[clang][Driver] Default to DIOp-based DIExpressions in SPIRV (llvm#1320)

Author: epilk

clang/include/clang/Driver/Options.td

@@ -4457,8 +4457,8 @@ def gheterogeneous_dwarf_EQ : Joined<["-"], "gheterogeneous-dwarf=">,
   MarshallingInfoEnum<CodeGenOpts<"HeterogeneousDwarfMode">, "Disabled">;
 def gheterogeneous_dwarf : Flag<["-"], "gheterogeneous-dwarf">, Group<g_Group>,
   Visibility<[ClangOption, CC1Option]>,
-  HelpText<"Enable DIExpr-based DWARF extensions for heterogeneous debugging">,
-  Alias<gheterogeneous_dwarf_EQ>, AliasArgs<["diexpr"]>;
+  HelpText<"Enable DIExpression-based DWARF extensions for heterogeneous debugging">,
+  Alias<gheterogeneous_dwarf_EQ>, AliasArgs<["diexpression"]>;
 def gno_heterogeneous_dwarf : Flag<["-"], "gno-heterogeneous-dwarf">,
   Visibility<[ClangOption, CC1Option]>,
   Group<g_Group>,

clang/lib/Driver/ToolChains/Clang.cpp

@@ -4821,10 +4821,16 @@ renderDebugOptions(const ToolChain &TC, const Driver &D, const llvm::Triple &T,
   renderDwarfFormat(D, T, Args, CmdArgs, EffectiveDWARFVersion);
   RenderDebugInfoCompressionArgs(Args, CmdArgs, D, TC);
 
-  bool EmitDwarfForAMDGCN = EmitDwarf && T.isAMDGCN();
+  bool EmitDwarfForAMDGCN =
+      EmitDwarf &&
+      (T.isAMDGCN() || (T.isSPIRV() && T.getVendor() == llvm::Triple::AMD));
   if (EmitDwarfForAMDGCN)
     CmdArgs.append({"-mllvm", "-amdgpu-spill-cfi-saved-regs"});
   if (Arg *A = Args.getLastArg(options::OPT_gheterogeneous_dwarf_EQ)) {
+    if (StringRef(A->getValue()) == "diexpr" && T.isSPIRV() &&
+        T.getVendor() == llvm::Triple::AMD)
+      D.Diag(clang::diag::err_drv_unsupported_opt_with_suggestion)
+          << A->getAsString(Args) << "-gheterogeneous-dwarf=diexpression";
     A->render(Args, CmdArgs);
   } else if (EmitDwarfForAMDGCN) {
 #ifndef NDEBUG
@@ -4842,11 +4848,12 @@ renderDebugOptions(const ToolChain &TC, const Driver &D, const llvm::Triple &T,
     assert(Aliased.isValid() && "gheterogeneous-dwarf must be an alias");
     assert(Aliased.getName() == "gheterogeneous-dwarf=" &&
            "gheterogeneous-dwarf must alias gheterogeneous-dwarf=");
-    assert(StringRef(GHeterogeneousDwarf.getAliasArgs()) == "diexpr" &&
-           GHeterogeneousDwarf.getAliasArgs()[strlen("diexpr") + 1] == '\0' &&
-           "gheterogeneous-dwarf must alias gheterogeneous-dwarf=diexpr");
+    assert(StringRef(GHeterogeneousDwarf.getAliasArgs()) == "diexpression" &&
+           GHeterogeneousDwarf.getAliasArgs()[strlen("diexpression") + 1] ==
+               '\0' &&
+           "gheterogeneous-dwarf must alias gheterogeneous-dwarf=diexpression");
 #endif
-    CmdArgs.push_back("-gheterogeneous-dwarf=diexpr");
+    CmdArgs.push_back("-gheterogeneous-dwarf=diexpression");
   }
 
   // This controls whether or not we perform JustMyCode instrumentation.

clang/test/CodeGenHIP/debug-info-cc1-option.hip

@@ -5,8 +5,7 @@
 // and aliases the new default. This is needed for transitioning flang-legacy
 // as it depends on the -cc1 interface.
 
-// CHECK: call void @llvm.dbg.def
-// CHECK: !DIExpr(
+// CHECK: #dbg_declare{{.*}}DIExpression{{.*}}DIOp
 __attribute__((device)) void kernel1(int Arg) {
   int FuncVar;
 }

clang/test/Driver/amdgpu-debug.cl

@@ -7,7 +7,7 @@
 // CHECK-SIMPLE-NOT: "-disable-O0-optnone"
 // CHECK-SIMPLE-NOT: "-debug-info-kind=line-tables-only"
 // CHECK-SIMPLE-DAG: "-mllvm" "-amdgpu-spill-cfi-saved-regs"
-// CHECK-SIMPLE-DAG: "-gheterogeneous-dwarf=diexpr"
+// CHECK-SIMPLE-DAG: "-gheterogeneous-dwarf=diexpression"
 // CHECK-SIMPLE-DAG: "-debugger-tuning=gdb"
 // CHECK-SIMPLE-NOT: "-disable-O0-optnone"
 // CHECK-SIMPLE-NOT: "-debug-info-kind=line-tables-only"
@@ -21,7 +21,7 @@
 // Check that -gheterogeneous-dwarf can be enabled for non-AMDGCN
 // RUN: %clang -### -target x86_64-linux-gnu -x cl -c -nogpuinc -nogpulib  -emit-llvm -gheterogeneous-dwarf %s 2>&1 | FileCheck -check-prefix=CHECK-EXPLICIT-HETEROGENEOUS %s
 // CHECK-EXPLICIT-HETEROGENEOUS: "-cc1"
-// CHECK-EXPLICIT-HETEROGENEOUS: "-gheterogeneous-dwarf=diexpr"
+// CHECK-EXPLICIT-HETEROGENEOUS: "-gheterogeneous-dwarf=diexpression"
 
 // Check that -gheterogeneous-dwarf can be disabled for AMDGCN
 // RUN: %clang -### -target amdgcn-amd-amdhsa -x cl -c -nogpuinc -nogpulib  -emit-llvm -g -gno-heterogeneous-dwarf %s 2>&1 | FileCheck -check-prefix=CHECK-NO-HETEROGENEOUS %s
@@ -46,3 +46,14 @@
 // Check that -gheterogeneous-dwarf= fails for unknown option
 // RUN: not %clang -target amdgcn-amd-amdhsa -x cl -c -nogpuinc -nogpulib  -emit-llvm -g -gheterogeneous-dwarf=unknown %s 2>&1 | FileCheck -check-prefix=CHECK-UNKNOWN %s
 // CHECK-UNKNOWN: error: invalid value
+
+// Check that =diexpression is implied by -g + spirv
+// RUN: %clang -### -target spirv64-amd-amdhsa -x cl -c -nogpuinc -nogpulib  -emit-llvm -g %s 2>&1 | FileCheck -check-prefix=CHECK-SPIRV %s
+// CHECK-SPIRV: "-cc1"
+// CHECK-SPIRV-DAG: "-mllvm" "-amdgpu-spill-cfi-saved-regs"
+// CHECK-SPIRV-DAG: "-gheterogeneous-dwarf=diexpression"
+// CHECK-SPIRV-DAG: "-debugger-tuning=gdb"
+
+// Check that =diexpr produces an error on spirv.
+// RUN: not %clang -### -target spirv64-amd-amdhsa -x cl -c -nogpuinc -nogpulib  -emit-llvm -g -gheterogeneous-dwarf=diexpr %s 2>&1 | FileCheck -check-prefix=CHECK-SPIRV-ERR %s
+// CHECK-SPIRV-ERR: error: unsupported option '-gheterogeneous-dwarf=diexpr'; did you mean '-gheterogeneous-dwarf=diexpression'?

llvm/lib/IR/BasicBlock.cpp

@@ -47,7 +47,7 @@ cl::opt<cl::boolOrDefault> PreserveInputDbgFormat(
 bool WriteNewDbgInfoFormatToBitcode /*set default value in cl::init() below*/;
 cl::opt<bool, true> WriteNewDbgInfoFormatToBitcode2(
     "write-experimental-debuginfo-iterators-to-bitcode", cl::Hidden,
-    cl::location(WriteNewDbgInfoFormatToBitcode), cl::init(false));
+    cl::location(WriteNewDbgInfoFormatToBitcode), cl::init(true));
 
 DbgMarker *BasicBlock::createMarker(Instruction *I) {
   assert(IsNewDbgInfoFormat &&

llvm/lib/IR/DebugProgramInstruction.cpp

@@ -474,11 +474,12 @@ DbgLabelRecord::createDebugIntrinsic(Module *M,
 
 Value *DbgVariableRecord::getAddress() const {
   auto *MD = getRawAddress();
-  if (auto *V = dyn_cast<ValueAsMetadata>(MD))
+  if (auto *V = dyn_cast_or_null<ValueAsMetadata>(MD))
     return V->getValue();
 
   // When the value goes to null, it gets replaced by an empty MDNode.
-  assert(!cast<MDNode>(MD)->getNumOperands() && "Expected an empty MDNode");
+  assert(!MD ||
+         !cast<MDNode>(MD)->getNumOperands() && "Expected an empty MDNode");
   return nullptr;
 }
 

llvm/lib/IR/TypeFinder.cpp

@@ -88,6 +88,24 @@ void TypeFinder::run(const Module &M, bool onlyNamed) {
         for (const auto &MD : MDForInst)
           incorporateMDNode(MD.second);
         MDForInst.clear();
+
+        // Incorporate types hiding in variable-location information.
+        for (const auto &Dbg : I.getDbgRecordRange()) {
+          // Pick out records that have Values.
+          if (const DbgVariableRecord *DVI =
+                  dyn_cast<DbgVariableRecord>(&Dbg)) {
+            for (Value *V : DVI->location_ops())
+              incorporateValue(V);
+            if (DVI->isDbgAssign()) {
+              if (Value *Addr = DVI->getAddress())
+                incorporateValue(Addr);
+              if (auto *Expr = DVI->getRawAddressExpression())
+                incorporateMDNode(Expr);
+            }
+            if (auto *Expr = DVI->getRawExpression())
+              incorporateMDNode(Expr);
+          }
+        }
       }
   }
 

llvm/test/Assembler/DIExpressionNewDebugRecords.ll

@@ -0,0 +1,28 @@
+; RUN: llvm-as < %s | llvm-dis | llvm-as | llvm-dis | FileCheck %s
+
+; CHECK: %struct.S = type { i32 }
+%struct.S = type { i32 }
+
+define dso_local i32 @f() !dbg !7 {
+entry:
+    ; CHECK: #dbg_value(ptr null, !9, !DIExpression(DIOpArg(0, ptr), DIOpDeref(%struct.S)), !11)
+    #dbg_value(ptr null, !9, !DIExpression(DIOpArg(0, ptr), DIOpDeref(%struct.S)), !11)
+  ret i32 0, !dbg !11
+}
+
+!llvm.dbg.cu = !{!0}
+!llvm.module.flags = !{!3, !4, !5}
+!llvm.ident = !{!6}
+
+!0 = distinct !DICompileUnit(language: DW_LANG_C99, file: !1, producer: "clang version 18.0.0", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !2, nameTableKind: None)
+!1 = !DIFile(filename: "print.c", directory: "/tmp")
+!2 = !{}
+!3 = !{i32 2, !"Dwarf Version", i32 5}
+!4 = !{i32 2, !"Debug Info Version", i32 3}
+!5 = !{i32 1, !"wchar_size", i32 4}
+!6 = !{!"clang version 18.0.0"}
+!7 = distinct !DISubprogram(name: "f", scope: !1, file: !1, line: 3, type: !8, scopeLine: 3, flags: DIFlagPrototyped, spFlags: DISPFlagDefinition | DISPFlagOptimized, unit: !0)
+!8 = !DISubroutineType(types: !2)
+!9 = !DILocalVariable(name: "a", arg: 1, scope: !7, file: !1, line: 3, type: !10)
+!10 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
+!11 = !DILocation(line: 3, column: 15, scope: !7)

llvm/test/DebugInfo/type-finder-w-dbg-records.ll

@@ -0,0 +1,51 @@
+; RUN: opt --passes=verify %s -o - -S | FileCheck %s
+
+;; Test that the type definitions are discovered when serialising to LLVM-IR,
+;; even if they're only present inside a DbgRecord, and thus not normally
+;; visible.
+
+; CHECK: %union.anon = type { %struct.a }
+; CHECK: %struct.a = type { i32 }
+; CHECK: %union.anon2 = type { %struct.a2 }
+; CHECK: %struct.a2 = type { i32 }
+
+; ModuleID = 'bbi-98372.ll'
+source_filename = "bbi-98372.ll"
+
+%union.anon = type { %struct.a }
+%struct.a = type { i32 }
+%union.anon2 = type { %struct.a2 }
+%struct.a2 = type { i32 }
+
+@d = global [1 x { i16, i16 }] [{ i16, i16 } { i16 0, i16 undef }], align 1
+@e = global [1 x { i16, i16 }] [{ i16, i16 } { i16 0, i16 undef }], align 1
+
+define void @f() {
+entry:
+    #dbg_value(ptr getelementptr inbounds ([1 x %union.anon], ptr @d, i32 0, i32 3), !7, !DIExpression(), !14)
+    #dbg_assign(ptr null, !7, !DIExpression(), !16, ptr getelementptr inbounds ([1 x %union.anon2], ptr @e, i32 0, i32 3), !17, !14)
+  ret void, !dbg !15
+}
+
+!llvm.dbg.cu = !{!0}
+!llvm.module.flags = !{!2, !3, !4, !5}
+!llvm.ident = !{!6}
+
+!0 = distinct !DICompileUnit(language: DW_LANG_C11, file: !1, producer: "clang", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, splitDebugInlining: false, nameTableKind: None)
+!1 = !DIFile(filename: "foo.c", directory: "/bar")
+!2 = !{i32 7, !"Dwarf Version", i32 4}
+!3 = !{i32 2, !"Debug Info Version", i32 3}
+!4 = !{i32 1, !"wchar_size", i32 1}
+!5 = !{i32 7, !"frame-pointer", i32 2}
+!6 = !{!"clang"}
+!7 = !DILocalVariable(name: "f", scope: !8, file: !1, line: 8, type: !12)
+!8 = distinct !DISubprogram(name: "e", scope: !1, file: !1, line: 8, type: !9, scopeLine: 8, flags: DIFlagAllCallsDescribed, spFlags: DISPFlagDefinition | DISPFlagOptimized, unit: !0, retainedNodes: !11)
+!9 = !DISubroutineType(types: !10)
+!10 = !{null}
+!11 = !{!7}
+!12 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: !13, size: 16)
+!13 = !DIBasicType(name: "int", size: 16, encoding: DW_ATE_signed)
+!14 = !DILocation(line: 0, scope: !8)
+!15 = !DILocation(line: 8, column: 28, scope: !8)
+!16 = distinct !DIAssignID()
+!17 = !DIExpression()