Port the mbsd_multi patch from freewrt, which adds -fhonour-copts. This will emit warnings in packages that don't use our target cflags properly

git-svn-id: svn://svn.openwrt.org/openwrt/trunk@8256 3c298f89-4303-0410-b956-a3cf2f4a3e73

1 files changed, 293 insertions, 0 deletions

diff --git a/toolchain/gcc/patches/4.2.1/910-mbsd_multi.patch b/toolchain/gcc/patches/4.2.1/910-mbsd_multi.patch
new file mode 100644
index 000000000..439d0762f
--- /dev/null
+++ b/toolchain/gcc/patches/4.2.1/910-mbsd_multi.patch
@@ -0,0 +1,293 @@
+
+	This patch brings over a few features from MirBSD:
+	* -fhonour-copts
+	  If this option is not given, it's warned (depending
+	  on environment variables). This is to catch errors
+	  of misbuilt packages which override CFLAGS themselves.
+	* -Werror-maybe-reset
+	  Has the effect of -Wno-error if GCC_NO_WERROR is
+	  set and not '0', a no-operation otherwise. This is
+	  to be able to use -Werror in "make" but prevent
+	  GNU autoconf generated configure scripts from
+	  freaking out.
+	* Make -fno-strict-aliasing and -fno-delete-null-pointer-checks
+	  the default for -O2/-Os, because they trigger gcc bugs
+	  and can delete code with security implications.
+
+	This patch was authored by Thorsten Glaser <tg@mirbsd.de>
+	with copyright assignment to the FSF in effect.
+
+Index: gcc-4.2.0/gcc/c-opts.c
+===================================================================
+--- gcc-4.2.0.orig/gcc/c-opts.c	2007-07-31 02:27:12.007256629 +0200
++++ gcc-4.2.0/gcc/c-opts.c	2007-07-31 02:27:39.324813371 +0200
+@@ -107,6 +107,9 @@
+ /* Number of deferred options scanned for -include.  */
+ static size_t include_cursor;
+ 
++/* Check if a port honours COPTS.  */
++static int honour_copts = 0;
++
+ static void set_Wimplicit (int);
+ static void handle_OPT_d (const char *);
+ static void set_std_cxx98 (int);
+@@ -449,6 +452,14 @@
+       mesg_implicit_function_declaration = 2;
+       break;
+ 
++    case OPT_Werror_maybe_reset:
++      {
++	char *ev = getenv ("GCC_NO_WERROR");
++	if ((ev != NULL) && (*ev != '0'))
++	  cpp_opts->warnings_are_errors = 0;
++      }
++      break;
++
+     case OPT_Wformat:
+       set_Wformat (value);
+       break;
+@@ -691,6 +702,12 @@
+       flag_exceptions = value;
+       break;
+ 
++    case OPT_fhonour_copts:
++      if (c_language == clk_c) {
++	honour_copts++;
++      }
++      break;
++
+     case OPT_fimplement_inlines:
+       flag_implement_inlines = value;
+       break;
+@@ -1151,6 +1168,47 @@
+   /* Has to wait until now so that cpplib has its hash table.  */
+   init_pragma ();
+ 
++  if (c_language == clk_c) {
++    char *ev = getenv ("GCC_HONOUR_COPTS");
++    int evv;
++    if (ev == NULL)
++      evv = 0;
++    else if ((*ev == '0') || (*ev == '\0'))
++      evv = 0;
++    else if (*ev == '1')
++      evv = 1;
++    else if (*ev == '2')
++      evv = 2;
++    else if (*ev == 's')
++      evv = -1;
++    else {
++      warning (0, "unknown GCC_HONOUR_COPTS value, assuming 1");
++      evv = 1; /* maybe depend this on something like MIRBSD_NATIVE?  */
++    }
++    if (evv == 1) {
++      if (honour_copts == 0) {
++	error ("someone does not honour COPTS at all in lenient mode");
++	return false;
++      } else if (honour_copts != 1) {
++	warning (0, "someone does not honour COPTS correctly, passed %d times",
++	 honour_copts);
++      }
++    } else if (evv == 2) {
++      if (honour_copts == 0) {
++	error ("someone does not honour COPTS at all in strict mode");
++	return false;
++      } else if (honour_copts != 1) {
++	error ("someone does not honour COPTS correctly, passed %d times",
++	 honour_copts);
++	return false;
++      }
++    } else if (evv == 0) {
++      if (honour_copts != 1)
++	inform ("someone does not honour COPTS correctly, passed %d times",
++	 honour_copts);
++    }
++  }
++
+   return true;
+ }
+ 
+Index: gcc-4.2.0/gcc/c.opt
+===================================================================
+--- gcc-4.2.0.orig/gcc/c.opt	2007-07-31 02:27:12.015257093 +0200
++++ gcc-4.2.0/gcc/c.opt	2007-07-31 02:27:39.328813597 +0200
+@@ -189,6 +189,10 @@
+ C ObjC RejectNegative
+ Make implicit function declarations an error
+ 
++Werror-maybe-reset
++C ObjC C++ ObjC++
++; Documented in common.opt
++
+ Wfloat-equal
+ C ObjC C++ ObjC++ Var(warn_float_equal)
+ Warn if testing floating point numbers for equality
+@@ -544,6 +548,9 @@
+ fhonor-std
+ C++ ObjC++
+ 
++fhonour-copts
++C ObjC C++ ObjC++ RejectNegative
++
+ fhosted
+ C ObjC
+ Assume normal C execution environment
+Index: gcc-4.2.0/gcc/common.opt
+===================================================================
+--- gcc-4.2.0.orig/gcc/common.opt	2007-07-31 02:27:12.023257546 +0200
++++ gcc-4.2.0/gcc/common.opt	2007-07-31 02:27:39.360815422 +0200
+@@ -81,6 +81,10 @@
+ Common Joined
+ Treat specified warning as error
+ 
++Werror-maybe-reset
++Common
++If environment variable GCC_NO_WERROR is set, act as -Wno-error
++
+ Wextra
+ Common
+ Print extra (possibly unwanted) warnings
+@@ -481,6 +485,9 @@
+ Common Report Var(flag_guess_branch_prob)
+ Enable guessing of branch probabilities
+ 
++fhonour-copts
++Common RejectNegative
++
+ ; Nonzero means ignore `#ident' directives.  0 means handle them.
+ ; Generate position-independent code for executables if possible
+ ; On SVR4 targets, it also controls whether or not to emit a
+Index: gcc-4.2.0/gcc/opts.c
+===================================================================
+--- gcc-4.2.0.orig/gcc/opts.c	2007-07-31 02:27:12.031257991 +0200
++++ gcc-4.2.0/gcc/opts.c	2007-07-31 02:28:36.320061346 +0200
+@@ -492,9 +492,6 @@
+       flag_schedule_insns_after_reload = 1;
+ #endif
+       flag_regmove = 1;
+-      flag_strict_aliasing = 1;
+-      flag_strict_overflow = 1;
+-      flag_delete_null_pointer_checks = 1;
+       flag_reorder_blocks = 1;
+       flag_reorder_functions = 1;
+       flag_tree_store_ccp = 1;
+@@ -510,6 +507,10 @@
+ 
+   if (optimize >= 3)
+     {
++      flag_strict_aliasing = 1;
++      flag_strict_overflow = 1;
++      flag_delete_null_pointer_checks = 1;
++
+       flag_inline_functions = 1;
+       flag_unswitch_loops = 1;
+       flag_gcse_after_reload = 1;
+@@ -711,6 +712,17 @@
+       }
+       break;
+ 
++    case OPT_Werror_maybe_reset:
++      {
++	char *ev = getenv ("GCC_NO_WERROR");
++	if ((ev != NULL) && (*ev != '0'))
++	  warnings_are_errors = 0;
++      }
++      break;
++
++    case OPT_fhonour_copts:
++      break;
++
+     case OPT_Wextra:
+       set_Wextra (value);
+       break;
+Index: gcc-4.2.0/gcc/doc/cppopts.texi
+===================================================================
+--- gcc-4.2.0.orig/gcc/doc/cppopts.texi	2007-07-31 02:27:12.039258455 +0200
++++ gcc-4.2.0/gcc/doc/cppopts.texi	2007-07-31 02:27:39.408818157 +0200
+@@ -166,6 +166,11 @@
+ Make all warnings into hard errors.  Source code which triggers warnings
+ will be rejected.
+ 
++@item -Werror-maybe-reset
++@opindex Werror-maybe-reset
++Act like @samp{-Wno-error} if the @env{GCC_NO_WERROR} environment
++variable is set to anything other than 0 or empty.
++
+ @item -Wsystem-headers
+ @opindex Wsystem-headers
+ Issue warnings for code in system headers.  These are normally unhelpful
+Index: gcc-4.2.0/gcc/doc/invoke.texi
+===================================================================
+--- gcc-4.2.0.orig/gcc/doc/invoke.texi	2007-07-31 02:27:12.047258920 +0200
++++ gcc-4.2.0/gcc/doc/invoke.texi	2007-07-31 02:29:13.218164047 +0200
+@@ -226,7 +226,7 @@
+ -Wc++-compat -Wcast-align  -Wcast-qual  -Wchar-subscripts  -Wcomment @gol
+ -Wconversion  -Wno-deprecated-declarations @gol
+ -Wdisabled-optimization  -Wno-div-by-zero  -Wno-endif-labels @gol
+--Werror  -Werror=* -Werror-implicit-function-declaration @gol
++-Werror -Werror-maybe-reset -Werror=* -Werror-implicit-function-declaration @gol
+ -Wfatal-errors  -Wfloat-equal  -Wformat  -Wformat=2 @gol
+ -Wno-format-extra-args -Wformat-nonliteral @gol
+ -Wformat-security  -Wformat-y2k @gol
+@@ -3569,6 +3569,22 @@
+ @option{-W}@var{foo}.  However, @option{-Wno-error=}@var{foo} does not
+ imply anything.
+ 
++@item -Werror-maybe-reset
++@opindex Werror-maybe-reset
++Act like @samp{-Wno-error} if the @env{GCC_NO_WERROR} environment
++variable is set to anything other than 0 or empty.
++
++@item -fhonour-copts
++@opindex fhonour-copts
++If @env{GCC_HONOUR_COPTS} is set to 1, abort if this option is not
++given at least once, and warn if it is given more than once.
++If @env{GCC_HONOUR_COPTS} is set to 2, abort if this option is not
++given exactly once.
++If @env{GCC_HONOUR_COPTS} is set to 0 or unset, warn if this option
++is not given exactly once.
++The warning is quelled if @env{GCC_HONOUR_COPTS} is set to @samp{s}.
++This flag and environment variable only affect the C language.
++
+ @item -Wstack-protector
+ @opindex Wstack-protector
+ This option is only active when @option{-fstack-protector} is active.  It
+@@ -4901,7 +4917,7 @@
+ second branch or a point immediately following it, depending on whether
+ the condition is known to be true or false.
+ 
+-Enabled at levels @option{-O2}, @option{-O3}, @option{-Os}.
++Enabled at levels @option{-O3}.
+ 
+ @item -fcse-follow-jumps
+ @opindex fcse-follow-jumps
+@@ -5019,7 +5035,7 @@
+ @option{-fno-delete-null-pointer-checks} to disable this optimization
+ for programs which depend on that behavior.
+ 
+-Enabled at levels @option{-O2}, @option{-O3}, @option{-Os}.
++Enabled at levels @option{-O3}.
+ 
+ @item -fexpensive-optimizations
+ @opindex fexpensive-optimizations
+@@ -5437,7 +5453,7 @@
+ allowed to alias.  For an example, see the C front-end function
+ @code{c_get_alias_set}.
+ 
+-Enabled at levels @option{-O2}, @option{-O3}, @option{-Os}.
++Enabled at levels @option{-O3}.
+ 
+ @item -fstrict-overflow
+ @opindex fstrict-overflow
+Index: gcc-4.2.0/gcc/java/jvspec.c
+===================================================================
+--- gcc-4.2.0.orig/gcc/java/jvspec.c	2007-07-31 02:27:12.055259364 +0200
++++ gcc-4.2.0/gcc/java/jvspec.c	2007-07-31 02:27:39.484822490 +0200
+@@ -632,6 +632,7 @@
+      class name.  Append dummy `.c' that can be stripped by set_input so %b
+      is correct.  */ 
+   set_input (concat (main_class_name, "main.c", NULL));
++  putenv ("GCC_HONOUR_COPTS=s"); /* XXX hack!  */
+   err = do_spec (jvgenmain_spec);
+   if (err == 0)
+     {