2007-05-21 Paul Thomas <pault@gcc.gnu.org>

[pf3gnuchains/gcc-fork.git] / libcpp / directives.c

diff --git a/libcpp/directives.c b/libcpp/directives.c
index 2ef914a..ccb9f32 100644 (file)
--- a/libcpp/directives.c
+++ b/libcpp/directives.c
@@ -103,7 +103,7 @@ static void push_conditional (cpp_reader *, int, int, const cpp_hashnode *);
 static unsigned int read_flag (cpp_reader *, unsigned int);
 static int strtoul_for_line (const uchar *, unsigned int, unsigned long *);
 static void do_diagnostic (cpp_reader *, int, int);
-static cpp_hashnode *lex_macro_node (cpp_reader *);
+static cpp_hashnode *lex_macro_node (cpp_reader *, bool);
 static int undefine_macros (cpp_reader *, cpp_hashnode *, void *);
 static void do_include_common (cpp_reader *, enum include_type);
 static struct pragma_entry *lookup_pragma_entry (struct pragma_entry *,
@@ -503,9 +503,11 @@ run_directive (cpp_reader *pfile, int dir_no, const char *buf, size_t count)
 }
 
 /* Checks for validity the macro name in #define, #undef, #ifdef and
-   #ifndef directives.  */
+   #ifndef directives.  IS_DEF_OR_UNDEF is true if this call is
+   processing a #define or #undefine directive, and false
+   otherwise.  */
 static cpp_hashnode *
-lex_macro_node (cpp_reader *pfile)
+lex_macro_node (cpp_reader *pfile, bool is_def_or_undef)
 {
   const cpp_token *token = _cpp_lex_token (pfile);
 
@@ -520,7 +522,7 @@ lex_macro_node (cpp_reader *pfile)
     {
       cpp_hashnode *node = token->val.node;
 
-      if (node == pfile->spec_nodes.n_defined)
+      if (is_def_or_undef && node == pfile->spec_nodes.n_defined)
        cpp_error (pfile, CPP_DL_ERROR,
                   "\"defined\" cannot be used as a macro name");
       else if (! (node->flags & NODE_POISONED))
@@ -543,7 +545,7 @@ lex_macro_node (cpp_reader *pfile)
 static void
 do_define (cpp_reader *pfile)
 {
-  cpp_hashnode *node = lex_macro_node (pfile);
+  cpp_hashnode *node = lex_macro_node (pfile, true);
 
   if (node)
     {
@@ -562,7 +564,7 @@ do_define (cpp_reader *pfile)
 static void
 do_undef (cpp_reader *pfile)
 {
-  cpp_hashnode *node = lex_macro_node (pfile);
+  cpp_hashnode *node = lex_macro_node (pfile, true);
 
   if (node)
     {
@@ -1606,7 +1608,7 @@ do_ifdef (cpp_reader *pfile)
 
   if (! pfile->state.skipping)
     {
-      const cpp_hashnode *node = lex_macro_node (pfile);
+      const cpp_hashnode *node = lex_macro_node (pfile, false);
 
       if (node)
        {
@@ -1628,7 +1630,7 @@ do_ifndef (cpp_reader *pfile)
 
   if (! pfile->state.skipping)
     {
-      node = lex_macro_node (pfile);
+      node = lex_macro_node (pfile, false);
 
       if (node)
        {
@@ -2076,6 +2078,65 @@ cpp_undef (cpp_reader *pfile, const char *macro)
   run_directive (pfile, T_UNDEF, buf, len);
 }
 
+/* Like lex_macro_node, but read the input from STR.  */
+static cpp_hashnode *
+lex_macro_node_from_str (cpp_reader *pfile, const char *str)
+{
+  size_t len = strlen (str);
+  uchar *buf = (uchar *) alloca (len + 1);
+  cpp_hashnode *node;
+
+  memcpy (buf, str, len);
+  buf[len] = '\n';
+  cpp_push_buffer (pfile, buf, len, true);
+  node = lex_macro_node (pfile, true);
+  _cpp_pop_buffer (pfile);
+
+  return node;
+}
+
+/* If STR is a defined macro, return its definition node, else return NULL.  */
+cpp_macro *
+cpp_push_definition (cpp_reader *pfile, const char *str)
+{
+  cpp_hashnode *node = lex_macro_node_from_str (pfile, str);
+  if (node && node->type == NT_MACRO)
+    return node->value.macro;
+  else
+    return NULL;
+}
+
+/* Replace a previous definition DFN of the macro STR.  If DFN is NULL,
+   then the macro should be undefined.  */
+void
+cpp_pop_definition (cpp_reader *pfile, const char *str, cpp_macro *dfn)
+{
+  cpp_hashnode *node = lex_macro_node_from_str (pfile, str);
+  if (node == NULL)
+    return;
+
+  if (node->type == NT_MACRO)
+    {
+      if (pfile->cb.undef)
+       pfile->cb.undef (pfile, pfile->directive_line, node);
+      if (CPP_OPTION (pfile, warn_unused_macros))
+       _cpp_warn_if_unused_macro (pfile, node, NULL);
+    }
+  if (node->type != NT_VOID)
+    _cpp_free_definition (node);
+
+  if (dfn)
+    {
+      node->type = NT_MACRO;
+      node->value.macro = dfn;
+      if (! ustrncmp (NODE_NAME (node), DSC ("__STDC_")))
+       node->flags |= NODE_WARN;
+
+      if (pfile->cb.define)
+       pfile->cb.define (pfile, pfile->directive_line, node);
+    }
+}
+
 /* Process the string STR as if it appeared as the body of a #assert.  */
 void
 cpp_assert (cpp_reader *pfile, const char *str)