* Makefile.in (cc1): Put C_OBJS, and thence @extra_c_objs@ last.

        (LIBCPP_OBJS): New.  Add cppulp.o.
        (cppmain, fix-header): Depend on and use libcpp.a.
        * configure.in (extra_c_objs, extra_cxx_objs): Use libcpp.a instead
        of the individual object files.
        * objc/Make-lang.in (cc1obj): Put OBJC_OBJS, and thence @extra_c_objs@,
        last.
        * cccp.c (user_label_prefix): New.
        (main): Set it off -f*leading-underscore.
        (special_symbol): Use it.
        * cpplib.c (special_symbol): Likewise.
        (cpp_handle_option): Handle -f*leading-underscore.
        * cppulp.c: New file.
        * output.h (user_label_prefix): Declare it.
        * dwarf2out.c (ASM_NAME_TO_STRING): Prepend user_label_prefix.
        * toplev.c (f_options, main): Handle -f*leading-underscore.
        * defaults.h (ASM_OUTPUT_LABELREF): Use asm_fprintf instead of
        referencing USER_LABEL_PREFIX directly.
        * config/nextstep.h (ASM_OUTPUT_LABELREF): Likewise.
        * m32r/m32r.h (ASM_OUTPUT_LABELREF): Likewise.
        * final.c (asm_fprintf): Use user_label_prefix instead.
        * arm/thumb.c (thumb_print_operand): Likewise.
        * gcc.c (default_compilers): Pass -f*leading-underscore on to
        cpp wherever appropriate.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@23415 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 28 insertions, 0 deletions

diff --git a/gcc/toplev.c b/gcc/toplev.c
index 197d2801d78..5acb8f014b2 100644
--- a/gcc/toplev.c
+++ b/gcc/toplev.c
@@ -770,6 +770,17 @@ typedef struct
 }
 lang_independent_options;
 
+/* Add or remove a leading underscore from user symbols.  */
+int flag_leading_underscore = -1;
+
+/* The user symbol prefix after having resolved same.  */
+char *user_label_prefix;
+
+/* A default for same.  */
+#ifndef USER_LABEL_PREFIX
+#define USER_LABEL_PREFIX ""
+#endif
+
 /* Table of language-independent -f options.
    STRING is the option name.  VARIABLE is the address of the variable.
    ON_VALUE is the value to store in VARIABLE
@@ -915,6 +926,8 @@ lang_independent_options f_options[] =
    "Suppress output of instruction numbers and line number notes in debugging dumps"},
   {"instrument-functions", &flag_instrument_function_entry_exit, 1,
    "Instrument function entry/exit with profiling calls"},
+  {"leading-underscore", &flag_leading_underscore, 1,
+   "External symbols have a leading underscore" }
 };
 
 #define NUM_ELEM(a)  (sizeof (a) / sizeof ((a)[0]))
@@ -4899,6 +4912,21 @@ main (argc, argv)
     warning ("this target machine does not have delayed branches");
 #endif
 
+  user_label_prefix = USER_LABEL_PREFIX;
+  if (flag_leading_underscore != -1)
+    {
+      /* If the default prefix is more complicated than "" or "_", 
+	 issue a warning and ignore this option.  */
+      if (user_label_prefix[0] == 0 ||
+	  (user_label_prefix[0] == '_' && user_label_prefix[1] == 0))
+	{
+	  user_label_prefix = flag_leading_underscore ? "_" : "";
+	}
+      else
+	warning ("-f%sleading-underscore not supported on this target machine",
+		 flag_leading_underscore ? "" : "no-");
+    }
+
   /* If we are in verbose mode, write out the version and maybe all the
      option flags in use.  */
   if (version_flag)