[analyzer] Prevent an assertion failure in PThreadLockChecker

When the implementations of the locking functions are available.

Differential Revision: https://reviews.llvm.org/D74003

clang/lib/StaticAnalyzer/Checkers/PthreadLockChecker.cpp

@@ -256,7 +256,9 @@ void PthreadLockChecker::checkPostCall(const CallEvent &Call,
   // are global C functions.
   // TODO: Maybe make this the default behavior of CallDescription
   // with exactly one identifier?
-  if (!Call.isGlobalCFunction())
+  // FIXME: Try to handle cases when the implementation was inlined rather
+  // than just giving up.
+  if (!Call.isGlobalCFunction() || C.wasInlined)
     return;
 
   if (const FnCheck *Callback = PThreadCallbacks.lookup(Call))

clang/test/Analysis/fuchsia_lock_impl.c

@@ -0,0 +1,18 @@
+// RUN: %clang_analyze_cc1 -analyzer-checker=fuchsia.Lock -verify %s
+// expected-no-diagnostics
+typedef int spin_lock_t;
+
+void spin_lock(spin_lock_t *lock);
+int getCond();
+int spin_trylock(spin_lock_t *lock) {
+    if (getCond())
+        return 0;
+    return -1;
+}
+void spin_unlock(spin_lock_t *lock);
+
+spin_lock_t mtx;
+void no_crash() {
+  if (spin_trylock(&mtx) == 0)
+    spin_unlock(&mtx);
+}