c-common.c (handle_used_attribute): Set DECL_PRESERVE_P.

        * c-common.c (handle_used_attribute): Set DECL_PRESERVE_P.
        * print-tree.c (print_node): Print DECL_PRESERVE_P.
        * target-def.h (TARGET_ASM_MARK_DECL_PRESERVED): New #define.
        (TARGET_ASM_OUT): New member, TARGET_ASM_MARK_DECL_PRESERVED
        * target.h (struct gcc_target): New member, mark_decl_preserved.
        * hooks.c (hook_void_charptr): Rename to ...
        (hook_void_constcharptr): ... new name.
        * hooks.h (hook_void_charptr): Rename to ..
        (hook_void_constcharptr): ... new name.
        * tree.h (DECL_PRESERVE_P): New #define.
        (struct tree_decl): New member, preserve_flag.
        * varasm.c (assemble_start_function): Mark decl preserved.
        (assemble_variable): Same.
        * darwin.c (darwin_mark_decl_preserved): New function.
        * darwin.h (TARGET_ASM_MARK_DECL_preserved): New #define.
        * darwin-protos.h (darwin_mark_decl_preserved): New decl.
        * doc/tm.texi (TARGET_ASM_MARK_DECL_PRESERVED): Document.

        testsuite:
        * gcc.dg/darwin-20040809-1.c: New test.

From-SVN: r86076

gcc/ChangeLog

+2004-08-16  Devang Patel  <dpatel@apple.com>
+
+	* c-common.c (handle_used_attribute): Set DECL_PRESERVE_P.
+	* print-tree.c (print_node): Print DECL_PRESERVE_P.
+	* target-def.h (TARGET_ASM_MARK_DECL_PRESERVED): New #define.
+	(TARGET_ASM_OUT): New member, TARGET_ASM_MARK_DECL_PRESERVED
+	* target.h (struct gcc_target): New member, mark_decl_preserved.
+        * hooks.c (hook_void_charptr): Rename to ...
+        (hook_void_constcharptr): ... new name.
+        * hooks.h (hook_void_charptr): Rename to ..
+        (hook_void_constcharptr): ... new name.
+	* tree.h (DECL_PRESERVE_P): New #define.
+	(struct tree_decl): New member, preserve_flag.
+	* varasm.c (assemble_start_function): Mark decl preserved.
+	(assemble_variable): Same.
+	* darwin.c (darwin_mark_decl_preserved): New function.
+	* darwin.h (TARGET_ASM_MARK_DECL_preserved): New #define.
+	* darwin-protos.h (darwin_mark_decl_preserved): New decl.
+	* doc/tm.texi (TARGET_ASM_MARK_DECL_PRESERVED): Document.
+
 2004-08-16  Joseph S. Myers  <jsm@polyomino.org.uk>
 
 	* c-decl.c (grokdeclarator): Allow for function definition where

gcc/c-common.c

@@ -4078,6 +4078,7 @@ handle_used_attribute (tree *pnode, tree name, tree ARG_UNUSED (args),
       || (TREE_CODE (node) == VAR_DECL && TREE_STATIC (node)))
     {
       TREE_USED (node) = 1;
+      DECL_PRESERVE_P (node) = 1;
     }
   else
     {

gcc/config/darwin-protos.h

@@ -82,6 +82,7 @@ extern void darwin_pragma_unused (struct cpp_reader *);
 extern void darwin_file_end (void);
 
 extern void darwin_make_decl_one_only (tree decl);
+extern void darwin_mark_decl_preserved (const char *);
 
 /* Expanded by EXTRA_SECTION_FUNCTIONS into varasm.o.  */
 extern void const_section (void);

gcc/config/darwin.c

@@ -914,6 +914,14 @@ darwin_make_decl_one_only (tree decl)
 }
 
 void
+darwin_mark_decl_preserved (const char *name)
+{
+  fprintf (asm_out_file, ".no_dead_strip ");
+  assemble_name (asm_out_file, name);
+  fputc ('\n', asm_out_file);
+}
+
+void
 machopic_select_section (tree exp, int reloc,
 			 unsigned HOST_WIDE_INT align ATTRIBUTE_UNUSED)
 {

gcc/config/darwin.h

@@ -799,6 +799,9 @@ objc_section_init (void)			\
 #define ASM_GENERATE_INTERNAL_LABEL(LABEL,PREFIX,NUM)	\
   sprintf (LABEL, "*%s%ld", PREFIX, (long)(NUM))
 
+#undef TARGET_ASM_MARK_DECL_PRESERVED
+#define TARGET_ASM_MARK_DECL_PRESERVED darwin_mark_decl_preserved
+
 /* Since we have a separate readonly data section, define this so that
    jump tables end up in text rather than data.  */
 

gcc/doc/tm.texi

@@ -6804,6 +6804,12 @@ pseudo-op to declare a library function name external.  The name of the
 library function is given by @var{symref}, which is a @code{symbol_ref}.
 @end deftypefn
 
+@deftypefn {Target Hook} void TARGET_ASM_MARK_DECL_PRESERVED (tree @var{decl})
+This target hook is a function to output to @var{asm_out_file} an assembler
+directive to annotate used symbol.  Darwin target use .no_dead_code_strip
+directive.
+@end deftypefn
+
 @defmac ASM_OUTPUT_LABELREF (@var{stream}, @var{name})
 A C statement (sans semicolon) to output to the stdio stream
 @var{stream} a reference in assembler syntax to a label named

gcc/hooks.c

@@ -142,7 +142,7 @@ hook_void_tree (tree a ATTRIBUTE_UNUSED)
 }
 
 void
-hook_void_charptr (char *a ATTRIBUTE_UNUSED)
+hook_void_constcharptr (const char *a ATTRIBUTE_UNUSED)
 {
 }
 

gcc/hooks.h

@@ -37,7 +37,7 @@ extern bool hook_bool_constcharptr_size_t_false (const char *, size_t);
 
 extern void hook_void_void (void);
 extern void hook_void_int (int);
-extern void hook_void_charptr (char *);
+extern void hook_void_constcharptr (const char *);
 extern void hook_void_FILEptr_constcharptr (FILE *, const char *);
 extern void hook_void_tree (tree);
 extern void hook_void_tree_treeptr (tree, tree *);

gcc/print-tree.c

@@ -353,6 +353,9 @@ print_node (FILE *file, const char *prefix, tree node, int indent)
       if (DECL_DEFER_OUTPUT (node))
 	fputs (" defer-output", file);
 
+      if (DECL_PRESERVE_P (node))
+	fputs (" preserve", file);
+
       if (DECL_LANG_FLAG_0 (node))
 	fputs (" decl_0", file);
       if (DECL_LANG_FLAG_1 (node))

gcc/target-def.h

@@ -183,6 +183,10 @@ Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
 #define TARGET_ASM_EXTERNAL_LIBCALL default_external_libcall
 #endif
 
+#ifndef TARGET_ASM_MARK_DECL_PRESERVED
+#define TARGET_ASM_MARK_DECL_PRESERVED hook_void_constcharptr
+#endif
+
 #define TARGET_ASM_ALIGNED_INT_OP				\
 		       {TARGET_ASM_ALIGNED_HI_OP,		\
 			TARGET_ASM_ALIGNED_SI_OP,		\
@@ -223,7 +227,8 @@ Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
                         TARGET_ASM_CAN_OUTPUT_MI_THUNK,         \
                         TARGET_ASM_FILE_START,                  \
                         TARGET_ASM_FILE_END,			\
-			TARGET_ASM_EXTERNAL_LIBCALL}
+			TARGET_ASM_EXTERNAL_LIBCALL,            \
+                        TARGET_ASM_MARK_DECL_PRESERVED}
 
 /* Scheduler hooks.  All of these default to null pointers, which
    haifa-sched.c looks for and handles.  */

gcc/target.h

@@ -172,6 +172,11 @@ struct gcc_target
     /* Output an assembler pseudo-op to declare a library function name
        external.  */
     void (*external_libcall) (rtx);
+
+     /* Output an assembler directive to mark decl live. This instructs
+	linker to not dead code strip this symbol.  */
+    void (*mark_decl_preserved) (const char *);
+
   } asm_out;
 
   /* Functions relating to instruction scheduling.  */

gcc/testsuite/ChangeLog

+2004-08-16  Devang Patel  <dpatel@apple.com>
+
+	* gcc.dg/darwin-20040809-1.c: New test.
+	
 2004-08-16  Joseph S. Myers  <jsm@polyomino.org.uk>
 
 	* gcc.dg/funcdef-attr-1.c: New test.

gcc/testsuite/gcc.dg/darwin-20040812-1.c

+/* Test dead code strip support.  */
+/* Contributed by Devang Patel  <dpatel@apple.com>  */
+ 
+/* { dg-do compile } */
+
+const char my_version_string[] __attribute__((__used__))
+  = "Do not remove this string\n";
+ 
+ static int
+ __attribute__((__used__))
+      static_debug_routine()
+{
+   int i;
+   i = 42;
+}
+ 
+int
+main ()
+{
+   return 0;
+}
+ 
+/* { dg-final { scan-assembler ".no_dead_strip _my_version_string" } } */
+/* { dg-final { scan-assembler ".no_dead_strip _static_debug_routine" } } */

gcc/tree.h

@@ -2165,6 +2165,11 @@ struct tree_binfo GTY (())
 #define DECL_POSSIBLY_INLINED(DECL) \
   FUNCTION_DECL_CHECK (DECL)->decl.possibly_inlined
 
+/* Nonzero for a decl that is decorated using attribute used.
+   This indicates compiler tools that this decl needs to be preserved.  */
+#define DECL_PRESERVE_P(DECL) \
+  DECL_CHECK (DECL)->decl.preserve_flag
+
 /* Enumerate visibility settings.  */
 #ifndef SYMBOL_VISIBILITY_DEFINED
 #define SYMBOL_VISIBILITY_DEFINED
@@ -2232,7 +2237,8 @@ struct tree_decl GTY(())
   unsigned lang_flag_7 : 1;
 
   unsigned possibly_inlined : 1;
-  /* 15 unused bits.  */
+  unsigned preserve_flag: 1;
+  /* 13 unused bits.  */
 
   union tree_decl_u1 {
     /* In a FUNCTION_DECL for which DECL_BUILT_IN holds, this is

gcc/varasm.c

@@ -1222,6 +1222,9 @@ assemble_start_function (tree decl, const char *fnname)
       maybe_assemble_visibility (decl);
     }
 
+  if (DECL_PRESERVE_P (decl))
+    targetm.asm_out.mark_decl_preserved (fnname);
+
   /* Do any machine/system dependent processing of the function name.  */
 #ifdef ASM_DECLARE_FUNCTION_NAME
   ASM_DECLARE_FUNCTION_NAME (asm_out_file, fnname, current_function_decl);
@@ -1562,6 +1565,9 @@ assemble_variable (tree decl, int top_level ATTRIBUTE_UNUSED,
   if (TREE_PUBLIC (decl))
     maybe_assemble_visibility (decl);
 
+  if (DECL_PRESERVE_P (decl))
+    targetm.asm_out.mark_decl_preserved (name);
+
   /* Output any data that we will need to use the address of.  */
   if (DECL_INITIAL (decl) == error_mark_node)
     reloc = contains_pointers_p (TREE_TYPE (decl)) ? 3 : 0;