c-common.c (fix_string_type): Split out of ...

        * c-common.c (fix_string_type): Split out of ...
        (combine_strings): ... here.  Take a varray, not a tree list.
        (c_expand_builtin_printf): Use fix_string_type.
        * c-common.h: Update decls.
        * c-parse.in (string): Remove.  Update all uses to use STRING
        instead, and not call combine_strings.
        (yylexstring): New.
        (_yylex): Use it.
        * c-typeck.c (simple_asm_stmt): Don't call combine_strings.
        (build_asm_stmt): Likewise.
        * objc/objc-act.c (my_build_string): Use fix_string_type.
        (build_objc_string_object): Build varray for combine_strings.

        * parse.y (string): Remove.  Update all uses to use STRING
        instead, and not call combine_strings.
        * rtti.c (tinfo_name): Use fix_string_type.
        * semantics.c (finish_asm_stmt): Don't call combine_strings.
        * spew.c (yylexstring): New.
        (read_token): Use it.

	* g++.dg/parse/concat1.C: New.
	* gcc.dg/concat2.c: New.

From-SVN: r52790

gcc/ChangeLog

+2002-04-26  Richard Henderson  <rth@redhat.com>
+
+	PR c/3581
+	* c-common.c (fix_string_type): Split out of ...
+	(combine_strings): ... here.  Take a varray, not a tree list.
+	(c_expand_builtin_printf): Use fix_string_type.
+	* c-common.h: Update decls.
+	* c-parse.in (string): Remove.  Update all uses to use STRING
+	instead, and not call combine_strings.
+	(yylexstring): New.
+	(_yylex): Use it.
+	* c-typeck.c (simple_asm_stmt): Don't call combine_strings.
+	(build_asm_stmt): Likewise.
+	* objc/objc-act.c (my_build_string): Use fix_string_type.
+	(build_objc_string_object): Build varray for combine_strings.
+
 2002-04-26  Bo Thorsen  <bo@suse.co.uk>
 
 	* config/i386/linux64.h (MD_FALLBACK_FRAME_STATE_FOR): Define for

gcc/c-common.c

@@ -683,105 +683,17 @@ fname_decl (rid, id)
   return decl;
 }
 
-/* Given a chain of STRING_CST nodes,
-   concatenate them into one STRING_CST
-   and give it a suitable array-of-chars data type.  */
+/* Given a STRING_CST, give it a suitable array-of-chars data type.  */
 
 tree
-combine_strings (strings)
-     tree strings;
+fix_string_type (value)
+      tree value;
 {
-  tree value, t;
-  int length = 1;
-  int wide_length = 0;
-  int wide_flag = 0;
-  int wchar_bytes = TYPE_PRECISION (wchar_type_node) / BITS_PER_UNIT;
-  int nchars;
+  const int wchar_bytes = TYPE_PRECISION (wchar_type_node) / BITS_PER_UNIT;
+  const int wide_flag = TREE_TYPE (value) == wchar_array_type_node;
   const int nchars_max = flag_isoc99 ? 4095 : 509;
-
-  if (TREE_CHAIN (strings))
-    {
-      /* More than one in the chain, so concatenate.  */
-      char *p, *q;
-
-      /* Don't include the \0 at the end of each substring,
-	 except for the last one.
-	 Count wide strings and ordinary strings separately.  */
-      for (t = strings; t; t = TREE_CHAIN (t))
-	{
-	  if (TREE_TYPE (t) == wchar_array_type_node)
-	    {
-	      wide_length += (TREE_STRING_LENGTH (t) - wchar_bytes);
-	      wide_flag = 1;
-	    }
-	  else
-	    {
-	      length += (TREE_STRING_LENGTH (t) - 1);
-	      if (C_ARTIFICIAL_STRING_P (t) && !in_system_header)
-		warning ("concatenation of string literals with __FUNCTION__ is deprecated.  This feature will be removed in future"); 
-	    }
-	}
-
-      /* If anything is wide, the non-wides will be converted,
-	 which makes them take more space.  */
-      if (wide_flag)
-	length = length * wchar_bytes + wide_length;
-
-      p = alloca (length);
-
-      /* Copy the individual strings into the new combined string.
-	 If the combined string is wide, convert the chars to ints
-	 for any individual strings that are not wide.  */
-
-      q = p;
-      for (t = strings; t; t = TREE_CHAIN (t))
-	{
-	  int len = (TREE_STRING_LENGTH (t)
-		     - ((TREE_TYPE (t) == wchar_array_type_node)
-			? wchar_bytes : 1));
-	  if ((TREE_TYPE (t) == wchar_array_type_node) == wide_flag)
-	    {
-	      memcpy (q, TREE_STRING_POINTER (t), len);
-	      q += len;
-	    }
-	  else
-	    {
-	      int i, j;
-	      for (i = 0; i < len; i++)
-		{
-		  if (BYTES_BIG_ENDIAN)
-		    {
-		      for (j=0; j<(WCHAR_TYPE_SIZE / BITS_PER_UNIT)-1; j++)
-			*q++ = 0;
-		      *q++ = TREE_STRING_POINTER (t)[i];
-		    }
-		  else
-		    {
-		      *q++ = TREE_STRING_POINTER (t)[i];
-		      for (j=0; j<(WCHAR_TYPE_SIZE / BITS_PER_UNIT)-1; j++)
-			*q++ = 0;
-		    }
-		}
-	    }
-	}
-      if (wide_flag)
-	{
-	  int i;
-	  for (i = 0; i < wchar_bytes; i++)
-	    *q++ = 0;
-	}
-      else
-	*q = 0;
-
-      value = build_string (length, p);
-    }
-  else
-    {
-      value = strings;
-      length = TREE_STRING_LENGTH (value);
-      if (TREE_TYPE (value) == wchar_array_type_node)
-	wide_flag = 1;
-    }
+  int length = TREE_STRING_LENGTH (value);
+  int nchars;
 
   /* Compute the number of elements, for the array type.  */
   nchars = wide_flag ? length / wchar_bytes : length;
@@ -813,6 +725,111 @@ combine_strings (strings)
   TREE_STATIC (value) = 1;
   return value;
 }
+
+/* Given a VARRAY of STRING_CST nodes, concatenate them into one
+   STRING_CST.  */
+
+tree
+combine_strings (strings)
+     varray_type strings;
+{
+  const int wchar_bytes = TYPE_PRECISION (wchar_type_node) / BITS_PER_UNIT;
+  const int nstrings = VARRAY_ACTIVE_SIZE (strings);
+  tree value, t;
+  int length = 1;
+  int wide_length = 0;
+  int wide_flag = 0;
+  int i;
+  char *p, *q;
+
+  /* Don't include the \0 at the end of each substring.  Count wide
+     strings and ordinary strings separately.  */
+  for (i = 0; i < nstrings; ++i)
+    {
+      t = VARRAY_TREE (strings, i);
+
+      if (TREE_TYPE (t) == wchar_array_type_node)
+	{
+	  wide_length += TREE_STRING_LENGTH (t) - wchar_bytes;
+	  wide_flag = 1;
+	}
+      else
+	{
+	  length += (TREE_STRING_LENGTH (t) - 1);
+	  if (C_ARTIFICIAL_STRING_P (t) && !in_system_header)
+	    warning ("concatenation of string literals with __FUNCTION__ is deprecated"); 
+	}
+    }
+
+  /* If anything is wide, the non-wides will be converted,
+     which makes them take more space.  */
+  if (wide_flag)
+    length = length * wchar_bytes + wide_length;
+
+  p = xmalloc (length);
+
+  /* Copy the individual strings into the new combined string.
+     If the combined string is wide, convert the chars to ints
+     for any individual strings that are not wide.  */
+
+  q = p;
+  for (i = 0; i < nstrings; ++i)
+    {
+      int len, this_wide;
+
+      t = VARRAY_TREE (strings, i);
+      this_wide = TREE_TYPE (t) == wchar_array_type_node;
+      len = TREE_STRING_LENGTH (t) - (this_wide ? wchar_bytes : 1);
+      if (this_wide == wide_flag)
+	{
+	  memcpy (q, TREE_STRING_POINTER (t), len);
+	  q += len;
+	}
+      else
+	{
+	  const int nzeros = (WCHAR_TYPE_SIZE / BITS_PER_UNIT) - 1;
+	  int j, k;
+
+	  if (BYTES_BIG_ENDIAN)
+	    {
+	      for (k = 0; k < len; k++)
+		{
+		  for (j = 0; j < nzeros; j++)
+		    *q++ = 0;
+		  *q++ = TREE_STRING_POINTER (t)[k];
+		}
+	    }
+	  else
+	    {
+	      for (k = 0; k < len; k++)
+		{
+		  *q++ = TREE_STRING_POINTER (t)[k];
+		  for (j = 0; j < nzeros; j++)
+		    *q++ = 0;
+		}
+	    }
+	}
+    }
+
+  /* Nul terminate the string.  */
+  if (wide_flag)
+    {
+      for (i = 0; i < wchar_bytes; i++)
+	*q++ = 0;
+    }
+  else
+    *q = 0;
+
+  value = build_string (length, p);
+  free (p);
+
+  if (wide_flag)
+    TREE_TYPE (value) = wchar_array_type_node;
+  else
+    TREE_TYPE (value) = char_array_type_node;
+
+  return value;
+}
 
 static int is_valid_printf_arglist PARAMS ((tree));
 static rtx c_expand_builtin PARAMS ((tree, rtx, enum machine_mode, enum expand_modifier));
@@ -4058,7 +4075,7 @@ c_expand_builtin_printf (arglist, target, tmode, modifier, ignore, unlocked)
 	  memcpy (newstr, TREE_STRING_POINTER (stripped_string), newlen - 1);
 	  newstr[newlen - 1] = 0;
 	  
-	  arglist = combine_strings (build_string (newlen, newstr));
+	  arglist = fix_string_type (build_string (newlen, newstr));
 	  arglist = build_tree_list (NULL_TREE, arglist);
 	  fn = fn_puts;
 	}

gcc/c-common.h

@@ -530,12 +530,13 @@ extern tree c_expand_expr_stmt			PARAMS ((tree));
 extern void c_expand_start_cond			PARAMS ((tree, int, tree));
 extern void c_finish_then                       PARAMS ((void));
 extern void c_expand_start_else			PARAMS ((void));
-extern void c_finish_else                   PARAMS ((void));
+extern void c_finish_else			PARAMS ((void));
 extern void c_expand_end_cond			PARAMS ((void));
 /* Validate the expression after `case' and apply default promotions.  */
 extern tree check_case_value			PARAMS ((tree));
-/* Concatenate a list of STRING_CST nodes into one STRING_CST.  */
-extern tree combine_strings			PARAMS ((tree));
+extern tree fix_string_type			PARAMS ((tree));
+struct varray_head_tag;
+extern tree combine_strings		PARAMS ((struct varray_head_tag *));
 extern void constant_expression_warning		PARAMS ((tree));
 extern tree convert_and_check			PARAMS ((tree, tree));
 extern void overflow_warning			PARAMS ((tree));

gcc/c-parse.in

@@ -181,7 +181,7 @@ do {									\
 %type <ttype> BREAK CONTINUE RETURN GOTO ASM_KEYWORD SIZEOF TYPEOF ALIGNOF
 
 %type <ttype> identifier IDENTIFIER TYPENAME CONSTANT expr nonnull_exprlist exprlist
-%type <ttype> expr_no_commas cast_expr unary_expr primary string STRING
+%type <ttype> expr_no_commas cast_expr unary_expr primary STRING
 %type <ttype> declspecs_nosc_nots_nosa_noea declspecs_nosc_nots_nosa_ea
 %type <ttype> declspecs_nosc_nots_sa_noea declspecs_nosc_nots_sa_ea
 %type <ttype> declspecs_nosc_ts_nosa_noea declspecs_nosc_ts_nosa_ea
@@ -329,6 +329,7 @@ end ifc
 static void yyprint	  PARAMS ((FILE *, int, YYSTYPE));
 static void yyerror	  PARAMS ((const char *));
 static int yylexname	  PARAMS ((void));
+static int yylexstring	  PARAMS ((void));
 static inline int _yylex  PARAMS ((void));
 static int  yylex	  PARAMS ((void));
 static void init_reswords PARAMS ((void));
@@ -658,8 +659,8 @@ primary:
 		  $$ = build_external_ref ($1, yychar == '(');
 		}
 	| CONSTANT
-	| string
-		{ $$ = combine_strings ($1); }
+	| STRING
+		{ $$ = fix_string_type ($$); }
 	| VAR_FUNC_NAME
 		{ $$ = fname_decl (C_RID_CODE ($$), $$); }
 	| '(' typename ')' '{' 
@@ -770,29 +771,6 @@ ifobjc
 end ifobjc
 	;
 
-/* Produces a STRING_CST with perhaps more STRING_CSTs chained onto it.  */
-string:
-	  STRING
-	| string STRING
-		{
-ifc
-                  static int last_lineno = 0;
-                  static const char *last_input_filename = 0;
-end ifc
-                  $$ = chainon ($1, $2);
-ifc
-		  if (warn_traditional && !in_system_header
-		      && (lineno != last_lineno || !last_input_filename ||
-			  strcmp (last_input_filename, input_filename)))
-		    {
-		      warning ("traditional C rejects string concatenation");
-		      last_lineno = lineno;
-		      last_input_filename = input_filename;
-		    }
-end ifc
-		}
-	;
-
 ifobjc
 /* Produces an STRING_CST with perhaps more STRING_CSTs chained
    onto it, which is to be read as an ObjC string object.  */
@@ -1433,10 +1411,8 @@ notype_initdecls:
 maybeasm:
 	  /* empty */
 		{ $$ = NULL_TREE; }
-	| ASM_KEYWORD '(' string ')'
-		{ if (TREE_CHAIN ($3)) $3 = combine_strings ($3);
-		  $$ = $3;
-		}
+	| ASM_KEYWORD '(' STRING ')'
+		{ $$ = $3; }
 	;
 
 initdcl:
@@ -2508,10 +2484,10 @@ asm_operand:
 	;
 
 asm_clobbers:
-	  string
-		{ $$ = tree_cons (NULL_TREE, combine_strings ($1), NULL_TREE); }
-	| asm_clobbers ',' string
-		{ $$ = tree_cons (NULL_TREE, combine_strings ($3), $1); }
+	  STRING
+		{ $$ = tree_cons (NULL_TREE, $1, NULL_TREE); }
+	| asm_clobbers ',' STRING
+		{ $$ = tree_cons (NULL_TREE, $3, $1); }
 	;
 
 /* This is what appears inside the parens in a function declarator.
@@ -3703,6 +3679,59 @@ end ifobjc
   return IDENTIFIER;
 }
 
+/* Concatenate strings before returning them to the parser.  This isn't quite
+   as good as having it done in the lexer, but it's better than nothing.  */
+
+static int
+yylexstring ()
+{
+  enum cpp_ttype next_type;
+  tree orig = yylval.ttype;
+
+  next_type = c_lex (&yylval.ttype);
+  if (next_type == CPP_STRING
+      || next_type == CPP_WSTRING
+      || (next_type == CPP_NAME && yylexname () == STRING))
+    {
+      varray_type strings;
+
+ifc
+      static int last_lineno = 0;
+      static const char *last_input_filename = 0;
+      if (warn_traditional && !in_system_header
+	  && (lineno != last_lineno || !last_input_filename ||
+	      strcmp (last_input_filename, input_filename)))
+	{
+	  warning ("traditional C rejects string concatenation");
+	  last_lineno = lineno;
+	  last_input_filename = input_filename;
+	}
+end ifc
+
+      VARRAY_TREE_INIT (strings, 32, "strings");
+      VARRAY_PUSH_TREE (strings, orig);
+
+      do
+	{
+	  VARRAY_PUSH_TREE (strings, yylval.ttype);
+	  next_type = c_lex (&yylval.ttype);
+	}
+      while (next_type == CPP_STRING
+	     || next_type == CPP_WSTRING
+	     || (next_type == CPP_NAME && yylexname () == STRING));
+
+      yylval.ttype = combine_strings (strings);
+
+      VARRAY_FREE (strings);
+    }
+  else
+    yylval.ttype = orig;
+
+  /* We will have always read one token too many.  */
+  _cpp_backup_tokens (parse_in, 1);
+
+  return STRING;
+}
 
 static inline int
 _yylex ()
@@ -3769,7 +3798,13 @@ _yylex ()
       return 0;
 
     case CPP_NAME:
-      return yylexname ();
+      {
+	int ret = yylexname ();
+	if (ret == STRING)
+	  return yylexstring ();
+	else
+	  return ret;
+      }
 
     case CPP_NUMBER:
     case CPP_CHAR:
@@ -3778,7 +3813,7 @@ _yylex ()
 
     case CPP_STRING:
     case CPP_WSTRING:
-      return STRING;
+      return yylexstring ();
       
       /* This token is Objective-C specific.  It gives the next token
 	 special significance.  */

gcc/c-typeck.c

@@ -6849,8 +6849,6 @@ simple_asm_stmt (expr)
     {
       tree stmt;
 
-      if (TREE_CHAIN (expr))
-	expr = combine_strings (expr);
       stmt = add_stmt (build_stmt (ASM_STMT, NULL_TREE, expr,
 				   NULL_TREE, NULL_TREE,
 				   NULL_TREE));
@@ -6875,8 +6873,6 @@ build_asm_stmt (cv_qualifier, string, outputs, inputs, clobbers)
 {
   tree tail;
 
-  if (TREE_CHAIN (string))
-    string = combine_strings (string);
   if (TREE_CODE (string) != STRING_CST)
     {
       error ("asm template is not a string constant");

gcc/cp/ChangeLog

+2002-04-26  Richard Henderson  <rth@redhat.com>
+
+	PR c/3581
+	* parse.y (string): Remove.  Update all uses to use STRING
+	instead, and not call combine_strings.
+	* rtti.c (tinfo_name): Use fix_string_type.
+	* semantics.c (finish_asm_stmt): Don't call combine_strings.
+	* spew.c (yylexstring): New.
+	(read_token): Use it.
+
 2002-04-25  Richard Henderson  <rth@redhat.com>
 
 	PR c/2161

gcc/cp/parse.y

@@ -378,7 +378,7 @@ cp_parse_init ()
 %type <ttype> PFUNCNAME maybe_identifier
 %type <ttype> paren_expr_or_null nontrivial_exprlist SELFNAME
 %type <ttype> expr_no_commas expr_no_comma_rangle
-%type <ttype> cast_expr unary_expr primary string STRING
+%type <ttype> cast_expr unary_expr primary STRING
 %type <ttype> reserved_declspecs boolean.literal
 %type <ttype> reserved_typespecquals
 %type <ttype> SCSPEC TYPESPEC CV_QUALIFIER maybe_cv_qualifier
@@ -543,9 +543,8 @@ extdef:
 		{ do_pending_inlines (); }
 	| template_def
 		{ do_pending_inlines (); }
-	| asm_keyword '(' string ')' ';'
-		{ if (TREE_CHAIN ($3)) $3 = combine_strings ($3);
-		  assemble_asm ($3); }
+	| asm_keyword '(' STRING ')' ';'
+		{ assemble_asm ($3); }
 	| extern_lang_string '{' extdefs_opt '}'
 		{ pop_lang_context (); }
 	| extern_lang_string .hush_warning fndef .warning_ok eat_saved_input
@@ -1608,10 +1607,10 @@ primary:
 		}		
 	| CONSTANT
 	| boolean.literal
-	| string
+	| STRING
 		{
-		  $$ = combine_strings ($$);
-		  /* combine_strings doesn't set up TYPE_MAIN_VARIANT of
+		  $$ = fix_string_type ($$);
+		  /* fix_string_type doesn't set up TYPE_MAIN_VARIANT of
 		     a const array the way we want, so fix it.  */
 		  if (flag_const_strings)
 		    TREE_TYPE ($$) = build_cplus_array_type
@@ -1812,13 +1811,6 @@ boolean.literal:
 		{ $$ = boolean_false_node; }
 	;
 
-/* Produces a STRING_CST with perhaps more STRING_CSTs chained onto it.  */
-string:
-	  STRING
-	| string STRING
-		{ $$ = chainon ($$, $2); }
-	;
-
 nodecls:
 	  /* empty */
 		{
@@ -2098,8 +2090,8 @@ nomods_initdecls:
 maybeasm:
 	  /* empty */
 		{ $$ = NULL_TREE; }
-	| asm_keyword '(' string ')'
-		{ if (TREE_CHAIN ($3)) $3 = combine_strings ($3); $$ = $3; }
+	| asm_keyword '(' STRING ')'
+		{ $$ = $3; }
 	;
 
 initdcl:
@@ -3494,27 +3486,27 @@ simple_stmt:
                 { $$ = finish_return_stmt (NULL_TREE); }
 	| RETURN_KEYWORD expr ';'
                 { $$ = finish_return_stmt ($2); }
-	| asm_keyword maybe_cv_qualifier '(' string ')' ';'
+	| asm_keyword maybe_cv_qualifier '(' STRING ')' ';'
 		{ $$ = finish_asm_stmt ($2, $4, NULL_TREE, NULL_TREE,
 					NULL_TREE);
 		  ASM_INPUT_P ($$) = 1; }
 	/* This is the case with just output operands.  */
-	| asm_keyword maybe_cv_qualifier '(' string ':' asm_operands ')' ';'
+	| asm_keyword maybe_cv_qualifier '(' STRING ':' asm_operands ')' ';'
 		{ $$ = finish_asm_stmt ($2, $4, $6, NULL_TREE, NULL_TREE); }
 	/* This is the case with input operands as well.  */
-	| asm_keyword maybe_cv_qualifier '(' string ':' asm_operands ':'
+	| asm_keyword maybe_cv_qualifier '(' STRING ':' asm_operands ':'
 	  asm_operands ')' ';'
 		{ $$ = finish_asm_stmt ($2, $4, $6, $8, NULL_TREE); }
-	| asm_keyword maybe_cv_qualifier '(' string SCOPE asm_operands ')' ';'
+	| asm_keyword maybe_cv_qualifier '(' STRING SCOPE asm_operands ')' ';'
 		{ $$ = finish_asm_stmt ($2, $4, NULL_TREE, $6, NULL_TREE); }
 	/* This is the case with clobbered registers as well.  */
-	| asm_keyword maybe_cv_qualifier '(' string ':' asm_operands ':'
+	| asm_keyword maybe_cv_qualifier '(' STRING ':' asm_operands ':'
 	  asm_operands ':' asm_clobbers ')' ';'
 		{ $$ = finish_asm_stmt ($2, $4, $6, $8, $10); }
-	| asm_keyword maybe_cv_qualifier '(' string SCOPE asm_operands ':'
+	| asm_keyword maybe_cv_qualifier '(' STRING SCOPE asm_operands ':'
 	  asm_clobbers ')' ';'
 		{ $$ = finish_asm_stmt ($2, $4, NULL_TREE, $6, $8); }
-	| asm_keyword maybe_cv_qualifier '(' string ':' asm_operands SCOPE
+	| asm_keyword maybe_cv_qualifier '(' STRING ':' asm_operands SCOPE
 	  asm_clobbers ')' ';'
 		{ $$ = finish_asm_stmt ($2, $4, $6, NULL_TREE, $8); }
 	| GOTO '*' expr ';'
@@ -3677,10 +3669,10 @@ asm_operand:
 	;
 
 asm_clobbers:
-	  string
-		{ $$ = tree_cons (NULL_TREE, combine_strings ($1), NULL_TREE);}
-	| asm_clobbers ',' string
-		{ $$ = tree_cons (NULL_TREE, combine_strings ($3), $1); }
+	  STRING
+		{ $$ = tree_cons (NULL_TREE, $1, NULL_TREE);}
+	| asm_clobbers ',' STRING
+		{ $$ = tree_cons (NULL_TREE, $3, $1); }
 	;
 
 /* This is what appears inside the parens in a function declarator.

gcc/cp/rtti.c

@@ -259,7 +259,7 @@ tinfo_name (type)
   tree name_string;
 
   name = mangle_type_string (type);
-  name_string = combine_strings (build_string (strlen (name) + 1, name));
+  name_string = fix_string_type (build_string (strlen (name) + 1, name));
   return name_string;
 }
 

gcc/cp/semantics.c

@@ -863,9 +863,6 @@ finish_asm_stmt (cv_qualifier, string, output_operands,
   tree r;
   tree t;
 
-  if (TREE_CHAIN (string))
-    string = combine_strings (string);
-
   if (cv_qualifier != NULL_TREE
       && cv_qualifier != ridpointers[(int) RID_VOLATILE])
     {

gcc/cp/spew.c

@@ -102,6 +102,7 @@ static SPEW_INLINE int identifier_type PARAMS ((tree));
 static void scan_tokens PARAMS ((int));
 static void feed_defarg PARAMS ((tree));
 static void finish_defarg PARAMS ((void));
+static void yylexstring PARAMS ((struct token *));
 static int read_token PARAMS ((struct token *));
 
 static SPEW_INLINE int num_tokens PARAMS ((void));
@@ -242,6 +243,43 @@ read_process_identifier (pyylval)
   return IDENTIFIER;
 }
 
+/* Concatenate strings before returning them to the parser.  This isn't quite
+   as good as having it done in the lexer, but it's better than nothing.  */
+
+static void
+yylexstring (t)
+     struct token *t;
+{
+  enum cpp_ttype next_type;
+  tree next;
+
+  next_type = c_lex (&next);
+  if (next_type == CPP_STRING || next_type == CPP_WSTRING)
+    {
+      varray_type strings;
+
+      VARRAY_TREE_INIT (strings, 32, "strings");
+      VARRAY_PUSH_TREE (strings, t->yylval.ttype);
+
+      do
+	{
+	  VARRAY_PUSH_TREE (strings, next);
+	  next_type = c_lex (&next);
+	}
+      while (next_type == CPP_STRING || next_type == CPP_WSTRING);
+
+      t->yylval.ttype = combine_strings (strings);
+      last_token_id = t->yylval.ttype;
+
+      VARRAY_FREE (strings);
+    }
+
+  /* We will have always read one token too many.  */
+  _cpp_backup_tokens (parse_in, 1);
+
+  t->yychar = STRING;
+}
+
 /* Read the next token from the input file.  The token is written into
    T, and its type number is returned.  */
 static int
@@ -336,7 +374,7 @@ read_token (t)
 
     case CPP_STRING:
     case CPP_WSTRING:
-      t->yychar = STRING;
+      yylexstring (t);
       break;
 
     default:

gcc/objc/objc-act.c

@@ -1201,21 +1201,7 @@ my_build_string (len, str)
      int len;
      const char *str;
 {
-  int wide_flag = 0;
-  tree a_string = build_string (len, str);
-
-  /* Some code from combine_strings, which is local to c-parse.y.  */
-  if (TREE_TYPE (a_string) == int_array_type_node)
-    wide_flag = 1;
-
-  TREE_TYPE (a_string)
-    = build_array_type (wide_flag ? integer_type_node : char_type_node,
-			build_index_type (build_int_2 (len - 1, 0)));
-
-  TREE_CONSTANT (a_string) = 1;	/* Puts string in the readonly segment */
-  TREE_STATIC (a_string) = 1;
-
-  return a_string;
+  return fix_string_type (build_string (len, str));
 }
 
 /* Given a chain of STRING_CST's, build a static instance of
@@ -1241,7 +1227,23 @@ build_objc_string_object (strings)
 
   add_class_reference (constant_string_id);
 
-  string = combine_strings (strings);
+  if (TREE_CHAIN (strings))
+    {
+      varray_type vstrings;
+      VARRAY_TREE_INIT (vstrings, 32, "strings");
+
+      for (; strings ; strings = TREE_CHAIN (strings))
+	VARRAY_PUSH_TREE (vstrings, strings);
+
+      string = combine_strings (vstrings);
+
+      VARRAY_FREE (vstrings);
+    }
+  else
+    string = strings;
+
+  string = fix_string_type (string);
+
   TREE_SET_CODE (string, STRING_CST);
   length = TREE_STRING_LENGTH (string) - 1;
 

gcc/testsuite/g++.dg/parse/concat1.C

+/* PR c/3581 */
+/* { dg-do compile } */
+
+/* Intended as a compile-time test for string literal concatenation.
+   The fact that the string isn't actually used in the resulting program
+   should allow this to compile for any target.  */
+
+#define e0	"a"
+#define e1	e0 e0 e0 e0 e0 e0 e0 e0 e0 e0
+#define e2	e1 e1 e1 e1 e1 e1 e1 e1 e1 e1
+#define e3	e2 e2 e2 e2 e2 e2 e2 e2 e2 e2
+#define e4	e3 e3 e3 e3 e3 e3 e3 e3 e3 e3
+#define e5	e4 e4 e4 e4 e4 e4 e4 e4 e4 e4
+
+void foo() { (void)(e5); }

gcc/testsuite/gcc.dg/concat2.c

+/* PR c/3581 */
+/* { dg-do compile } */
+/* { dg-options "" } */
+
+/* Intended as a compile-time test for string literal concatenation.
+   The fact that the string isn't actually used in the resulting program
+   should allow this to compile for any target.  */
+
+#define e0	"a"
+#define e1	e0 e0 e0 e0 e0 e0 e0 e0 e0 e0
+#define e2	e1 e1 e1 e1 e1 e1 e1 e1 e1 e1
+#define e3	e2 e2 e2 e2 e2 e2 e2 e2 e2 e2
+#define e4	e3 e3 e3 e3 e3 e3 e3 e3 e3 e3
+#define e5	e4 e4 e4 e4 e4 e4 e4 e4 e4 e4
+
+void foo() { (void)(e5); }