[CodeGen] Emit lifetime.end intrinsic after objects are destructed in

landing pads.

Previously, lifetime.end intrinsics were inserted only on normal control
flows. This prevented StackColoring from merging stack slots for objects
that were destroyed on the exception handling control flow since it
couldn't tell their lifetime ranges were disjoint. This patch fixes
code-gen to emit the intrinsic on both control flows.

rdar://problem/22181976

Differential Revision: http://reviews.llvm.org/D18196

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@265197 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/CodeGen/CGCleanup.cpp b/lib/CodeGen/CGCleanup.cpp
index 2678b33f392ba1eb849b390c8f696f36f7346d67..95333d0ddac496120631b64424d63138d9592d92 100644 (file)
--- a/lib/CodeGen/CGCleanup.cpp
+++ b/lib/CodeGen/CGCleanup.cpp
@@ -157,6 +157,20 @@ bool EHScopeStack::containsOnlyLifetimeMarkers(
   return true;
 }
 
+bool EHScopeStack::requiresLandingPad() const {
+  for (stable_iterator si = getInnermostEHScope(); si != stable_end(); ) {
+    // Skip lifetime markers.
+    if (auto *cleanup = dyn_cast<EHCleanupScope>(&*find(si)))
+      if (cleanup->isLifetimeMarker()) {
+        si = cleanup->getEnclosingEHScope();
+        continue;
+      }
+    return true;
+  }
+
+  return false;
+}
+
 EHScopeStack::stable_iterator
 EHScopeStack::getInnermostActiveNormalCleanup() const {
   for (stable_iterator si = getInnermostNormalCleanup(), se = stable_end();

diff --git a/lib/CodeGen/CGDecl.cpp b/lib/CodeGen/CGDecl.cpp
index e0c297508fafcf860fc56a3697b39cbffe488634..c39b980ef2c25a7c5633fd7a660cd199afd8e614 100644 (file)
--- a/lib/CodeGen/CGDecl.cpp
+++ b/lib/CodeGen/CGDecl.cpp
@@ -1388,7 +1388,7 @@ void CodeGenFunction::EmitAutoVarCleanups(const AutoVarEmission &emission) {
   // Make sure we call @llvm.lifetime.end.  This needs to happen
   // *last*, so the cleanup needs to be pushed *first*.
   if (emission.useLifetimeMarkers()) {
-    EHStack.pushCleanup<CallLifetimeEnd>(NormalCleanup,
+    EHStack.pushCleanup<CallLifetimeEnd>(NormalAndEHCleanup,
                                          emission.getAllocatedAddress(),
                                          emission.getSizeForLifetimeMarkers());
     EHCleanupScope &cleanup = cast<EHCleanupScope>(*EHStack.begin());

diff --git a/lib/CodeGen/EHScopeStack.h b/lib/CodeGen/EHScopeStack.h
index 85cd1543e5bf276891baa84d3a6c0b4580599fc9..8352c75d64f854627c843848f05323ad36ae91b2 100644 (file)
--- a/lib/CodeGen/EHScopeStack.h
+++ b/lib/CodeGen/EHScopeStack.h
@@ -341,9 +341,7 @@ public:
   /// Determines whether the exception-scopes stack is empty.
   bool empty() const { return StartOfData == EndOfBuffer; }
 
-  bool requiresLandingPad() const {
-    return InnermostEHScope != stable_end();
-  }
+  bool requiresLandingPad() const;
 
   /// Determines whether there are any normal cleanups on the stack.
   bool hasNormalCleanups() const {

diff --git a/test/CodeGenCXX/destructors.cpp b/test/CodeGenCXX/destructors.cpp
index 529603142d31454c6b74d6d49f2f526f41013210..d6aabee58b9e6b93c1fa0ef07513acb1a08508a0 100644 (file)
--- a/test/CodeGenCXX/destructors.cpp
+++ b/test/CodeGenCXX/destructors.cpp
@@ -4,6 +4,9 @@
 // RUN: FileCheck --check-prefix=CHECK3 --input-file=%t %s
 // RUN: FileCheck --check-prefix=CHECK4 --input-file=%t %s
 // RUN: FileCheck --check-prefix=CHECK5 --input-file=%t %s
+// RUN: %clang_cc1 %s -triple x86_64-apple-darwin10 -emit-llvm -o - -fcxx-exceptions -fexceptions -O1 -disable-llvm-optzns -std=c++11 > %t2
+// RUN: FileCheck --check-prefix=CHECK6 --input-file=%t2 %s
+// REQUIRES: asserts
 
 struct A {
   int a;
@@ -428,3 +431,64 @@ namespace test10 {
     return true;
   }
 }
+
+#if __cplusplus >= 201103L
+namespace test11 {
+
+// Check that lifetime.end is emitted in the landing pad.
+
+// CHECK6-LABEL: define void @_ZN6test1115testLifetimeEndEi(
+// CHECK6: entry:
+// CHECK6: [[T1:%[a-z0-9]+]] = alloca %"struct.test11::S1"
+// CHECK6: [[T2:%[a-z0-9]+]] = alloca %"struct.test11::S1"
+// CHECK6: [[T3:%[a-z0-9]+]] = alloca %"struct.test11::S1"
+
+// CHECK6: {{^}}invoke.cont
+// CHECK6: call void @_ZN6test112S1D1Ev(%"struct.test11::S1"* [[T1]])
+// CHECK6: [[BC1:%[a-z0-9]+]] = bitcast %"struct.test11::S1"* [[T1]] to i8*
+// CHECK6: call void @llvm.lifetime.end(i64 32, i8* [[BC1]])
+// CHECK6: {{^}}lpad
+// CHECK6: call void @_ZN6test112S1D1Ev(%"struct.test11::S1"* [[T1]])
+// CHECK6: [[BC2:%[a-z0-9]+]] = bitcast %"struct.test11::S1"* [[T1]] to i8*
+// CHECK6: call void @llvm.lifetime.end(i64 32, i8* [[BC2]])
+
+// CHECK6: {{^}}invoke.cont
+// CHECK6: call void @_ZN6test112S1D1Ev(%"struct.test11::S1"* [[T2]])
+// CHECK6: [[BC3:%[a-z0-9]+]] = bitcast %"struct.test11::S1"* [[T2]] to i8*
+// CHECK6: call void @llvm.lifetime.end(i64 32, i8* [[BC3]])
+// CHECK6: {{^}}lpad
+// CHECK6: call void @_ZN6test112S1D1Ev(%"struct.test11::S1"* [[T2]])
+// CHECK6: [[BC4:%[a-z0-9]+]] = bitcast %"struct.test11::S1"* [[T2]] to i8*
+// CHECK6: call void @llvm.lifetime.end(i64 32, i8* [[BC4]])
+
+// CHECK6: {{^}}invoke.cont
+// CHECK6: call void @_ZN6test112S1D1Ev(%"struct.test11::S1"* [[T3]])
+// CHECK6: [[BC5:%[a-z0-9]+]] = bitcast %"struct.test11::S1"* [[T3]] to i8*
+// CHECK6: call void @llvm.lifetime.end(i64 32, i8* [[BC5]])
+// CHECK6: {{^}}lpad
+// CHECK6: call void @_ZN6test112S1D1Ev(%"struct.test11::S1"* [[T3]])
+// CHECK6: [[BC6:%[a-z0-9]+]] = bitcast %"struct.test11::S1"* [[T3]] to i8*
+// CHECK6: call void @llvm.lifetime.end(i64 32, i8* [[BC6]])
+
+  struct S1 {
+    ~S1();
+    int a[8];
+  };
+
+  void func1(S1 &) noexcept(false);
+
+  void testLifetimeEnd(int n) {
+    if (n < 10) {
+      S1 t1;
+      func1(t1);
+    } else if (n < 100) {
+      S1 t2;
+      func1(t2);
+    } else if (n < 1000) {
+      S1 t3;
+      func1(t3);
+    }
+  }
+
+}
+#endif

diff --git a/test/CodeGenCXX/microsoft-abi-eh-cleanups.cpp b/test/CodeGenCXX/microsoft-abi-eh-cleanups.cpp
index bf05c693ec0dd56f567ecb102814e2f9c36ae262..3afee1c1f12ed94bca61a48fd719641aa8a6d6e1 100644 (file)
--- a/test/CodeGenCXX/microsoft-abi-eh-cleanups.cpp
+++ b/test/CodeGenCXX/microsoft-abi-eh-cleanups.cpp
@@ -1,4 +1,5 @@
 // RUN: %clang_cc1 -std=c++11 -emit-llvm %s -o - -triple=i386-pc-win32 -mconstructor-aliases -fexceptions -fcxx-exceptions -fno-rtti | FileCheck -check-prefix WIN32 %s
+// RUN: %clang_cc1 -std=c++11 -emit-llvm -O3 -disable-llvm-optzns %s -o - -triple=i386-pc-win32 -mconstructor-aliases -fexceptions -fcxx-exceptions -fno-rtti | FileCheck -check-prefix WIN32 -check-prefix WIN32-LIFETIME %s
 
 struct A {
   A();
@@ -206,3 +207,36 @@ void f() {
 // WIN32: cleanuppad
 // WIN32: call x86_thiscallcc void @"\01??1D@noexcept_false_dtor@@QAE@XZ"(%"struct.noexcept_false_dtor::D"* %{{.*}})
 // WIN32: cleanupret
+
+namespace lifetime_marker {
+struct C {
+  ~C();
+};
+void g();
+void f() {
+  C c;
+  g();
+}
+
+// WIN32-LIFETIME-LABEL: define void @"\01?f@lifetime_marker@@YAXXZ"()
+// WIN32-LIFETIME: %[[c:.*]] = alloca %"struct.lifetime_marker::C"
+// WIN32-LIFETIME: %[[bc0:.*]] = bitcast %"struct.lifetime_marker::C"* %c to i8*
+// WIN32-LIFETIME: call void @llvm.lifetime.start(i64 1, i8* %[[bc0]])
+// WIN32-LIFETIME: invoke void @"\01?g@lifetime_marker@@YAXXZ"()
+// WIN32-LIFETIME-NEXT: to label %[[cont:[^ ]*]] unwind label %[[lpad0:[^ ]*]]
+//
+// WIN32-LIFETIME: [[cont]]:
+// WIN32-LIFETIME: call x86_thiscallcc void @"\01??1C@lifetime_marker@@QAE@XZ"({{.*}})
+// WIN32-LIFETIME: %[[bc1:.*]] = bitcast %"struct.lifetime_marker::C"* %[[c]] to i8*
+// WIN32-LIFETIME: call void @llvm.lifetime.end(i64 1, i8* %[[bc1]])
+//
+// WIN32-LIFETIME: [[lpad0]]:
+// WIN32-LIFETIME-NEXT: cleanuppad
+// WIN32-LIFETIME: call x86_thiscallcc void @"\01??1C@lifetime_marker@@QAE@XZ"({{.*}})
+// WIN32-LIFETIME: cleanupret {{.*}} unwind label %[[lpad1:[^ ]*]]
+//
+// WIN32-LIFETIME: [[lpad1]]:
+// WIN32-LIFETIME-NEXT: cleanuppad
+// WIN32-LIFETIME: %[[bc2:.*]] = bitcast %"struct.lifetime_marker::C"* %[[c]] to i8*
+// WIN32-LIFETIME: call void @llvm.lifetime.end(i64 1, i8* %[[bc2]])
+}