[pulse] Add model for malloc_no_fail

Summary:
We model `malloc` in Objective-C as `malloc_not_fail` I think because the null case is not normally handled in iOS apps because the OS will just killed the app after giving some memory warnings.
So adding `malloc_not_fail` model to Pulse.

Reviewed By: jvillard

Differential Revision: D21278527

fbshipit-source-id: 17a5008fe

infer/src/pulse/PulseModels.ml

@@ -677,6 +677,7 @@ module ProcNameDispatcher = struct
       ; -"CFBridgingRelease" <>$ capt_arg_payload $--> C.cf_bridging_release
       ; +match_builtin BuiltinDecl.__free_cf <>$ capt_arg_payload $--> C.cf_bridging_release
       ; +PatternMatch.ObjectiveC.is_modelled_as_alloc &++> C.malloc_not_null
+      ; +match_builtin BuiltinDecl.malloc_no_fail <>$ capt_arg_payload $--> C.malloc_not_null
       ; +PatternMatch.ObjectiveC.is_modelled_as_free <>$ capt_arg_payload $--> C.free ]
 end
 

infer/tests/codetoanalyze/objc/pulse/MallocInObjC.m

@@ -0,0 +1,16 @@
+/*
+ * Copyright (c) Facebook, Inc. and its affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+#import <Foundation/NSObject.h>
+
+void wrap_free(void* x) { free(x); }
+
+void interproc_free_ok() {
+  int* p = malloc(sizeof(int));
+  wrap_free(p);
+}
+
+void leak_bad() { int* p = malloc(sizeof(int)); }

infer/tests/codetoanalyze/objc/pulse/issues.exp

@@ -1,4 +1,5 @@
 codetoanalyze/objc/pulse/AllocPatternMemLeak.m, A::create_no_release_leak_bad, 1, PULSE_MEMORY_LEAK, no_bucket, ERROR, [allocation part of the trace starts here,allocated by call to `ABFDataCreate` (modelled),allocation part of the trace ends here,memory becomes unreachable here]
+codetoanalyze/objc/pulse/MallocInObjC.m, leak_bad, 0, PULSE_MEMORY_LEAK, no_bucket, ERROR, [allocation part of the trace starts here,allocated by call to `malloc_no_fail` (modelled),allocation part of the trace ends here,memory becomes unreachable here]
 codetoanalyze/objc/pulse/MemoryLeaks.m, MemoryLeaks::cg_path_create_mutable_leak_bad:, 2, PULSE_MEMORY_LEAK, no_bucket, ERROR, [allocation part of the trace starts here,allocated by call to `CGPathCreateMutable` (modelled),allocation part of the trace ends here,memory becomes unreachable here]
 codetoanalyze/objc/pulse/MemoryLeaks.m, MemoryLeaks::cg_path_create_with_rect_leak_bad, 3, PULSE_MEMORY_LEAK, no_bucket, ERROR, [allocation part of the trace starts here,allocated by call to `CGPathCreateWithRect` (modelled),allocation part of the trace ends here,memory becomes unreachable here]
 codetoanalyze/objc/pulse/MemoryLeaks.m, MemoryLeaks::no_bridge_leak_bad, 1, PULSE_MEMORY_LEAK, no_bucket, ERROR, [allocation part of the trace starts here,allocated by call to `CFLocaleCreate` (modelled),allocation part of the trace ends here,memory becomes unreachable here]