From: Sam McCall <sam.mccall@gmail.com>
Date: Wed, 10 Oct 2018 10:51:48 +0000 (+0000)
Subject: [CodeComplete] Fix crash when completing params function declarations.
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=37521757fa2168cc9b401c37069623f19d07b0b7;p=clang

[CodeComplete] Fix crash when completing params function declarations.

Summary:
In a decl like `int AA(BB cc)` where BB isn't defined, we end up trying to
parse `BB cc` as an expression (vexing parse) and end up triggering the
parser's "recovery-in-function" completion with no actual function
scope.

This patch avoids the assumption that such a scope exists in this context.

Reviewers: kadircet

Subscribers: cfe-commits

Differential Revision: https://reviews.llvm.org/D53070

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@344133 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/Sema/SemaCodeComplete.cpp b/lib/Sema/SemaCodeComplete.cpp
index 33bb1229ac..bdf538b9dc 100644
--- a/lib/Sema/SemaCodeComplete.cpp
+++ b/lib/Sema/SemaCodeComplete.cpp
@@ -1881,7 +1881,8 @@ static void AddOrdinaryNameResults(Sema::ParserCompletionContext CCC,
     }
 
     // Switch-specific statements.
-    if (!SemaRef.getCurFunction()->SwitchStack.empty()) {
+    if (SemaRef.getCurFunction() &&
+        !SemaRef.getCurFunction()->SwitchStack.empty()) {
       // case expression:
       Builder.AddTypedTextChunk("case");
       Builder.AddChunk(CodeCompletionString::CK_HorizontalSpace);
diff --git a/test/CodeCompletion/crash-func-decl.cpp b/test/CodeCompletion/crash-func-decl.cpp
new file mode 100644
index 0000000000..7abcdcdb27
--- /dev/null
+++ b/test/CodeCompletion/crash-func-decl.cpp
@@ -0,0 +1,5 @@
+// Important that BB is unknown.
+// This triggers completion in PCC_RecoveryInFunction context, with no function.
+int AA(BB cc);
+// RUN: not %clang_cc1 -fsyntax-only -code-completion-at=%s:3:12 %s | FileCheck %s
+// CHECK: COMPLETION: char