[clang][DebugInfo] Stop emitting DW_AT_const_value on static member declarations

Since `f07cf5aaf96a70123530239d07c1e655dc91b98d` we emit a definition
for any static data member with a constant initializer. That definition
will either have a location or constant attached to it. So having the
constant on the declaration is redundant. It also helps with the
type merging inconsistencies encountered in
#68721

Author: Michael137

clang/lib/CodeGen/CGDebugInfo.cpp

@@ -1677,21 +1677,11 @@ CGDebugInfo::CreateRecordStaticField(const VarDecl *Var, llvm::DIType *RecordTy,
 
   unsigned LineNumber = getLineNumber(Var->getLocation());
   StringRef VName = Var->getName();
-  llvm::Constant *C = nullptr;
-  if (Var->getInit()) {
-    const APValue *Value = Var->evaluateValue();
-    if (Value) {
-      if (Value->isInt())
-        C = llvm::ConstantInt::get(CGM.getLLVMContext(), Value->getInt());
-      if (Value->isFloat())
-        C = llvm::ConstantFP::get(CGM.getLLVMContext(), Value->getFloat());
-    }
-  }
 
   llvm::DINode::DIFlags Flags = getAccessFlag(Var->getAccess(), RD);
   auto Align = getDeclAlignIfRequired(Var, CGM.getContext());
   llvm::DIDerivedType *GV = DBuilder.createStaticMemberType(
-      RecordTy, VName, VUnit, LineNumber, VTy, Flags, C, Align);
+      RecordTy, VName, VUnit, LineNumber, VTy, Flags, /* Val */ nullptr, Align);
   StaticDataMemberCache[Var->getCanonicalDecl()].reset(GV);
   StaticDataMemberDefinitionsToEmit.push_back(Var->getCanonicalDecl());
   return GV;

clang/test/CodeGenCXX/debug-info-static-inline-member.cpp

@@ -42,25 +42,32 @@ int main() {
 // CHECK-SAME:                isLocal: false, isDefinition: true, declaration: ![[INT_DECL:[0-9]+]])
 
 // CHECK:      ![[INT_DECL]] = !DIDerivedType(tag: DW_TAG_member, name: "cexpr_int",
-// CHECK-SAME:                 flags: DIFlagStaticMember, extraData: i32 25)
+// CHECK-SAME:                 flags: DIFlagStaticMember
+// CHECK-NOT:                  extraData:
 
 // CHECK:      ![[INT_DECL2:[0-9]+]] = !DIDerivedType(tag: DW_TAG_member, name: "cexpr_int2",
-// CHECK-SAME:                         flags: DIFlagStaticMember, extraData: i32 26)
+// CHECK-SAME:                         flags: DIFlagStaticMember
+// CHECK-NOT:                          extraData:
 
 // CHECK:      ![[FLOAT_DECL:[0-9]+]] = !DIDerivedType(tag: DW_TAG_member, name: "cexpr_float",
-// CHECK-SAME:                          flags: DIFlagStaticMember, extraData: float
+// CHECK-SAME:                          flags: DIFlagStaticMember
+// CHECK-NOT:                           extraData:
 
 // CHECK:      ![[ENUM_DECL:[0-9]+]] = !DIDerivedType(tag: DW_TAG_member, name: "cexpr_enum",
-// CHECK-SAME:                         flags: DIFlagStaticMember, extraData: i32 -1)
+// CHECK-SAME:                         flags: DIFlagStaticMember
+// CHECK-NOT:                          extraData:
 
 // CHECK:      ![[EMPTY_DECL:[0-9]+]] = !DIDerivedType(tag: DW_TAG_member, name: "cexpr_empty",
-// CHECK-SAME:                          flags: DIFlagStaticMember)
+// CHECK-SAME:                          flags: DIFlagStaticMember
+// CHECK-NOT:                           extraData:
 
 // CHECK:      ![[IENUM_DECL:[0-9]+]] = !DIDerivedType(tag: DW_TAG_member, name: "inline_enum",
-// CHECK-SAME:                          flags: DIFlagStaticMember, extraData: i32 -1)
+// CHECK-SAME:                          flags: DIFlagStaticMember
+// CHECK-NOT:                           extraData:
 
 // CHECK:      ![[TEMPLATE_DECL:[0-9]+]] = !DIDerivedType(tag: DW_TAG_member, name: "cexpr_template",
-// CHECK-SAME:                             flags: DIFlagStaticMember, extraData: i16 0)
+// CHECK-SAME:                             flags: DIFlagStaticMember
+// CHECK-NOT:                              extraData:
 
 // CHECK:      !DIGlobalVariableExpression(var: ![[EMPTY_VAR:[0-9]+]], expr: !DIExpression())
 // CHECK:      ![[EMPTY_VAR]] = distinct !DIGlobalVariable(name: "cexpr_empty", linkageName:

clang/test/CodeGenCXX/debug-info-static-member.cpp

@@ -67,15 +67,15 @@ int C::a = 4;
 // CHECK-NOT:            size:
 // CHECK-NOT:            align:
 // CHECK-NOT:            offset:
-// CHECK-SAME:           flags: DIFlagStaticMember,
-// CHECK-SAME:           extraData: i1 true)
+// CHECK-SAME:           flags: DIFlagStaticMember
+// CHECK-NOT:            extraData:
 
 // CHECK: !DIDerivedType(tag: DW_TAG_member, name: "const_b"
 // CHECK-NOT:            size:
 // CHECK-NOT:            align:
 // CHECK-NOT:            offset:
-// CHECK-SAME:           flags: DIFlagProtected | DIFlagStaticMember,
-// CHECK-SAME:           extraData: float 0x{{.*}})
+// CHECK-SAME:           flags: DIFlagProtected | DIFlagStaticMember
+// CHECK-NOT:            extraData:
 
 // CHECK: ![[DECL_C:[0-9]+]] = !DIDerivedType(tag: DW_TAG_member, name: "c"
 // CHECK-NOT:                                 size:
@@ -87,8 +87,8 @@ int C::a = 4;
 // CHECK-NOT:            size:
 // CHECK-NOT:            align:
 // CHECK-NOT:            offset:
-// CHECK-SAME:           flags: DIFlagPublic | DIFlagStaticMember,
-// CHECK-SAME:           extraData: i32 18)
+// CHECK-SAME:           flags: DIFlagPublic | DIFlagStaticMember
+// CHECK-NOT:            extraData:
 //
 // CHECK: !DIDerivedType(tag: DW_TAG_member, name: "x_a"
 // CHECK-SAME:           flags: DIFlagPublic | DIFlagStaticMember)
@@ -144,7 +144,7 @@ struct V {
 // const_va is not emitted for MS targets.
 // NOT-MS: !DIDerivedType(tag: DW_TAG_member, name: "const_va",
 // NOT-MS-SAME:           line: [[@LINE-5]]
-// NOT-MS-SAME:           extraData: i32 42
+// NOT-MS-NOT:            extraData:
 const int V::const_va;
 
 namespace x {