PR macros/13205:

* macrotab.h: (macro_define_special): Declare.
	(enum macro_special_kind): New.
	(struct macro_definition) <argc, replacement>: Update comments.
	* macrotab.c (new_macro_definition): Unconditionally set 'argc'.
	(macro_define_object_internal): New function.
	(macro_define_object): Use it.
	(macro_define_special): New function.
	(fixup_definition): New function.
	(macro_lookup_definition, foreach_macro_in_scope)
	(foreach_macro): Use fixup_definition.
	* macroexp.h (macro_stringify): Declare.
	* macroexp.c (free_buffer_return_text): New function.
	(stringify): Constify "arg".
	(macro_stringify): New function.
	* dwarf2read.c (macro_start_file): Call macro_define_special.
testsuite
	* gdb.base/macscp1.c (macscp_expr): Add comment.
	* gdb.base/macscp.exp: Test __FILE__ and __LINE__.

gdb/macrotab.c

@@ -28,6 +28,7 @@
 #include "gdb_assert.h"
 #include "bcache.h"
 #include "complaints.h"
+#include "macroexp.h"
 
 
 /* The macro table structure.  */
@@ -565,6 +566,7 @@ new_macro_definition (struct macro_table *t,
   d->table = t;
   d->kind = kind;
   d->replacement = macro_bcache_str (t, replacement);
+  d->argc = argc;
 
   if (kind == macro_function_like)
     {
@@ -579,7 +581,6 @@ new_macro_definition (struct macro_table *t,
 
       /* Now bcache the array of argument pointers itself.  */
       d->argv = macro_bcache (t, cached_argv, cached_argv_size);
-      d->argc = argc;
     }
 
   /* We don't bcache the entire definition structure because it's got
@@ -742,10 +743,12 @@ check_for_redefinition (struct macro_source_file *source, int line,
     return 0;
 }
 
+/* A helper function to define a new object-like macro.  */
 
-void
-macro_define_object (struct macro_source_file *source, int line,
-                     const char *name, const char *replacement)
+static void
+macro_define_object_internal (struct macro_source_file *source, int line,
+			      const char *name, const char *replacement,
+			      enum macro_special_kind kind)
 {
   struct macro_table *t = source->table;
   struct macro_key *k = NULL;
@@ -771,10 +774,28 @@ macro_define_object (struct macro_source_file *source, int line,
     return;
 
   k = new_macro_key (t, name, source, line);
-  d = new_macro_definition (t, macro_object_like, 0, 0, replacement);
+  d = new_macro_definition (t, macro_object_like, kind, 0, replacement);
   splay_tree_insert (t->definitions, (splay_tree_key) k, (splay_tree_value) d);
 }
 
+void
+macro_define_object (struct macro_source_file *source, int line,
+		     const char *name, const char *replacement)
+{
+  macro_define_object_internal (source, line, name, replacement,
+				macro_ordinary);
+}
+
+/* See macrotab.h.  */
+
+void
+macro_define_special (struct macro_table *table)
+{
+  macro_define_object_internal (table->main_source, -1, "__FILE__", "",
+				macro_FILE);
+  macro_define_object_internal (table->main_source, -1, "__LINE__", "",
+				macro_LINE);
+}
 
 void
 macro_define_function (struct macro_source_file *source, int line,
@@ -859,6 +880,36 @@ macro_undef (struct macro_source_file *source, int line,
     }
 }
 
+/* A helper function that rewrites the definition of a special macro,
+   when needed.  */
+
+static struct macro_definition *
+fixup_definition (const char *filename, int line, struct macro_definition *def)
+{
+  static char *saved_expansion;
+
+  if (saved_expansion)
+    {
+      xfree (saved_expansion);
+      saved_expansion = NULL;
+    }
+
+  if (def->kind == macro_object_like)
+    {
+      if (def->argc == macro_FILE)
+	{
+	  saved_expansion = macro_stringify (filename);
+	  def->replacement = saved_expansion;
+	}
+      else if (def->argc == macro_LINE)
+	{
+	  saved_expansion = xstrprintf ("%d", line);
+	  def->replacement = saved_expansion;
+	}
+    }
+
+  return def;
+}
 
 struct macro_definition *
 macro_lookup_definition (struct macro_source_file *source,
@@ -867,7 +918,8 @@ macro_lookup_definition (struct macro_source_file *source,
   splay_tree_node n = find_definition (name, source, line);
 
   if (n)
-    return (struct macro_definition *) n->value;
+    return fixup_definition (source->filename, line,
+			     (struct macro_definition *) n->value);
   else
     return 0;
 }
@@ -910,7 +962,9 @@ foreach_macro (splay_tree_node node, void *arg)
 {
   struct macro_for_each_data *datum = (struct macro_for_each_data *) arg;
   struct macro_key *key = (struct macro_key *) node->key;
-  struct macro_definition *def = (struct macro_definition *) node->value;
+  struct macro_definition *def
+    = fixup_definition (key->start_file->filename, key->start_line,
+			(struct macro_definition *) node->value);
 
   (*datum->fn) (key->name, def, key->start_file, key->start_line,
 		datum->user_data);
@@ -936,7 +990,9 @@ foreach_macro_in_scope (splay_tree_node node, void *info)
 {
   struct macro_for_each_data *datum = (struct macro_for_each_data *) info;
   struct macro_key *key = (struct macro_key *) node->key;
-  struct macro_definition *def = (struct macro_definition *) node->value;
+  struct macro_definition *def
+    = fixup_definition (datum->file->filename, datum->line,
+			(struct macro_definition *) node->value);
 
   /* See if this macro is defined before the passed-in line, and
      extends past that line.  */