[analyzer] Teach RetainCountChecker about CVFooRetain

Change the retain count checker to treat CoreFoundation-style "CV"-prefixed
reference types from CoreVideo similarly to CoreGraphics types. With this
change, we treat CVFooRetain() on a CVFooRef type as a retain. CVFooRelease()
APIs are annotated as consuming their parameter, so this change prevents false
positives about incorrect decrements of reference counts.

<rdar://problem/27116090>

llvm-svn: 278382

1 files changed, 20 insertions, 0 deletions

diff --git a/clang/test/Analysis/retain-release.m b/clang/test/Analysis/retain-release.m
index f0d91e34c1b..3acf86c7d9e 100644
--- a/clang/test/Analysis/retain-release.m
+++ b/clang/test/Analysis/retain-release.m
@@ -1247,6 +1247,26 @@ CVReturn rdar_7283567_2(CFAllocatorRef allocator, size_t width, size_t height,
               pixelBufferAttributes, pixelBufferOut) ;
 }
 
+#pragma clang arc_cf_code_audited begin
+typedef struct SomeOpaqueStruct *CMSampleBufferRef;
+CVImageBufferRef _Nonnull CMSampleBufferGetImageBuffer(CMSampleBufferRef _Nonnull sbuf);
+#pragma clang arc_cf_code_audited end
+
+CVBufferRef _Nullable CVBufferRetain(CVBufferRef _Nullable buffer);
+void CVBufferRelease(CF_CONSUMED CVBufferRef _Nullable buffer);
+
+void testCVPrefixRetain(CMSampleBufferRef sbuf) {
+  // Make sure RetainCountChecker treats CVFooRetain() as a CF-style retain.
+  CVPixelBufferRef pixelBuf = CMSampleBufferGetImageBuffer(sbuf);
+  CVBufferRetain(pixelBuf);
+  CVBufferRelease(pixelBuf); // no-warning
+
+
+  // Make sure result of CVFooRetain() is the same as its argument.
+  CVPixelBufferRef pixelBufAlias = CVBufferRetain(pixelBuf);
+  CVBufferRelease(pixelBufAlias); // no-warning
+}
+
 //===----------------------------------------------------------------------===//
 // <rdar://problem/7358899> False leak associated with 
 //  CGBitmapContextCreateWithData