Change HANDLE_PRAGMA macro so that it will work with USE_CPPLIB.

Add INSERT_ATTRIBUTES macro.

From-SVN: r22165

8 files changed, 164 insertions, 55 deletions

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 11143ff..7af0d14 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,35 @@
+Wed Sep 2 09:25:29 1998  Nick Clifton  <nickc@cygnus.com>
+
+	* c-lex.c (check_newline):  Call HANDLE_PRAGMA before
+	HANDLE_SYSV_PRAGMA if both are defined.  Generate warning messages
+	if unknown pragmas are encountered.
+	(handle_sysv_pragma): Interpret return code from
+	handle_pragma_token ().  Return success/failure indication rather
+	than next unprocessed character. 
+	(pragma_getc): New function: retrieves characters from the
+	input stream.  Defined when HANDLE_PRAGMA is enabled.
+	(pragma_ungetc): New function: replaces characters back into the
+	input stream.  Defined when HANDLE_PRAGMA is enabled.
+	
+	* c-pragma.c (handle_pragma_token): Return success/failure status
+	of the parse.
+	
+	* c-pragma.h: Change prototype of handle_pragma_token().
+
+	* varasm.c: (handle_pragma_weak): Only create this function if
+	HANDLE_PRAGMA_WEAK is defined.
+
+	* c-common,c (decl_attributes): If defined call the expression
+	contained within the INSERT_ATTRIBUTES macro before adding
+	attributes to a decl.
+
+	* tm.texi (HANDLE_PRAGMA): Document the new verion of
+	HANDLE_PRAGMA, which takes three arguments.
+	(INSERT_ATTRIBUTES): Document this new macro.  
+
+	* LANGUAGES: Document the new version of HANDLE_PRAGMA and the
+	new INSERT_ATTRIBUTES macro.
+
 Wed Sep  2 02:03:23 1998  David S. Miller  <davem@pierdol.cobaltmicro.com>
 
 	* config/sparc/sparc.md (movdf): Only generate special RTL for
diff --git a/gcc/LANGUAGES b/gcc/LANGUAGES
index bce134c..c3d4223 100644
--- a/gcc/LANGUAGES
+++ b/gcc/LANGUAGES
@@ -6,6 +6,18 @@ time as we can formally start documenting the interface this file will
 serve as a repository for information on these interface and any incompatable
 changes we've made.
 
+Aug 31, 1998:
+  The interface to HANDLE_PRAGMA has changed.  It now takes three arguments.
+  The first two are pointers to functions that should be used to read characters
+  from the input stream, and to push them back into the input stream respectively.
+  The third argument is a pointer to a null terminate string which is the first
+  word after #pragma.  The expression supplied by HANDLE_PRAGMA should return
+  non-zero if it parsed and implemented the pragma.  Otherwise it should return
+  zero, and leave the input stream as it was before the expression was evaluated.
+
+  A new back-end definable macro has been added: INSERT_ATTRIBUTES.  This macro
+  allows backend to add attributes to decls as they are created.
+
 Jun 10, 1998:
   The interface to lang_decode_option has changed. It now uses and argc/argv
   interface to allow for options that use more than one input string. The new
diff --git a/gcc/c-common.c b/gcc/c-common.c
index 8916958..a5f738b 100644
--- a/gcc/c-common.c
+++ b/gcc/c-common.c
@@ -420,6 +420,10 @@ decl_attributes (node, attributes, prefix_attributes)
   else if (TREE_CODE_CLASS (TREE_CODE (node)) == 't')
     type = node, is_type = 1;
 
+#ifdef INSERT_ATTRIBUTES
+  INSERT_ATTRIBUTES (node, & attributes, & prefix_attributes);
+#endif
+  
   attributes = chainon (prefix_attributes, attributes);
 
   for (a = attributes; a; a = TREE_CHAIN (a))
@@ -644,7 +648,7 @@ decl_attributes (node, attributes, prefix_attributes)
 	      = (args ? TREE_VALUE (args)
 		 : size_int (BIGGEST_ALIGNMENT / BITS_PER_UNIT));
 	    int align;
-
+	    
 	    /* Strip any NOPs of any kind.  */
 	    while (TREE_CODE (align_expr) == NOP_EXPR
 		   || TREE_CODE (align_expr) == CONVERT_EXPR
diff --git a/gcc/c-lex.c b/gcc/c-lex.c
index 69055f4..2f22528 100644
--- a/gcc/c-lex.c
+++ b/gcc/c-lex.c
@@ -479,6 +479,22 @@ extend_token_buffer (p)
   return token_buffer + offset;
 }
 
+#if defined HANDLE_PRAGMA 
+/* Local versions of these macros, that can be passed as function pointers.  */
+static int
+pragma_getc ()
+{
+  return GETC();
+}
+
+static void
+pragma_ungetc (arg)
+     int arg;
+{
+  UNGETC (arg);
+}
+#endif
+
 /* At the beginning of a line, increment the line number
    and process any #-directive on this line.
    If the line is a #-directive, read the entire line and return a newline.
@@ -530,34 +546,43 @@ check_newline ()
 		c = GETC ();
 	      if (c == '\n')
 		return c;
-#ifdef HANDLE_SYSV_PRAGMA
+
+#if defined HANDLE_PRAGMA || defined HANDLE_SYSV_PRAGMA	      
 	      UNGETC (c);
 	      token = yylex ();
 	      if (token != IDENTIFIER)
 		goto skipline;
-	      return handle_sysv_pragma (token);
-#else /* !HANDLE_SYSV_PRAGMA */
+	      
 #ifdef HANDLE_PRAGMA
+	      /* We invoke HANDLE_PRAGMA before HANDLE_SYSV_PRAGMA
+		 (if both are defined), in order to give the back
+		 end a chance to override the interpretation of
+		 SYSV style pragmas.  */
 #if !USE_CPPLIB
-	      UNGETC (c);
-	      token = yylex ();
-	      if (token != IDENTIFIER)
-		goto skipline;
 	      if (nextchar >= 0)
-		c = nextchar, nextchar = -1;
-	      else
-		c = GETC ();
-	      ungetc (c, finput);
-	      if (HANDLE_PRAGMA (finput, yylval.ttype))
 		{
-		  c = GETC ();
-		  return c;
+		  c = nextchar, nextchar = -1;
+		  UNGETC (c);
 		}
-#else
-	      ??? do not know what to do ???;
-#endif /* !USE_CPPLIB */
+#endif
+	      if (HANDLE_PRAGMA (pragma_getc, pragma_ungetc,
+				 IDENTIFIER_POINTER (yylval.ttype)))
+		return GETC ();
 #endif /* HANDLE_PRAGMA */
+	      
+#ifdef HANDLE_SYSV_PRAGMA
+	      if (handle_sysv_pragma (token))
+		return GETC ();
 #endif /* !HANDLE_SYSV_PRAGMA */
+#endif /* HANDLE_PRAGMA || HANDLE_SYSV_PRAGMA */
+	      
+	      /* Issue a warning message if we have been asked to do so.
+		 Ignoring unknown pragmas in system header file unless
+		 an explcit -Wunknown-pragmas has been given. */
+	      if (warn_unknown_pragmas > 1
+		  || (warn_unknown_pragmas && ! in_system_header))
+		warning ("ignoring pragma: %s", token_buffer);
+	      
 	      goto skipline;
 	    }
 	}
@@ -842,7 +867,7 @@ handle_sysv_pragma (token)
 	  handle_pragma_token (token_buffer, yylval.ttype);
 	  break;
 	default:
-	  handle_pragma_token (token_buffer, 0);
+	  handle_pragma_token (token_buffer, NULL);
 	}
 #if !USE_CPPLIB
       if (nextchar >= 0)
@@ -853,12 +878,11 @@ handle_sysv_pragma (token)
 
       while (c == ' ' || c == '\t')
 	c = GETC ();
-      if (c == '\n' || c == EOF)
-	{
-	  handle_pragma_token (0, 0);
-	  return c;
-	}
       UNGETC (c);
+      
+      if (c == '\n' || c == EOF)
+	return handle_pragma_token (NULL, NULL);
+
       token = yylex ();
     }
 }
diff --git a/gcc/c-pragma.c b/gcc/c-pragma.c
index 3d01925..cb21570 100644
--- a/gcc/c-pragma.c
+++ b/gcc/c-pragma.c
@@ -1,5 +1,5 @@
 /* Handle #pragma, system V.4 style.  Supports #pragma weak and #pragma pack.
-   Copyright (C) 1992, 1997 Free Software Foundation, Inc.
+   Copyright (C) 1992, 1997, 1998 Free Software Foundation, Inc.
 
 This file is part of GNU CC.
 
@@ -37,13 +37,12 @@ Boston, MA 02111-1307, USA.  */
 
 extern int maximum_field_alignment;
 
-/* File used for outputting assembler code.  */
-extern FILE *asm_out_file;
-
 /* Handle one token of a pragma directive.  TOKEN is the
-   current token, and STRING is its printable form.  */
+   current token, and STRING is its printable form. 
+   Return zero if an entire pragma was parsed, but it was
+   flawed in some way.  Return non-zero in all other cases.  */
 
-void
+int
 handle_pragma_token (string, token)
      char *string;
      tree token;
@@ -53,26 +52,33 @@ handle_pragma_token (string, token)
   static char *value;
   static int align;
 
-  if (string == 0)
+  if (string == NULL)
     {
+      int ret_val = 1;
+      
       if (type == ps_pack)
 	{
 	  if (state == ps_right)
 	    maximum_field_alignment = align * 8;
 	  else
-	    warning ("malformed `#pragma pack'");
+	    {
+	      warning ("malformed `#pragma pack'");
+	      ret_val = 0;
+	    }
 	}
+      else if (type == ps_bad)
+	ret_val = 0;
       else if (type == ps_weak)
 	{
 #ifdef HANDLE_PRAGMA_WEAK
 	  if (HANDLE_PRAGMA_WEAK)
 	    handle_pragma_weak (state, name, value);
-
 #endif /* HANDLE_PRAGMA_WEAK */
 	}
 
       type = state = ps_start;
-      return;
+      
+      return ret_val;
     }
 
   switch (state)
@@ -82,24 +88,18 @@ handle_pragma_token (string, token)
 	{
 	  if (strcmp (IDENTIFIER_POINTER (token), "pack") == 0)
 	    type = state = ps_pack;
+#ifdef HANDLE_PRAGMA_WEAK
 	  else if (strcmp (IDENTIFIER_POINTER (token), "weak") == 0)
 	    type = state = ps_weak;
+#endif	  
 	  else
-	    {
-	      type = state = ps_done;
-
-	      /* Issue a warning message if we have been asked to do so.
-		 Ignoring unknown pragmas in system header file unless          
-		 an explcit -Wunknown-pragmas has been given. */                
-	      if (warn_unknown_pragmas > 1
-		  || (warn_unknown_pragmas && ! in_system_header))
-		warning ("ignoring pragma: %s", string);
-	    }
+	    type = state = ps_done;
 	}
       else
 	type = state = ps_done;
       break;
-
+      
+#ifdef HANDLE_PRAGMA_WEAK
     case ps_weak:
       if (token && TREE_CODE (token) == IDENTIFIER_NODE)
 	{
@@ -109,7 +109,8 @@ handle_pragma_token (string, token)
       else
 	state = ps_bad;
       break;
-
+#endif
+      
     case ps_name:
       state = (strcmp (string, "=") ? ps_bad : ps_equals);
       break;
@@ -177,5 +178,7 @@ handle_pragma_token (string, token)
     default:
       abort ();
     }
+
+  return 1;
 }
 #endif /* HANDLE_SYSV_PRAGMA */
diff --git a/gcc/c-pragma.h b/gcc/c-pragma.h
index 49c39fa..5478977 100644
--- a/gcc/c-pragma.h
+++ b/gcc/c-pragma.h
@@ -1,5 +1,5 @@
 /* Pragma related interfaces.
-   Copyright (C) 1995 Free Software Foundation, Inc.
+   Copyright (C) 1995, 1998 Free Software Foundation, Inc.
 
 This file is part of GNU CC.
 
@@ -18,6 +18,8 @@ along with GNU CC; see the file COPYING.  If not, write to
 the Free Software Foundation, 59 Temple Place - Suite 330,
 Boston, MA 02111-1307, USA.  */
 
+#ifdef HANDLE_SYSV_PRAGMA
+
 /* Support #pragma weak iff ASM_WEAKEN_LABEL and ASM_OUTPUT_DEF are
    defined.  */
 #if defined (ASM_WEAKEN_LABEL) && defined (ASM_OUTPUT_DEF)
@@ -43,4 +45,6 @@ enum pragma_state
 extern void handle_pragma_weak PROTO((enum pragma_state, char *, char *));
 
 /* Handle a C style pragma */
-extern void handle_pragma_token PROTO((char *, tree));
+extern int handle_pragma_token PROTO((char *, tree));
+
+#endif /* HANDLE_SYSV_PRAGMA */
diff --git a/gcc/tm.texi b/gcc/tm.texi
index 2f72176..bf6fdd1 100644
--- a/gcc/tm.texi
+++ b/gcc/tm.texi
@@ -7315,18 +7315,32 @@ C++, which is to pretend that the file's contents are enclosed in
 @findex HANDLE_PRAGMA
 @findex #pragma
 @findex pragma
-@item HANDLE_PRAGMA (@var{stream}, @var{node})
+@item HANDLE_PRAGMA (@var{getc}, @var{ungetc}, @var{node})
 Define this macro if you want to implement any pragmas.  If defined, it
-is a C expression whose value is 1 if the pragma was handled by the function.
-The argument @var{stream} is the stdio input stream from which the source text
-can be read.  @var{node} is the tree node for the identifier after the
-@code{#pragma}.
+is a C expression whose value is 1 if the pragma was handled by the
+function, zero otherwise.  The argument @var{getc} is a function of type
+@samp{int (*)(void)} which will return the next character in the input
+stream, or EOF if no characters are left.  The argument @var{ungetc} is
+a function of type @samp{void (*)(int)} which will push a character back
+into the input stream.  The argument @var{name} is the word following
+#pragma in the input stream.  The input stream pointer will be pointing
+just beyond the end of this word.  The input stream should be left
+undistrubed if the expression returns zero, otherwise it should be
+pointing at the last character after the end of the pragma (newline or
+end-of-file). 
 
 It is generally a bad idea to implement new uses of @code{#pragma}.  The
 only reason to define this macro is for compatibility with other
 compilers that do support @code{#pragma} for the sake of any user
 programs which already use it.
 
+If the pragma can be implemented by atttributes then the macro
+@samp{INSERT_ATTRIBUTES} might be a useful one to define as well.
+
+Note: older versions of this macro only had two arguments: @var{stream}
+and @var{token}.  The macro was changed in order to allow it to work
+when gcc is built both with and without a cpp library.
+
 @findex VALID_MACHINE_DECL_ATTRIBUTE
 @item VALID_MACHINE_DECL_ATTRIBUTE (@var{decl}, @var{attributes}, @var{identifier}, @var{args})
 If defined, a C expression whose value is nonzero if @var{identifier} with
@@ -7367,11 +7381,27 @@ of @var{olddecl}.  Examples of when this is needed are when one attribute
 overrides another, or when an attribute is nullified by a subsequent
 definition.
 
+@findex INSERT_ATTRIBUTES
+@item INSERT_ATTRIBUTES (@var{node}, @var{attr_ptr}, @var{prefix_ptr})
+Define this macro if you want to be able to add attributes to a decl
+when it is being created.  This is normally useful for backends which
+wish to implement a pragma by using the attributes which correspond to
+the pragma's effect.  The @var{node} argument is the decl which is being
+created.  The @var{attr_ptr} argument is a pointer to the attribute list
+for this decl.  The @var{prefix_ptr} is a pointer to the list of
+attributes that have appeared after the specifiers and modifiers of the
+declaration, but before the declaration proper.
+
 @findex SET_DEFAULT_DECL_ATTRIBUTES
 @item SET_DEFAULT_DECL_ATTRIBUTES (@var{decl}, @var{attributes})
 If defined, a C statement that assigns default attributes to
 newly defined @var{decl}.
 
+@findex SET_DEFAULT_SECTION_NAME
+@item SET_DEFAULT_SECTION_NAME (@var{decl})
+If defined, a C statement that assigns a section name to the newly
+created @var{decl}.
+
 @findex DOLLARS_IN_IDENTIFIERS
 @item DOLLARS_IN_IDENTIFIERS
 Define this macro to control use of the character @samp{$} in identifier
diff --git a/gcc/varasm.c b/gcc/varasm.c
index 4d98dbc..495a860 100644
--- a/gcc/varasm.c
+++ b/gcc/varasm.c
@@ -4244,6 +4244,7 @@ output_constructor (exp, size)
     assemble_zeros (size - total_bytes);
 }
 
+#ifdef HANDLE_PRAGMA_WEAK
 /* Output asm to handle ``#pragma weak'' */
 
 void
@@ -4251,7 +4252,6 @@ handle_pragma_weak (what, name, value)
      enum pragma_state what;
      char *name, *value;
 {
-#ifdef HANDLE_PRAGMA_WEAK
   if (what == ps_name || what == ps_value)
     {
       struct weak_syms *weak =
@@ -4273,8 +4273,8 @@ handle_pragma_weak (what, name, value)
     }
   else if (! (what == ps_done || what == ps_start))
     warning ("malformed `#pragma weak'");
-#endif /* HANDLE_PRAGMA_WEAK */
 }
+#endif /* HANDLE_PRAGMA_WEAK */
 
 /* Declare DECL to be a weak symbol.  */