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.
In public MS headers for XAudio, clang would fail to generate a valid UUID due to the UUID components being combined with the '-' UUID separators. Clang would attempting to recover but would preserve the leading whitespace from the tokens after each failed paste leading to spaces creeping into the UUID and causing an error in the __declspace(uuid()) parsing.
Reference: Microsoft DirectX SDK (June 2010)\Include\XAudio2.h(51)
Resolves http://llvm.org/pr23071
llvm-svn: 235186
Aaron Ballman