Avoid printing a space at the beginning of lines in the output.

This fixes more differences compared to "gcc -E" so removes several
cases of erroneously failing test cases. The implementation isn't very
elegant, but it is functional.

glcpp-lex.l

@@ -173,7 +173,12 @@ TOKEN		[^[:space:](),]+
 }
 
 \n {
+	/* XXX: Printing here (rather than in a parser production)
+	 * *and* frobbing a bit of the parser state here are both ugly
+	 * things. But all my attempts to avoid this by returning a
+	 * NEWLINE token here have led to even more ugly things. */
 	printf ("\n");
+	yyextra->just_printed_separator = 1;
 }
 
 {HSPACE}+

glcpp-parse.y

@@ -114,7 +114,7 @@ glcpp_parser_lex (glcpp_parser_t *parser);
 %lex-param {glcpp_parser_t *parser}
 
 %token DEFINE FUNC_MACRO IDENTIFIER IDENTIFIER_FINALIZED OBJ_MACRO NEWLINE SEPARATOR SPACE TOKEN UNDEF
-%type <ival> input punctuator
+%type <ival> punctuator
 %type <str> content FUNC_MACRO IDENTIFIER IDENTIFIER_FINALIZED OBJ_MACRO
 %type <argument_list> argument_list
 %type <string_list> macro parameter_list
@@ -144,7 +144,7 @@ glcpp_parser_lex (glcpp_parser_t *parser);
 	 * character between any two. */
 input:
 	/* empty */ {
-		$$ = SEPARATOR;
+		parser->just_printed_separator = 1;
 	}
 |	input content {
 		int is_token;
@@ -157,16 +157,18 @@ input:
 						(c >= '0' && c <= '9') ||
 						(c == '_'));
 
-			if ($1 == TOKEN && is_not_separator)
+			if (! parser->just_printed_separator && is_not_separator)
+			{
 				printf (" ");
+			}
 			printf ("%s", $2);
+
 			if (is_not_separator)
-				$$ = TOKEN;
+				parser->just_printed_separator = 0;
 			else
-				$$ = SEPARATOR;
-		} else {
-			$$ = $1;
+				parser->just_printed_separator = 1;
 		}
+
 		if ($2)
 			talloc_free ($2);
 	}
@@ -561,6 +563,8 @@ glcpp_parser_create (void)
 					   hash_table_string_compare);
 	parser->expansions = NULL;
 
+	parser->just_printed_separator = 1;
+
 	return parser;
 }
 

glcpp.h

@@ -101,6 +101,7 @@ struct glcpp_parser {
 	yyscan_t scanner;
 	struct hash_table *defines;
 	expansion_node_t *expansions;
+	int just_printed_separator;
 };
 
 void