cse.c (cse_insn): Call never_reached_warning when a jump is changed to be unconditional.

* cse.c (cse_insn): Call never_reached_warning when a jump is
changed to be unconditional.
* flags.h: Declare warn_notreached.
* flow.c (delete_block): Call never_reached_warning when
a block is deleted.
* jump.c (delete_barrier_successors): Call never_reached_warning
when we delete everything after a BARRIER.
(never_reached_warning): New function.
* rtl.h: Declare never_reached_warning.
* toplev.c (warn_notreached): New variable.
(lang_independent_options): Set warn_notreached
when -Wunreachable-code.
(compile_file): We need line numbers for -Wunreachable-code.

Also modify documentation to suit.

From-SVN: r28747

1 files changed, 2 insertions, 0 deletions

diff --git a/gcc/flow.c b/gcc/flow.c
index 1154188..c38d0b3 100644
--- a/gcc/flow.c
+++ b/gcc/flow.c
@@ -1682,6 +1682,8 @@ delete_block (b)
 
   insn = b->head;
   
+  never_reached_warning (insn);
+
   if (GET_CODE (insn) == CODE_LABEL)
     {
       rtx x, *prev = &exception_handler_labels;