[linker] Allow asserts in sections

[Nathan Sidwell <nathan at codesourcery dot com>]

This patch does 2 things

1) allow assert statements inside section scripts.  This means one doesn't have 
to write the awful
	foo : {
		. = . + (ASSERT (foo, bar) & 0);
	}
any more.

I also changed the lexer to not allow ',' in NAMES when in expression mode.  I 
kept getting tripped up by
	ASSERT (FOO, "FOO zero");
which parses the first token as "FOO,".  Also I recently got bitten by EXTERN 
which allows both comma and whitespace to separate the symbol names.  Thus
	EXTERN (FOO, BAR, BAZ)
parses ok, but does not pull in the symbols you think it might.

tested on m68k-elf, ok?

nathan
--
Nathan Sidwell    ::   http://www.codesourcery.com   ::         CodeSourcery
nathan@codesourcery.com    ::     http://www.planetfall.pwp.blueyonder.co.uk

2007-05-22  Nathan Sidwell  <nathan@codesourcery.com>

	* ldlex.l: ASSERT is recognized in SCRIPT env.  NAMES cannot
	contain commas in EXP env.
	* ldgram.y (extern_name_list): Push to EXP env, move body to ...
	(extern_name_list_body): ... here.
	(script_file, ifile_list): Reformat.
	(statement): Add ASSERT.

	testsuite/
	* ld/ld-scripts/assert.t: Add additional cases.

Index: testsuite/ld-scripts/assert.t
===================================================================
--- testsuite/ld-scripts/assert.t	(revision 171892)
+++ testsuite/ld-scripts/assert.t	(working copy)
@@ -1,5 +1,9 @@
 SECTIONS
 {
-  .empty : {}
+  .empty : {
+  here = !.;
+  ASSERT (!., "dot is not zero");
+  ASSERT (here, "here is zero");
+  }
   ASSERT (!SIZEOF(.empty), "Empty is not empty")
 }
Index: ldlex.l
===================================================================
--- ldlex.l	(revision 171892)
+++ ldlex.l	(working copy)
@@ -256,7 +256,7 @@ V_IDENTIFIER [*?.$_a-zA-Z\[\]\-\!\^\\]([
 <EXPRESSION,BOTH,SCRIPT>"LOADADDR"	{ RTOKEN(LOADADDR);}
 <EXPRESSION,BOTH>"MAX"			{ RTOKEN(MAX_K); }
 <EXPRESSION,BOTH>"MIN"			{ RTOKEN(MIN_K); }
-<EXPRESSION,BOTH>"ASSERT"		{ RTOKEN(ASSERT_K); }
+<EXPRESSION,BOTH,SCRIPT>"ASSERT"	{ RTOKEN(ASSERT_K); }
 <BOTH,SCRIPT>"ENTRY"			{ RTOKEN(ENTRY);}
 <BOTH,SCRIPT,MRI>"EXTERN"		{ RTOKEN(EXTERN);}
 <EXPRESSION,BOTH,SCRIPT>"NEXT"		{ RTOKEN(NEXT);}
@@ -363,11 +363,19 @@ V_IDENTIFIER [*?.$_a-zA-Z\[\]\-\!\^\\]([
 				}
 
 
-<BOTH,EXPRESSION>{FILENAMECHAR1}{FILENAMECHAR}*	{
+<BOTH>{FILENAMECHAR1}{FILENAMECHAR}*	{
 				 yylval.name = xstrdup (yytext);
 				  return NAME;
 				}
-<BOTH,EXPRESSION>"-l"{FILENAMECHAR}+ {
+<BOTH>"-l"{FILENAMECHAR}+ {
+				  yylval.name = xstrdup (yytext + 2);
+				  return LNAME;
+				}
+<EXPRESSION>{FILENAMECHAR1}{NOCFILENAMECHAR}*	{
+				 yylval.name = xstrdup (yytext);
+				  return NAME;
+				}
+<EXPRESSION>"-l"{NOCFILENAMECHAR}+ {
 				  yylval.name = xstrdup (yytext + 2);
 				  return LNAME;
 				}
Index: ldgram.y
===================================================================
--- ldgram.y	(revision 171892)
+++ ldgram.y	(working copy)
@@ -280,7 +280,13 @@ casesymlist:
 	| casesymlist ',' NAME
 	;
 
+/* Parsed as expressions so that commas separate entries */
 extern_name_list:
+	{ ldlex_expression (); }
+	extern_name_list_body
+	{ ldlex_popstate (); }
+
+extern_name_list_body:
 	  NAME
 			{ ldlang_add_undef ($1); }
 	| extern_name_list NAME
@@ -290,23 +296,17 @@ extern_name_list:
 	;
 
 script_file:
-	{
-	 ldlex_both();
-	}
-       ifile_list
-	{
-	ldlex_popstate();
-	}
+	{ ldlex_both(); }
+	ifile_list
+	{ ldlex_popstate(); }
         ;
 
-
 ifile_list:
-       ifile_list ifile_p1
+	ifile_list ifile_p1
         |
 	;
 
 
-
 ifile_p1:
 		memory
 	|	sections
@@ -573,6 +573,9 @@ statement:
 			{
 			  lang_add_fill ($3);
 			}
+	| ASSERT_K  {ldlex_expression ();} '(' exp ',' NAME ')' end
+			{ ldlex_popstate ();
+			  lang_add_assignment (exp_assert ($4, $6)); }
 	;
 
 statement_list: