[clang] [Clang] Emit type metadata on vtables when IRPGO instrumentation option is on. (PR #70841)

[via cfe-commits]

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-clang

Author: Mingming Liu (minglotus-6)

<details>
<summary>Changes</summary>

The motivating use case is to have type metadata on vtables if IRPGO instrumentation is on (without the requirement of `-fwhole-program-vtables` or `-flto`).

A related rfc is in https://discourse.llvm.org/t/rfc-dynamic-type-profiling-and-optimizations-in-llvm/74600

---
Full diff: https://github.com/llvm/llvm-project/pull/70841.diff


3 Files Affected:

- (modified) clang/lib/CodeGen/CGVTables.cpp (+1-1) 
- (modified) clang/lib/CodeGen/MicrosoftCXXABI.cpp (+2-1) 
- (added) clang/test/Driver/type-metadata.cpp (+145) 


``````````diff
diff --git a/clang/lib/CodeGen/CGVTables.cpp b/clang/lib/CodeGen/CGVTables.cpp
index 25e4b1c27932026..895e160dfa8a536 100644
--- a/clang/lib/CodeGen/CGVTables.cpp
+++ b/clang/lib/CodeGen/CGVTables.cpp
@@ -1312,7 +1312,7 @@ llvm::GlobalObject::VCallVisibility CodeGenModule::GetVCallVisibilityLevel(
 void CodeGenModule::EmitVTableTypeMetadata(const CXXRecordDecl *RD,
                                            llvm::GlobalVariable *VTable,
                                            const VTableLayout &VTLayout) {
-  if (!getCodeGenOpts().LTOUnit)
+  if (!getCodeGenOpts().LTOUnit && !getCodeGenOpts().hasProfileIRInstr())
     return;
 
   CharUnits ComponentWidth = GetTargetTypeStoreSize(getVTableComponentType());
diff --git a/clang/lib/CodeGen/MicrosoftCXXABI.cpp b/clang/lib/CodeGen/MicrosoftCXXABI.cpp
index d623f8f63ae56c4..740c0b6cb1aac04 100644
--- a/clang/lib/CodeGen/MicrosoftCXXABI.cpp
+++ b/clang/lib/CodeGen/MicrosoftCXXABI.cpp
@@ -1673,7 +1673,8 @@ void MicrosoftCXXABI::EmitDestructorCall(CodeGenFunction &CGF,
 void MicrosoftCXXABI::emitVTableTypeMetadata(const VPtrInfo &Info,
                                              const CXXRecordDecl *RD,
                                              llvm::GlobalVariable *VTable) {
-  if (!CGM.getCodeGenOpts().LTOUnit)
+  if (!CGM.getCodeGenOpts().LTOUnit &&
+      !CGM.getCodeGenOpts().hasProfileIRInstr())
     return;
 
   // TODO: Should VirtualFunctionElimination also be supported here?
diff --git a/clang/test/Driver/type-metadata.cpp b/clang/test/Driver/type-metadata.cpp
new file mode 100644
index 000000000000000..a34b3b08e7a4493
--- /dev/null
+++ b/clang/test/Driver/type-metadata.cpp
@@ -0,0 +1,145 @@
+// Test that type metadata are emitted with -fprofile-generate
+//
+// RUN: %clang -fprofile-generate -fno-lto -target x86_64-unknown-linux -emit-llvm -S %s -o - | FileCheck %s --check-prefix=ITANIUM
+// RUN: %clang -fprofile-generate -fno-lto -target x86_64-pc-windows-msvc -emit-llvm -S %s -o - | FileCheck %s --check-prefix=MS
+
+// ITANIUM: @_ZTV1A = {{[^!]*}}, !type [[A16:![0-9]+]]
+// ITANIUM-SAME:  !type [[AF16:![0-9]+]]
+
+// ITANIUM: @_ZTV1B = {{[^!]*}}, !type  [[A32:![0-9]+]]
+// ITANIUM-SAME: !type [[AF32:![0-9]+]]
+// ITANIUM-SAME: !type [[AF40:![0-9]+]]
+// ITANIUM-SAME: !type [[AF48:![0-9]+]]
+// ITANIUM-SAME: !type [[B32:![0-9]+]]
+// ITANIUM-SAME: !type [[BF32:![0-9]+]]
+// ITANIUM-SAME: !type [[BF40:![0-9]+]]
+// ITANIUM-SAME: !type [[BF48:![0-9]+]]
+
+// ITANIUM: @_ZTV1C = {{[^!]*}}, !type [[A32]]
+// ITANIUM-SAME: !type [[AF32]]
+// ITANIUM-SAME: !type [[C32:![0-9]+]]
+// ITANIUM-SAME: !type [[CF32:![0-9]+]]
+
+// ITANIUM: @_ZTVN12_GLOBAL__N_11DE = {{[^!]*}}, !type [[A32]]
+// ITANIUM-SAME: !type [[AF32]]
+// ITANIUM-SAME: !type [[AF40]]
+// ITANIUM-SAME: !type [[AF48]]
+// ITANIUM-SAME: !type [[B32]]
+// ITANIUM-SAME: !type [[BF32]]
+// ITANIUM-SAME: !type [[BF40]]
+// ITANIUM-SAME: !type [[BF48]]
+// ITANIUM-SAME: !type [[C88:![0-9]+]]
+// ITANIUM-SAME: !type [[CF32]]
+// ITANIUM-SAME: !type [[CF40:![0-9]+]]
+// ITANIUM-SAME: !type [[CF48:![0-9]+]]
+// ITANIUM-SAME: !type [[D32:![0-9]+]]
+// ITANIUM-SAME: !type [[DF32:![0-9]+]]
+// ITANIUM-SAME: !type [[DF40:![0-9]+]]
+// ITANIUM-SAME: !type [[DF48:![0-9]+]]
+
+// ITANIUM: @_ZTCN12_GLOBAL__N_11DE0_1B = {{[^!]*}}, !type [[A32]]
+// ITANIUM-SAME: !type [[B32]]
+
+// ITANIUM: @_ZTCN12_GLOBAL__N_11DE8_1C = {{[^!]*}}, !type [[A64:![0-9]+]]
+// ITANIUM-SAME: !type [[AF64:![0-9]+]]
+// ITANIUM-SAME: !type [[C32]]
+// ITANIUM-SAME: !type [[CF64:![0-9]+]]
+
+// ITANIUM: @_ZTVZ3foovE2FA = {{[^!]*}}, !type [[A16]]
+// ITANIUM-SAME: !type [[AF16]]
+// ITANIUM-SAME: !type [[FA16:![0-9]+]]
+// ITANIUM-SAME: !type [[FAF16:![0-9]+]]
+
+// MS: comdat($"??_7A@@6B@"), !type [[A8:![0-9]+]]
+// MS: comdat($"??_7B@@6B0@@"), !type [[B8:![0-9]+]]
+// MS: comdat($"??_7B@@6BA@@@"), !type [[A8]]
+// MS: comdat($"??_7C@@6B@"), !type [[A8]]
+// MS: comdat($"??_7D@?A0x{{[^@]*}}@@6BB@@@"), !type [[B8]], !type [[D8:![0-9]+]]
+// MS: comdat($"??_7D@?A0x{{[^@]*}}@@6BA@@@"), !type [[A8]]
+// MS: comdat($"??_7FA@?1??foo@@YAXXZ at 6B@"), !type [[A8]], !type [[FA8:![0-9]+]]
+
+struct A {
+  A();
+  virtual void f();
+};
+
+struct B : virtual A {
+  B();
+  virtual void g();
+  virtual void h();
+};
+
+struct C : virtual A {
+  C();
+};
+
+namespace {
+
+struct D : B, C {
+  D();
+  virtual void f();
+  virtual void h();
+};
+
+}
+
+A::A() {}
+B::B() {}
+C::C() {}
+D::D() {}
+
+void A::f() {
+}
+
+void B::g() {
+}
+
+void D::f() {
+}
+
+void D::h() {
+}
+
+void af(A *a) {
+  a->f();
+}
+
+void df1(D *d) {
+ 
+  d->f();
+}
+
+void dg1(D *d) {
+ 
+  d->g();
+}
+
+void dh1(D *d) {
+  
+  d->h();
+}
+
+void df2(D *d) {
+
+  d->f();
+}
+
+void df3(D *d) {
+
+  d->f();
+}
+
+D d;
+
+void foo() {
+  df1(&d);
+  dg1(&d);
+  dh1(&d);
+  df2(&d);
+  df3(&d);
+
+  struct FA : A {
+    void f() {}
+  } fa;
+  af(&fa);
+}

``````````

</details>


https://github.com/llvm/llvm-project/pull/70841