[clang] 9ca395b - [clang][AST] Propagate the contains-errors bit to DeclRefExpr from VarDecl's initializer.

[Haojian Wu via cfe-commits]

Author: Haojian Wu
Date: 2023-07-11T09:14:27+02:00
New Revision: 9ca395b5ade105aee63db20534d49a1c58ac76c7

URL: https://github.com/llvm/llvm-project/commit/9ca395b5ade105aee63db20534d49a1c58ac76c7
DIFF: https://github.com/llvm/llvm-project/commit/9ca395b5ade105aee63db20534d49a1c58ac76c7.diff

LOG: [clang][AST] Propagate the contains-errors bit to DeclRefExpr from VarDecl's initializer.

Similar to the https://reviews.llvm.org/D86048 (it only sets the bit for C++
code), we propagate the contains-errors bit for C-code path.

Fixes https://github.com/llvm/llvm-project/issues/50236
Fixes https://github.com/llvm/llvm-project/issues/50243
Fixes https://github.com/llvm/llvm-project/issues/48636
Fixes https://github.com/llvm/llvm-project/issues/50320

Differential Revision: https://reviews.llvm.org/D154861

Added: 
    

Modified: 
    clang/docs/ReleaseNotes.rst
    clang/lib/AST/ComputeDependence.cpp
    clang/test/AST/ast-dump-recovery.c
    clang/test/SemaCXX/cxx11-crashes.cpp

Removed: 
    


################################################################################
diff  --git a/clang/docs/ReleaseNotes.rst b/clang/docs/ReleaseNotes.rst
index ae88de6a4aa7e6..6a1e2fc3ea0e64 100644
--- a/clang/docs/ReleaseNotes.rst
+++ b/clang/docs/ReleaseNotes.rst
@@ -576,6 +576,12 @@ Bug Fixes in This Version
 - Fixed false positive error diagnostic when pack expansion appears in template
   parameters of a member expression.
   (`#48731 <https://github.com/llvm/llvm-project/issues/48731>`_)
+- Fix the contains-errors bit not being set for DeclRefExpr that refers to a
+  VarDecl with invalid initializer. This fixes:
+  (`#50236 <https://github.com/llvm/llvm-project/issues/50236>`_),
+  (`#50243 <https://github.com/llvm/llvm-project/issues/50243>`_),
+  (`#48636 <https://github.com/llvm/llvm-project/issues/48636>`_),
+  (`#50320 <https://github.com/llvm/llvm-project/issues/50320>`_).
 
 Bug Fixes to Compiler Builtins
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

diff  --git a/clang/lib/AST/ComputeDependence.cpp b/clang/lib/AST/ComputeDependence.cpp
index 632f38f711fb1b..09df5401d6693a 100644
--- a/clang/lib/AST/ComputeDependence.cpp
+++ b/clang/lib/AST/ComputeDependence.cpp
@@ -489,7 +489,7 @@ ExprDependence clang::computeDependence(DeclRefExpr *E, const ASTContext &Ctx) {
   // more bullets here that we handle by treating the declaration as having a
   // dependent type if they involve a placeholder type that can't be deduced.]
   if (Type->isDependentType())
-    return Deps | ExprDependence::TypeValueInstantiation;
+    Deps |= ExprDependence::TypeValueInstantiation;
   else if (Type->isInstantiationDependentType())
     Deps |= ExprDependence::Instantiation;
 
@@ -525,13 +525,13 @@ ExprDependence clang::computeDependence(DeclRefExpr *E, const ASTContext &Ctx) {
   //   - it names a potentially-constant variable that is initialized with an
   //     expression that is value-dependent
   if (const auto *Var = dyn_cast<VarDecl>(Decl)) {
-    if (Var->mightBeUsableInConstantExpressions(Ctx)) {
-      if (const Expr *Init = Var->getAnyInitializer()) {
-        if (Init->isValueDependent())
-          Deps |= ExprDependence::ValueInstantiation;
-        if (Init->containsErrors())
-          Deps |= ExprDependence::Error;
-      }
+    if (const Expr *Init = Var->getAnyInitializer()) {
+      if (Init->containsErrors())
+        Deps |= ExprDependence::Error;
+
+      if (Var->mightBeUsableInConstantExpressions(Ctx) &&
+          Init->isValueDependent())
+        Deps |= ExprDependence::ValueInstantiation;
     }
 
     // - it names a static data member that is a dependent member of the

diff  --git a/clang/test/AST/ast-dump-recovery.c b/clang/test/AST/ast-dump-recovery.c
index 969e0e7941244a..68d3f182dd9f64 100644
--- a/clang/test/AST/ast-dump-recovery.c
+++ b/clang/test/AST/ast-dump-recovery.c
@@ -126,3 +126,25 @@ void test6_GH50244() {
   // CHECK-NEXT:   `-RecoveryExpr {{.*}} '<dependent type>'
   sizeof array / sizeof foo(undef);
 }
+
+// No crash on DeclRefExpr that refers to ValueDecl with invalid initializers.
+void test7() {
+  int b[] = {""()};
+
+  // CHECK:      CStyleCastExpr {{.*}} 'unsigned int' contains-errors
+  // CHECK-NEXT: | `-DeclRefExpr {{.*}} 'int[]' contains-errors
+  (unsigned) b; // GH50236
+
+  // CHECK:      BinaryOperator {{.*}} '<dependent type>' contains-errors '+'
+  // CHECK-NEXT: |-DeclRefExpr {{.*}} 'int[]' contains-errors
+  // CHECK-NEXT: `-IntegerLiteral {{.*}}
+  b + 1; // GH50243
+
+  // CHECK:      CallExpr {{.*}} '<dependent type>' contains-errors
+  // CHECK-NEXT: |-DeclRefExpr {{.*}} 'int ()' Function
+  // CHECK-NEXT: `-DeclRefExpr {{.*}} 'int[]' contains-errors
+  return c(b); // GH48636
+}
+int test8_GH50320_b[] = {""()};
+// CHECK: ArraySubscriptExpr {{.*}} 'int' contains-errors lvalue
+int test8 = test_8GH50320_b[0];

diff  --git a/clang/test/SemaCXX/cxx11-crashes.cpp b/clang/test/SemaCXX/cxx11-crashes.cpp
index a15fea336f8c5e..11bc42315421d6 100644
--- a/clang/test/SemaCXX/cxx11-crashes.cpp
+++ b/clang/test/SemaCXX/cxx11-crashes.cpp
@@ -65,7 +65,7 @@ namespace b6981007 {
   struct S {}; // expected-note 3{{candidate}}
   void f() {
     S s(1, 2, 3); // expected-error {{no matching}}
-    for (auto x : s) { // expected-error {{invalid range expression of}}
+    for (auto x : s) {
       // We used to attempt to evaluate the initializer of this variable,
       // and crash because it has an undeduced type.
       const int &n(x);