Add -fforce-emit-vtables

Summary:
 In many cases we can't devirtualize
 because definition of vtable is not present. Most of the
 time it is caused by inline virtual function not beeing
 emitted. Forcing emitting of vtable adds a reference of these
 inline virtual functions.
 Note that GCC was always doing it.

Reviewers: rjmccall, rsmith, amharc, kuhar

Subscribers: llvm-commits, cfe-commits

Differential Revision: https://reviews.llvm.org/D47108

Co-authored-by: Krzysztof Pszeniczny <krzysztof.pszeniczny@gmail.com>

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@334600 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 128 insertions, 0 deletions

diff --git a/test/CodeGenCXX/vtable-available-externally.cpp b/test/CodeGenCXX/vtable-available-externally.cpp
index 0e7e8b4a32..b52527d36c 100644
--- a/test/CodeGenCXX/vtable-available-externally.cpp
+++ b/test/CodeGenCXX/vtable-available-externally.cpp
@@ -1,5 +1,6 @@
 // RUN: %clang_cc1 %s -I%S -triple=x86_64-apple-darwin10 -std=c++98 -emit-llvm -o %t
 // RUN: %clang_cc1 %s -I%S -triple=x86_64-apple-darwin10 -std=c++98 -O2 -disable-llvm-passes -emit-llvm -o %t.opt
+// RUN: %clang_cc1 %s -I%S -triple=x86_64-apple-darwin10 -std=c++98 -O2 -disable-llvm-passes -emit-llvm -o %t.vtable -fforce-emit-vtables -fstrict-vtable-pointers -mconstructor-aliases
 // RUN: FileCheck --check-prefix=CHECK-TEST1 %s < %t
 // RUN: FileCheck --check-prefix=CHECK-TEST2 %s < %t
 // RUN: FileCheck --check-prefix=CHECK-TEST5 %s < %t
@@ -13,10 +14,13 @@
 // RUN: FileCheck --check-prefix=CHECK-TEST15 %s < %t.opt
 // RUN: FileCheck --check-prefix=CHECK-TEST16 %s < %t.opt
 // RUN: FileCheck --check-prefix=CHECK-TEST17 %s < %t.opt
+// RUN: FileCheck --check-prefix=CHECK-FORCE-EMIT %s < %t.vtable
+
 
 #include <typeinfo>
 
 // CHECK-TEST1: @_ZTVN5Test11AE = external unnamed_addr constant
+// CHECK-FORCE-EMIT-DAG: @_ZTVN5Test11AE = available_externally unnamed_addr constant
 namespace Test1 {
 
 struct A {
@@ -213,6 +217,7 @@ namespace Test10 {
 
 // because A's key function is defined here, vtable is generated in this TU
 // CHECK-TEST10-DAG: @_ZTVN6Test101AE = unnamed_addr constant
+// CHECK-FORCE-EMIT-DAG: @_ZTVN6Test101AE = unnamed_addr constant
 struct A {
   virtual void foo();
   virtual void bar();
@@ -221,6 +226,7 @@ void A::foo() {}
 
 // Because key function is inline we will generate vtable as linkonce_odr.
 // CHECK-TEST10-DAG: @_ZTVN6Test101DE = linkonce_odr unnamed_addr constant
+// CHECK-FORCE-EMIT-DAG: @_ZTVN6Test101DE = linkonce_odr unnamed_addr constant
 struct D : A {
   void bar();
 };
@@ -237,6 +243,7 @@ struct B : A {
 // can't guarantee that we will be able to refer to bar from name
 // so (at the moment) we can't emit vtable available_externally.
 // CHECK-TEST10-DAG: @_ZTVN6Test101CE = external unnamed_addr constant
+// CHECK-FORCE-EMIT-DAG: @_ZTVN6Test101CE = available_externally unnamed_addr constant
 struct C : A {
   void bar() {}               // defined in body - not key function
   virtual inline void gar();  // inline in body - not key function
@@ -245,6 +252,8 @@ struct C : A {
 
 // no key function, vtable will be generated everywhere it will be used
 // CHECK-TEST10-DAG: @_ZTVN6Test101EE = linkonce_odr unnamed_addr constant
+// CHECK-FORCE-EMIT-DAG: @_ZTVN6Test101EE = linkonce_odr unnamed_addr constant
+
 struct E : A {};
 
 void g(A& a) {
@@ -298,11 +307,13 @@ void g() {
 namespace Test12 {
 
 // CHECK-TEST12: @_ZTVN6Test121AE = external unnamed_addr constant
+// CHECK-FORCE-EMIT-DAG: @_ZTVN6Test121AE = available_externally unnamed_addr constant
 struct A {
   virtual void foo();
   virtual ~A() {}
 };
 // CHECK-TEST12: @_ZTVN6Test121BE = external unnamed_addr constant
+// CHECK-FORCE-EMIT-DAG: @_ZTVN6Test121BE = available_externally unnamed_addr constant
 struct B : A {
   void foo();
 };
@@ -319,6 +330,9 @@ namespace Test13 {
 
 // CHECK-TEST13-DAG: @_ZTVN6Test131AE = available_externally unnamed_addr constant
 // CHECK-TEST13-DAG: @_ZTVN6Test131BE = external unnamed_addr constant
+// CHECK-FORCE-EMIT-DAG: @_ZTVN6Test131AE = available_externally unnamed_addr constant
+// CHECK-FORCE-EMIT-DAG: @_ZTVN6Test131BE = available_externally unnamed_addr constant
+
 struct A {
   virtual ~A();
 };
@@ -371,6 +385,8 @@ namespace Test16 {
 // generate available_externally vtable for it.
 // CHECK-TEST16-DAG: @_ZTVN6Test161SE = external unnamed_addr constant
 // CHECK-TEST16-DAG: @_ZTVN6Test162S2E = available_externally
+// CHECK-FORCE-EMIT-DAG: @_ZTVN6Test161SE = external unnamed_addr constant
+// CHECK-FORCE-EMIT-DAG: @_ZTVN6Test162S2E = available_externally
 
 struct S {
   __attribute__((visibility("hidden"))) virtual void doStuff();
@@ -395,6 +411,10 @@ namespace Test17 {
 // This test checks if we emit vtables opportunistically.
 // CHECK-TEST17-DAG: @_ZTVN6Test171AE = available_externally
 // CHECK-TEST17-DAG: @_ZTVN6Test171BE = external
+// CHECK-FORCE-EMIT-DAG: @_ZTVN6Test171AE = available_externally
+// CHECK-FORCE-EMIT-DAG: @_ZTVN6Test171BE = available_externally
+// CHECK-FORCE-EMIT-DAG: define linkonce_odr void @_ZN6Test171BD2Ev(
+// CHECK-FORCE-EMIT-DAG: define linkonce_odr void @_ZN6Test171BD0Ev(
 
 struct A {
   virtual void key();
@@ -418,3 +438,111 @@ void testcaseB() {
 }
 
 } // namespace Test17
+
+namespace Test18 {
+// Here vtable will be only emitted because it is referenced by assume-load
+// after the Derived construction.
+// CHECK-FORCE-EMIT-DAG: @_ZTVN6Test187DerivedE = linkonce_odr unnamed_addr constant {{.*}} @_ZTIN6Test187DerivedE {{.*}} @_ZN6Test184Base3funEv {{.*}} @_ZN6Test184BaseD2Ev {{.*}} @_ZN6Test187DerivedD0Ev
+// CHECK-FORCE-EMIT-DAG: define linkonce_odr void @_ZN6Test187DerivedD0Ev
+// CHECK-FORCE-EMIT-DAG: define linkonce_odr void @_ZN6Test184BaseD2Ev
+// CHECK-FORCE-EMIT-DAG: define linkonce_odr i32 @_ZN6Test184Base3funEv
+// CHECK-FORCE-EMIT-DAG: @_ZTIN6Test187DerivedE = linkonce_odr constant
+
+struct Base {
+  virtual int fun() { return 42; }
+  virtual ~Base() { }
+};
+
+struct Derived : Base {
+  Derived();
+};
+
+int foo() {
+  Derived *der = new Derived();
+  return der->fun();
+}
+}
+
+namespace TestTemplates {
+
+// CHECK-FORCE-EMIT-DAG: @_ZTVN13TestTemplates8TemplateIiEE = linkonce_odr unnamed_addr constant {{.*}} @_ZTIN13TestTemplates8TemplateIiEE {{.*}} @_ZN13TestTemplates8TemplateIiE3fooEi {{.*}}@_ZN13TestTemplates8TemplateIiE22thisShouldBeEmittedTooEi {{.*}}@_ZN13TestTemplates8TemplateIiED1Ev {{.*}}@_ZN13TestTemplates8TemplateIiED0Ev
+// CHECK-FORCE-EMIT-DAG: define linkonce_odr i32 @_ZN13TestTemplates8TemplateIiE22thisShouldBeEmittedTooEi
+
+template<class T>
+struct Template {
+  Template();
+  virtual T foo(T val);
+  // CHECK-FORCE-EMIT-DAG: define linkonce_odr i32 @_ZN13TestTemplates8TemplateIiE22thisShouldBeEmittedTooEi
+  virtual T thisShouldBeEmittedToo(T val) { return val; }
+  virtual ~Template();
+};
+
+
+struct NonTemplate {
+  typedef int T;
+  NonTemplate();
+  virtual T foo(T val);
+  // CHECK-FORCE-EMIT-DAG: define linkonce_odr i32 @_ZN13TestTemplates11NonTemplate22thisShouldBeEmittedTooEi
+  virtual T thisShouldBeEmittedToo(T val) { return val; }
+  virtual ~NonTemplate();
+};
+
+// CHECK-FORCE-EMIT-DAG: @_ZTVN13TestTemplates16OuterNonTemplate27NestedTemplateInNonTemplateIiEE = linkonce_odr {{.*}} @_ZTIN13TestTemplates16OuterNonTemplate27NestedTemplateInNonTemplateIiEE {{.*}} @_ZN13TestTemplates16OuterNonTemplate27NestedTemplateInNonTemplateIiE3fooEi {{.*}} @_ZN13TestTemplates16OuterNonTemplate27NestedTemplateInNonTemplateIiE22thisShouldBeEmittedTooEi {{.*}} @_ZN13TestTemplates16OuterNonTemplate27NestedTemplateInNonTemplateIiED1Ev {{.*}} @_ZN13TestTemplates16OuterNonTemplate27NestedTemplateInNonTemplateIiED0Ev
+
+struct OuterNonTemplate {
+  template<class T>
+  struct NestedTemplateInNonTemplate {
+    NestedTemplateInNonTemplate();
+    virtual T foo(T val);
+    // CHECK-FORCE-EMIT-DAG: define linkonce_odr i32 @_ZN13TestTemplates16OuterNonTemplate27NestedTemplateInNonTemplateIiE22thisShouldBeEmittedTooEi
+    virtual T thisShouldBeEmittedToo(T val) { return val; }
+    virtual ~NestedTemplateInNonTemplate();
+  };
+
+  struct NestedNonTemplateInNonTemplate {
+    typedef int T;
+    NestedNonTemplateInNonTemplate();
+    virtual T foo(T val);
+    // CHECK-FORCE-EMIT-DAG: define linkonce_odr i32 @_ZN13TestTemplates16OuterNonTemplate30NestedNonTemplateInNonTemplate22thisShouldBeEmittedTooEi
+    virtual T thisShouldBeEmittedToo(T val) { return val; }
+    virtual ~NestedNonTemplateInNonTemplate();
+  };
+};
+
+template<class>
+struct OuterTemplate {
+  template<class T>
+  struct NestedTemplateInTemplate {
+    NestedTemplateInTemplate();
+    virtual T foo(T val);
+    // CHECK-FORCE-EMIT-DAG: define linkonce_odr i32 @_ZN13TestTemplates13OuterTemplateIlE24NestedTemplateInTemplateIiE22thisShouldBeEmittedTooEi
+    virtual T thisShouldBeEmittedToo(T val) { return val; }
+    virtual ~NestedTemplateInTemplate();
+  };
+
+  struct NestedNonTemplateInTemplate {
+    typedef int T;
+    NestedNonTemplateInTemplate();
+    virtual T foo(T val);
+    // CHECK-FORCE-EMIT-DAG: define linkonce_odr i32 @_ZN13TestTemplates13OuterTemplateIlE27NestedNonTemplateInTemplate22thisShouldBeEmittedTooEi
+    virtual T thisShouldBeEmittedToo(T val) { return val; }
+    virtual ~NestedNonTemplateInTemplate();
+  };
+};
+
+template<class T>
+int use() {
+  T *ptr = new T();
+  return ptr->foo(42);
+}
+
+void test() {
+  use<Template<int> >();
+  use<OuterTemplate<long>::NestedTemplateInTemplate<int> >();
+  use<OuterNonTemplate::NestedTemplateInNonTemplate<int> >();
+
+  use<NonTemplate>();
+  use<OuterTemplate<long>::NestedNonTemplateInTemplate>();
+  use<OuterNonTemplate::NestedNonTemplateInNonTemplate>();
+}
+}