New clang warns Wincompatible-pointer-types in OCMConstraint.m

[nico]

We're seeing this in the Chromium build when using trunk clang:

FAILED: obj/third_party/ocmock/ocmock/OCMConstraint.o 
../../third_party/llvm-build/Release+Asserts/bin/clang -MMD -MF obj/third_party/ocmock/ocmock/OCMConstraint.o.d -DV8_DEPRECATION_WARNINGS -DNO_TCMALLOC -DFULL_SAFE_BROWSING -DSAFE_BROWSING_CSD -DSAFE_BROWSING_DB_LOCAL -DCHROMIUM_BUILD -DFIELDTRIAL_TESTING_ENABLED -D_LIBCPP_HAS_NO_ALIGNED_ALLOCATION -DCR_XCODE_VERSION=0832 -DCR_CLANG_REVISION=\"350301\" -DCOMPONENT_BUILD -D__ASSERT_MACROS_DEFINE_VERSIONS_WITHOUT_UNDERSCORE=0 -DNDEBUG -DNVALGRIND -DDYNAMIC_ANNOTATIONS_ENABLED=0 -DGTEST_API_= -DGTEST_HAS_POSIX_RE=0 -DGTEST_LANG_CXX11=1 -DGTEST_HAS_TR1_TUPLE=0 -DUNIT_TEST -I../.. -Igen -I../../third_party/ocmock -I../../third_party/googletest/custom -I../../third_party/googletest/src/googletest/include -fno-strict-aliasing -fstack-protector -Wno-builtin-macro-redefined -D__DATE__= -D__TIME__= -D__TIMESTAMP__= -fcolor-diagnostics -fmerge-all-constants -Xclang -mllvm -Xclang -instcombine-lower-dbg-declare=0 -no-canonical-prefixes -arch x86_64 -O2 -fno-omit-frame-pointer -g1 -isysroot ../../build/mac_files/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.12.sdk -mmacosx-version-min=10.9.0 -fvisibility=hidden -Wheader-hygiene -Wstring-conversion -Wtautological-overlap-compare -Wno-semicolon-before-method-body -Wno-undeclared-selector -Werror -Wall -Wno-unused-variable -Wunguarded-availability -Wno-missing-field-initializers -Wno-unused-parameter -Wno-c++11-narrowing -Wno-unneeded-internal-declaration -Wno-undefined-var-template -Wno-null-pointer-arithmetic -Wno-ignored-pragma-optimize -std=c11 -c ../../third_party/ocmock/OCMock/OCMConstraint.m -o obj/third_party/ocmock/ocmock/OCMConstraint.o
../../third_party/ocmock/OCMock/OCMConstraint.m:52:27: error: incompatible pointer types initializing 'OCMInvocationConstraint *' with an expression of type 'OCMConstraint *' [-Werror,-Wincompatible-pointer-types]
        OCMInvocationConstraint *constraint = [self constraintWithSelector:aSelector onObject:anObject];
                                 ^            ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
../../third_party/ocmock/OCMock/OCMConstraint.h:29:1: note: class method 'constraintWithSelector:onObject:' is assumed to return an instance of its receiver type ('OCMConstraint *')
+ (instancetype)constraintWithSelector:(SEL)aSelector onObject:(id)anObject;
^
1 error generated

Looks like the warning is correct. constraintWithSelector: seems to always return an OCMInvocationConstraint though, so the return type of that method should probably just be OCMInvocationConstraint instead of instancetype.

[erikdoe]

Let me know whether the fix works for you.

[erikdoe]

Assuming this is fixed.