[analyzer] Fix unknown block calls to have zero parameters.

Right now they report to have one parameter with null decl,
because initializing an ArrayRef of pointers with a nullptr
yields an ArrayRef to an array of one null pointer.

Fixes a crash in the OSObject section of RetainCountChecker.

Differential Revision: https://reviews.llvm.org/D55671

llvm-svn: 349229

2 files changed, 11 insertions, 2 deletions

diff --git a/clang/lib/StaticAnalyzer/Core/CallEvent.cpp b/clang/lib/StaticAnalyzer/Core/CallEvent.cpp
index 767116630f4..8d9338b21c1 100644
--- a/clang/lib/StaticAnalyzer/Core/CallEvent.cpp
+++ b/clang/lib/StaticAnalyzer/Core/CallEvent.cpp
@@ -837,7 +837,7 @@ const BlockDataRegion *BlockCall::getBlockRegion() const {
 ArrayRef<ParmVarDecl*> BlockCall::parameters() const {
   const BlockDecl *D = getDecl();
   if (!D)
-    return nullptr;
+    return None;
   return D->parameters();
 }
 
diff --git a/clang/test/Analysis/osobject-retain-release.cpp b/clang/test/Analysis/osobject-retain-release.cpp
index b8eb462d20e..c8bc4aeaa0a 100644
--- a/clang/test/Analysis/osobject-retain-release.cpp
+++ b/clang/test/Analysis/osobject-retain-release.cpp
@@ -1,4 +1,5 @@
-// RUN: %clang_analyze_cc1 -analyze -analyzer-checker=core,osx -analyzer-output=text -verify %s
+// RUN: %clang_analyze_cc1 -fblocks -analyze -analyzer-output=text\
+// RUN:                    -analyzer-checker=core,osx -verify %s
 
 struct OSMetaClass;
 
@@ -399,3 +400,11 @@ unsigned int ok_release_with_unknown_source(ArrayOwner *owner) {
   arr->release(); // +0
   return arr->getCount();
 }
+
+OSObject *getObject();
+typedef bool (^Blk)(OSObject *);
+
+void test_escape_to_unknown_block(Blk blk) {
+  blk(getObject()); // no-crash
+}
+