https://github.com/ahatanak updated https://github.com/llvm/llvm-project/pull/79230
>From 678cd8ea37f1d02c70fd09b7107542c8301c3bd2 Mon Sep 17 00:00:00 2001 From: Akira Hatanaka <ahata...@gmail.com> Date: Tue, 16 Jan 2024 13:18:09 -0800 Subject: [PATCH 01/11] Add support for builtin_verbose_trap The builtin causes the program to stop its execution abnormally and shows a human-readable description of the reason for the termination when a debugger is attached or in a symbolicated crash log. The motivation for the builtin is explained in the following RFC: https://discourse.llvm.org/t/rfc-adding-builtin-verbose-trap-string-literal/75845 --- clang/docs/LanguageExtensions.rst | 48 ++++++++++++++++++ clang/include/clang/AST/Expr.h | 5 ++ clang/include/clang/Basic/Builtins.td | 6 +++ .../clang/Basic/DiagnosticSemaKinds.td | 2 + clang/lib/AST/ExprConstant.cpp | 18 +++++-- clang/lib/CodeGen/CGBuiltin.cpp | 12 +++++ clang/lib/CodeGen/CGDebugInfo.cpp | 42 ++++++++++++++++ clang/lib/CodeGen/CGDebugInfo.h | 20 ++++++++ clang/lib/Sema/SemaChecking.cpp | 22 +++++++++ .../CodeGenCXX/debug-info-verbose-trap.cpp | 49 +++++++++++++++++++ clang/test/SemaCXX/verbose-trap.cpp | 28 +++++++++++ 11 files changed, 249 insertions(+), 3 deletions(-) create mode 100644 clang/test/CodeGenCXX/debug-info-verbose-trap.cpp create mode 100644 clang/test/SemaCXX/verbose-trap.cpp diff --git a/clang/docs/LanguageExtensions.rst b/clang/docs/LanguageExtensions.rst index c1420079f75118..4526bc2df53e42 100644 --- a/clang/docs/LanguageExtensions.rst +++ b/clang/docs/LanguageExtensions.rst @@ -3379,6 +3379,54 @@ Query for this feature with ``__has_builtin(__builtin_debugtrap)``. Query for this feature with ``__has_builtin(__builtin_trap)``. +``__builtin_verbose_trap`` +------------------ + +``__builtin_verbose_trap`` causes the program to stop its execution abnormally +and shows a human-readable description of the reason for the termination when a +debugger is attached or in a symbolicated crash log. + +**Syntax**: + +.. code-block:: c++ + + __builtin_verbose_trap(const char *reason) + +**Description** + +``__builtin_verbose_trap`` is lowered to the ` ``llvm.trap`` <https://llvm.org/docs/LangRef.html#llvm-trap-intrinsic>`_ builtin. +Additionally, clang emits debug metadata that represents an artificial inline +frame whose name encodes the string passed to the builtin, prefixed by a "magic" +prefix. + +For example, consider the following code: + +.. code-block:: c++ + + void foo(int* p) { + if (p == nullptr) + __builtin_verbose_trap("Argument_must_not_be_null"); + } + +The debug metadata would look as if it were produced for the following code: + +.. code-block:: c++ + + __attribute__((always_inline)) + inline void "__llvm_verbose_trap: Argument_must_not_be_null"() { + __builtin_trap(); + } + + void foo(int* p) { + if (p == nullptr) + "__llvm_verbose_trap: Argument_must_not_be_null"(); + } + +However, the LLVM IR would not actually contain a call to the artificial +function — it only exists in the debug metadata. + +Query for this feature with ``__has_builtin(__builtin_verbose_trap)``. + ``__builtin_nondeterministic_value`` ------------------------------------ diff --git a/clang/include/clang/AST/Expr.h b/clang/include/clang/AST/Expr.h index 59f0aee2c0cedd..68447b19a4a107 100644 --- a/clang/include/clang/AST/Expr.h +++ b/clang/include/clang/AST/Expr.h @@ -775,6 +775,11 @@ class Expr : public ValueStmt { const Expr *PtrExpression, ASTContext &Ctx, EvalResult &Status) const; + /// If the current Expr can be evaluated to a pointer to a null-terminated + /// constant string, return the constant string (without the terminating null) + /// in Result. Return true if it succeeds. + bool tryEvaluateString(std::string &Result, ASTContext &Ctx) const; + /// Enumeration used to describe the kind of Null pointer constant /// returned from \c isNullPointerConstant(). enum NullPointerConstantKind { diff --git a/clang/include/clang/Basic/Builtins.td b/clang/include/clang/Basic/Builtins.td index 22e616e6cde599..217c09e85a55cc 100644 --- a/clang/include/clang/Basic/Builtins.td +++ b/clang/include/clang/Basic/Builtins.td @@ -1096,6 +1096,12 @@ def Trap : Builtin { let Prototype = "void()"; } +def VerboseTrap : Builtin { + let Spellings = ["__builtin_verbose_trap"]; + let Attributes = [NoThrow, NoReturn]; + let Prototype = "void(char const*)"; +} + def Debugtrap : Builtin { let Spellings = ["__builtin_debugtrap"]; let Attributes = [NoThrow]; diff --git a/clang/include/clang/Basic/DiagnosticSemaKinds.td b/clang/include/clang/Basic/DiagnosticSemaKinds.td index a1c32abb4dcd88..40482a964b39d5 100644 --- a/clang/include/clang/Basic/DiagnosticSemaKinds.td +++ b/clang/include/clang/Basic/DiagnosticSemaKinds.td @@ -8794,6 +8794,8 @@ def err_expected_callable_argument : Error< "expected a callable expression as %ordinal0 argument to %1, found %2">; def note_building_builtin_dump_struct_call : Note< "in call to printing function with arguments '(%0)' while dumping struct">; +def err_builtin_verbose_trap_arg : Error< + "argument to __builtin_verbose_trap must be a non-empty string literal">; def err_atomic_load_store_uses_lib : Error< "atomic %select{load|store}0 requires runtime support that is not " diff --git a/clang/lib/AST/ExprConstant.cpp b/clang/lib/AST/ExprConstant.cpp index f1d07d022b2584..33fc9a089a3941 100644 --- a/clang/lib/AST/ExprConstant.cpp +++ b/clang/lib/AST/ExprConstant.cpp @@ -1880,7 +1880,8 @@ static bool EvaluateAtomic(const Expr *E, const LValue *This, APValue &Result, EvalInfo &Info); static bool EvaluateAsRValue(EvalInfo &Info, const Expr *E, APValue &Result); static bool EvaluateBuiltinStrLen(const Expr *E, uint64_t &Result, - EvalInfo &Info); + EvalInfo &Info, + std::string *StringResult = nullptr); /// Evaluate an integer or fixed point expression into an APResult. static bool EvaluateFixedPointOrInteger(const Expr *E, APFixedPoint &Result, @@ -16625,7 +16626,7 @@ bool Expr::tryEvaluateObjectSize(uint64_t &Result, ASTContext &Ctx, } static bool EvaluateBuiltinStrLen(const Expr *E, uint64_t &Result, - EvalInfo &Info) { + EvalInfo &Info, std::string *StringResult) { if (!E->getType()->hasPointerRepresentation() || !E->isPRValue()) return false; @@ -16652,6 +16653,8 @@ static bool EvaluateBuiltinStrLen(const Expr *E, uint64_t &Result, Str = Str.substr(0, Pos); Result = Str.size(); + if (StringResult) + *StringResult = Str; return true; } @@ -16667,12 +16670,21 @@ static bool EvaluateBuiltinStrLen(const Expr *E, uint64_t &Result, if (!Char.getInt()) { Result = Strlen; return true; - } + } else if (StringResult) + StringResult->push_back(Char.getInt().getExtValue()); if (!HandleLValueArrayAdjustment(Info, E, String, CharTy, 1)) return false; } } +bool Expr::tryEvaluateString(std::string &StringResult, ASTContext &Ctx) const { + Expr::EvalStatus Status; + EvalInfo Info(Ctx, Status, EvalInfo::EM_ConstantFold); + uint64_t Result; + + return EvaluateBuiltinStrLen(this, Result, Info, &StringResult); +} + bool Expr::EvaluateCharRangeAsString(std::string &Result, const Expr *SizeExpression, const Expr *PtrExpression, ASTContext &Ctx, diff --git a/clang/lib/CodeGen/CGBuiltin.cpp b/clang/lib/CodeGen/CGBuiltin.cpp index 27183c69b7ea37..a701bb7917fd8c 100644 --- a/clang/lib/CodeGen/CGBuiltin.cpp +++ b/clang/lib/CodeGen/CGBuiltin.cpp @@ -3452,6 +3452,18 @@ RValue CodeGenFunction::EmitBuiltinExpr(const GlobalDecl GD, unsigned BuiltinID, case Builtin::BI__builtin_trap: EmitTrapCall(Intrinsic::trap); return RValue::get(nullptr); + case Builtin::BI__builtin_verbose_trap: { + llvm::DILocation *TrapLocation = Builder.getCurrentDebugLocation(); + if (getDebugInfo()) { + std::string Str; + E->getArg(0)->tryEvaluateString(Str, getContext()); + TrapLocation = getDebugInfo()->CreateTrapFailureMessageFor( + TrapLocation, "__llvm_verbose_trap", Str); + } + ApplyDebugLocation ApplyTrapDI(*this, TrapLocation); + EmitTrapCall(Intrinsic::trap); + return RValue::get(nullptr); + } case Builtin::BI__debugbreak: EmitTrapCall(Intrinsic::debugtrap); return RValue::get(nullptr); diff --git a/clang/lib/CodeGen/CGDebugInfo.cpp b/clang/lib/CodeGen/CGDebugInfo.cpp index 0f3f684d61dc94..fadbc0a80f8a11 100644 --- a/clang/lib/CodeGen/CGDebugInfo.cpp +++ b/clang/lib/CodeGen/CGDebugInfo.cpp @@ -1628,6 +1628,27 @@ llvm::DIType *CGDebugInfo::createFieldType( offsetInBits, flags, debugType, Annotations); } +llvm::DISubprogram * +CGDebugInfo::getFakeFuncSubprogram(const std::string &FakeFuncName) { + llvm::DISubprogram *&SP = FakeFuncMap[FakeFuncName]; + + if (!SP) { + auto FileScope = TheCU->getFile(); + llvm::DISubroutineType *DIFnTy = DBuilder.createSubroutineType(nullptr); + // Note: We use `FileScope` rather than `TheCU` as the scope because that's + // what LLVM's inliner seems to do. + SP = DBuilder.createFunction( + /*Scope=*/FileScope, /*Name=*/FakeFuncName, /*LinkageName=*/StringRef(), + /*File=*/FileScope, /*LineNo=*/0, /*Ty=*/DIFnTy, + /*ScopeLine=*/0, + /*Flags=*/llvm::DINode::FlagArtificial, + /*SPFlags=*/llvm::DISubprogram::SPFlagDefinition, + /*TParams=*/nullptr, /*ThrownTypes=*/nullptr, /*Annotations=*/nullptr); + } + + return SP; +} + void CGDebugInfo::CollectRecordLambdaFields( const CXXRecordDecl *CXXDecl, SmallVectorImpl<llvm::Metadata *> &elements, llvm::DIType *RecordTy) { @@ -3424,6 +3445,27 @@ llvm::DIMacroFile *CGDebugInfo::CreateTempMacroFile(llvm::DIMacroFile *Parent, return DBuilder.createTempMacroFile(Parent, Line, FName); } +llvm::DILocation *CGDebugInfo::CreateTrapFailureMessageFor( + llvm::DebugLoc TrapLocation, StringRef Prefix, StringRef FailureMsg) { + // Create debug info that describes a fake function whose name is the failure + // message. + std::string FuncName(Prefix); + if (!FailureMsg.empty()) { + // A space in the function name identifies this as not being a real function + // because it's not a valid symbol name. + FuncName += ": "; + FuncName += FailureMsg; + } + + assert(FuncName.size() > 0); + assert(FuncName.find(' ') != std::string::npos && + "Fake function name must contain a space"); + + llvm::DISubprogram *TrapSP = getFakeFuncSubprogram(FuncName); + return llvm::DILocation::get(CGM.getLLVMContext(), /*Line=*/0, /*Column=*/0, + /*Scope=*/TrapSP, /*InlinedAt=*/TrapLocation); +} + static QualType UnwrapTypeForDebugInfo(QualType T, const ASTContext &C) { Qualifiers Quals; do { diff --git a/clang/lib/CodeGen/CGDebugInfo.h b/clang/lib/CodeGen/CGDebugInfo.h index 7b60e94555d060..21edb553674260 100644 --- a/clang/lib/CodeGen/CGDebugInfo.h +++ b/clang/lib/CodeGen/CGDebugInfo.h @@ -346,6 +346,14 @@ class CGDebugInfo { const FieldDecl *BitFieldDecl, const llvm::DIDerivedType *BitFieldDI, llvm::ArrayRef<llvm::Metadata *> PreviousFieldsDI, const RecordDecl *RD); + // A cache that maps fake function names used for __builtin_verbose_trap to + // subprograms. + std::map<std::string, llvm::DISubprogram *> FakeFuncMap; + + // A function that returns the subprogram corresponding to the fake function + // name. + llvm::DISubprogram *getFakeFuncSubprogram(const std::string &FakeFuncName); + /// Helpers for collecting fields of a record. /// @{ void CollectRecordLambdaFields(const CXXRecordDecl *CXXDecl, @@ -602,6 +610,18 @@ class CGDebugInfo { return CoroutineParameterMappings; } + // Create a debug location from `TrapLocation` that adds a fake + // inline frame where the frame name is + // + // * `<Prefix>: <FailureMsg>` if `<FailureMsg>` is not empty. + // * `<Prefix>` if `<FailureMsg>` is empty. Note `<Prefix>` must + // contain a space. + // + // This is used to store failure reasons for traps. + llvm::DILocation *CreateTrapFailureMessageFor(llvm::DebugLoc TrapLocation, + StringRef Prefix, + StringRef FailureMsg); + private: /// Emit call to llvm.dbg.declare for a variable declaration. /// Returns a pointer to the DILocalVariable associated with the diff --git a/clang/lib/Sema/SemaChecking.cpp b/clang/lib/Sema/SemaChecking.cpp index 4d280f25cc04c2..4cdd6703c52fdf 100644 --- a/clang/lib/Sema/SemaChecking.cpp +++ b/clang/lib/Sema/SemaChecking.cpp @@ -171,6 +171,23 @@ static bool checkArgCount(Sema &S, CallExpr *Call, unsigned DesiredArgCount) { << /*is non object*/ 0 << Call->getArg(1)->getSourceRange(); } +static bool checkBuiltinVerboseTrap(CallExpr *Call, Sema &S) { + Expr *Arg = Call->getArg(0); + + if (Arg->isValueDependent()) + return true; + + // FIXME: Add more checks and reject strings that can't be handled by + // debuggers. + std::string Result; + if (!Arg->tryEvaluateString(Result, S.Context) || Result.empty()) { + S.Diag(Arg->getBeginLoc(), diag::err_builtin_verbose_trap_arg) + << Arg->getSourceRange(); + return false; + } + return true; +} + static bool convertArgumentToType(Sema &S, Expr *&Value, QualType Ty) { if (Value->isTypeDependent()) return false; @@ -2882,6 +2899,11 @@ Sema::CheckBuiltinFunctionCall(FunctionDecl *FDecl, unsigned BuiltinID, case Builtin::BI__builtin_matrix_column_major_store: return SemaBuiltinMatrixColumnMajorStore(TheCall, TheCallResult); + case Builtin::BI__builtin_verbose_trap: + if (!checkBuiltinVerboseTrap(TheCall, *this)) + return ExprError(); + break; + case Builtin::BI__builtin_get_device_side_mangled_name: { auto Check = [](CallExpr *TheCall) { if (TheCall->getNumArgs() != 1) diff --git a/clang/test/CodeGenCXX/debug-info-verbose-trap.cpp b/clang/test/CodeGenCXX/debug-info-verbose-trap.cpp new file mode 100644 index 00000000000000..04fa68ae93ecb6 --- /dev/null +++ b/clang/test/CodeGenCXX/debug-info-verbose-trap.cpp @@ -0,0 +1,49 @@ +// RUN: %clang_cc1 -std=c++20 -emit-llvm -debug-info-kind=limited %s -o - | FileCheck %s + +// CHECK-LABEL: define void @_Z2f0v() +// CHECK: call void @llvm.trap(), !dbg ![[LOC17:.*]] + +// CHECK-LABEL: define void @_Z2f1v() +// CHECK: call void @llvm.trap(), !dbg ![[LOC23:.*]] +// CHECK: call void @llvm.trap(), !dbg ![[LOC25:.*]] + +// CHECK-LABEL: define void @_Z2f3v() +// CHECK: call void @_Z2f2IXadsoKcL_ZL8constMsgEEEEvv() + +// CHECK-LABEL: define internal void @_Z2f2IXadsoKcL_ZL8constMsgEEEEvv() +// CHECK: call void @llvm.trap(), !dbg ![[LOC36:.*]] + +// CHECK: ![[FILESCOPE:.*]] = !DIFile(filename: +// CHECK: ![[SUBPROG14:.*]] = distinct !DISubprogram(name: "f0", linkageName: "_Z2f0v", +// CHECK: ![[LOC17]] = !DILocation(line: 0, scope: ![[SUBPROG18:.*]], inlinedAt: ![[LOC20:.*]]) +// CHECK: ![[SUBPROG18]] = distinct !DISubprogram(name: "__llvm_verbose_trap: Argument_must_not_be_null", scope: ![[FILESCOPE]], file: ![[FILESCOPE]], type: !{{.*}}, flags: DIFlagArtificial, spFlags: DISPFlagDefinition, unit: !{{.*}}) +// CHECK: ![[LOC20]] = !DILocation(line: 34, column: 3, scope: ![[SUBPROG14]]) +// CHECK: ![[SUBPROG22:.*]] = distinct !DISubprogram(name: "f1", linkageName: "_Z2f1v", +// CHECK: ![[LOC23]] = !DILocation(line: 0, scope: ![[SUBPROG18]], inlinedAt: ![[LOC24:.*]]) +// CHECK: ![[LOC24]] = !DILocation(line: 38, column: 3, scope: ![[SUBPROG22]]) +// CHECK: ![[LOC25]] = !DILocation(line: 0, scope: ![[SUBPROG26:.*]], inlinedAt: ![[LOC27:.*]]) +// CHECK: ![[SUBPROG26]] = distinct !DISubprogram(name: "__llvm_verbose_trap: hello", scope: ![[FILESCOPE]], file: ![[FILESCOPE]], type: !{{.*}}, flags: DIFlagArtificial, spFlags: DISPFlagDefinition, unit: !{{.*}}) +// CHECK: ![[LOC27]] = !DILocation(line: 39, column: 3, scope: ![[SUBPROG22]]) +// CHECK: ![[SUBPROG32:.*]] = distinct !DISubprogram(name: "f2<&constMsg[0]>", linkageName: "_Z2f2IXadsoKcL_ZL8constMsgEEEEvv", +// CHECK: ![[LOC36]] = !DILocation(line: 0, scope: ![[SUBPROG26]], inlinedAt: ![[LOC37:.*]]) +// CHECK: ![[LOC37]] = !DILocation(line: 44, column: 3, scope: ![[SUBPROG32]]) + +char const constMsg[] = "hello"; + +void f0() { + __builtin_verbose_trap("Argument_must_not_be_null"); +} + +void f1() { + __builtin_verbose_trap("Argument_must_not_be_null"); + __builtin_verbose_trap("hello"); +} + +template <const char * const str> +void f2() { + __builtin_verbose_trap(str); +} + +void f3() { + f2<constMsg>(); +} diff --git a/clang/test/SemaCXX/verbose-trap.cpp b/clang/test/SemaCXX/verbose-trap.cpp new file mode 100644 index 00000000000000..7c152325d30815 --- /dev/null +++ b/clang/test/SemaCXX/verbose-trap.cpp @@ -0,0 +1,28 @@ +// RUN: %clang_cc1 -std=c++11 -fsyntax-only -fcxx-exceptions -verify %s + +#if !__has_builtin(__builtin_verbose_trap) +#error +#endif + +constexpr char const* constMsg1 = "hello"; +char const* const constMsg2 = "hello"; +char const constMsg3[] = "hello"; + +template <const char * const str> +void f(const char * arg) { + __builtin_verbose_trap("Argument_must_not_be_null"); + __builtin_verbose_trap("hello" "world"); + __builtin_verbose_trap(constMsg1); + __builtin_verbose_trap(constMsg2); + __builtin_verbose_trap(""); // expected-error {{argument to __builtin_verbose_trap must be a non-empty string literal}} + __builtin_verbose_trap(); // expected-error {{too few arguments}} + __builtin_verbose_trap(0); // expected-error {{argument to __builtin_verbose_trap must be a non-empty string literal}} + __builtin_verbose_trap(1); // expected-error {{cannot initialize a parameter of type 'const char *' with}} + __builtin_verbose_trap(arg); // expected-error {{argument to __builtin_verbose_trap must be a non-empty string literal}} + __builtin_verbose_trap(str); + __builtin_verbose_trap(u8"hello"); +} + +void test() { + f<constMsg3>(nullptr); +} >From 6c65805633f9a4f7d12be00fd0106f2b0c67e7fb Mon Sep 17 00:00:00 2001 From: Akira Hatanaka <ahata...@gmail.com> Date: Tue, 23 Jan 2024 16:05:13 -0800 Subject: [PATCH 02/11] Fix documentation build error --- clang/docs/LanguageExtensions.rst | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/clang/docs/LanguageExtensions.rst b/clang/docs/LanguageExtensions.rst index 4526bc2df53e42..9a873700f65880 100644 --- a/clang/docs/LanguageExtensions.rst +++ b/clang/docs/LanguageExtensions.rst @@ -3380,7 +3380,7 @@ Query for this feature with ``__has_builtin(__builtin_debugtrap)``. Query for this feature with ``__has_builtin(__builtin_trap)``. ``__builtin_verbose_trap`` ------------------- +-------------------------- ``__builtin_verbose_trap`` causes the program to stop its execution abnormally and shows a human-readable description of the reason for the termination when a >From 3e54bf3cf88a5f85b54766cbe4ded3a882db200c Mon Sep 17 00:00:00 2001 From: Akira Hatanaka <ahata...@gmail.com> Date: Tue, 23 Jan 2024 16:13:14 -0800 Subject: [PATCH 03/11] Fix diagnostic message --- clang/include/clang/Basic/DiagnosticSemaKinds.td | 3 ++- clang/test/SemaCXX/verbose-trap.cpp | 6 +++--- 2 files changed, 5 insertions(+), 4 deletions(-) diff --git a/clang/include/clang/Basic/DiagnosticSemaKinds.td b/clang/include/clang/Basic/DiagnosticSemaKinds.td index 40482a964b39d5..c7101b84b0777f 100644 --- a/clang/include/clang/Basic/DiagnosticSemaKinds.td +++ b/clang/include/clang/Basic/DiagnosticSemaKinds.td @@ -8795,7 +8795,8 @@ def err_expected_callable_argument : Error< def note_building_builtin_dump_struct_call : Note< "in call to printing function with arguments '(%0)' while dumping struct">; def err_builtin_verbose_trap_arg : Error< - "argument to __builtin_verbose_trap must be a non-empty string literal">; + "argument to __builtin_verbose_trap must be a pointer to a non-empty constant " + "string">; def err_atomic_load_store_uses_lib : Error< "atomic %select{load|store}0 requires runtime support that is not " diff --git a/clang/test/SemaCXX/verbose-trap.cpp b/clang/test/SemaCXX/verbose-trap.cpp index 7c152325d30815..2cbfad6c817f82 100644 --- a/clang/test/SemaCXX/verbose-trap.cpp +++ b/clang/test/SemaCXX/verbose-trap.cpp @@ -14,11 +14,11 @@ void f(const char * arg) { __builtin_verbose_trap("hello" "world"); __builtin_verbose_trap(constMsg1); __builtin_verbose_trap(constMsg2); - __builtin_verbose_trap(""); // expected-error {{argument to __builtin_verbose_trap must be a non-empty string literal}} + __builtin_verbose_trap(""); // expected-error {{argument to __builtin_verbose_trap must be a pointer to a non-empty constant string}} __builtin_verbose_trap(); // expected-error {{too few arguments}} - __builtin_verbose_trap(0); // expected-error {{argument to __builtin_verbose_trap must be a non-empty string literal}} + __builtin_verbose_trap(0); // expected-error {{argument to __builtin_verbose_trap must be a pointer to a non-empty constant string}} __builtin_verbose_trap(1); // expected-error {{cannot initialize a parameter of type 'const char *' with}} - __builtin_verbose_trap(arg); // expected-error {{argument to __builtin_verbose_trap must be a non-empty string literal}} + __builtin_verbose_trap(arg); // expected-error {{argument to __builtin_verbose_trap must be a pointer to a non-empty constant string}} __builtin_verbose_trap(str); __builtin_verbose_trap(u8"hello"); } >From 9cd883e1e1a3996cff190fbef592fd59ebea8dc9 Mon Sep 17 00:00:00 2001 From: Akira Hatanaka <ahata...@gmail.com> Date: Thu, 25 Jan 2024 14:15:16 -0800 Subject: [PATCH 04/11] Address review comments --- clang/docs/LanguageExtensions.rst | 19 +++++++++++-------- clang/lib/CodeGen/CGDebugInfo.cpp | 19 +++++++++---------- clang/lib/CodeGen/CGDebugInfo.h | 16 ++++++++-------- clang/test/SemaCXX/verbose-trap.cpp | 1 + 4 files changed, 29 insertions(+), 26 deletions(-) diff --git a/clang/docs/LanguageExtensions.rst b/clang/docs/LanguageExtensions.rst index 9a873700f65880..ecb0f6feec37fd 100644 --- a/clang/docs/LanguageExtensions.rst +++ b/clang/docs/LanguageExtensions.rst @@ -3395,9 +3395,9 @@ debugger is attached or in a symbolicated crash log. **Description** ``__builtin_verbose_trap`` is lowered to the ` ``llvm.trap`` <https://llvm.org/docs/LangRef.html#llvm-trap-intrinsic>`_ builtin. -Additionally, clang emits debug metadata that represents an artificial inline -frame whose name encodes the string passed to the builtin, prefixed by a "magic" -prefix. +Additionally, clang emits debugging information that represents an artificial +inline frame whose name encodes the string passed to the builtin, prefixed by a +"magic" prefix. For example, consider the following code: @@ -3405,27 +3405,30 @@ For example, consider the following code: void foo(int* p) { if (p == nullptr) - __builtin_verbose_trap("Argument_must_not_be_null"); + __builtin_verbose_trap("Argument must not be null!"); } -The debug metadata would look as if it were produced for the following code: +The debugging information would look as if it were produced for the following code: .. code-block:: c++ __attribute__((always_inline)) - inline void "__llvm_verbose_trap: Argument_must_not_be_null"() { + inline void "__llvm_verbose_trap: Argument must not be null!"() { __builtin_trap(); } void foo(int* p) { if (p == nullptr) - "__llvm_verbose_trap: Argument_must_not_be_null"(); + "__llvm_verbose_trap: Argument must not be null!"(); } However, the LLVM IR would not actually contain a call to the artificial function — it only exists in the debug metadata. -Query for this feature with ``__has_builtin(__builtin_verbose_trap)``. +Query for this feature with ``__has_builtin(__builtin_verbose_trap)``. Note that +users need to enable debug information to enable this feature. A call to this +builtin is equivalent to a call to ``__builtin_trap`` if debug information isn't +enabled. ``__builtin_nondeterministic_value`` ------------------------------------ diff --git a/clang/lib/CodeGen/CGDebugInfo.cpp b/clang/lib/CodeGen/CGDebugInfo.cpp index fadbc0a80f8a11..a9ae6da6541891 100644 --- a/clang/lib/CodeGen/CGDebugInfo.cpp +++ b/clang/lib/CodeGen/CGDebugInfo.cpp @@ -1629,8 +1629,8 @@ llvm::DIType *CGDebugInfo::createFieldType( } llvm::DISubprogram * -CGDebugInfo::getFakeFuncSubprogram(const std::string &FakeFuncName) { - llvm::DISubprogram *&SP = FakeFuncMap[FakeFuncName]; +CGDebugInfo::createInlinedTrapSubprogram(const std::string &FuncName) { + llvm::DISubprogram *&SP = InlinedTrapFuncMap[FuncName]; if (!SP) { auto FileScope = TheCU->getFile(); @@ -1638,7 +1638,7 @@ CGDebugInfo::getFakeFuncSubprogram(const std::string &FakeFuncName) { // Note: We use `FileScope` rather than `TheCU` as the scope because that's // what LLVM's inliner seems to do. SP = DBuilder.createFunction( - /*Scope=*/FileScope, /*Name=*/FakeFuncName, /*LinkageName=*/StringRef(), + /*Scope=*/FileScope, /*Name=*/FuncName, /*LinkageName=*/StringRef(), /*File=*/FileScope, /*LineNo=*/0, /*Ty=*/DIFnTy, /*ScopeLine=*/0, /*Flags=*/llvm::DINode::FlagArtificial, @@ -3447,8 +3447,11 @@ llvm::DIMacroFile *CGDebugInfo::CreateTempMacroFile(llvm::DIMacroFile *Parent, llvm::DILocation *CGDebugInfo::CreateTrapFailureMessageFor( llvm::DebugLoc TrapLocation, StringRef Prefix, StringRef FailureMsg) { - // Create debug info that describes a fake function whose name is the failure - // message. + assert((!FailureMsg.empty() || Prefix.find(' ') != std::string::npos) && + "Prefix must contain a space when FailureMsg is empty"); + + // Create debug info that describes an inlined function whose name is the + // failure message. std::string FuncName(Prefix); if (!FailureMsg.empty()) { // A space in the function name identifies this as not being a real function @@ -3457,11 +3460,7 @@ llvm::DILocation *CGDebugInfo::CreateTrapFailureMessageFor( FuncName += FailureMsg; } - assert(FuncName.size() > 0); - assert(FuncName.find(' ') != std::string::npos && - "Fake function name must contain a space"); - - llvm::DISubprogram *TrapSP = getFakeFuncSubprogram(FuncName); + llvm::DISubprogram *TrapSP = createInlinedTrapSubprogram(FuncName); return llvm::DILocation::get(CGM.getLLVMContext(), /*Line=*/0, /*Column=*/0, /*Scope=*/TrapSP, /*InlinedAt=*/TrapLocation); } diff --git a/clang/lib/CodeGen/CGDebugInfo.h b/clang/lib/CodeGen/CGDebugInfo.h index 21edb553674260..ff559153291836 100644 --- a/clang/lib/CodeGen/CGDebugInfo.h +++ b/clang/lib/CodeGen/CGDebugInfo.h @@ -346,13 +346,13 @@ class CGDebugInfo { const FieldDecl *BitFieldDecl, const llvm::DIDerivedType *BitFieldDI, llvm::ArrayRef<llvm::Metadata *> PreviousFieldsDI, const RecordDecl *RD); - // A cache that maps fake function names used for __builtin_verbose_trap to - // subprograms. - std::map<std::string, llvm::DISubprogram *> FakeFuncMap; + // A cache that maps artificial inlined function names used for + // __builtin_verbose_trap to subprograms. + std::map<std::string, llvm::DISubprogram *> InlinedTrapFuncMap; - // A function that returns the subprogram corresponding to the fake function - // name. - llvm::DISubprogram *getFakeFuncSubprogram(const std::string &FakeFuncName); + // A function that returns the subprogram corresponding to the artificial + // inlined function for traps. + llvm::DISubprogram *createInlinedTrapSubprogram(const std::string &FuncName); /// Helpers for collecting fields of a record. /// @{ @@ -610,8 +610,8 @@ class CGDebugInfo { return CoroutineParameterMappings; } - // Create a debug location from `TrapLocation` that adds a fake - // inline frame where the frame name is + // Create a debug location from `TrapLocation` that adds an artificial inline + // frame where the frame name is // // * `<Prefix>: <FailureMsg>` if `<FailureMsg>` is not empty. // * `<Prefix>` if `<FailureMsg>` is empty. Note `<Prefix>` must diff --git a/clang/test/SemaCXX/verbose-trap.cpp b/clang/test/SemaCXX/verbose-trap.cpp index 2cbfad6c817f82..7968e999520957 100644 --- a/clang/test/SemaCXX/verbose-trap.cpp +++ b/clang/test/SemaCXX/verbose-trap.cpp @@ -10,6 +10,7 @@ char const constMsg3[] = "hello"; template <const char * const str> void f(const char * arg) { + __builtin_verbose_trap("Arbitrary string literals can be used!"); __builtin_verbose_trap("Argument_must_not_be_null"); __builtin_verbose_trap("hello" "world"); __builtin_verbose_trap(constMsg1); >From a5af532e833d86984d20ae44cda49ad81cc9af7a Mon Sep 17 00:00:00 2001 From: Akira Hatanaka <ahata...@gmail.com> Date: Mon, 29 Jan 2024 07:43:50 -0800 Subject: [PATCH 05/11] Address review comments 1. Test long string argument. 2. Test c++20 unicode. 3. Allow empty string arguments. 4. #inlcude <map> and <string>. --- clang/include/clang/Basic/DiagnosticSemaKinds.td | 3 +-- clang/lib/CodeGen/CGDebugInfo.h | 2 ++ clang/lib/Sema/SemaChecking.cpp | 2 +- clang/test/SemaCXX/verbose-trap.cpp | 12 +++++++++--- 4 files changed, 13 insertions(+), 6 deletions(-) diff --git a/clang/include/clang/Basic/DiagnosticSemaKinds.td b/clang/include/clang/Basic/DiagnosticSemaKinds.td index c7101b84b0777f..e299dd09fb5037 100644 --- a/clang/include/clang/Basic/DiagnosticSemaKinds.td +++ b/clang/include/clang/Basic/DiagnosticSemaKinds.td @@ -8795,8 +8795,7 @@ def err_expected_callable_argument : Error< def note_building_builtin_dump_struct_call : Note< "in call to printing function with arguments '(%0)' while dumping struct">; def err_builtin_verbose_trap_arg : Error< - "argument to __builtin_verbose_trap must be a pointer to a non-empty constant " - "string">; + "argument to __builtin_verbose_trap must be a pointer to a constant string">; def err_atomic_load_store_uses_lib : Error< "atomic %select{load|store}0 requires runtime support that is not " diff --git a/clang/lib/CodeGen/CGDebugInfo.h b/clang/lib/CodeGen/CGDebugInfo.h index ff559153291836..17a49a0fb990a9 100644 --- a/clang/lib/CodeGen/CGDebugInfo.h +++ b/clang/lib/CodeGen/CGDebugInfo.h @@ -29,7 +29,9 @@ #include "llvm/IR/DebugInfo.h" #include "llvm/IR/ValueHandle.h" #include "llvm/Support/Allocator.h" +#include <map> #include <optional> +#include <string> namespace llvm { class MDNode; diff --git a/clang/lib/Sema/SemaChecking.cpp b/clang/lib/Sema/SemaChecking.cpp index 4cdd6703c52fdf..8a72581c444345 100644 --- a/clang/lib/Sema/SemaChecking.cpp +++ b/clang/lib/Sema/SemaChecking.cpp @@ -180,7 +180,7 @@ static bool checkBuiltinVerboseTrap(CallExpr *Call, Sema &S) { // FIXME: Add more checks and reject strings that can't be handled by // debuggers. std::string Result; - if (!Arg->tryEvaluateString(Result, S.Context) || Result.empty()) { + if (!Arg->tryEvaluateString(Result, S.Context)) { S.Diag(Arg->getBeginLoc(), diag::err_builtin_verbose_trap_arg) << Arg->getSourceRange(); return false; diff --git a/clang/test/SemaCXX/verbose-trap.cpp b/clang/test/SemaCXX/verbose-trap.cpp index 7968e999520957..e10529cc7c5480 100644 --- a/clang/test/SemaCXX/verbose-trap.cpp +++ b/clang/test/SemaCXX/verbose-trap.cpp @@ -1,4 +1,5 @@ // RUN: %clang_cc1 -std=c++11 -fsyntax-only -fcxx-exceptions -verify %s +// RUN: %clang_cc1 -std=c++20 -fsyntax-only -fcxx-exceptions -verify %s #if !__has_builtin(__builtin_verbose_trap) #error @@ -15,13 +16,18 @@ void f(const char * arg) { __builtin_verbose_trap("hello" "world"); __builtin_verbose_trap(constMsg1); __builtin_verbose_trap(constMsg2); - __builtin_verbose_trap(""); // expected-error {{argument to __builtin_verbose_trap must be a pointer to a non-empty constant string}} + __builtin_verbose_trap(""); __builtin_verbose_trap(); // expected-error {{too few arguments}} - __builtin_verbose_trap(0); // expected-error {{argument to __builtin_verbose_trap must be a pointer to a non-empty constant string}} + __builtin_verbose_trap(0); // expected-error {{argument to __builtin_verbose_trap must be a pointer to a constant string}} __builtin_verbose_trap(1); // expected-error {{cannot initialize a parameter of type 'const char *' with}} - __builtin_verbose_trap(arg); // expected-error {{argument to __builtin_verbose_trap must be a pointer to a non-empty constant string}} + __builtin_verbose_trap(arg); // expected-error {{argument to __builtin_verbose_trap must be a pointer to a constant string}} __builtin_verbose_trap(str); __builtin_verbose_trap(u8"hello"); +#if __cplusplus >= 202002L + // FIXME: Accept c++20 u8 string literals. + // expected-error@-3 {{cannot initialize a parameter of type 'const char *' with an lvalue of type 'const char8_t[6]'}} +#endif + __builtin_verbose_trap("abcdabcdabcdabcdabcdabcdabcdabcdabcdabcdabcdabcdabcdabcdabcdabcdabcdabcdabcdabcdabcdabcdabcdabcdabcdabcdabcdabcdabcdabcdabcdabcdabcdabcdabcdabcdabcdabcdabcdabcdabcdabcdabcdabcdabcdabcdabcdabcdabcdabcdabcdabcdabcdabcdabcdabcdabcdabcdabcdabcdabcdabcdabcdabcd"); } void test() { >From 9eb197b6f73b7e5a7e4b73753b0a09cdac74536c Mon Sep 17 00:00:00 2001 From: Akira Hatanaka <ahata...@gmail.com> Date: Mon, 29 Jan 2024 17:36:05 -0800 Subject: [PATCH 06/11] Add triple to test --- clang/test/CodeGenCXX/debug-info-verbose-trap.cpp | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/clang/test/CodeGenCXX/debug-info-verbose-trap.cpp b/clang/test/CodeGenCXX/debug-info-verbose-trap.cpp index 04fa68ae93ecb6..54a21a96440001 100644 --- a/clang/test/CodeGenCXX/debug-info-verbose-trap.cpp +++ b/clang/test/CodeGenCXX/debug-info-verbose-trap.cpp @@ -1,4 +1,4 @@ -// RUN: %clang_cc1 -std=c++20 -emit-llvm -debug-info-kind=limited %s -o - | FileCheck %s +// RUN: %clang_cc1 -triple arm64-apple-ios -std=c++20 -emit-llvm -debug-info-kind=limited %s -o - | FileCheck %s // CHECK-LABEL: define void @_Z2f0v() // CHECK: call void @llvm.trap(), !dbg ![[LOC17:.*]] >From d163926ce7440004902b054905d4302ff04552d1 Mon Sep 17 00:00:00 2001 From: Akira Hatanaka <ahata...@gmail.com> Date: Thu, 1 Feb 2024 08:43:34 -0800 Subject: [PATCH 07/11] Address review comments --- clang/lib/CodeGen/CGBuiltin.cpp | 4 ++-- clang/lib/CodeGen/CGDebugInfo.cpp | 17 ++++++++--------- clang/lib/CodeGen/CGDebugInfo.h | 7 ++++--- 3 files changed, 14 insertions(+), 14 deletions(-) diff --git a/clang/lib/CodeGen/CGBuiltin.cpp b/clang/lib/CodeGen/CGBuiltin.cpp index a701bb7917fd8c..4554b4d2b662b0 100644 --- a/clang/lib/CodeGen/CGBuiltin.cpp +++ b/clang/lib/CodeGen/CGBuiltin.cpp @@ -3457,8 +3457,8 @@ RValue CodeGenFunction::EmitBuiltinExpr(const GlobalDecl GD, unsigned BuiltinID, if (getDebugInfo()) { std::string Str; E->getArg(0)->tryEvaluateString(Str, getContext()); - TrapLocation = getDebugInfo()->CreateTrapFailureMessageFor( - TrapLocation, "__llvm_verbose_trap", Str); + TrapLocation = + getDebugInfo()->CreateTrapFailureMessageFor(TrapLocation, Str); } ApplyDebugLocation ApplyTrapDI(*this, TrapLocation); EmitTrapCall(Intrinsic::trap); diff --git a/clang/lib/CodeGen/CGDebugInfo.cpp b/clang/lib/CodeGen/CGDebugInfo.cpp index a9ae6da6541891..f579d53e3984ab 100644 --- a/clang/lib/CodeGen/CGDebugInfo.cpp +++ b/clang/lib/CodeGen/CGDebugInfo.cpp @@ -1629,7 +1629,7 @@ llvm::DIType *CGDebugInfo::createFieldType( } llvm::DISubprogram * -CGDebugInfo::createInlinedTrapSubprogram(const std::string &FuncName) { +CGDebugInfo::createInlinedTrapSubprogram(StringRef FuncName) { llvm::DISubprogram *&SP = InlinedTrapFuncMap[FuncName]; if (!SP) { @@ -3445,14 +3445,13 @@ llvm::DIMacroFile *CGDebugInfo::CreateTempMacroFile(llvm::DIMacroFile *Parent, return DBuilder.createTempMacroFile(Parent, Line, FName); } -llvm::DILocation *CGDebugInfo::CreateTrapFailureMessageFor( - llvm::DebugLoc TrapLocation, StringRef Prefix, StringRef FailureMsg) { - assert((!FailureMsg.empty() || Prefix.find(' ') != std::string::npos) && - "Prefix must contain a space when FailureMsg is empty"); - - // Create debug info that describes an inlined function whose name is the - // failure message. - std::string FuncName(Prefix); +llvm::DILocation * +CGDebugInfo::CreateTrapFailureMessageFor(llvm::DebugLoc TrapLocation, + StringRef FailureMsg) { + // Create a debug location from `TrapLocation` that adds an artificial inline + // frame. + const char *Prefix = "__llvm_verbose_trap"; + SmallString<64> FuncName(Prefix); if (!FailureMsg.empty()) { // A space in the function name identifies this as not being a real function // because it's not a valid symbol name. diff --git a/clang/lib/CodeGen/CGDebugInfo.h b/clang/lib/CodeGen/CGDebugInfo.h index 17a49a0fb990a9..e440b91b56a15b 100644 --- a/clang/lib/CodeGen/CGDebugInfo.h +++ b/clang/lib/CodeGen/CGDebugInfo.h @@ -350,11 +350,11 @@ class CGDebugInfo { // A cache that maps artificial inlined function names used for // __builtin_verbose_trap to subprograms. - std::map<std::string, llvm::DISubprogram *> InlinedTrapFuncMap; + llvm::StringMap<llvm::DISubprogram *> InlinedTrapFuncMap; // A function that returns the subprogram corresponding to the artificial // inlined function for traps. - llvm::DISubprogram *createInlinedTrapSubprogram(const std::string &FuncName); + llvm::DISubprogram *createInlinedTrapSubprogram(StringRef FuncName); /// Helpers for collecting fields of a record. /// @{ @@ -619,9 +619,10 @@ class CGDebugInfo { // * `<Prefix>` if `<FailureMsg>` is empty. Note `<Prefix>` must // contain a space. // + // Currently `<Prefix>` is always "__llvm_verbose_trap". + // // This is used to store failure reasons for traps. llvm::DILocation *CreateTrapFailureMessageFor(llvm::DebugLoc TrapLocation, - StringRef Prefix, StringRef FailureMsg); private: >From 5fd32e29c2360c51a0ebb515f7bf11b5592d3ba8 Mon Sep 17 00:00:00 2001 From: Akira Hatanaka <ahata...@gmail.com> Date: Thu, 1 Feb 2024 11:12:18 -0800 Subject: [PATCH 08/11] Pass a better file scope when creating the subprogram for the artificial inlined function `TheCU->getFile()` returns `<stdin>` when `-main-file-name` is empty. --- clang/lib/CodeGen/CGDebugInfo.cpp | 9 ++++----- clang/lib/CodeGen/CGDebugInfo.h | 3 ++- clang/test/CodeGenCXX/debug-info-verbose-trap.cpp | 2 +- 3 files changed, 7 insertions(+), 7 deletions(-) diff --git a/clang/lib/CodeGen/CGDebugInfo.cpp b/clang/lib/CodeGen/CGDebugInfo.cpp index f579d53e3984ab..0a3c8ca48549a6 100644 --- a/clang/lib/CodeGen/CGDebugInfo.cpp +++ b/clang/lib/CodeGen/CGDebugInfo.cpp @@ -1629,14 +1629,12 @@ llvm::DIType *CGDebugInfo::createFieldType( } llvm::DISubprogram * -CGDebugInfo::createInlinedTrapSubprogram(StringRef FuncName) { +CGDebugInfo::createInlinedTrapSubprogram(StringRef FuncName, + llvm::DIFile *FileScope) { llvm::DISubprogram *&SP = InlinedTrapFuncMap[FuncName]; if (!SP) { - auto FileScope = TheCU->getFile(); llvm::DISubroutineType *DIFnTy = DBuilder.createSubroutineType(nullptr); - // Note: We use `FileScope` rather than `TheCU` as the scope because that's - // what LLVM's inliner seems to do. SP = DBuilder.createFunction( /*Scope=*/FileScope, /*Name=*/FuncName, /*LinkageName=*/StringRef(), /*File=*/FileScope, /*LineNo=*/0, /*Ty=*/DIFnTy, @@ -3459,7 +3457,8 @@ CGDebugInfo::CreateTrapFailureMessageFor(llvm::DebugLoc TrapLocation, FuncName += FailureMsg; } - llvm::DISubprogram *TrapSP = createInlinedTrapSubprogram(FuncName); + llvm::DISubprogram *TrapSP = + createInlinedTrapSubprogram(FuncName, TrapLocation->getFile()); return llvm::DILocation::get(CGM.getLLVMContext(), /*Line=*/0, /*Column=*/0, /*Scope=*/TrapSP, /*InlinedAt=*/TrapLocation); } diff --git a/clang/lib/CodeGen/CGDebugInfo.h b/clang/lib/CodeGen/CGDebugInfo.h index e440b91b56a15b..2f1d907692ede0 100644 --- a/clang/lib/CodeGen/CGDebugInfo.h +++ b/clang/lib/CodeGen/CGDebugInfo.h @@ -354,7 +354,8 @@ class CGDebugInfo { // A function that returns the subprogram corresponding to the artificial // inlined function for traps. - llvm::DISubprogram *createInlinedTrapSubprogram(StringRef FuncName); + llvm::DISubprogram *createInlinedTrapSubprogram(StringRef FuncName, + llvm::DIFile *FileScope); /// Helpers for collecting fields of a record. /// @{ diff --git a/clang/test/CodeGenCXX/debug-info-verbose-trap.cpp b/clang/test/CodeGenCXX/debug-info-verbose-trap.cpp index 54a21a96440001..0b156c23a54a24 100644 --- a/clang/test/CodeGenCXX/debug-info-verbose-trap.cpp +++ b/clang/test/CodeGenCXX/debug-info-verbose-trap.cpp @@ -13,7 +13,7 @@ // CHECK-LABEL: define internal void @_Z2f2IXadsoKcL_ZL8constMsgEEEEvv() // CHECK: call void @llvm.trap(), !dbg ![[LOC36:.*]] -// CHECK: ![[FILESCOPE:.*]] = !DIFile(filename: +// CHECK: ![[FILESCOPE:.*]] = !DIFile(filename: "{{.*}}debug-info-verbose-trap.cpp" // CHECK: ![[SUBPROG14:.*]] = distinct !DISubprogram(name: "f0", linkageName: "_Z2f0v", // CHECK: ![[LOC17]] = !DILocation(line: 0, scope: ![[SUBPROG18:.*]], inlinedAt: ![[LOC20:.*]]) // CHECK: ![[SUBPROG18]] = distinct !DISubprogram(name: "__llvm_verbose_trap: Argument_must_not_be_null", scope: ![[FILESCOPE]], file: ![[FILESCOPE]], type: !{{.*}}, flags: DIFlagArtificial, spFlags: DISPFlagDefinition, unit: !{{.*}}) >From 88a07b3ad1dcbb4f76f0900b0ede4305be5dc9eb Mon Sep 17 00:00:00 2001 From: Akira Hatanaka <ahata...@gmail.com> Date: Mon, 4 Mar 2024 21:31:49 -0800 Subject: [PATCH 09/11] Address review comments --- clang/docs/LanguageExtensions.rst | 3 ++ clang/include/clang/AST/Expr.h | 6 ++-- clang/lib/AST/ExprConstant.cpp | 7 +++-- clang/lib/CodeGen/CGBuiltin.cpp | 6 ++-- clang/lib/CodeGen/CGDebugInfo.cpp | 5 ++-- clang/lib/CodeGen/CGDebugInfo.h | 3 +- clang/lib/Sema/SemaChecking.cpp | 3 +- .../CodeGenCXX/debug-info-verbose-trap.cpp | 30 +++++++++++-------- clang/test/SemaCXX/verbose-trap.cpp | 2 +- 9 files changed, 36 insertions(+), 29 deletions(-) diff --git a/clang/docs/LanguageExtensions.rst b/clang/docs/LanguageExtensions.rst index ecb0f6feec37fd..ac68f45caebcc5 100644 --- a/clang/docs/LanguageExtensions.rst +++ b/clang/docs/LanguageExtensions.rst @@ -3430,6 +3430,9 @@ users need to enable debug information to enable this feature. A call to this builtin is equivalent to a call to ``__builtin_trap`` if debug information isn't enabled. +The optimizer can merge calls to trap with different messages, which degrades +the debugging experience. + ``__builtin_nondeterministic_value`` ------------------------------------ diff --git a/clang/include/clang/AST/Expr.h b/clang/include/clang/AST/Expr.h index 68447b19a4a107..fcade83a595c86 100644 --- a/clang/include/clang/AST/Expr.h +++ b/clang/include/clang/AST/Expr.h @@ -776,9 +776,9 @@ class Expr : public ValueStmt { EvalResult &Status) const; /// If the current Expr can be evaluated to a pointer to a null-terminated - /// constant string, return the constant string (without the terminating null) - /// in Result. Return true if it succeeds. - bool tryEvaluateString(std::string &Result, ASTContext &Ctx) const; + /// constant string, return the constant string (without the terminating + /// null). + std::optional<std::string> tryEvaluateString(ASTContext &Ctx) const; /// Enumeration used to describe the kind of Null pointer constant /// returned from \c isNullPointerConstant(). diff --git a/clang/lib/AST/ExprConstant.cpp b/clang/lib/AST/ExprConstant.cpp index 33fc9a089a3941..b2407a10e9e532 100644 --- a/clang/lib/AST/ExprConstant.cpp +++ b/clang/lib/AST/ExprConstant.cpp @@ -16677,12 +16677,15 @@ static bool EvaluateBuiltinStrLen(const Expr *E, uint64_t &Result, } } -bool Expr::tryEvaluateString(std::string &StringResult, ASTContext &Ctx) const { +std::optional<std::string> Expr::tryEvaluateString(ASTContext &Ctx) const { Expr::EvalStatus Status; EvalInfo Info(Ctx, Status, EvalInfo::EM_ConstantFold); uint64_t Result; + std::string StringResult; - return EvaluateBuiltinStrLen(this, Result, Info, &StringResult); + if (EvaluateBuiltinStrLen(this, Result, Info, &StringResult)) + return StringResult; + return {}; } bool Expr::EvaluateCharRangeAsString(std::string &Result, diff --git a/clang/lib/CodeGen/CGBuiltin.cpp b/clang/lib/CodeGen/CGBuiltin.cpp index 4554b4d2b662b0..c3b95ba537c43c 100644 --- a/clang/lib/CodeGen/CGBuiltin.cpp +++ b/clang/lib/CodeGen/CGBuiltin.cpp @@ -3455,10 +3455,8 @@ RValue CodeGenFunction::EmitBuiltinExpr(const GlobalDecl GD, unsigned BuiltinID, case Builtin::BI__builtin_verbose_trap: { llvm::DILocation *TrapLocation = Builder.getCurrentDebugLocation(); if (getDebugInfo()) { - std::string Str; - E->getArg(0)->tryEvaluateString(Str, getContext()); - TrapLocation = - getDebugInfo()->CreateTrapFailureMessageFor(TrapLocation, Str); + TrapLocation = getDebugInfo()->CreateTrapFailureMessageFor( + TrapLocation, *E->getArg(0)->tryEvaluateString(getContext())); } ApplyDebugLocation ApplyTrapDI(*this, TrapLocation); EmitTrapCall(Intrinsic::trap); diff --git a/clang/lib/CodeGen/CGDebugInfo.cpp b/clang/lib/CodeGen/CGDebugInfo.cpp index 0a3c8ca48549a6..0e3562bb36f2b1 100644 --- a/clang/lib/CodeGen/CGDebugInfo.cpp +++ b/clang/lib/CodeGen/CGDebugInfo.cpp @@ -1631,6 +1631,9 @@ llvm::DIType *CGDebugInfo::createFieldType( llvm::DISubprogram * CGDebugInfo::createInlinedTrapSubprogram(StringRef FuncName, llvm::DIFile *FileScope) { + // We are caching the subprogram because we don't want to duplicate + // subprograms with the same message. Note that `SPFlagDefinition` prevents + // subprograms from being uniqued. llvm::DISubprogram *&SP = InlinedTrapFuncMap[FuncName]; if (!SP) { @@ -3451,8 +3454,6 @@ CGDebugInfo::CreateTrapFailureMessageFor(llvm::DebugLoc TrapLocation, const char *Prefix = "__llvm_verbose_trap"; SmallString<64> FuncName(Prefix); if (!FailureMsg.empty()) { - // A space in the function name identifies this as not being a real function - // because it's not a valid symbol name. FuncName += ": "; FuncName += FailureMsg; } diff --git a/clang/lib/CodeGen/CGDebugInfo.h b/clang/lib/CodeGen/CGDebugInfo.h index 2f1d907692ede0..4aef93f76520ed 100644 --- a/clang/lib/CodeGen/CGDebugInfo.h +++ b/clang/lib/CodeGen/CGDebugInfo.h @@ -617,8 +617,7 @@ class CGDebugInfo { // frame where the frame name is // // * `<Prefix>: <FailureMsg>` if `<FailureMsg>` is not empty. - // * `<Prefix>` if `<FailureMsg>` is empty. Note `<Prefix>` must - // contain a space. + // * `<Prefix>` if `<FailureMsg>` is empty. // // Currently `<Prefix>` is always "__llvm_verbose_trap". // diff --git a/clang/lib/Sema/SemaChecking.cpp b/clang/lib/Sema/SemaChecking.cpp index 8a72581c444345..40d1ed43c1443f 100644 --- a/clang/lib/Sema/SemaChecking.cpp +++ b/clang/lib/Sema/SemaChecking.cpp @@ -179,8 +179,7 @@ static bool checkBuiltinVerboseTrap(CallExpr *Call, Sema &S) { // FIXME: Add more checks and reject strings that can't be handled by // debuggers. - std::string Result; - if (!Arg->tryEvaluateString(Result, S.Context)) { + if (!Arg->tryEvaluateString(S.Context).has_value()) { S.Diag(Arg->getBeginLoc(), diag::err_builtin_verbose_trap_arg) << Arg->getSourceRange(); return false; diff --git a/clang/test/CodeGenCXX/debug-info-verbose-trap.cpp b/clang/test/CodeGenCXX/debug-info-verbose-trap.cpp index 0b156c23a54a24..0854b76a4bdea4 100644 --- a/clang/test/CodeGenCXX/debug-info-verbose-trap.cpp +++ b/clang/test/CodeGenCXX/debug-info-verbose-trap.cpp @@ -3,6 +3,8 @@ // CHECK-LABEL: define void @_Z2f0v() // CHECK: call void @llvm.trap(), !dbg ![[LOC17:.*]] +// CHECK: declare void @llvm.trap() #[[ATTR1:.*]] + // CHECK-LABEL: define void @_Z2f1v() // CHECK: call void @llvm.trap(), !dbg ![[LOC23:.*]] // CHECK: call void @llvm.trap(), !dbg ![[LOC25:.*]] @@ -13,32 +15,34 @@ // CHECK-LABEL: define internal void @_Z2f2IXadsoKcL_ZL8constMsgEEEEvv() // CHECK: call void @llvm.trap(), !dbg ![[LOC36:.*]] +// CHECK: attributes #[[ATTR1]] = { cold {{.*}}} + // CHECK: ![[FILESCOPE:.*]] = !DIFile(filename: "{{.*}}debug-info-verbose-trap.cpp" -// CHECK: ![[SUBPROG14:.*]] = distinct !DISubprogram(name: "f0", linkageName: "_Z2f0v", -// CHECK: ![[LOC17]] = !DILocation(line: 0, scope: ![[SUBPROG18:.*]], inlinedAt: ![[LOC20:.*]]) -// CHECK: ![[SUBPROG18]] = distinct !DISubprogram(name: "__llvm_verbose_trap: Argument_must_not_be_null", scope: ![[FILESCOPE]], file: ![[FILESCOPE]], type: !{{.*}}, flags: DIFlagArtificial, spFlags: DISPFlagDefinition, unit: !{{.*}}) -// CHECK: ![[LOC20]] = !DILocation(line: 34, column: 3, scope: ![[SUBPROG14]]) -// CHECK: ![[SUBPROG22:.*]] = distinct !DISubprogram(name: "f1", linkageName: "_Z2f1v", -// CHECK: ![[LOC23]] = !DILocation(line: 0, scope: ![[SUBPROG18]], inlinedAt: ![[LOC24:.*]]) -// CHECK: ![[LOC24]] = !DILocation(line: 38, column: 3, scope: ![[SUBPROG22]]) -// CHECK: ![[LOC25]] = !DILocation(line: 0, scope: ![[SUBPROG26:.*]], inlinedAt: ![[LOC27:.*]]) -// CHECK: ![[SUBPROG26]] = distinct !DISubprogram(name: "__llvm_verbose_trap: hello", scope: ![[FILESCOPE]], file: ![[FILESCOPE]], type: !{{.*}}, flags: DIFlagArtificial, spFlags: DISPFlagDefinition, unit: !{{.*}}) -// CHECK: ![[LOC27]] = !DILocation(line: 39, column: 3, scope: ![[SUBPROG22]]) -// CHECK: ![[SUBPROG32:.*]] = distinct !DISubprogram(name: "f2<&constMsg[0]>", linkageName: "_Z2f2IXadsoKcL_ZL8constMsgEEEEvv", -// CHECK: ![[LOC36]] = !DILocation(line: 0, scope: ![[SUBPROG26]], inlinedAt: ![[LOC37:.*]]) -// CHECK: ![[LOC37]] = !DILocation(line: 44, column: 3, scope: ![[SUBPROG32]]) char const constMsg[] = "hello"; +// CHECK: ![[SUBPROG14:.*]] = distinct !DISubprogram(name: "f0", linkageName: "_Z2f0v", +// CHECK: ![[LOC17]] = !DILocation(line: 0, scope: ![[SUBPROG18:.*]], inlinedAt: ![[LOC20:.*]]) +// CHECK: ![[SUBPROG18]] = distinct !DISubprogram(name: "__llvm_verbose_trap: Argument_must_not_be_null", scope: ![[FILESCOPE]], file: ![[FILESCOPE]], type: !{{.*}}, flags: DIFlagArtificial, spFlags: DISPFlagDefinition, unit: !{{.*}}) +// CHECK: ![[LOC20]] = !DILocation(line: [[@LINE+2]], column: 3, scope: ![[SUBPROG14]]) void f0() { __builtin_verbose_trap("Argument_must_not_be_null"); } +// CHECK: ![[SUBPROG22:.*]] = distinct !DISubprogram(name: "f1", linkageName: "_Z2f1v", +// CHECK: ![[LOC23]] = !DILocation(line: 0, scope: ![[SUBPROG18]], inlinedAt: ![[LOC24:.*]]) +// CHECK: ![[LOC24]] = !DILocation(line: [[@LINE+5]], column: 3, scope: ![[SUBPROG22]]) +// CHECK: ![[LOC25]] = !DILocation(line: 0, scope: ![[SUBPROG26:.*]], inlinedAt: ![[LOC27:.*]]) +// CHECK: ![[SUBPROG26]] = distinct !DISubprogram(name: "__llvm_verbose_trap: hello", scope: ![[FILESCOPE]], file: ![[FILESCOPE]], type: !{{.*}}, flags: DIFlagArtificial, spFlags: DISPFlagDefinition, unit: !{{.*}}) +// CHECK: ![[LOC27]] = !DILocation(line: [[@LINE+3]], column: 3, scope: ![[SUBPROG22]]) void f1() { __builtin_verbose_trap("Argument_must_not_be_null"); __builtin_verbose_trap("hello"); } +// CHECK: ![[SUBPROG32:.*]] = distinct !DISubprogram(name: "f2<&constMsg[0]>", linkageName: "_Z2f2IXadsoKcL_ZL8constMsgEEEEvv", +// CHECK: ![[LOC36]] = !DILocation(line: 0, scope: ![[SUBPROG26]], inlinedAt: ![[LOC37:.*]]) +// CHECK: ![[LOC37]] = !DILocation(line: [[@LINE+3]], column: 3, scope: ![[SUBPROG32]]) template <const char * const str> void f2() { __builtin_verbose_trap(str); diff --git a/clang/test/SemaCXX/verbose-trap.cpp b/clang/test/SemaCXX/verbose-trap.cpp index e10529cc7c5480..86458a3957e7fc 100644 --- a/clang/test/SemaCXX/verbose-trap.cpp +++ b/clang/test/SemaCXX/verbose-trap.cpp @@ -19,7 +19,7 @@ void f(const char * arg) { __builtin_verbose_trap(""); __builtin_verbose_trap(); // expected-error {{too few arguments}} __builtin_verbose_trap(0); // expected-error {{argument to __builtin_verbose_trap must be a pointer to a constant string}} - __builtin_verbose_trap(1); // expected-error {{cannot initialize a parameter of type 'const char *' with}} + __builtin_verbose_trap(1); // expected-error {{cannot initialize a parameter of type 'const char *' with an rvalue of type 'int'}} __builtin_verbose_trap(arg); // expected-error {{argument to __builtin_verbose_trap must be a pointer to a constant string}} __builtin_verbose_trap(str); __builtin_verbose_trap(u8"hello"); >From 965a93461e9092b0a6ae1d6843667a23c39baa58 Mon Sep 17 00:00:00 2001 From: Akira Hatanaka <ahata...@gmail.com> Date: Tue, 12 Mar 2024 16:58:23 -0700 Subject: [PATCH 10/11] Define CLANG_VERBOSE_TRAP_PREFIX in public header --- clang/include/clang/CodeGen/ModuleBuilder.h | 3 +++ clang/lib/CodeGen/CGDebugInfo.cpp | 3 ++- 2 files changed, 5 insertions(+), 1 deletion(-) diff --git a/clang/include/clang/CodeGen/ModuleBuilder.h b/clang/include/clang/CodeGen/ModuleBuilder.h index edacd82bf899db..69f4537330ba57 100644 --- a/clang/include/clang/CodeGen/ModuleBuilder.h +++ b/clang/include/clang/CodeGen/ModuleBuilder.h @@ -27,6 +27,9 @@ namespace llvm { } } +// Prefix for __builtin_verbose_trap. +#define CLANG_VERBOSE_TRAP_PREFIX "__llvm_verbose_trap" + namespace clang { class CodeGenOptions; class CoverageSourceInfo; diff --git a/clang/lib/CodeGen/CGDebugInfo.cpp b/clang/lib/CodeGen/CGDebugInfo.cpp index 0e3562bb36f2b1..561e21cfca97c8 100644 --- a/clang/lib/CodeGen/CGDebugInfo.cpp +++ b/clang/lib/CodeGen/CGDebugInfo.cpp @@ -32,6 +32,7 @@ #include "clang/Basic/FileManager.h" #include "clang/Basic/SourceManager.h" #include "clang/Basic/Version.h" +#include "clang/CodeGen/ModuleBuilder.h" #include "clang/Frontend/FrontendOptions.h" #include "clang/Lex/HeaderSearchOptions.h" #include "clang/Lex/ModuleMap.h" @@ -3451,7 +3452,7 @@ CGDebugInfo::CreateTrapFailureMessageFor(llvm::DebugLoc TrapLocation, StringRef FailureMsg) { // Create a debug location from `TrapLocation` that adds an artificial inline // frame. - const char *Prefix = "__llvm_verbose_trap"; + const char *Prefix = CLANG_VERBOSE_TRAP_PREFIX; SmallString<64> FuncName(Prefix); if (!FailureMsg.empty()) { FuncName += ": "; >From b188391e12765aec369491f3d46c3f1f47755597 Mon Sep 17 00:00:00 2001 From: Akira Hatanaka <ahata...@gmail.com> Date: Tue, 19 Mar 2024 18:56:37 -0700 Subject: [PATCH 11/11] Address review comments --- clang/docs/LanguageExtensions.rst | 4 ++-- clang/lib/CodeGen/CGBuiltin.cpp | 1 + clang/lib/CodeGen/CGDebugInfo.h | 22 +++++++++++----------- 3 files changed, 14 insertions(+), 13 deletions(-) diff --git a/clang/docs/LanguageExtensions.rst b/clang/docs/LanguageExtensions.rst index ac68f45caebcc5..2dc16cc4eae0b2 100644 --- a/clang/docs/LanguageExtensions.rst +++ b/clang/docs/LanguageExtensions.rst @@ -3422,8 +3422,8 @@ The debugging information would look as if it were produced for the following co "__llvm_verbose_trap: Argument must not be null!"(); } -However, the LLVM IR would not actually contain a call to the artificial -function — it only exists in the debug metadata. +However, the generated code would not actually contain a call to the artificial +function — it only exists in the debugging information. Query for this feature with ``__has_builtin(__builtin_verbose_trap)``. Note that users need to enable debug information to enable this feature. A call to this diff --git a/clang/lib/CodeGen/CGBuiltin.cpp b/clang/lib/CodeGen/CGBuiltin.cpp index c3b95ba537c43c..2c5df479fa7a3c 100644 --- a/clang/lib/CodeGen/CGBuiltin.cpp +++ b/clang/lib/CodeGen/CGBuiltin.cpp @@ -3459,6 +3459,7 @@ RValue CodeGenFunction::EmitBuiltinExpr(const GlobalDecl GD, unsigned BuiltinID, TrapLocation, *E->getArg(0)->tryEvaluateString(getContext())); } ApplyDebugLocation ApplyTrapDI(*this, TrapLocation); + // Currently no attempt is made to prevent traps from being merged. EmitTrapCall(Intrinsic::trap); return RValue::get(nullptr); } diff --git a/clang/lib/CodeGen/CGDebugInfo.h b/clang/lib/CodeGen/CGDebugInfo.h index 4aef93f76520ed..857a4711db16b9 100644 --- a/clang/lib/CodeGen/CGDebugInfo.h +++ b/clang/lib/CodeGen/CGDebugInfo.h @@ -348,8 +348,8 @@ class CGDebugInfo { const FieldDecl *BitFieldDecl, const llvm::DIDerivedType *BitFieldDI, llvm::ArrayRef<llvm::Metadata *> PreviousFieldsDI, const RecordDecl *RD); - // A cache that maps artificial inlined function names used for - // __builtin_verbose_trap to subprograms. + /// A cache that maps artificial inlined function names used for + /// __builtin_verbose_trap to subprograms. llvm::StringMap<llvm::DISubprogram *> InlinedTrapFuncMap; // A function that returns the subprogram corresponding to the artificial @@ -613,15 +613,15 @@ class CGDebugInfo { return CoroutineParameterMappings; } - // Create a debug location from `TrapLocation` that adds an artificial inline - // frame where the frame name is - // - // * `<Prefix>: <FailureMsg>` if `<FailureMsg>` is not empty. - // * `<Prefix>` if `<FailureMsg>` is empty. - // - // Currently `<Prefix>` is always "__llvm_verbose_trap". - // - // This is used to store failure reasons for traps. + /// Create a debug location from `TrapLocation` that adds an artificial inline + /// frame where the frame name is + /// + /// * `<Prefix>: <FailureMsg>` if `<FailureMsg>` is not empty. + /// * `<Prefix>` if `<FailureMsg>` is empty. + /// + /// Currently `<Prefix>` is always "__llvm_verbose_trap". + /// + /// This is used to store failure reasons for traps. llvm::DILocation *CreateTrapFailureMessageFor(llvm::DebugLoc TrapLocation, StringRef FailureMsg); _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
