toolchain/gcc/patches/4.4.3+cs/910-mbsd_multi.patch

   1
   2         This patch brings over a few features from MirBSD:
   3         * -fhonour-copts
   4           If this option is not given, it's warned (depending
   5           on environment variables). This is to catch errors
   6           of misbuilt packages which override CFLAGS themselves.
   7         * Make -fno-strict-aliasing and -fno-delete-null-pointer-checks
   8           the default for -O2/-Os, because they trigger gcc bugs
   9           and can delete code with security implications.
  10
  11         This patch was authored by Thorsten Glaser <tg at mirbsd.de>
  12         with copyright assignment to the FSF in effect.
  13
  14 --- a/gcc/c-opts.c
  15 +++ b/gcc/c-opts.c
  16 @@ -105,6 +105,9 @@
  17  /* Number of deferred options scanned for -include.  */
  18  static size_t include_cursor;
  19
  20 +/* Check if a port honours COPTS.  */
  21 +static int honour_copts = 0;
  22 +
  23  static void set_Wimplicit (int);
  24  static void handle_OPT_d (const char *);
  25  static void set_std_cxx98 (int);
  26 @@ -690,6 +701,12 @@
  27        flag_exceptions = value;
  28        break;
  29
  30 +    case OPT_fhonour_copts:
  31 +      if (c_language == clk_c) {
  32 +       honour_copts++;
  33 +      }
  34 +      break;
  35 +
  36      case OPT_fimplement_inlines:
  37        flag_implement_inlines = value;
  38        break;
  39 @@ -1209,6 +1226,47 @@
  40        return false;
  41      }
  42
  43 +  if (c_language == clk_c) {
  44 +    char *ev = getenv ("GCC_HONOUR_COPTS");
  45 +    int evv;
  46 +    if (ev == NULL)
  47 +      evv = -1;
  48 +    else if ((*ev == '0') || (*ev == '\0'))
  49 +      evv = 0;
  50 +    else if (*ev == '1')
  51 +      evv = 1;
  52 +    else if (*ev == '2')
  53 +      evv = 2;
  54 +    else if (*ev == 's')
  55 +      evv = -1;
  56 +    else {
  57 +      warning (0, "unknown GCC_HONOUR_COPTS value, assuming 1");
  58 +      evv = 1; /* maybe depend this on something like MIRBSD_NATIVE?  */
  59 +    }
  60 +    if (evv == 1) {
  61 +      if (honour_copts == 0) {
  62 +       error ("someone does not honour COPTS at all in lenient mode");
  63 +       return false;
  64 +      } else if (honour_copts != 1) {
  65 +       warning (0, "someone does not honour COPTS correctly, passed %d times",
  66 +        honour_copts);
  67 +      }
  68 +    } else if (evv == 2) {
  69 +      if (honour_copts == 0) {
  70 +       error ("someone does not honour COPTS at all in strict mode");
  71 +       return false;
  72 +      } else if (honour_copts != 1) {
  73 +       error ("someone does not honour COPTS correctly, passed %d times",
  74 +        honour_copts);
  75 +       return false;
  76 +      }
  77 +    } else if (evv == 0) {
  78 +      if (honour_copts != 1)
  79 +       inform (0, "someone does not honour COPTS correctly, passed %d times",
  80 +        honour_copts);
  81 +    }
  82 +  }
  83 +
  84    return true;
  85  }
  86
  87 --- a/gcc/c.opt
  88 +++ b/gcc/c.opt
  89 @@ -609,6 +613,9 @@
  90  fhonor-std
  91  C++ ObjC++
  92
  93 +fhonour-copts
  94 +C ObjC C++ ObjC++ RejectNegative
  95 +
  96  fhosted
  97  C ObjC
  98  Assume normal C execution environment
  99 --- a/gcc/common.opt
 100 +++ b/gcc/common.opt
 101 @@ -573,6 +577,9 @@
 102  Common Report Var(flag_guess_branch_prob) Optimization
 103  Enable guessing of branch probabilities
 104
 105 +fhonour-copts
 106 +Common RejectNegative
 107 +
 108  ; Nonzero means ignore `#ident' directives.  0 means handle them.
 109  ; Generate position-independent code for executables if possible
 110  ; On SVR4 targets, it also controls whether or not to emit a
 111 --- a/gcc/opts.c
 112 +++ b/gcc/opts.c
 113 @@ -896,9 +896,6 @@
 114    flag_schedule_insns_after_reload = opt2;
 115  #endif
 116    flag_regmove = opt2;
 117 -  flag_strict_aliasing = opt2;
 118 -  flag_strict_overflow = opt2;
 119 -  flag_delete_null_pointer_checks = opt2;
 120    flag_reorder_blocks = opt2;
 121    flag_reorder_functions = opt2;
 122    flag_tree_vrp = opt2;
 123 @@ -922,6 +919,9 @@
 124
 125    /* -O3 optimizations.  */
 126    opt3 = (optimize >= 3);
 127 +  flag_strict_aliasing = opt3;
 128 +  flag_strict_overflow = opt3;
 129 +  flag_delete_null_pointer_checks = opt3;
 130    flag_predictive_commoning = opt3;
 131    flag_inline_functions = opt3;
 132    flag_unswitch_loops = opt3;
 133 --- a/gcc/doc/invoke.texi
 134 +++ b/gcc/doc/invoke.texi
 135 @@ -5699,7 +5715,7 @@
 136  second branch or a point immediately following it, depending on whether
 137  the condition is known to be true or false.
 138
 139 -Enabled at levels @option{-O2}, @option{-O3}, @option{-Os}.
 140 +Enabled at levels @option{-O3}.
 141
 142  @item -fsplit-wide-types
 143  @opindex fsplit-wide-types
 144 @@ -5844,7 +5860,7 @@
 145  @option{-fno-delete-null-pointer-checks} to disable this optimization
 146  for programs which depend on that behavior.
 147
 148 -Enabled at levels @option{-O2}, @option{-O3}, @option{-Os}.
 149 +Enabled at levels @option{-O3}.
 150
 151  @item -fexpensive-optimizations
 152  @opindex fexpensive-optimizations
 153 --- a/gcc/java/jvspec.c
 154 +++ b/gcc/java/jvspec.c
 155 @@ -670,6 +670,7 @@
 156       class name.  Append dummy `.c' that can be stripped by set_input so %b
 157       is correct.  */
 158    set_input (concat (main_class_name, "main.c", NULL));
 159 +  putenv ("GCC_HONOUR_COPTS=s"); /* XXX hack!  */
 160    err = do_spec (jvgenmain_spec);
 161    if (err == 0)
 162      {