[DebugInfo] Add test cases for FlagNonTrivial

[asmith]

Summary

This is a test case to go with D44406 which added FlagNonTrivial to mark that a C++ record is non-trivial to support CodeView debug emission.

While it looks like FlagTypePassByValue can imply triviality and FlagTypePassByReference can imply non-triviality that is not true. Some non-trivial cases use a combination of FlagNonTrivial and FlagTypePassByValue instead of FlagTypePassByReference. See the test cases and D44406 for discussion.

[dblaikie]

Mind adding at least one example with neither triviality flag? (I guess a type that's not a struct or class? A union maybe?)

(in some ways this test is retesting some of the triviality that's already tested by other parts of the compiler that relies on triviality properties - so I'm ambivalent about testing /all/ these combinations (for instance, I'd probably not both testing any cases related to access modifiers at least - public/private doesn't have any effect on triviality, right? (so I'd leave all the tests public/struct))

test/CodeGenCXX/debug-info-composite-triviality.cpp

5–6

Would it be sufficient for this function to just be:

void Func(T&) {}

Since C++ supports overloading, there shouldn't be a need to mangle the type name into the function name manually, and any reference to the type should be enough for it to be emitted.

[asmith]

Any additional comments on the tests?

[dblaikie]

Looks good - thanks!

test/CodeGenCXX/debug-info-composite-triviality.cpp

+// RUN: %clang_cc1 -emit-llvm -debug-info-kind=standalone -triple %itanium_abi_triple %s -o - | FileCheck %s
+
+// Cases to show some non-trivial types with flags combined with DIFlagNonTrivial and DIFlagTypePassByValue.
+
+// CHECK-DAG: !DICompositeType({{.*}}, name: "Explicit",{{.*}}flags: DIFlagTypePassByValue | DIFlagNonTrivial
+struct Explicit {
+  explicit Explicit();
+  int a;
+} Explicit;
+
+// CHECK-DAG: !DICompositeType({{.*}}, name: "Struct",{{.*}}flags: DIFlagTypePassByValue | DIFlagNonTrivial
+struct Struct {
+  Struct() {}
+} Struct;
+
+// CHECK-DAG: !DICompositeType({{.*}}, name: "Annotated",{{.*}}flags: DIFlagTypePassByValue | DIFlagNonTrivial
+struct __attribute__((trivial_abi)) Annotated {
+  Annotated() {};
+} Annotated;
+
+
+// Check a non-composite type
+// CHECK-DAG: !DIGlobalVariable(name: "GlobalVar", {{.*}}type: {{.*}}, isLocal: false, isDefinition: true)
+int GlobalVar = 0;
+
+// Cases to test composite type's triviality
+
+// CHECK-DAG: !DICompositeType({{.*}}, name: "Union",{{.*}}flags: {{.*}}DIFlagTrivial
+union Union {
+  int a;
+} Union;
+
+// CHECK-DAG: !DICompositeType({{.*}}, name: "Trivial",{{.*}}flags: {{.*}}DIFlagTrivial
+struct Trivial {
+  int i;
+} Trivial;
+
+// CHECK-DAG: !DICompositeType({{.*}}, name: "TrivialA",{{.*}}flags: {{.*}}DIFlagTrivial
+struct TrivialA {
+  TrivialA() = default;
+} TrivialA;
+
+// CHECK-DAG: !DICompositeType({{.*}}, name: "TrivialB",{{.*}}flags: {{.*}}DIFlagTrivial
+struct TrivialB {
+  int m;
+  TrivialB(int x) { m = x; }
+  TrivialB() = default;
+} TrivialB;
+
+// CHECK-DAG: !DICompositeType({{.*}}, name: "TrivialC",{{.*}}flags: {{.*}}DIFlagTrivial
+struct TrivialC {
+  struct Trivial x;
+} TrivialC;
+
+// CHECK-DAG: !DICompositeType({{.*}}, name: "TrivialD",{{.*}}flags: {{.*}}DIFlagTrivial
+struct NT {
+  NT() {};
+};
+struct TrivialD {
+  static struct NT x; // Member is non-trivial but is static.
+} TrivialD;
+
+
+// CHECK-DAG: !DICompositeType({{.*}}, name: "NonTrivial",{{.*}}flags: {{.*}}DIFlagNonTrivial
+struct NonTrivial {
+  NonTrivial() {}
+} NonTrivial;
+
+// CHECK-DAG: !DICompositeType({{.*}}, name: "NonTrivialA",{{.*}}flags: {{.*}}DIFlagNonTrivial
+struct NonTrivialA {
+  ~NonTrivialA();
+} NonTrivialA;
+
+// CHECK-DAG: !DICompositeType({{.*}}, name: "NonTrivialB",{{.*}}flags: {{.*}}DIFlagNonTrivial
+struct NonTrivialB {
+  struct NonTrivial x;
+} NonTrivialB;
+
+// CHECK-DAG: !DICompositeType({{.*}}, name: "NonTrivialC",{{.*}}flags: {{.*}}DIFlagNonTrivial
+struct NonTrivialC {
+  virtual void f() {}
+} NonTrivialC;
+
+// CHECK-DAG: !DICompositeType({{.*}}, name: "NonTrivialD",{{.*}}flags: {{.*}}DIFlagNonTrivial
+struct NonTrivialD : NonTrivial {
+} NonTrivialD;
+
+// CHECK-DAG: !DICompositeType({{.*}}, name: "NonTrivialE",{{.*}}flags: {{.*}}DIFlagNonTrivial
+struct NonTrivialE : Trivial, NonTrivial {
+} NonTrivialE;