[llvm-commits] CVS: llvm-gcc/gcc/llvm-expand.c

[Chris Lattner]

Changes in directory llvm-gcc/gcc:

llvm-expand.c updated: 1.100 -> 1.101
---
Log message:

Rename to llvm_expand_exit_something -> llvm_expand_break_something, as it
inserts code for the 'break' statement.

Fix PR580: http://llvm.cs.uiuc.edu/PR580  by always emitting a new label after emitting an unconditional goto.
This fixes PR580: http://llvm.cs.uiuc.edu/PR580 , including cases where the continue is replaced with a 
break or a goto.

Testcase here: Regression/CFrontend/2005-06-15-ExpandGotoInternalProblem.c



---
Diffs of the changes:  (+29 -7)

 llvm-expand.c |   36 +++++++++++++++++++++++++++++-------
 1 files changed, 29 insertions(+), 7 deletions(-)


Index: llvm-gcc/gcc/llvm-expand.c
diff -u llvm-gcc/gcc/llvm-expand.c:1.100 llvm-gcc/gcc/llvm-expand.c:1.101
--- llvm-gcc/gcc/llvm-expand.c:1.100	Tue Jun 14 16:40:55 2005
+++ llvm-gcc/gcc/llvm-expand.c	Wed Jun 15 17:44:27 2005
@@ -1566,7 +1566,7 @@
 /* Generate LLVM for the start of an if-then.  COND is the expression whose
    truth should be tested.
 
-   If EXITFLAG is nonzero, this conditional is visible to `exit_something'.  */
+   If EXITFLAG is nonzero, this conditional is visible to `break_something'.  */
 
 static void llvm_expand_start_cond (llvm_function *Fn, tree cond, int exitflag,
                                     int has_else) {
@@ -1825,7 +1825,7 @@
 }
 
 /* Generate RTL for the start of a loop.  EXIT_FLAG is nonzero if this
-   loop should be exited by `exit_something'.  This is a loop for which
+   loop should be exited by `break_something'.  This is a loop for which
    `expand_continue' will jump to the top of the loop.
 
    Make an entry on loop_stack to record the labels associated with
@@ -1917,6 +1917,12 @@
 
   whichloop->x.loop.ContinueFound = 1;
   llvm_expand_goto_internal(Fn, whichloop->x.loop.continue_label, 1, 0);
+
+  /* Start a new block so that if statements are emitted after the continue,
+   * that they will have the correct "current block".
+   */
+  llvm_emit_label(Fn, llvm_basicblock_new("dead_block_after_continue"));
+
   return 1;
 }
 
@@ -1992,12 +1998,17 @@
    If not currently inside anything that can be exited,
    return 0 and do nothing; caller will print an error message.  */
 
-static int llvm_expand_exit_something(llvm_function *Fn) {
+static int llvm_expand_break_something(llvm_function *Fn) {
   llvm_nesting *n;
   for (n = Fn->ExpandInfo->InnermostScope; n; n = n->all)
     if (n->exit_block) {
       n->BreakFound = 1;
       llvm_expand_goto_internal(Fn, n->exit_block, 1, 0);
+
+      /* Start a new block so that if statements are emitted after the break,
+       * that they will have the correct "current block".
+       */
+      llvm_emit_label(Fn, llvm_basicblock_new("dead_block_after_break"));
       return 1;
     }
 
@@ -2010,8 +2021,8 @@
    case-labels that are seen and to record the labels generated for the
    statement.
 
-   EXIT_FLAG is nonzero if `exit_something' should exit this case stmt.
-   Otherwise, this construct is transparent for `exit_something'.
+   EXIT_FLAG is nonzero if `break_something' should exit this case stmt.
+   Otherwise, this construct is transparent for `break_something'.
 
    EXPR is the index-expression to be dispatched on.
 */
@@ -2208,14 +2219,25 @@
     append_inst(Fn, create_store_inst(V, Fn->ExpandInfo->IndirectGotoValue, 0));
 
     /* FIXME: This is HORRIBLY INCORRECT in the presence of exception handlers.
-     * There should be one collector block per cleanup level!
+     * There should be one collector block per cleanup level!  Note that
+     * standard GCC gets this wrong as well.
      */
     llvm_expand_goto_internal(Fn, Fn->ExpandInfo->IndirectGotoBlock, 1, 0);
+
+    /* Start a new block so that if statements are emitted after the goto, that
+     * they will have the correct "current block".
+     */
+    llvm_emit_label(Fn, llvm_basicblock_new("dead_block_after_goto"));
     return;
   }
 
   TREE_USED(dest) = 1;
   llvm_expand_goto_internal(Fn, getLabelDeclBlock(dest), 1, 0);
+
+  /* Start a new block so that if statements are emitted after the goto, that
+   * they will have the correct "current block".
+   */
+  llvm_emit_label(Fn, llvm_basicblock_new("dead_block_after_goto"));
 }
 
 /* Generate LLVM code for a RETURN_STMT */
@@ -2766,7 +2788,7 @@
       break;
 
     case BREAK_STMT:
-      if (!llvm_expand_exit_something(Fn))
+      if (!llvm_expand_break_something(Fn))
         error ("break statement not within loop or switch");
       break;