Validated by nightly-test runs on x86 and x86-64 darwin, including after

self-host.  Hopefully these results hold up on different platforms.  

I tried to keep the GNU ObjC runtime happy, but it's hard for me to test.
Reimplement how clang generates IR for exceptions.  Instead of creating new
invoke destinations which sequentially chain to the previous destination,
push a more semantic representation of *why* we need the cleanup/catch/filter
behavior, then collect that information into a single landing pad upon request.

Also reorganizes how normal cleanups (i.e. cleanups triggered by non-exceptional
control flow) are generated, since it's actually fairly closely tied in with
the former.  Remove the need to track which cleanup scope a block is associated
with.

Document a lot of previously poorly-understood (by me, at least) behavior.

The new framework implements the Horrible Hack (tm), which requires every
landing pad to have a catch-all so that inlining will work.  Clang no longer
requires the Horrible Hack just to make exceptions flow correctly within
a function, however.  The HH is an unfortunate requirement of LLVM's EH IR.

llvm-svn: 107631

1 files changed, 94 insertions, 28 deletions

diff --git a/clang/test/CodeGenCXX/condition.cpp b/clang/test/CodeGenCXX/condition.cpp
index f5b43d2ef49..b1fa9f1c80a 100644
--- a/clang/test/CodeGenCXX/condition.cpp
+++ b/clang/test/CodeGenCXX/condition.cpp
@@ -96,66 +96,132 @@ void switch_destruct(int z) {
 
 int foo();
 
+// CHECK: define void @_Z14while_destructi
 void while_destruct(int z) {
-  // CHECK: define void @_Z14while_destructi
-  // CHECK: {{while.cond:|:3}}
+  // CHECK: [[Z:%.*]] = alloca i32
+  // CHECK: [[CLEANUPDEST:%.*]] = alloca i32
   while (X x = X()) {
     // CHECK: call void @_ZN1XC1Ev
+    // CHECK-NEXT: [[COND:%.*]] = call zeroext i1 @_ZN1XcvbEv
+    // CHECK-NEXT: br i1 [[COND]]
 
-    // CHECK: {{while.body:|:5}}
-    // CHECK: store i32 21
+    // Loop-exit staging block.
+    // CHECK: store i32 1, i32* [[CLEANUPDEST]]
+    // CHECK-NEXT: br
+
+    // While body.
+    // CHECK: store i32 21, i32* [[Z]]
+    // CHECK: store i32 2, i32* [[CLEANUPDEST]]
+    // CHECK-NEXT: br
     z = 21;
 
-    // CHECK: {{while.cleanup:|:6}}
+    // Cleanup.
     // CHECK: call void @_ZN1XD1Ev
+    // CHECK-NEXT: [[DEST:%.*]] = load i32* [[CLEANUPDEST]]
+    // CHECK-NEXT: switch i32 [[DEST]]
   }
-  // CHECK: {{while.end|:8}}
-  // CHECK: store i32 22
+
+  // CHECK: store i32 22, i32* [[Z]]
   z = 22;
 
   // CHECK: call void @_Z4getXv
-  // CHECK: call zeroext i1 @_ZN1XcvbEv
-  // CHECK: call void @_ZN1XD1Ev
-  // CHECK: br
+  // CHECK-NEXT: call zeroext i1 @_ZN1XcvbEv
+  // CHECK-NEXT: call void @_ZN1XD1Ev
+  // CHECK-NEXT: br
   while(getX()) { }
 
-  // CHECK: store i32 25
+  // CHECK: store i32 25, i32* [[Z]]
   z = 25;
 
   // CHECK: ret
 }
 
+// CHECK: define void @_Z12for_destructi(
 void for_destruct(int z) {
-  // CHECK: define void @_Z12for_destruct
+  // CHECK: [[Z:%.*]] = alloca i32
+  // CHECK: [[XDEST:%.*]] = alloca i32
+  // CHECK: [[I:%.*]] = alloca i32
   // CHECK: call void @_ZN1YC1Ev
-  for(Y y = Y(); X x = X(); ++z)
-    // CHECK: {{for.cond:|:4}}
+  // CHECK-NEXT: br
+  // -> %for.cond
+
+  for(Y y = Y(); X x = X(); ++z) {
+    // %for.cond: The loop condition.
     // CHECK: call void @_ZN1XC1Ev
-    // CHECK: {{for.body:|:6}}
-    // CHECK: store i32 23
+    // CHECK-NEXT: [[COND:%.*]] = call zeroext i1 @_ZN1XcvbEv(
+    // CHECK-NEXT: br i1 [[COND]]
+    // -> %for.body, %for.cond.cleanup
+
+    // %for.cond.cleanup: Exit cleanup staging.
+    // CHECK: store i32 1, i32* [[XDEST]]
+    // CHECK-NEXT: br
+    // -> %cleanup
+
+    // %for.body:
+    // CHECK: store i32 23, i32* [[Z]]
+    // CHECK-NEXT: br
+    // -> %for.inc
     z = 23;
-    // CHECK: {{for.inc:|:7}}
-    // CHECK: br label %{{for.cond.cleanup|10}}
-    // CHECK: {{for.cond.cleanup:|:10}}
+
+    // %for.inc:
+    // CHECK: [[TMP:%.*]] = load i32* [[Z]]
+    // CHECK-NEXT: [[INC:%.*]] = add nsw i32 [[TMP]], 1
+    // CHECK-NEXT: store i32 [[INC]], i32* [[Z]]
+    // CHECK-NEXT: store i32 2, i32* [[XDEST]]
+    // CHECK-NEXT: br
+    // -> %cleanup
+
+    // %cleanup:  Destroys X.
     // CHECK: call void @_ZN1XD1Ev
-  // CHECK: {{for.end:|:12}}
-  // CHECK: call void @_ZN1YD1Ev
+    // CHECK-NEXT: [[YDESTTMP:%.*]] = load i32* [[XDEST]]
+    // CHECK-NEXT: switch i32 [[YDESTTMP]]
+    // 1 -> %cleanup4, 2 -> %cleanup.cont
+
+    // %cleanup.cont:  (eliminable)
+    // CHECK: br
+    // -> %for.cond
+
+    // %cleanup4: Destroys Y.
+    // CHECK: call void @_ZN1YD1Ev(
+    // CHECK-NEXT: br
+    // -> %for.end
+  }
+
+  // %for.end:
   // CHECK: store i32 24
   z = 24;
 
+  // CHECK-NEXT: store i32 0, i32* [[I]]
+  // CHECK-NEXT: br
+  // -> %for.cond6
+
+  // %for.cond6:
   // CHECK: call void @_Z4getXv
-  // CHECK: call zeroext i1 @_ZN1XcvbEv
-  // CHECK: call void @_ZN1XD1Ev
+  // CHECK-NEXT: call zeroext i1 @_ZN1XcvbEv
+  // CHECK-NEXT: call void @_ZN1XD1Ev
+  // CHECK-NEXT: br
+  // -> %for.body10, %for.end16
+
+  // %for.body10:
   // CHECK: br
+  // -> %for.inc11
+
+  // %for.inc11:
   // CHECK: call void @_Z4getXv
-  // CHECK: load
-  // CHECK: add
-  // CHECK: call void @_ZN1XD1Ev
+  // CHECK-NEXT: load i32* [[I]]
+  // CHECK-NEXT: add
+  // CHECK-NEXT: store
+  // CHECK-NEXT: call void @_ZN1XD1Ev
+  // CHECK-NEXT: br
+  // -> %for.cond6
   int i = 0;
   for(; getX(); getX(), ++i) { }
-  z = 26;
+
+  // %for.end16
   // CHECK: store i32 26
-  // CHECK: ret
+  z = 26;
+
+  // CHECK-NEXT: ret void
 }
 
 void do_destruct(int z) {