Second Lit tests C++11 compatibility patch: using preprocessor to filter expected-error

[Richard Smith via cfe-commits]

On Mon, Aug 17, 2015 at 9:56 AM, Li, Charles via cfe-commits <
cfe-commits at lists.llvm.org> wrote:

> Hi Clang developers,
>
>
>
> We here at Sony are continuing to update the Lit tests for C++ dialects
> compatibility.
>
> Attached is the second patch. (As a reference, here is the link to the
> discussion on the previous Lit patch.
> http://lists.cs.uiuc.edu/pipermail/cfe-commits/Week-of-Mon-20150727/134667.html
> )
>
> In this second patch, there is 1 complicated change and 3 simple changes.
>
>
>
> Here is the complicated change first.
>
>
>
> test/Sema/switch-1.c
>
>   This test verifies the diagnostics for integer overflows.
>
>   Due to C++11’s more strict requirements on constant-expressions in
> 5.19p2 [expr.const],
>
>   The diagnostics have changed from “overflow in expression” to “not a
> constant expression”.
>
>
>
>   Usually we would create a C++11 version of the switch-1.c file.
>
>   But here we propose a novel approach to “#ifdef” the expected
> diagnostics. (We hope to use this approach for all similar cases in the
> future.)
>
>   Normally ‘// expected-error’ does not honor any ‘#ifdef’.
>
>   But if we first preprocess the source into a temporary file, only the
> valid ‘#ifdef’ sections remain.
>
>   We then run the preprocessed file at the desired dialect.
>
>   The main downside to this approach is If the test fails, the errors are
> reported on the temporary file, not on the original file, and the line
> numbers of these two files  do not match
>

The only thing novel about this approach is using the preprocessor to
achieve it. -verify *does* respect #ifdef, and we have a lot of tests that
rely on that.


> Here are the simple changes.
>
>
>
> test/Analysis/temp-obj-dtors-cfg-output.cpp
>
>   This test verifies CFG dump for temporary destructors
>
>   C++11 no longer has the following implicit cast.
>
>     (ImplicitCastExpr, NoOp, const struct D)
>
>   We modified the test using the #ifdef approach to have the preprocessor
> generate the desired CHECK lines.
>
>
>
> test/CodeCompletion/ordinary-name.cpp
>
>   This test verifies for code completion patterns.
>
>   Since C++11 has more keywords than C++98,
>
>   We made this test to be C++98 specific, and create a separate C++11
> version.
>
>
>
> test/CodeCompletion/ordinary-name-cxx11.cpp
>
>   This is the C++11 specific version of the code completion.
>
>   This test added patterns for the following keywords:
>
>     char16, char32, noexcept, nullptr, sizeof...,
>
>     auto, decltype, char16_t, char32_t
>
>
>
> test/Sema/thread-specifier.c
>
>   Tests for __thread specifier at various C++ dialects
>
>   We made the default RUN line explicit to be at –std=c++98
>
>
>
>
>
> If there is anything that seems confusing to you, please let me know.
>
> I would be more than happy to expand on the reasons for the these changes.
>
>
>
>
>
> Thanks,
>
> Charles
>
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>
>
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