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.




git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@107631 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 89 insertions, 0 deletions

diff --git a/test/CodeGenCXX/eh.cpp b/test/CodeGenCXX/eh.cpp
index f2629d19d9..4d0955877d 100644
--- a/test/CodeGenCXX/eh.cpp
+++ b/test/CodeGenCXX/eh.cpp
@@ -38,6 +38,7 @@ void test2() {
 // CHECK:     define void @_Z5test2v()
 // CHECK:       [[FREEVAR:%.*]] = alloca i1
 // CHECK-NEXT:  [[EXNOBJVAR:%.*]] = alloca i8*
+// CHECK-NEXT:  [[EXNSLOTVAR:%.*]] = alloca i8*
 // CHECK-NEXT:  store i1 false, i1* [[FREEVAR]]
 // CHECK-NEXT:  [[EXNOBJ:%.*]] = call i8* @__cxa_allocate_exception(i64 16)
 // CHECK-NEXT:  store i8* [[EXNOBJ]], i8** [[EXNOBJVAR]]
@@ -104,3 +105,91 @@ namespace test5 {
 //      :    [[HANDLER]]:  (can't check this in Release-Asserts builds)
 // CHECK:      {{%.*}} = call i32 @llvm.eh.typeid.for(i8* bitcast ({{%.*}}* @_ZTIN5test51AE to i8*))
 }
+
+namespace test6 {
+  template <class T> struct allocator {
+    ~allocator() throw() { }
+  };
+
+  void foo() {
+    allocator<int> a;
+  }
+}
+
+// PR7127
+namespace test7 {
+// CHECK:      define i32 @_ZN5test73fooEv() 
+  int foo() {
+// CHECK:      [[FREEEXNOBJ:%.*]] = alloca i1
+// CHECK-NEXT: [[EXNALLOCVAR:%.*]] = alloca i8*
+// CHECK-NEXT: [[CAUGHTEXNVAR:%.*]] = alloca i8*
+// CHECK-NEXT: [[INTCATCHVAR:%.*]] = alloca i32
+// CHECK-NEXT: store i1 false, i1* [[FREEEXNOBJ]]
+    try {
+      try {
+// CHECK-NEXT: [[EXNALLOC:%.*]] = call i8* @__cxa_allocate_exception
+// CHECK-NEXT: store i8* [[EXNALLOC]], i8** [[EXNALLOCVAR]]
+// CHECK-NEXT: store i1 true, i1* [[FREEEXNOBJ]]
+// CHECK-NEXT: bitcast i8* [[EXNALLOC]] to i32*
+// CHECK-NEXT: store i32 1, i32*
+// CHECK-NEXT: store i1 false, i1* [[FREEEXNOBJ]]
+// CHECK-NEXT: invoke void @__cxa_throw(i8* [[EXNALLOC]], i8* bitcast (i8** @_ZTIi to i8*), i8* null
+        throw 1;
+      }
+// This cleanup ends up here for no good reason.  It's actually unused.
+// CHECK:      load i8** [[EXNALLOCVAR]]
+// CHECK-NEXT: call void @__cxa_free_exception(
+
+// CHECK:      [[CAUGHTEXN:%.*]] = call i8* @llvm.eh.exception()
+// CHECK-NEXT: store i8* [[CAUGHTEXN]], i8** [[CAUGHTEXNVAR]]
+// CHECK-NEXT: call i32 (i8*, i8*, ...)* @llvm.eh.selector(i8* [[CAUGHTEXN]], i8* bitcast (i32 (...)* @__gxx_personality_v0 to i8*), i8* bitcast (i8** @_ZTIi to i8*), i8* null)
+// CHECK-NEXT: call i32 @llvm.eh.typeid.for(i8* bitcast (i8** @_ZTIi to i8*))
+// CHECK-NEXT: icmp eq
+// CHECK-NEXT: br i1
+// CHECK:      load i8** [[CAUGHTEXNVAR]]
+// CHECK-NEXT: call i8* @__cxa_begin_catch
+// CHECK:      invoke void @__cxa_rethrow
+      catch (int) {
+        throw;
+      }
+    }
+// CHECK:      [[CAUGHTEXN:%.*]] = call i8* @llvm.eh.exception()
+// CHECK-NEXT: store i8* [[CAUGHTEXN]], i8** [[CAUGHTEXNVAR]]
+// CHECK-NEXT: call i32 (i8*, i8*, ...)* @llvm.eh.selector(i8* [[CAUGHTEXN]], i8* bitcast (i32 (...)* @__gxx_personality_v0 to i8*), i8* null)
+// CHECK-NEXT: call void @__cxa_end_catch()
+// CHECK-NEXT: br label
+// CHECK:      load i8** [[CAUGHTEXNVAR]]
+// CHECK-NEXT: call i8* @__cxa_begin_catch
+// CHECK-NEXT: call void @__cxa_end_catch
+    catch (...) {
+    }
+// CHECK:      ret i32 0
+    return 0;
+  }
+}
+
+// Ordering of destructors in a catch handler.
+namespace test8 {
+  struct A { A(const A&); ~A(); };
+  void bar();
+
+  // CHECK: define void @_ZN5test83fooEv()
+  void foo() {
+    try {
+      // CHECK:      invoke void @_ZN5test83barEv()
+      bar();
+    } catch (A a) {
+      // CHECK:      call i8* @__cxa_get_exception_ptr
+      // CHECK-NEXT: bitcast
+      // CHECK-NEXT: invoke void @_ZN5test81AC1ERKS0_(
+      // CHECK:      call i8* @__cxa_begin_catch
+      // CHECK-NEXT: invoke void @_ZN5test81AD1Ev(
+
+      // CHECK:      call void @__cxa_end_catch()
+      // CHECK-NEXT: load
+      // CHECK-NEXT: switch
+
+      // CHECK:      ret void
+    }
+  }
+}