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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.
* 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 at mirbsd.de>
with copyright assignment to the FSF in effect.
--- a/gcc/c-opts.c
+++ b/gcc/c-opts.c
@@ -105,6 +105,9 @@
/* 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);
@@ -690,6 +701,12 @@
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;
@@ -1209,6 +1226,47 @@
return false;
}
+ if (c_language == clk_c) {
+ char *ev = getenv ("GCC_HONOUR_COPTS");
+ int evv;
+ if (ev == NULL)
+ evv = -1;
+ 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 (0, "someone does not honour COPTS correctly, passed %d times",
+ honour_copts);
+ }
+ }
+
return true;
}
--- a/gcc/c.opt
+++ b/gcc/c.opt
@@ -609,6 +613,9 @@
fhonor-std
C++ ObjC++
+fhonour-copts
+C ObjC C++ ObjC++ RejectNegative
+
fhosted
C ObjC
Assume normal C execution environment
--- a/gcc/common.opt
+++ b/gcc/common.opt
@@ -573,6 +577,9 @@
Common Report Var(flag_guess_branch_prob) Optimization
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
--- a/gcc/opts.c
+++ b/gcc/opts.c
@@ -896,9 +896,6 @@
flag_schedule_insns_after_reload = opt2;
#endif
flag_regmove = opt2;
- flag_strict_aliasing = opt2;
- flag_strict_overflow = opt2;
- flag_delete_null_pointer_checks = opt2;
flag_reorder_blocks = opt2;
flag_reorder_functions = opt2;
flag_tree_vrp = opt2;
@@ -922,6 +919,9 @@
/* -O3 optimizations. */
opt3 = (optimize >= 3);
+ flag_strict_aliasing = opt3;
+ flag_strict_overflow = opt3;
+ flag_delete_null_pointer_checks = opt3;
flag_predictive_commoning = opt3;
flag_inline_functions = opt3;
flag_unswitch_loops = opt3;
--- a/gcc/doc/invoke.texi
+++ b/gcc/doc/invoke.texi
@@ -5699,7 +5715,7 @@
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 -fsplit-wide-types
@opindex fsplit-wide-types
@@ -5844,7 +5860,7 @@
@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
--- a/gcc/java/jvspec.c
+++ b/gcc/java/jvspec.c
@@ -670,6 +670,7 @@
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)
{
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