[analyzer] Fix GCDAntipatternChecker to only fire when the semaphore is initialized to zero
Initializing a semaphore with a different constant most likely signals a different intent
rdar://41802552
Differential Revision: https://reviews.llvm.org/D48911
llvm-svn: 337212
diff --git a/clang/lib/StaticAnalyzer/Checkers/GCDAntipatternChecker.cpp b/clang/lib/StaticAnalyzer/Checkers/GCDAntipatternChecker.cpp
index 1b7ea53..5cb51b0 100644
--- a/clang/lib/StaticAnalyzer/Checkers/GCDAntipatternChecker.cpp
+++ b/clang/lib/StaticAnalyzer/Checkers/GCDAntipatternChecker.cpp
@@ -93,7 +93,9 @@
static auto findGCDAntiPatternWithSemaphore() -> decltype(compoundStmt()) {
const char *SemaphoreBinding = "semaphore_name";
- auto SemaphoreCreateM = callExpr(callsName("dispatch_semaphore_create"));
+ auto SemaphoreCreateM = callExpr(allOf(
+ callsName("dispatch_semaphore_create"),
+ hasArgument(0, ignoringParenCasts(integerLiteral(equals(0))))));
auto SemaphoreBindingM = anyOf(
forEachDescendant(
diff --git a/clang/test/Analysis/gcdantipatternchecker_test.m b/clang/test/Analysis/gcdantipatternchecker_test.m
index adc7a52..24ffe89 100644
--- a/clang/test/Analysis/gcdantipatternchecker_test.m
+++ b/clang/test/Analysis/gcdantipatternchecker_test.m
@@ -333,3 +333,13 @@
}];
dispatch_semaphore_wait(sema1, 100); // expected-warning{{Waiting on a callback using a semaphore}}
}
+
+void no_warn_on_nonzero_semaphore(MyInterface1 *M) {
+ dispatch_semaphore_t sema1 = dispatch_semaphore_create(1);
+
+ [M acceptBlock:^{
+ dispatch_semaphore_signal(sema1);
+ }];
+ dispatch_semaphore_wait(sema1, 100); // no-warning
+}
+