re PR c++/17577 (#pragma implementation no longer diagnoses use after file to which it applies)

gcc/cp
	PR c++/17577:
	* lex.c (handle_pragma_implementation): Use cpp_included_before.
gcc/testsuite
	PR c++/17577:
	* g++.dg/ext/pr17577.h: New file.
	* g++.dg/ext/pr17577.C: New file.
libcpp
	PR c++/17557:
	* include/cpplib.h (cpp_included_before): Declare.
	* files.c (struct file_hash_entry) <location>: New field.
	(_cpp_find_file): Initialize new field.
	(make_cpp_dir): Likewise.
	(cpp_included_before): New function.

From-SVN: r130093

1 files changed, 24 insertions, 0 deletions

diff --git a/libcpp/files.c b/libcpp/files.c
index 73f88bb3cde..ae2f2945d9e 100644
--- a/libcpp/files.c
+++ b/libcpp/files.c
@@ -142,6 +142,7 @@ struct file_hash_entry
 {
   struct file_hash_entry *next;
   cpp_dir *start_dir;
+  source_location location;
   union
   {
     _cpp_file *file;
@@ -521,6 +522,7 @@ _cpp_find_file (cpp_reader *pfile, const char *fname, cpp_dir *start_dir, bool f
   entry = new_file_hash_entry (pfile);
   entry->next = *hash_slot;
   entry->start_dir = start_dir;
+  entry->location = pfile->line_table->highest_location;
   entry->u.file = file;
   *hash_slot = entry;
 
@@ -533,6 +535,7 @@ _cpp_find_file (cpp_reader *pfile, const char *fname, cpp_dir *start_dir, bool f
       entry = new_file_hash_entry (pfile);
       entry->next = *hash_slot;
       entry->start_dir = pfile->bracket_include;
+      entry->location = pfile->line_table->highest_location;
       entry->u.file = file;
       *hash_slot = entry;
     }
@@ -543,6 +546,7 @@ _cpp_find_file (cpp_reader *pfile, const char *fname, cpp_dir *start_dir, bool f
       entry = new_file_hash_entry (pfile);
       entry->next = *hash_slot;
       entry->start_dir = pfile->quote_include;
+      entry->location = pfile->line_table->highest_location;
       entry->u.file = file;
       *hash_slot = entry;
     }
@@ -993,6 +997,7 @@ make_cpp_dir (cpp_reader *pfile, const char *dir_name, int sysp)
   entry = new_file_hash_entry (pfile);
   entry->next = *hash_slot;
   entry->start_dir = NULL;
+  entry->location = pfile->line_table->highest_location;
   entry->u.dir = dir;
   *hash_slot = entry;
 
@@ -1036,6 +1041,25 @@ cpp_included (cpp_reader *pfile, const char *fname)
   return entry != NULL;
 }
 
+/* Returns TRUE if a file FNAME has ever been successfully opened
+   before LOCATION.  This routine is not intended to correctly handle
+   filenames aliased by links or redundant . or .. traversals etc.  */
+bool
+cpp_included_before (cpp_reader *pfile, const char *fname,
+		     source_location location)
+{
+  struct file_hash_entry *entry;
+
+  entry = (struct file_hash_entry *)
+     htab_find_with_hash (pfile->file_hash, fname, htab_hash_string (fname));
+
+  while (entry && (entry->start_dir == NULL || entry->u.file->err_no
+		   || entry->location > location))
+    entry = entry->next;
+
+  return entry != NULL;
+}
+
 /* Calculate the hash value of a file hash entry P.  */
 
 static hashval_t