re PR preprocessor/7358 (Changes to Sun's make Dependencies)

PR preprocessor/7358
	PR preprocessor/7357
	PR preprocessor/7526
	* cppfiles.c (stack_include_file): Ignore main file if
	appropriate.  Correct test of whether a dependency should
	be output.
	* cppinit.c (init_dependency_output): Ignore main file
	for SUNPRO_DEPENDENCIES.
	(struct lang_flags): Rename trigraphs std.
	(set_lang): Update.
	* cpplib.c (run_directive): Kludge so _Pragma dependency works.
	* cpplib.h (struct cpp_options): New members.
	* cppmacro.c (collect_args): Flag whether to swallow a possible
	future comma pasted with varargs.
	(replace_args): Use this flag.
	* doc/cpp.texi: Update varargs extension documentation.
	* doc/cppenv.texi: Update.
testsuite:
	* gcc.dg/cpp/_Pragma3.c, gcc.dg/cpp/vararg3.c, gcc.dg/cpp/vararg4.c:
	New tests.

From-SVN: r56355

gcc/ChangeLog

@@ -1,3 +1,23 @@
+2002-08-15  Neil Booth  <neil@daikokuya.co.uk>
+
+	PR preprocessor/7358
+	PR preprocessor/7357
+	PR preprocessor/7526
+	* cppfiles.c (stack_include_file): Ignore main file if
+	appropriate.  Correct test of whether a dependency should
+	be output.
+	* cppinit.c (init_dependency_output): Ignore main file
+	for SUNPRO_DEPENDENCIES.
+	(struct lang_flags): Rename trigraphs std.
+	(set_lang): Update.
+	* cpplib.c (run_directive): Kludge so _Pragma dependency works.
+	* cpplib.h (struct cpp_options): New members.
+	* cppmacro.c (collect_args): Flag whether to swallow a possible
+	future comma pasted with varargs.
+	(replace_args): Use this flag.
+	* doc/cpp.texi: Update varargs extension documentation.
+	* doc/cppenv.texi: Update.
+
 2002-08-14  Release Manager
 
 	* GCC 3.2 Released.

gcc/cppfiles.c

@@ -310,9 +310,12 @@ stack_include_file (pfile, inc)
   sysp = MAX ((pfile->map ? pfile->map->sysp : 0),
 	      (inc->foundhere ? inc->foundhere->sysp : 0));
 
-  /* For -M, add the file to the dependencies on its first inclusion.  */
-  if (CPP_OPTION (pfile, print_deps) > sysp && !inc->include_count)
-    deps_add_dep (pfile->deps, inc->name);
+  /* Add the file to the dependencies on its first inclusion.  */
+  if (CPP_OPTION (pfile, print_deps) > !!sysp && !inc->include_count)
+    {
+      if (pfile->buffer || CPP_OPTION (pfile, deps_ignore_main_file) == 0)
+	deps_add_dep (pfile->deps, inc->name);
+    }
 
   /* Not in cache?  */
   if (! inc->buffer)

gcc/cppinit.c

@@ -396,7 +396,7 @@ struct lang_flags
   char objc;
   char cplusplus;
   char extended_numbers;
-  char trigraphs;
+  char std;
   char dollars_in_ident;
   char cplusplus_comments;
   char digraphs;
@@ -404,7 +404,7 @@ struct lang_flags
 
 /* ??? Enable $ in identifiers in assembly? */
 static const struct lang_flags lang_defaults[] =
-{ /*              c99 objc c++ xnum trig dollar c++comm digr  */
+{ /*              c99 objc c++ xnum std dollar c++comm digr  */
   /* GNUC89 */  { 0,  0,   0,  1,   0,   1,     1,      1     },
   /* GNUC99 */  { 1,  0,   0,  1,   0,   1,     1,      1     },
   /* STDC89 */  { 0,  0,   0,  0,   1,   0,     0,      0     },
@@ -431,7 +431,8 @@ set_lang (pfile, lang)
   CPP_OPTION (pfile, objc)		 = l->objc;
   CPP_OPTION (pfile, cplusplus)		 = l->cplusplus;
   CPP_OPTION (pfile, extended_numbers)	 = l->extended_numbers;
-  CPP_OPTION (pfile, trigraphs)		 = l->trigraphs;
+  CPP_OPTION (pfile, std)		 = l->std;
+  CPP_OPTION (pfile, trigraphs)		 = l->std;
   CPP_OPTION (pfile, dollars_in_ident)	 = l->dollars_in_ident;
   CPP_OPTION (pfile, cplusplus_comments) = l->cplusplus_comments;
   CPP_OPTION (pfile, digraphs)		 = l->digraphs;
@@ -1880,7 +1881,10 @@ init_dependency_output (pfile)
 	{
 	  spec = getenv ("SUNPRO_DEPENDENCIES");
 	  if (spec)
-	    CPP_OPTION (pfile, print_deps) = 2;
+	    {
+	      CPP_OPTION (pfile, print_deps) = 2;
+	      CPP_OPTION (pfile, deps_ignore_main_file) = 1;
+	    }
 	  else
 	    return;
 	}

gcc/cpplib.c

@@ -406,12 +406,17 @@ run_directive (pfile, dir_no, buf, count)
 {
   cpp_push_buffer (pfile, (const U_CHAR *) buf, count,
 		   /* from_stage3 */ true, 1);
+  /* Disgusting hack.  */
+  if (dir_no == T_PRAGMA)
+    pfile->buffer->inc = pfile->buffer->prev->inc;
   start_directive (pfile);
   /* We don't want a leading # to be interpreted as a directive.  */
   pfile->buffer->saved_flags = 0;
   pfile->directive = &dtable[dir_no];
   (void) (*pfile->directive->handler) (pfile);
   end_directive (pfile, 1);
+  if (dir_no == T_PRAGMA)
+    pfile->buffer->inc = NULL;
   _cpp_pop_buffer (pfile);
 }
 

gcc/cpplib.h

@@ -279,6 +279,9 @@ struct cpp_options
   /* If true, fopen (deps_file, "a") else fopen (deps_file, "w").  */
   unsigned char print_deps_append;
 
+  /* If true, no dependency is generated on the main file.  */
+  unsigned char deps_ignore_main_file;
+
   /* Nonzero means print names of header files (-H).  */
   unsigned char print_include_names;
 
@@ -335,6 +338,9 @@ struct cpp_options
   /* Nonzero for the 1999 C Standard, including corrigenda and amendments.  */
   unsigned char c99;
 
+  /* Nonzero if conforming to some particular standard.  */
+  unsigned char std;
+
   /* Nonzero means give all the error messages the ANSI standard requires.  */
   unsigned char pedantic;
 

gcc/cppmacro.c

@@ -613,7 +613,20 @@ collect_args (pfile, node)
     }
 
   if (!error)
-    return base_buff;
+    {
+      /* GCC has special semantics for , ## b where b is a varargs
+	 parameter: we remove the comma if b was omitted entirely.
+	 If b was merely an empty argument, the comma is retained.
+	 If the macro takes just one (varargs) parameter, then we
+	 retain the comma only if we are standards conforming.
+
+	 If FIRST is NULL replace_args () swallows the comma.  */
+      if (macro->variadic && (argc < macro->paramc
+			      || (argc == 1 && args[0].count == 0
+				  && !CPP_OPTION (pfile, std))))
+	args[macro->paramc - 1].first = NULL;
+      return base_buff;
+    }
 
   _cpp_release_buff (pfile, base_buff);
   return NULL;
@@ -799,15 +812,13 @@ replace_args (pfile, node, args)
 	  count = arg->count, from = arg->first;
 	  if (dest != first)
 	    {
-	      /* GCC has special semantics for , ## b where b is a
-		 varargs parameter: the comma disappears if b was
-		 given no actual arguments (not merely if b is an
-		 empty argument); otherwise the paste flag is removed.  */
 	      if (dest[-1]->type == CPP_COMMA
 		  && macro->variadic
 		  && src->val.arg_no == macro->paramc)
 		{
-		  if (count == 0)
+		  /* Swallow a pasted comma if from == NULL, otherwise
+		     drop the paste flag.  */
+		  if (from == NULL)
 		    dest--;
 		  else
 		    paste_flag = dest - 1;

gcc/doc/cpp.texi

@@ -1676,6 +1676,15 @@ eprintf ("success!\n")
      @expansion{} fprintf(stderr, "success!\n");
 @end example
 
+@noindent
+The above explanation is ambiguous about the case where the only macro
+parameter is a variable arguments parameter, as it is meaningless to
+try to distinguish whether no argument at all is an empty argument or
+a missing argument.  In this case the C99 standard is clear that the
+comma must remain, however the existing GCC extension used to swallow
+the comma.  So CPP retains the comma when conforming to a specific C
+standard, and drops it otherwise.
+
 C99 mandates that the only place the identifier @code{@w{__VA_ARGS__}}
 can appear is in the replacement list of a variadic macro.  It may not
 be used as a macro name, macro argument name, or within a different type

gcc/doc/cppenv.texi

@@ -66,7 +66,8 @@ with an optional @option{-MT} switch too.
 This variable is the same as the environment variable
 @env{DEPENDENCIES_OUTPUT} (@pxref{DEPENDENCIES_OUTPUT}), except that
 system header files are not ignored, so it implies @option{-M} rather
-than @option{-MM}.
+than @option{-MM}.  However, the dependence on the main input file is
+omitted.
 @ifset cppmanual
 @xref{Invocation}.
 @end ifset

gcc/testsuite/ChangeLog

@@ -1,3 +1,8 @@
+2002-08-15  Neil Booth  <neil@daikokuya.co.uk>
+
+	* gcc.dg/cpp/_Pragma3.c, gcc.dg/cpp/vararg3.c, gcc.dg/cpp/vararg4.c:
+	New tests.
+
 2002-08-14  Release Manager
 
 	* GCC 3.2 Released.