Based on post-commit review discussion on
2bd84938470bf2e337801faafb8a67710f46429d with Richard Smith.
Other uses of forcing HasEmptyPlaceHolder to false seem OK to me -
they're all around pointer/reference types where the pointer/reference
token will appear at the rightmost side of the left side of the type
name, so they make nested types (eg: the "int" in "int *") behave as
though there is a non-empty placeholder (because the "*" is essentially
the placeholder as far as the "int" is concerned).
This was originally committed in 277623f4d5a672d707390e2c3eaf30a9eb4b075c
Reverted in f9ad1d1c775a8e264bebc15d75e0c6e5c20eefc7 due to breakages
outside of clang - lldb seems to have some strange/strong dependence on
"char [N]" versus "char[N]" when printing strings (not due to that name
appearing in DWARF, but probably due to using clang to stringify type
names) that'll need to be addressed, plus a few other odds and ends in
other subprojects (clang-tools-extra, compiler-rt, etc).
Looks like lldb has some issues with this - somehow it causes lldb to
treat a "char[N]" type as an array of chars (prints them out
individually) but a "char [N]" is printed as a string. (even though the
DWARF doesn't have this string in it - it's something to do with the
string lldb generates for itself using clang)
This reverts commit 277623f4d5a672d707390e2c3eaf30a9eb4b075c.
Based on post-commit review discussion on
2bd84938470bf2e337801faafb8a67710f46429d with Richard Smith.
Other uses of forcing HasEmptyPlaceHolder to false seem OK to me -
they're all around pointer/reference types where the pointer/reference
token will appear at the rightmost side of the left side of the type
name, so they make nested types (eg: the "int" in "int *") behave as
though there is a non-empty placeholder (because the "*" is essentially
the placeholder as far as the "int" is concerned).
Summary:
In our codebase, `static_assert(std::some_type_trait<Ts...>::value, "msg")`
(where `some_type_trait` is an std type_trait and `Ts...` is the
appropriate template parameters) account for 11.2% of the `static_assert`s.
In these cases, the `Ts` are typically not spelled out explicitly, e.g.
`static_assert(std::is_same<SomeT::TypeT, typename SomeDependentT::value_type>::value, "message");`
The diagnostic when the assert fails is typically not very useful, e.g.
`static_assert failed due to requirement 'std::is_same<SomeT::TypeT, typename SomeDependentT::value_type>::value' "message"`
This change makes the diagnostic spell out the types explicitly , e.g.
`static_assert failed due to requirement 'std::is_same<int, float>::value' "message"`
See tests for more examples.
After this is submitted, I intend to handle
`static_assert(!std::some_type_trait<Ts...>::value, "msg")`,
which is another 6.6% of static_asserts.
Subscribers: cfe-commits
Differential Revision: https://reviews.llvm.org/D54903
llvm-svn: 348239
