- Disable warning C4127 "conditional expression is constant" globally
in curl_setup.h for when building with Microsoft's compiler.
This mainly affects building with the Visual Studio project files found
in the projects dir.
Prior to this change the cmake and winbuild build systems already
disabled 4127 globally for when building with Microsoft's compiler.
Also, 4127 was already disabled for all build systems in the limited
circumstance of the WHILE_FALSE macro which disabled the warning
specifically for while(0). This commit removes the WHILE_FALSE macro and
all other cruft in favor of disabling globally in curl_setup.
Background:
We have various macros that cause 0 or 1 to be evaluated, which would
cause warning C4127 in Visual Studio. For example this causes it:
#define Curl_resolver_asynch() 1
Full behavior is not clearly defined and inconsistent across versions.
However it is documented that since VS 2015 Update 3 Microsoft has
addressed this somewhat but not entirely, not warning on while(true) for
example.
Prior to this change some C4127 warnings occurred when I built with
Visual Studio using the generated projects in the projects dir.
Closes https://github.com/curl/curl/pull/4658
The WHILE_FALSE construction is used to avoid compiler warnings in
macro constructions. This fixes a few instances where it was not
used in order to keep the code consistent.
Closes#4649
Reviewed-by: Daniel Stenberg <daniel@haxx.se>
The regexp looking for assignments within conditions was too greedy
and matched a too long string in the case of multiple conditionals
on the same line. This is basically only a problem in single line
macros, and the code which exemplified this was essentially:
do { if((x) != NULL) { x = NULL; } } while(0)
..where the final parenthesis of while(0) matched the regexp, and
the legal assignment in the block triggered the warning. Fix by
making the regexp less greedy by matching for the tell-tale signs
of the if statement ending.
Also remove the one occurrence where the warning was disabled due
to a construction like the above, where the warning didn't apply
when fixed.
Closes#4647
Reviewed-by: Daniel Stenberg <daniel@haxx.se>
