Index: llvm/docs/SourceLevelDebugging.rst =================================================================== --- llvm/docs/SourceLevelDebugging.rst +++ llvm/docs/SourceLevelDebugging.rst @@ -1087,6 +1087,10 @@ !DILocalVariable(name: "string", arg: 1, scope: !10, file: !3, line: 4, type: !15) !DIStringType(name: "character(*)!2", stringLength: !16, stringLengthExpression: !DIExpression(), size: 32) +A fortran deferred-length character can also contain the information of raw storage of the characters in addition to the length of the string. This information is encoded in the stringLocationExpression field. Based on this information, DW_AT_data_location attribute is emitted in a DW_TAG_string_type debug info. + + !DIStringType(name: "character(*)!2", stringLengthExpression: !DIExpression(), stringLocationExpression: !DIExpression(DW_OP_push_object_address, DW_OP_deref), size: 32) + and this will materialize in DWARF tags as: .. code-block:: text @@ -1097,6 +1101,7 @@ 0x00000064: DW_TAG_variable DW_AT_location (DW_OP_fbreg +16) DW_AT_type (0x00000083 "integer*8") + DW_AT_data_location (DW_OP_push_object_address, DW_OP_deref) ... DW_AT_artificial (true) Index: llvm/include/llvm/IR/DIBuilder.h =================================================================== --- llvm/include/llvm/IR/DIBuilder.h +++ llvm/include/llvm/IR/DIBuilder.h @@ -221,6 +221,23 @@ /// \param SizeInBits Size of the type. DIStringType *createStringType(StringRef Name, uint64_t SizeInBits); + /// Create debugging information entry for Fortran + /// assumed length string type. + /// \param Name Type name. + /// \param StringLength String length expressed as DIVariable *. + /// \param StrLocationExp Optional memory location of the string. + DIStringType *createStringType(StringRef Name, DIVariable *StringLength, + DIExpression *StrLocationExp = nullptr); + + /// Create debugging information entry for Fortran + /// assumed length string type. + /// \param Name Type name. + /// \param StringLengthExp String length expressed in DIExpression form. + /// \param StrLocationExp Optional memory location of the string. + DIStringType *createStringType(StringRef Name, + DIExpression *StringLengthExp, + DIExpression *StrLocationExp = nullptr); + /// Create debugging information entry for a qualified /// type, e.g. 'const int'. /// \param Tag Tag identifing type, e.g. dwarf::TAG_volatile_type Index: llvm/lib/IR/DIBuilder.cpp =================================================================== --- llvm/lib/IR/DIBuilder.cpp +++ llvm/lib/IR/DIBuilder.cpp @@ -293,6 +293,22 @@ SizeInBits, 0); } +DIStringType *DIBuilder::createStringType(StringRef Name, + DIVariable *StringLength, + DIExpression *StrLocationExp) { + assert(!Name.empty() && "Unable to create type without name"); + return DIStringType::get(VMContext, dwarf::DW_TAG_string_type, Name, + StringLength, nullptr, StrLocationExp, 0, 0, 0); +} + +DIStringType *DIBuilder::createStringType(StringRef Name, + DIExpression *StringLengthExp, + DIExpression *StrLocationExp) { + assert(!Name.empty() && "Unable to create type without name"); + return DIStringType::get(VMContext, dwarf::DW_TAG_string_type, Name, nullptr, + StringLengthExp, StrLocationExp, 0, 0, 0); +} + DIDerivedType *DIBuilder::createQualifiedType(unsigned Tag, DIType *FromTy) { return DIDerivedType::get(VMContext, Tag, "", nullptr, 0, nullptr, FromTy, 0, 0, 0, None, DINode::FlagZero); Index: llvm/unittests/IR/DebugInfoTest.cpp =================================================================== --- llvm/unittests/IR/DebugInfoTest.cpp +++ llvm/unittests/IR/DebugInfoTest.cpp @@ -247,6 +247,45 @@ EXPECT_TRUE(isa_and_nonnull(SetType)); } +TEST(DIBuilder, CreateStringType) { + LLVMContext Ctx; + std::unique_ptr M(new Module("MyModule", Ctx)); + DIBuilder DIB(*M); + DIScope *Scope = DISubprogram::getDistinct( + Ctx, nullptr, "", "", nullptr, 0, nullptr, 0, nullptr, 0, 0, + DINode::FlagZero, DISubprogram::SPFlagZero, nullptr); + DIFile *F = DIB.createFile("main.c", "/"); + StringRef StrName = "string"; + DIVariable *StringLen = DIB.createAutoVariable(Scope, StrName, F, 0, nullptr, + false, DINode::FlagZero, 0); + auto getDIExpression = [&DIB](int offset) { + SmallVector ops; + ops.push_back(llvm::dwarf::DW_OP_push_object_address); + DIExpression::appendOffset(ops, offset); + ops.push_back(llvm::dwarf::DW_OP_deref); + + return DIB.createExpression(ops); + }; + DIExpression *StringLocationExp = getDIExpression(1); + DIStringType *StringType = + DIB.createStringType(StrName, StringLen, StringLocationExp); + + EXPECT_TRUE(isa_and_nonnull(StringType)); + EXPECT_EQ(StringType->getName(), StrName); + EXPECT_EQ(StringType->getStringLength(), StringLen); + EXPECT_EQ(StringType->getStringLocationExp(), StringLocationExp); + + StringRef StrNameExp = "stringexp"; + DIExpression *StringLengthExp = getDIExpression(2); + DIStringType *StringTypeExp = + DIB.createStringType(StrNameExp, StringLengthExp, StringLocationExp); + + EXPECT_TRUE(isa_and_nonnull(StringTypeExp)); + EXPECT_EQ(StringTypeExp->getName(), StrNameExp); + EXPECT_EQ(StringTypeExp->getStringLocationExp(), StringLocationExp); + EXPECT_EQ(StringTypeExp->getStringLengthExp(), StringLengthExp); +} + TEST(DIBuilder, DIEnumerator) { LLVMContext Ctx; std::unique_ptr M(new Module("MyModule", Ctx));