses  -Wpedantic-ms-format -Wno-pedantic-ms-format @gol

 -Wpointer-arith  -Wno-pointer-to-int-cast @gol

+-Wno-poison-system-directories @gol

 -Wredundant-decls @gol

 -Wreturn-type  -Wsequence-point  -Wshadow @gol

 -Wsign-compare  -Wsign-conversion  -Wstack-protector @gol

@@ -3880,6 +3881,14 @@

  for most targets, it is made up of code and thus requires the stack

  to be made executable in order for the program to work properly.

+@item -Wno-poison-system-directories

+@opindex Wno-poison-system-directories

+Do not warn for @option{-I} or @option{-L} options using system

+directories such as @file{/usr/include} when cross compiling.  This

+option is intended for use in chroot environments when such

+directories contain the correct headers and libraries for the target

+system rather than the host.

+

 @item -Wfloat-equal

 @opindex Wfloat-equal

 @opindex Wno-float-equal

Index: b/gcc/gcc.c

===================================================================

--- a/gcc/gcc.c

+++ b/gcc/gcc.c

@@ -674,6 +674,8 @@

     %{flto} %{flto=*} %l " LINK_PIE_SPEC \

    "%X %{o*} %{e*} %{N} %{n} %{r}\

     %{s} %{t} %{u*} %{z} %{Z} %{!nostdlib:%{!nostartfiles:%S}}\

+    %{Wno-poison-system-directories:--no-poison-system-directories}\

+    %{Werror=poison-system-directories:--error-poison-system-directories}\

     %{static:} %{L*} %(mfwrap) %(link_libgcc) %o\

     %{fopenmp|ftree-parallelize-loops=*:%:include(libgomp.spec)%(link_gomp)}\

     %{fgnu-tm:%:include(libitm.spec)%(link_itm)}\

@@ -3907,6 +3909,12 @@

       gcc_assert (!compare_debug_opt);

     }

+  temp = getenv("BR_COMPILER_PARANOID_UNSAFE_PATH");

+  if (temp && strlen(temp) > 0)

+    {

+      save_switch("-Werror=poison-system-directories", 0, NULL, false);

+    }

+

   /* Set up the search paths.  We add directories that we expect to

      contain GNU Toolchain components before directories specified by

      the machine description so that we will find GNU components (like

Index: b/gcc/incpath.c

===================================================================

--- a/gcc/incpath.c

+++ b/gcc/incpath.c

@@ -30,6 +30,7 @@

 #include "intl.h"

 #include "incpath.h"

 #include "cppdefault.h"

+#include "diagnostic-core.h"

 /* Microsoft Windows does not natively support inodes.

    VMS has non-numeric inodes.  */

@@ -373,6 +374,24 @@

 	}

       fprintf (stderr, _("End of search list.\n"));

     }

+

+#ifdef ENABLE_POISON_SYSTEM_DIRECTORIES

+  if (flag_poison_system_directories)

+    {

+       struct cpp_dir *p;

+

+       for (p = heads[QUOTE]; p; p = p->next)

+         {

+          if ((!strncmp (p->name, "/usr/include", 12))

+              || (!strncmp (p->name, "/usr/local/include", 18))

+              || (!strncmp (p->name, "/usr/X11R6/include", 18)))

+            warning (OPT_Wpoison_system_directories,

+                     "include location \"%s\" is unsafe for "

+                     "cross-compilation",

+                     p->name);

+         }

+    }

+#endif

 }

 /* Use given -I paths for #include "..." but not #include <...>, and