r345029 - [clang] Fix a null pointer dereference.

[Kadir Cetinkaya via cfe-commits]

Author: kadircet
Date: Tue Oct 23 06:49:37 2018
New Revision: 345029

URL: http://llvm.org/viewvc/llvm-project?rev=345029&view=rev
Log:
[clang] Fix a null pointer dereference.

Summary:
Sometimes expression inside switch statement can be invalid, for
example type might be incomplete. In those cases code were causing a null
pointer dereference. This patch fixes that.

Reviewers: sammccall, ioeric, hokein

Reviewed By: sammccall

Subscribers: arphaman, cfe-commits

Differential Revision: https://reviews.llvm.org/D53561

Added:
    cfe/trunk/test/Index/complete-switch.c
Modified:
    cfe/trunk/lib/Sema/SemaCodeComplete.cpp

Modified: cfe/trunk/lib/Sema/SemaCodeComplete.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaCodeComplete.cpp?rev=345029&r1=345028&r2=345029&view=diff
==============================================================================
--- cfe/trunk/lib/Sema/SemaCodeComplete.cpp (original)
+++ cfe/trunk/lib/Sema/SemaCodeComplete.cpp Tue Oct 23 06:49:37 2018
@@ -4419,6 +4419,9 @@ void Sema::CodeCompleteCase(Scope *S) {
     return;
 
   SwitchStmt *Switch = getCurFunction()->SwitchStack.back().getPointer();
+  // Condition expression might be invalid, do not continue in this case.
+  if (!Switch->getCond())
+    return;
   QualType type = Switch->getCond()->IgnoreImplicit()->getType();
   if (!type->isEnumeralType()) {
     CodeCompleteExpressionData Data(type);

Added: cfe/trunk/test/Index/complete-switch.c
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Index/complete-switch.c?rev=345029&view=auto
==============================================================================
--- cfe/trunk/test/Index/complete-switch.c (added)
+++ cfe/trunk/test/Index/complete-switch.c Tue Oct 23 06:49:37 2018
@@ -0,0 +1,10 @@
+void f() {
+  auto foo = bar;
+  switch(foo) {
+    case x:
+      break;
+  }
+}
+
+// RUN: not %clang_cc1 -fsyntax-only -code-completion-at=%s:4:10 %s | FileCheck %s -allow-empty
+// CHECK-NOT: COMPLETION: foo