[clang][AST] Fix AST IgnoreUnlessSpelledInSource traversal nullptr dereference (#146103)
In summary dumping a `catch(...)` statement using
IgnoreUnlessSpelledInSource AST traversal causes a seg fault, as the
variable declaration of the catch is `nullptr`.
Diagnosed the cause by attaching the debugger to `clang-query`, this PR
adds a fix to check for `nullptr` before accessing the `isImplicit()`
method of the `Decl` pointee in the AST node traverser visitor
Fixes #146101
diff --git a/clang/docs/ReleaseNotes.rst b/clang/docs/ReleaseNotes.rst
index 45b5f77..f13d998 100644
--- a/clang/docs/ReleaseNotes.rst
+++ b/clang/docs/ReleaseNotes.rst
@@ -903,6 +903,7 @@
- Fixed dependency calculation for TypedefTypes (#GH89774)
- The ODR checker now correctly hashes the names of conversion operators. (#GH143152)
- Fixed the right parenthesis source location of ``CXXTemporaryObjectExpr``. (#GH143711)
+- Fixed a crash when performing an ``IgnoreUnlessSpelledInSource`` traversal of ASTs containing ``catch(...)`` statements. (#GH146103)
Miscellaneous Bug Fixes
^^^^^^^^^^^^^^^^^^^^^^^
diff --git a/clang/include/clang/AST/ASTNodeTraverser.h b/clang/include/clang/AST/ASTNodeTraverser.h
index 8d02a50..8ebabb2 100644
--- a/clang/include/clang/AST/ASTNodeTraverser.h
+++ b/clang/include/clang/AST/ASTNodeTraverser.h
@@ -99,7 +99,7 @@
TraversalKind GetTraversalKind() const { return Traversal; }
void Visit(const Decl *D, bool VisitLocs = false) {
- if (Traversal == TK_IgnoreUnlessSpelledInSource && D->isImplicit())
+ if (Traversal == TK_IgnoreUnlessSpelledInSource && D && D->isImplicit())
return;
getNodeDelegate().AddChild([=] {
diff --git a/clang/unittests/AST/ASTTraverserTest.cpp b/clang/unittests/AST/ASTTraverserTest.cpp
index 8b6e3e9..988e81d 100644
--- a/clang/unittests/AST/ASTTraverserTest.cpp
+++ b/clang/unittests/AST/ASTTraverserTest.cpp
@@ -28,6 +28,10 @@
: TextTreeStructure(OS, /* showColors */ false), OS(OS) {}
void Visit(const Decl *D) {
+ if (!D) {
+ OS << "<<<NULL>>>";
+ return;
+ }
OS << D->getDeclKindName() << "Decl";
if (auto *ND = dyn_cast<NamedDecl>(D)) {
OS << " '" << ND->getDeclName() << "'";
@@ -1932,4 +1936,75 @@
}
}
+TEST(Traverse, CatchStatements) {
+
+ auto AST = buildASTFromCode(R"cpp(
+void test()
+{
+ try
+ {
+ int a;
+ }
+ catch (...)
+ {
+ int b;
+ }
+
+ try
+ {
+ int a;
+ }
+ catch (const int&)
+ {
+ int b;
+ }
+}
+)cpp");
+
+ auto BN =
+ ast_matchers::match(cxxCatchStmt().bind("catch"), AST->getASTContext());
+ EXPECT_EQ(BN.size(), 2u);
+ const auto *catchWithoutDecl = BN[0].getNodeAs<Stmt>("catch");
+
+ llvm::StringRef Expected = R"cpp(
+CXXCatchStmt
+|-<<<NULL>>>
+`-CompoundStmt
+ `-DeclStmt
+ `-VarDecl 'b'
+)cpp";
+ EXPECT_EQ(dumpASTString(TK_AsIs, catchWithoutDecl), Expected);
+
+ Expected = R"cpp(
+CXXCatchStmt
+|-<<<NULL>>>
+`-CompoundStmt
+ `-DeclStmt
+ `-VarDecl 'b'
+)cpp";
+ EXPECT_EQ(dumpASTString(TK_IgnoreUnlessSpelledInSource, catchWithoutDecl),
+ Expected);
+
+ const auto *catchWithDecl = BN[1].getNodeAs<Stmt>("catch");
+
+ Expected = R"cpp(
+CXXCatchStmt
+|-VarDecl ''
+`-CompoundStmt
+ `-DeclStmt
+ `-VarDecl 'b'
+)cpp";
+ EXPECT_EQ(dumpASTString(TK_AsIs, catchWithDecl), Expected);
+
+ Expected = R"cpp(
+CXXCatchStmt
+|-VarDecl ''
+`-CompoundStmt
+ `-DeclStmt
+ `-VarDecl 'b'
+)cpp";
+ EXPECT_EQ(dumpASTString(TK_IgnoreUnlessSpelledInSource, catchWithDecl),
+ Expected);
+}
+
} // namespace clang
