Backport of GC branch patches part 1: kill eh status saving.

From-SVN: r28357

1 files changed, 62 insertions, 18 deletions

diff --git a/gcc/except.h b/gcc/except.h
index a8c4f9c..2e3e794 100644
--- a/gcc/except.h
+++ b/gcc/except.h
@@ -24,10 +24,6 @@ typedef struct rtx_def *_except_rtx;
 #define rtx _except_rtx
 #endif
 
-/* The label generated by expand_builtin_eh_return.  */
-
-extern rtx eh_return_stub_label;
-
 #ifdef TREE_CODE
 
 /* A stack of labels. CHAIN points to the next entry in the stack.  */
@@ -67,6 +63,10 @@ struct eh_entry {
   rtx false_label;
   rtx rethrow_label;
 };
+#else
+struct label_node;
+struct eh_entry;
+#endif
 
 /* A list of EH_ENTRYs. ENTRY is the entry; CHAIN points to the next
    entry in the list, or is NULL if this is the last entry.  */
@@ -92,6 +92,64 @@ struct eh_queue {
   struct eh_node *tail;
 };
 
+/* Used to save exception handling status for each function.  */
+struct eh_status
+{
+  /* A stack used for keeping track of the currently active exception
+     handling region.  As each exception region is started, an entry
+     describing the region is pushed onto this stack.  The current
+     region can be found by looking at the top of the stack, and as we
+     exit regions, the corresponding entries are popped. 
+
+     Entries cannot overlap; they can be nested. So there is only one
+     entry at most that corresponds to the current instruction, and that
+     is the entry on the top of the stack.  */
+  struct eh_stack x_ehstack;
+  /* This stack is used to represent what the current eh region is
+     for the catch blocks beings processed */
+  struct eh_stack x_catchstack;
+  /* A queue used for tracking which exception regions have closed but
+     whose handlers have not yet been expanded. Regions are emitted in
+     groups in an attempt to improve paging performance.
+
+     As we exit a region, we enqueue a new entry. The entries are then
+     dequeued during expand_leftover_cleanups and expand_start_all_catch,
+
+     We should redo things so that we either take RTL for the handler,
+     or we expand the handler expressed as a tree immediately at region
+     end time.  */
+  struct eh_queue x_ehqueue;
+  /* Insns for all of the exception handlers for the current function.
+     They are currently emitted by the frontend code.  */
+  rtx x_catch_clauses;
+  /* A random data area for the front end's own use.  */
+  struct label_node *x_false_label_stack;
+  /* Keeps track of the label to resume to should one want to resume
+     normal control flow out of a handler (instead of, say, returning to
+     the caller of the current function or exiting the program).  */
+  struct label_node *x_caught_return_label_stack;
+  /* A TREE_CHAINed list of handlers for regions that are not yet
+     closed. The TREE_VALUE of each entry contains the handler for the
+     corresponding entry on the ehstack.  */
+  union tree_node *x_protect_list;
+  /* The EH context.  Nonzero if the function has already
+     fetched a pointer to the EH context  for exception handling.  */
+  rtx ehc;
+  /* The label generated by expand_builtin_eh_return.  */
+  rtx x_eh_return_stub_label;
+};
+
+#define ehstack (current_function->eh->x_ehstack)
+#define catchstack (current_function->eh->x_catchstack)
+#define ehqueue (current_function->eh->x_ehqueue)
+#define catch_clauses (current_function->eh->x_catch_clauses)
+#define false_label_stack (current_function->eh->x_false_label_stack)
+#define caught_return_label_stack (current_function->eh->x_caught_return_label_stack)
+#define protect_list (current_function->eh->x_protect_list)
+#define current_function_ehc (current_function->eh->ehc)
+#define eh_return_stub_label (current_function->eh->x_eh_return_stub_label)
+
+#ifdef TREE_CODE
 /* Start an exception handling region.  All instructions emitted after
    this point are considered to be part of the region until
    expand_eh_region_end () is invoked.  */
@@ -145,11 +203,6 @@ extern rtx pop_label_entry			PROTO((struct label_node **labelstack));
 
 extern tree top_label_entry			PROTO((struct label_node **labelstack));
 
-/* A set of insns for the catch clauses in the current function. They
-   will be emitted at the end of the current function.  */
-
-extern rtx catch_clauses;
-
 #endif
 
 /* Test: is exception handling turned on? */
@@ -318,20 +371,11 @@ extern int is_exception_handler_label           PROTO((int));
 
 extern void check_exception_handler_labels	PROTO((void));
 
-/* A stack used to keep track of the label used to resume normal program
-   flow out of the current exception handler region.  */
-
-extern struct label_node *caught_return_label_stack;
-
 /* Keeps track of the label used as the context of a throw to rethrow an
    exception to the outer exception region.  */
 
 extern struct label_node *outer_context_label_stack;
 
-/* A random area used for purposes elsewhere.  */
-
-extern struct label_node *false_label_stack;
-
 /* A list of labels used for exception handlers. It is created by
    find_exception_handler_labels for the optimization passes.  */