Author: Cyndy Ishida Date: 2025-06-06T13:45:16-07:00 New Revision: 897b0301d2e2ff28d3976fe95b64be5a85815908
URL: https://github.com/llvm/llvm-project/commit/897b0301d2e2ff28d3976fe95b64be5a85815908 DIFF: https://github.com/llvm/llvm-project/commit/897b0301d2e2ff28d3976fe95b64be5a85815908.diff LOG: [clang][dep-scan] Resolve lexer crash from a permutation of invalid tokens (#142452) Sometimes, when a user writes invalid code, the minimization used for scanning can create a stream of tokens that is invalid at lex time. This patch protects against the case where there are valid (non-c++20) import directives discovered in the middle of an invalid `import` declaration. Mostly authored by: @akyrtzi resolves: rdar://152335844 Added: Modified: clang/lib/Lex/DependencyDirectivesScanner.cpp clang/unittests/Lex/DependencyDirectivesScannerTest.cpp Removed: ################################################################################ diff --git a/clang/lib/Lex/DependencyDirectivesScanner.cpp b/clang/lib/Lex/DependencyDirectivesScanner.cpp index 088d1cc96e3a2..4606b85d42fe7 100644 --- a/clang/lib/Lex/DependencyDirectivesScanner.cpp +++ b/clang/lib/Lex/DependencyDirectivesScanner.cpp @@ -496,7 +496,15 @@ bool Scanner::lexModuleDirectiveBody(DirectiveKind Kind, const char *&First, const char *const End) { const char *DirectiveLoc = Input.data() + CurDirToks.front().Offset; for (;;) { + // Keep a copy of the First char incase it needs to be reset. + const char *Previous = First; const dependency_directives_scan::Token &Tok = lexToken(First, End); + if ((Tok.is(tok::hash) || Tok.is(tok::at)) && + (Tok.Flags & clang::Token::StartOfLine)) { + CurDirToks.pop_back(); + First = Previous; + return false; + } if (Tok.is(tok::eof)) return reportError( DirectiveLoc, @@ -846,6 +854,7 @@ bool Scanner::lexPPLine(const char *&First, const char *const End) { if (*First == '@') return lexAt(First, End); + // Handle module directives for C++20 modules. if (*First == 'i' || *First == 'e' || *First == 'm') return lexModule(First, End); diff --git a/clang/unittests/Lex/DependencyDirectivesScannerTest.cpp b/clang/unittests/Lex/DependencyDirectivesScannerTest.cpp index bdb5e23510118..377c066f031d3 100644 --- a/clang/unittests/Lex/DependencyDirectivesScannerTest.cpp +++ b/clang/unittests/Lex/DependencyDirectivesScannerTest.cpp @@ -677,13 +677,28 @@ TEST(MinimizeSourceToDependencyDirectivesTest, EmptyIncludesAndImports) { Out.data()); } -TEST(MinimizeSourceToDependencyDirectivesTest, AtImportFailures) { +TEST(MinimizeSourceToDependencyDirectivesTest, ImportFailures) { SmallVector<char, 128> Out; ASSERT_TRUE(minimizeSourceToDependencyDirectives("@import A\n", Out)); ASSERT_FALSE( minimizeSourceToDependencyDirectives("@import MACRO(A);\n", Out)); ASSERT_FALSE(minimizeSourceToDependencyDirectives("@import \" \";\n", Out)); + + ASSERT_FALSE(minimizeSourceToDependencyDirectives("import <Foo.h>\n" + "@import Foo;", + Out)); + EXPECT_STREQ("@import Foo;\n", Out.data()); + + ASSERT_FALSE( + minimizeSourceToDependencyDirectives("import <Foo.h>\n" + "#import <Foo.h>\n" + "@;\n" + "#pragma clang module import Foo", + Out)); + EXPECT_STREQ("#import <Foo.h>\n" + "#pragma clang module import Foo\n", + Out.data()); } TEST(MinimizeSourceToDependencyDirectivesTest, RawStringLiteral) { _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
