llvmorg-github-actions[bot] wrote:
<!--LLVM PR SUMMARY COMMENT--> @llvm/pr-subscribers-lldb Author: Jonas Devlieghere (JDevlieghere) <details> <summary>Changes</summary> Evaluating any expression against a WebAssembly target aborted LLDB: ``` (lldb) expr (int)sizeof(Point) LLVM ERROR: Objective-C support is unimplemented for object file format ``` WebAssembly can't JIT expressions (RuntimeDyld doesn't support the Wasm object format, so ProcessWasm sets CanJIT to false), but it can handle simple expressions that can be IR interpreted. When setting up the expression's language options, LLDB speculatively enables Objective-C, which trips up the fatal error as Objective-C code generation only supports Mach-O, ELF, and COFF. Add ObjCLanguageRuntime::IsSupportedForArchitecture and disable Objective-C in the expression's language options when the target's object file format can't support it, parsing as C/C++ instead. The IR interpreter can then evaluate what it supports, and the rest fails cleanly instead of crashing. --- Full diff: https://github.com/llvm/llvm-project/pull/204639.diff 4 Files Affected: - (modified) lldb/source/Plugins/ExpressionParser/Clang/ClangExpressionParser.cpp (+6) - (modified) lldb/source/Plugins/LanguageRuntime/ObjC/ObjCLanguageRuntime.cpp (+14) - (modified) lldb/source/Plugins/LanguageRuntime/ObjC/ObjCLanguageRuntime.h (+5) - (added) lldb/test/Shell/Expr/wasm-no-objc-codegen.test (+18) ``````````diff diff --git a/lldb/source/Plugins/ExpressionParser/Clang/ClangExpressionParser.cpp b/lldb/source/Plugins/ExpressionParser/Clang/ClangExpressionParser.cpp index 861522623f68b..deab9a2a572ef 100644 --- a/lldb/source/Plugins/ExpressionParser/Clang/ClangExpressionParser.cpp +++ b/lldb/source/Plugins/ExpressionParser/Clang/ClangExpressionParser.cpp @@ -652,6 +652,12 @@ static void SetupLangOpts(CompilerInstance &compiler, break; } + // The cases above enable Objective-C speculatively; undo that for targets + // whose object file format can't support it. + if (!ObjCLanguageRuntime::IsSupportedForArchitecture( + ArchSpec(compiler.getTargetOpts().Triple))) + lang_opts.ObjC = false; + diagnostic_manager.AddDiagnostic( llvm::formatv("{0}Ran expression as '{1}'.", language_fallback_reason, lldb_private::Language::GetDisplayNameForLanguageType( diff --git a/lldb/source/Plugins/LanguageRuntime/ObjC/ObjCLanguageRuntime.cpp b/lldb/source/Plugins/LanguageRuntime/ObjC/ObjCLanguageRuntime.cpp index d0dc252199800..170546f4243f5 100644 --- a/lldb/source/Plugins/LanguageRuntime/ObjC/ObjCLanguageRuntime.cpp +++ b/lldb/source/Plugins/LanguageRuntime/ObjC/ObjCLanguageRuntime.cpp @@ -19,6 +19,7 @@ #include "lldb/Symbol/Variable.h" #include "lldb/Target/ABI.h" #include "lldb/Target/Target.h" +#include "lldb/Utility/ArchSpec.h" #include "lldb/Utility/LLDBLog.h" #include "lldb/Utility/Log.h" #include "lldb/Utility/Timer.h" @@ -36,6 +37,19 @@ char ObjCLanguageRuntime::ID = 0; // Destructor ObjCLanguageRuntime::~ObjCLanguageRuntime() = default; +bool ObjCLanguageRuntime::IsSupportedForArchitecture(const ArchSpec &arch) { + // These are the only object file formats clang can emit Objective-C + // metadata for; it aborts on any other. + switch (arch.GetTriple().getObjectFormat()) { + case llvm::Triple::MachO: + case llvm::Triple::ELF: + case llvm::Triple::COFF: + return true; + default: + return false; + } +} + ObjCLanguageRuntime::ObjCLanguageRuntime(Process *process) : LanguageRuntime(process), m_impl_cache(), m_impl_str_cache(), m_has_new_literals_and_indexing(eLazyBoolCalculate), diff --git a/lldb/source/Plugins/LanguageRuntime/ObjC/ObjCLanguageRuntime.h b/lldb/source/Plugins/LanguageRuntime/ObjC/ObjCLanguageRuntime.h index 8b5d6af54cbc3..4e8210c23e0d4 100644 --- a/lldb/source/Plugins/LanguageRuntime/ObjC/ObjCLanguageRuntime.h +++ b/lldb/source/Plugins/LanguageRuntime/ObjC/ObjCLanguageRuntime.h @@ -226,6 +226,11 @@ class ObjCLanguageRuntime : public LanguageRuntime { process.GetLanguageRuntime(lldb::eLanguageTypeObjC)); } + /// Returns whether the architecture's object file format supports + /// Objective-C code generation. Generating Objective-C for a format that + /// does not aborts the compiler. + static bool IsSupportedForArchitecture(const ArchSpec &arch); + virtual TaggedPointerVendor *GetTaggedPointerVendor() { return nullptr; } typedef std::shared_ptr<EncodingToType> EncodingToTypeSP; diff --git a/lldb/test/Shell/Expr/wasm-no-objc-codegen.test b/lldb/test/Shell/Expr/wasm-no-objc-codegen.test new file mode 100644 index 0000000000000..27586babe4590 --- /dev/null +++ b/lldb/test/Shell/Expr/wasm-no-objc-codegen.test @@ -0,0 +1,18 @@ +# Evaluating an expression for a target whose object file format has no +# Objective-C code generation used to abort the compiler, because LLDB enables +# Objective-C speculatively. It should fall back to C/C++ instead. + +# RUN: yaml2obj %s -o %t +# RUN: %lldb %t -b -o "expr 1 + 1" 2>&1 | FileCheck %s + +# CHECK: (int) $0 = 2 + +--- !WASM +FileHeader: + Version: 0x00000001 +Sections: + - Type: CODE + Functions: + - Index: 0 + Locals: [] + Body: 0B `````````` </details> https://github.com/llvm/llvm-project/pull/204639 _______________________________________________ lldb-commits mailing list [email protected] https://lists.llvm.org/cgi-bin/mailman/listinfo/lldb-commits
