[MLIR][DebugInfo] Enable the use of DILocalVariable DIFlags (#100190)

This patch enables the use of flags for local variables in debug info.
They were defaulted as always zero, but allowing them is pretty trivial.

Author: walter-erquinigo

flang/lib/Optimizer/Transforms/AddDebugInfo.cpp

@@ -129,7 +129,7 @@ void AddDebugInfoPass::handleDeclareOp(fir::cg::XDeclareOp declOp,
   auto localVarAttr = mlir::LLVM::DILocalVariableAttr::get(
       context, scopeAttr, mlir::StringAttr::get(context, result.second.name),
       fileAttr, getLineFromLoc(declOp.getLoc()), argNo, /* alignInBits*/ 0,
-      tyAttr);
+      tyAttr, mlir::LLVM::DIFlags::Zero);
   declOp->setLoc(builder.getFusedLoc({declOp->getLoc()}, localVarAttr));
 }
 

mlir/include/mlir-c/Dialect/LLVM.h

@@ -309,7 +309,7 @@ MLIR_CAPI_EXPORTED MlirAttribute mlirLLVMDILexicalBlockFileAttrGet(
 MLIR_CAPI_EXPORTED MlirAttribute mlirLLVMDILocalVariableAttrGet(
     MlirContext ctx, MlirAttribute scope, MlirAttribute name,
     MlirAttribute diFile, unsigned int line, unsigned int arg,
-    unsigned int alignInBits, MlirAttribute diType);
+    unsigned int alignInBits, MlirAttribute diType, int64_t flags);
 
 /// Creates a LLVM DISubprogramAttr attribute.
 MLIR_CAPI_EXPORTED MlirAttribute mlirLLVMDISubprogramAttrGet(

mlir/include/mlir/Dialect/LLVMIR/LLVMAttrDefs.td

@@ -532,17 +532,18 @@ def LLVM_DILocalVariableAttr : LLVM_Attr<"DILocalVariable", "di_local_variable",
     OptionalParameter<"unsigned">:$line,
     OptionalParameter<"unsigned">:$arg,
     OptionalParameter<"unsigned">:$alignInBits,
-    OptionalParameter<"DITypeAttr">:$type
+    OptionalParameter<"DITypeAttr">:$type,
+    OptionalParameter<"DIFlags", "DIFlags::Zero">:$flags
   );
   let builders = [
     AttrBuilderWithInferredContext<(ins
       "DIScopeAttr":$scope, "StringRef":$name, "DIFileAttr":$file,
       "unsigned":$line, "unsigned":$arg, "unsigned":$alignInBits,
-      "DITypeAttr":$type
+      "DITypeAttr":$type, "DIFlags":$flags
     ), [{
       MLIRContext *ctx = scope.getContext();
       return $_get(ctx, scope, StringAttr::get(ctx, name), file, line,
-                   arg, alignInBits, type);
+                   arg, alignInBits, type, flags);
     }]>
   ];
   let assemblyFormat = "`<` struct(params) `>`";

mlir/lib/CAPI/Dialect/LLVM.cpp

@@ -266,15 +266,14 @@ MlirAttribute mlirLLVMDILexicalBlockFileAttrGet(MlirContext ctx,
       cast<DIFileAttr>(unwrap(file)), discriminator));
 }
 
-MlirAttribute
-mlirLLVMDILocalVariableAttrGet(MlirContext ctx, MlirAttribute scope,
-                               MlirAttribute name, MlirAttribute diFile,
-                               unsigned int line, unsigned int arg,
-                               unsigned int alignInBits, MlirAttribute diType) {
+MlirAttribute mlirLLVMDILocalVariableAttrGet(
+    MlirContext ctx, MlirAttribute scope, MlirAttribute name,
+    MlirAttribute diFile, unsigned int line, unsigned int arg,
+    unsigned int alignInBits, MlirAttribute diType, int64_t flags) {
   return wrap(DILocalVariableAttr::get(
       unwrap(ctx), cast<DIScopeAttr>(unwrap(scope)),
       cast<StringAttr>(unwrap(name)), cast<DIFileAttr>(unwrap(diFile)), line,
-      arg, alignInBits, cast<DITypeAttr>(unwrap(diType))));
+      arg, alignInBits, cast<DITypeAttr>(unwrap(diType)), DIFlags(flags)));
 }
 
 MlirAttribute mlirLLVMDISubroutineTypeAttrGet(MlirContext ctx,

mlir/lib/Target/LLVMIR/DebugImporter.cpp

@@ -180,7 +180,8 @@ DILocalVariableAttr DebugImporter::translateImpl(llvm::DILocalVariable *node) {
   return DILocalVariableAttr::get(
       context, scope, getStringAttrOrNull(node->getRawName()),
       translate(node->getFile()), node->getLine(), node->getArg(),
-      node->getAlignInBits(), translate(node->getType()));
+      node->getAlignInBits(), translate(node->getType()),
+      symbolizeDIFlags(node->getFlags()).value_or(DIFlags::Zero));
 }
 
 DIVariableAttr DebugImporter::translateImpl(llvm::DIVariable *node) {

mlir/lib/Target/LLVMIR/DebugTranslation.cpp

@@ -228,8 +228,8 @@ DebugTranslation::translateImpl(DILocalVariableAttr attr) {
   return llvm::DILocalVariable::get(
       llvmCtx, translate(attr.getScope()), getMDStringOrNull(attr.getName()),
       translate(attr.getFile()), attr.getLine(), translate(attr.getType()),
-      attr.getArg(),
-      /*Flags=*/llvm::DINode::FlagZero, attr.getAlignInBits(),
+      attr.getArg(), static_cast<llvm::DINode::DIFlags>(attr.getFlags()),
+      attr.getAlignInBits(),
       /*Annotations=*/nullptr);
 }
 

mlir/test/CAPI/llvm.c

@@ -294,7 +294,7 @@ static void testDebugInfoAttributes(MlirContext ctx) {
 
   // CHECK: #llvm.di_local_variable<{{.*}}>
   MlirAttribute local_var = mlirLLVMDILocalVariableAttrGet(
-      ctx, compile_unit, foo, file, 1, 0, 8, di_type);
+      ctx, compile_unit, foo, file, 1, 0, 8, di_type, 0);
   mlirAttributeDump(local_var);
   // CHECK: #llvm.di_derived_type<{{.*}}>
   // CHECK-NOT: dwarfAddressSpace

mlir/test/Target/LLVMIR/Import/debug-info.ll

@@ -781,7 +781,7 @@ define void @string_type(ptr %arg1) {
 !6 = !DIStringType(name: "character(*)", stringLength: !4, size: 32, align: 8, stringLengthExpression: !8, stringLocationExpression: !7)
 !7 = !DIExpression(DW_OP_push_object_address, DW_OP_deref)
 !8 = !DIExpression(DW_OP_push_object_address, DW_OP_plus_uconst, 8)
-!9 = !DILocalVariable(scope: !5, name: "str", file: !2, type: !6);
+!9 = !DILocalVariable(scope: !5, name: "str", file: !2, type: !6, flags: 64);
 !10 = !DILocation(line: 1, column: 2, scope: !5)
 
 ; CHECK: #[[VAR:.+]] = #llvm.di_local_variable<{{.*}}name = "string_size"{{.*}}>
@@ -791,3 +791,4 @@ define void @string_type(ptr %arg1) {
 ; CHECK-SAME: stringLength = #[[VAR]]
 ; CHECK-SAME: stringLengthExp = <[DW_OP_push_object_address, DW_OP_plus_uconst(8)]>
 ; CHECK-SAME: stringLocationExp = <[DW_OP_push_object_address, DW_OP_deref]>>
+; CHECK: #di_local_variable1 = #llvm.di_local_variable<scope = #di_subprogram, name = "str", file = #di_file, type = #di_string_type, flags = Artificial>

mlir/test/Target/LLVMIR/llvmir-debug.mlir

@@ -603,7 +603,7 @@ llvm.func @subranges(%arg: !llvm.ptr) {
  file = #file, isOptimized = false, emissionKind = Full>
 #sp = #llvm.di_subprogram<compileUnit = #cu, scope = #file, name = "test",
  file = #file, subprogramFlags = Definition>
-#var = #llvm.di_local_variable<scope = #sp, name = "string_size", type = #bt>
+#var = #llvm.di_local_variable<scope = #sp, name = "string_size", type = #bt, flags = Artificial>
 #ty = #llvm.di_string_type<tag = DW_TAG_string_type, name = "character(*)",
  sizeInBits = 32, alignInBits = 8, stringLength = #var,
  stringLengthExp = <[DW_OP_push_object_address, DW_OP_plus_uconst(8)]>,
@@ -620,4 +620,4 @@ llvm.func @string_ty(%arg0: !llvm.ptr) {
 #loc2 = loc(fused<#sp>[#loc1])
 
 // CHECK-DAG: !DIStringType(name: "character(*)", stringLength: ![[VAR:[0-9]+]], stringLengthExpression: !DIExpression(DW_OP_push_object_address, DW_OP_plus_uconst, 8), stringLocationExpression: !DIExpression(DW_OP_push_object_address, DW_OP_deref), size: 32, align: 8)
-// CHECK-DAG: ![[VAR]] = !DILocalVariable(name: "string_size"{{.*}})
+// CHECK-DAG: ![[VAR]] = !DILocalVariable(name: "string_size"{{.*}} flags: DIFlagArtificial)