[OpenMP][FIX] Emit debug declares only if debug info is available

[jdoerfert]

Summary

The EmitDeclareOfAutoVariable introduced in D114504 and D115510 has a
precondition that cannot be violated. It is unclear if we should call it
directly given the sparse usage in clang but for now we should at least
not crash if the debug info kind is too low.

Fixes #52938.

[jdoerfert]

Clang format

[ye-luo]

Confirm that #52938 is fixed by this patch.

clang/lib/CodeGen/CGStmtOpenMP.cpp

if (auto *DI = CGF.getDebugInfo()) {
         //            metadata !DIExpression(DW_OP_plus_uconst, 8, DW_OP_deref))
         for (auto It = CaptureFields.begin(); It != CaptureFields.end(); ++It) {
           const VarDecl *SharedVar = It->first;
           RecordDecl *CaptureRecord = It->second->getParent();
           const ASTRecordLayout &Layout =
               CGF.getContext().getASTRecordLayout(CaptureRecord);
           unsigned Offset =
               Layout.getFieldOffset(It->second->getFieldIndex()) / CharWidth;
+          if (CGF.CGM.getCodeGenOpts().hasReducedDebugInfo())
             (void)DI->EmitDeclareOfAutoVariable(SharedVar, ContextValue,
                                                 CGF.Builder, false);
           llvm::Instruction &Last = CGF.Builder.GetInsertBlock()->back();
           // Get the call dbg.declare instruction we just created and update
           // its DIExpression to add offset to base address.
           if (auto DDI = dyn_cast<llvm::DbgVariableIntrinsic>(&Last)) {
             SmallVector<uint64_t, 8> Ops;
             // Add offset to the base address if non zero.
             if (Offset) {
               Ops.push_back(llvm::dwarf::DW_OP_plus_uconst);
if (!Data.PrivateVars.empty() || !Data.FirstprivateVars.empty() ||
           return CGF.EmitLValue(&DRE).getAddress(CGF);
         });
       }
       for (const auto &Pair : PrivatePtrs) {
         Address Replacement(CGF.Builder.CreateLoad(Pair.second),
                             CGF.getContext().getDeclAlign(Pair.first));
         Scope.addPrivate(Pair.first, [Replacement]() { return Replacement; });
         if (auto *DI = CGF.getDebugInfo())
-          DI->EmitDeclareOfAutoVariable(Pair.first, Pair.second.getPointer(),
+          if (CGF.CGM.getCodeGenOpts().hasReducedDebugInfo())
+            (void)DI->EmitDeclareOfAutoVariable(Pair.first, Pair.second.getPointer(),
                                           CGF.Builder, /*UsePointerValue*/ true);
       }
       // Adjust mapping for internal locals by mapping actual memory instead of
       // a pointer to this memory.
       for (auto &Pair : UntiedLocalVars) {
         if (isAllocatableDecl(Pair.first)) {
           llvm::Value *Ptr = CGF.Builder.CreateLoad(Pair.second.first);
           Address Replacement(Ptr, CGF.getPointerAlign());
           Pair.second.first = Replacement;

clang/test/OpenMP/debug_private.c

 // This testcase checks emission of debug info for variables inside
 // private/firstprivate/lastprivate.
 
 // REQUIRES: x86_64-linux
 
 // RUN: %clang_cc1 -debug-info-kind=constructor -x c -verify -triple x86_64-pc-linux-gnu -fopenmp -emit-llvm %s -o - | FileCheck %s
+// RUN: %clang_cc1 -debug-info-kind=line-directives-only -x c -verify -triple x86_64-pc-linux-gnu -fopenmp -emit-llvm %s -o - | FileCheck %s --check-prefix=NEG
+// RUN: %clang_cc1 -debug-info-kind=line-tables-only -x c -verify -triple x86_64-pc-linux-gnu -fopenmp -emit-llvm %s -o - | FileCheck %s --check-prefix=NEG
+// RUN: %clang_cc1 -debug-info-kind=limited -x c -verify -triple x86_64-pc-linux-gnu -fopenmp -emit-llvm %s -o - | FileCheck %s
 // expected-no-diagnostics
 
 // CHECK: define internal i32 @.omp_task_entry.
 
 // CHECK:  call void @llvm.dbg.declare(metadata i32** %.priv.ptr.addr.i, metadata [[PRIV1:![0-9]+]], metadata !DIExpression(DW_OP_deref))
 // CHECK:  call void @llvm.dbg.declare(metadata i32** %.priv.ptr.addr1.i, metadata [[PRIV2:![0-9]+]], metadata !DIExpression(DW_OP_deref))
 // CHECK:  call void @llvm.dbg.declare(metadata i32** %.firstpriv.ptr.addr.i, metadata [[FPRIV:![0-9]+]], metadata !DIExpression(DW_OP_deref))
+// NEG-NOT: call void @llvm.dbg.declare
 
 // CHECK: [[PRIV1]] = !DILocalVariable(name: "priv1"
 // CHECK: [[PRIV2]] = !DILocalVariable(name: "priv2"
 // CHECK: [[FPRIV]] = !DILocalVariable(name: "fpriv"
 
 extern int printf(const char *, ...);
 
 int foo(int n) {

clang/test/OpenMP/debug_task_shared.c

 // This testcase checks emission of debug info for variables
 // inside shared clause of task construct.
 
 // REQUIRES: x86_64-linux
 
 // RUN: %clang_cc1 -debug-info-kind=constructor -DSHARED -x c -verify -triple x86_64-pc-linux-gnu -fopenmp -emit-llvm %s -o - | FileCheck %s --check-prefix=CHECK
 // RUN: %clang_cc1 -debug-info-kind=constructor -x c -verify -triple x86_64-pc-linux-gnu -fopenmp -emit-llvm %s -o - | FileCheck %s --check-prefix=NEG
+// RUN: %clang_cc1 -debug-info-kind=line-directives-only -DSHARED -x c -verify -triple x86_64-pc-linux-gnu -fopenmp -emit-llvm %s -o - | FileCheck %s --check-prefix=NEG
+// RUN: %clang_cc1 -debug-info-kind=line-tables-only -DSHARED -x c -verify -triple x86_64-pc-linux-gnu -fopenmp -emit-llvm %s -o - | FileCheck %s --check-prefix=NEG
+// RUN: %clang_cc1 -debug-info-kind=limited -DSHARED -x c -verify -triple x86_64-pc-linux-gnu -fopenmp -emit-llvm %s -o - | FileCheck %s --check-prefix=CHECK
 // expected-no-diagnostics
 
 // CHECK-LABEL: define internal i32 @.omp_task_entry.
 
 // CHECK-DAG:  [[CONTEXT:%[0-9]+]] = load %struct.anon*, %struct.anon** %__context.addr.i, align 8
 // CHECK-DAG:  call void @llvm.dbg.declare(metadata %struct.anon* [[CONTEXT]], metadata [[SHARE2:![0-9]+]], metadata !DIExpression(DW_OP_deref))
 // CHECK-DAG:  call void @llvm.dbg.declare(metadata %struct.anon* [[CONTEXT]], metadata [[SHARE3:![0-9]+]], metadata !DIExpression(DW_OP_plus_uconst, 8, DW_OP_deref))
 // CHECK-DAG:  call void @llvm.dbg.declare(metadata %struct.anon* [[CONTEXT]], metadata [[SHARE1:![0-9]+]], metadata !DIExpression(DW_OP_plus_uconst, 16, DW_OP_deref))