Code breaking reformat for simdjson.h

[Quuxplusone]

Bugzilla Link	PR46933
Status	NEW
Importance	P enhancement
Reported by	Šimon Tóth (happy.cerberus@gmail.com)
Reported on	2020-07-31 07:03:52 -0700
Last modified on	2020-07-31 08:28:02 -0700
Version	10.0
Hardware	PC Windows NT
CC	djasper@google.com, Jake.Merdich@amd.com, klimek@google.com, llvm-bugs@lists.llvm.org
Fixed by commit(s)
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See also

Code breaking reformat. The warning disabling macros are broken when processed
with this style (spaces inserted in places where they shouldn't).

Example after reformat:
SIMDJSON_DISABLE_GCC_WARNING(-Wmicrosoft - include)

Processing this file:
https://github.com/simdjson/simdjson/blob/master/singleheader/simdjson.h

With this style:
BasedOnStyle: Google
---
Language: Cpp
AlignOperands: true
AlignAfterOpenBracket: AlwaysBreak
AllowAllParametersOfDeclarationOnNextLine: true
BinPackParameters: false
BinPackArguments: false
DerivePointerAlignment: false
PointerAlignment: Left
ColumnLimit: 100

[Quuxplusone]

I'm not aware of any other place in cpp where whitespace matters for the '-'
sign. Also, clang-format has *really* limited context information inside of
macros, especially ones that evaluate to compiler-specific pragmas. That means
we can't detect this automatically.

Good news is that we recently added a flag for a similar case that fits this
perfectly. Try WhitespaceSensitiveMacros: ['SIMDJSON_DISABLE_GCC_WARNING'].

This will be available in the final release of clang-format 11 (already
available on linux prerelease packages but not in windows snapshots).