llvmorg-github-actions[bot] wrote:
<!--LLVM PR SUMMARY COMMENT--> @llvm/pr-subscribers-clang Author: Aditi Medhane (AditiRM) <details> <summary>Changes</summary> When encountering invalid declarations during error recovery (e.g., explicit template specialization after instantiation), `getASTRecordLayout()` would assert and crash instead of handling the error gracefully. This patch adds a check for invalid/incomplete declarations and returns a minimal safe layout (1-byte size/alignment) to allow error recovery to continue, enabling the compiler to report all errors and exit cleanly. Before this fix: - Assertion failed: `!D->isInvalidDecl()` - Exit code: 134 (SIGABRT) After this fix: - Clean error messages - Exit code: 1 Test updated: `clang/test/SemaCXX/explicit-specialization-after-instantiation-crash.cpp` Addresses this issue : https://github.com/llvm/llvm-project/issues/207953 --- Full diff: https://github.com/llvm/llvm-project/pull/208153.diff 2 Files Affected: - (modified) clang/lib/AST/RecordLayoutBuilder.cpp (+26) - (added) clang/test/SemaCXX/explicit-specialization-after-instantiation-crash.cpp (+42) ``````````diff diff --git a/clang/lib/AST/RecordLayoutBuilder.cpp b/clang/lib/AST/RecordLayoutBuilder.cpp index 854f88f20b2b6..6b5027772885d 100644 --- a/clang/lib/AST/RecordLayoutBuilder.cpp +++ b/clang/lib/AST/RecordLayoutBuilder.cpp @@ -3384,6 +3384,32 @@ ASTContext::getASTRecordLayout(const RecordDecl *D) const { // not a complete definition (which is what isCompleteDefinition() tests) // until we *finish* parsing the definition. D = D->getDefinition(); + + // Handle invalid declarations gracefully during error recovery + // This can happen when there are template specialization errors + if (!D || D->isInvalidDecl() || !D->isCompleteDefinition()) { + // Check if we already have a cached layout + const ASTRecordLayout *Entry = ASTRecordLayouts[D]; + if (Entry) + return *Entry; + + // Create a minimal safe layout for error recovery + // Use 1-byte size and alignment to avoid division by zero or other issues + ASTRecordLayout *NewEntry = new (*this) + ASTRecordLayout(*this, + CharUnits::One(), // Size = 1 byte + CharUnits::One(), // Alignment = 1 byte + CharUnits::One(), // PreferredAlignment = 1 byte + CharUnits::One(), // UnadjustedAlignment = 1 byte + CharUnits::One(), // RequiredAlignment = 1 byte + CharUnits::One(), // DataSize = 1 byte + ArrayRef<uint64_t>() // Empty field offsets + ); + + ASTRecordLayouts[D] = NewEntry; + return *NewEntry; + } + assert(D && "Cannot get layout of forward declarations!"); assert(!D->isInvalidDecl() && "Cannot get layout of invalid decl!"); assert(D->isCompleteDefinition() && "Cannot layout type before complete!"); diff --git a/clang/test/SemaCXX/explicit-specialization-after-instantiation-crash.cpp b/clang/test/SemaCXX/explicit-specialization-after-instantiation-crash.cpp new file mode 100644 index 0000000000000..37b00db4d3877 --- /dev/null +++ b/clang/test/SemaCXX/explicit-specialization-after-instantiation-crash.cpp @@ -0,0 +1,42 @@ +// RUN: %clang_cc1 -fsyntax-only -verify %s +// +// Test that explicit template specialization after instantiation +// is handled gracefully without assertion failure. +// +// Before the fix, this code triggered an assertion failure: +// Assertion failed: !D->isInvalidDecl() && "Cannot get layout of invalid decl!" +// Location: clang/lib/AST/RecordLayoutBuilder.cpp:3388 +// Exit code: 134 (SIGABRT) +// +// After the fix: +// Clean error messages are reported +// Exit code: 1 +// +// The fix adds error handling in getASTRecordLayout() to return a minimal +// safe layout (1-byte size/alignment) for invalid declarations, allowing +// error recovery to continue and report all errors. + +template <typename T> +struct X { + struct Y { + Y() : v(0) {} + int v; + int getValue(); + } y; +}; + +template <typename T> +int X<T>::Y::getValue() { + return ++v; +} + +// expected-error@+1 {{explicit specialization of 'Y' after instantiation}} +template <> struct X<int>::Y { int getValue() { return 55; } }; +// expected-note@-10 {{implicit instantiation first required here}} + +extern template class X<int>::Y; + +int main() { + X<int> x; + return x.y.getValue(); // expected-error {{no member named 'getValue' in 'X<int>::Y'}} +} `````````` </details> https://github.com/llvm/llvm-project/pull/208153 _______________________________________________ cfe-commits mailing list [email protected] https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
