re PR c++/24009 (C++ fails to print #include stack)

	PR c++/24009
	* input.h (restore_input_file_stack): Declare.
	(INPUT_FILE_STACK_BITS): Define.
	* toplev.c (fs_p, input_file_stack_history,
	input_file_stack_restored, restore_input_file_stack): New.
	(push_srcloc, pop_srcloc): Check for input_file_stack_tick
	overflowing INPUT_FILE_STACK_BITS bits.  Save new state of stack.
	(pop_srcloc): Don't free old state of stack.

cp:
	* parser.c (struct cp_token): Add input_file_stack_index.
	(eof_token): Update.
	(cp_lexer_get_preprocessor_token): Save input_file_stack_tick.
	(cp_lexer_set_source_position_from_token): Restore input file
	stack.

From-SVN: r116479

1 files changed, 35 insertions, 1 deletions

diff --git a/gcc/toplev.c b/gcc/toplev.c
index 55019ed..53fcdfe 100644
--- a/gcc/toplev.c
+++ b/gcc/toplev.c
@@ -164,6 +164,16 @@ struct file_stack *input_file_stack;
 /* Incremented on each change to input_file_stack.  */
 int input_file_stack_tick;
 
+/* Record of input_file_stack at each tick.  */
+typedef struct file_stack *fs_p;
+DEF_VEC_P(fs_p);
+DEF_VEC_ALLOC_P(fs_p,heap);
+static VEC(fs_p,heap) *input_file_stack_history;
+
+/* Whether input_file_stack has been restored to a previous state (in
+   which case there should be no more pushing).  */
+static bool input_file_stack_restored;
+
 /* Name to use as base of names for dump output files.  */
 
 const char *dump_base_name;
@@ -951,6 +961,10 @@ push_srcloc (const char *file, int line)
 {
   struct file_stack *fs;
 
+  gcc_assert (!input_file_stack_restored);
+  if (input_file_stack_tick == (int) ((1U << INPUT_FILE_STACK_BITS) - 1))
+    sorry ("GCC supports only %d input file changes", input_file_stack_tick);
+
   fs = XNEW (struct file_stack);
   fs->location = input_location;
   fs->next = input_file_stack;
@@ -962,6 +976,7 @@ push_srcloc (const char *file, int line)
 #endif
   input_file_stack = fs;
   input_file_stack_tick++;
+  VEC_safe_push (fs_p, heap, input_file_stack_history, input_file_stack);
 }
 
 /* Pop the top entry off the stack of presently open source files.
@@ -973,11 +988,30 @@ pop_srcloc (void)
 {
   struct file_stack *fs;
 
+  gcc_assert (!input_file_stack_restored);
+  if (input_file_stack_tick == (int) ((1U << INPUT_FILE_STACK_BITS) - 1))
+    sorry ("GCC supports only %d input file changes", input_file_stack_tick);
+
   fs = input_file_stack;
   input_location = fs->location;
   input_file_stack = fs->next;
-  free (fs);
   input_file_stack_tick++;
+  VEC_safe_push (fs_p, heap, input_file_stack_history, input_file_stack);
+}
+
+/* Restore the input file stack to its state as of TICK, for the sake
+   of diagnostics after processing the whole input.  Once this has
+   been called, push_srcloc and pop_srcloc may no longer be
+   called.  */
+void
+restore_input_file_stack (int tick)
+{
+  if (tick == 0)
+    input_file_stack = NULL;
+  else
+    input_file_stack = VEC_index (fs_p, input_file_stack_history, tick - 1);
+  input_file_stack_tick = tick;
+  input_file_stack_restored = true;
 }
 
 /* Compile an entire translation unit.  Write a file of assembly