C89 allowed a type specifier to be elided with the resulting type being
int, aka implicit int behavior. This feature was subsequently removed
in C99 without a deprecation period, so implementations continued to
support the feature. Now, as with implicit function declarations, is a
good time to reevaluate the need for this support.
This patch allows -Wimplicit-int to issue warnings in C89 mode (off by
default), defaults the warning to an error in C99 through C17, and
disables support for the feature entirely in C2x. It also removes a
warning about missing declaration specifiers that really was just an
implicit int warning in disguise and other minor related cleanups.
(This relands 59337263ab45d7657e and makes sure comma operator
diagnostics are suppressed in a SFINAE context.)
While at it, add the diagnosis message "left operand of comma operator has no effect" (used by GCC) for comma operator.
This also makes Clang diagnose in the constant evaluation context which aligns with GCC/MSVC behavior. (https://godbolt.org/z/7zxb8Tx96)
Reviewed By: aaron.ballman
Differential Revision: https://reviews.llvm.org/D103938
While at it, add the diagnosis message "left operand of comma operator has no effect" (used by GCC) for comma operator.
This also makes Clang diagnose in the constant evaluation context which aligns with GCC/MSVC behavior. (https://godbolt.org/z/7zxb8Tx96)
Reviewed By: aaron.ballman
Differential Revision: https://reviews.llvm.org/D103938
While at it, add the diagnosis message "left operand of comma operator has no effect" (used by GCC) for comma operator.
This also makes Clang diagnose in the constant evaluation context which aligns with GCC/MSVC behavior. (https://godbolt.org/z/7zxb8Tx96)
Reviewed By: aaron.ballman
Differential Revision: https://reviews.llvm.org/D103938
When Sema::RequireCompleteType() is given a class template
specialization type that then fails to instantiate, it returns
'true'. On subsequent invocations, it can return false. Make sure that
this difference doesn't change the result of
Sema::CompareReferenceRelationship, which is expected to remain stable
while we're checking an initialization sequence.
llvm-svn: 178088
the base class. If the base class deduction succeeds, use those results. If
it fails, keep using the results from the derived class template deduction.
This prevents an assertion later where the type of deduction failure doesn't
match up with the template deduction info.
llvm-svn: 167550
