[Bug libstdc++/69782] [6 Regression] defining min() macro causes thousand of lines of error messages
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=69782
--- Comment #8 from Jonathan Wakely ---
(In reply to Jakub Jelinek from comment #7)
> So is the plan to uglify all
> find libstdc++-v3/include -type f | xargs grep '[^a-zA-Z_]\(min\|max\)(' |
> wc -l
> 461
> with ()s around min/max or whatever id-expression it appears at the end of?
I started doing that, and it made me want to hit myself in the face with a
hammer.
Adding a header that #undefs the macros and including it everywhere necessary
is a much smaller patch, and doesn't obfuscate hundreds of valid uses of
min/max functions in the library. It also means users can call the std min/max
functions without parentheses because any macros have been removed. It doesn't
allow people to continue using their undefined macros, but those people are
immoral anyway.
> For 6.x or just 7.x?
I find it hard to care about code with min/max macros.
[Bug libstdc++/69782] [6 Regression] defining min() macro causes thousand of lines of error messages
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=69782
Jakub Jelinek changed:
What|Removed |Added
CC||jakub at gcc dot gnu.org
--- Comment #7 from Jakub Jelinek ---
So is the plan to uglify all
find libstdc++-v3/include -type f | xargs grep '[^a-zA-Z_]\(min\|max\)(' | wc
-l
461
with ()s around min/max or whatever id-expression it appears at the end of?
For 6.x or just 7.x?
[Bug libstdc++/69782] [6 Regression] defining min() macro causes thousand of lines of error messages
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=69782 Andrew Pinski changed: What|Removed |Added Target Milestone|--- |6.0
[Bug libstdc++/69782] [6 Regression] defining min() macro causes thousand of lines of error messages
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=69782 --- Comment #1 from Markus Trippelsdorf --- The fix is easy in this case, just #include after the macro definition. luminance-hdr-2.3.0/src/HdrCreation/robertson02.cpp From 30 #include "arch/math.h" 31 #include "arch/minmax.h" 32 33 #include To 30 #include "arch/minmax.h" 31 #include "arch/math.h" 32 33 #include
[Bug libstdc++/69782] [6 Regression] defining min() macro causes thousand of lines of error messages
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=69782 Manuel López-Ibáñez changed: What|Removed |Added CC||manu at gcc dot gnu.org --- Comment #3 from Manuel López-Ibáñez --- (In reply to Jonathan Wakely from comment #2) > I assume clang does it by not having header guards in its __undef_min_max > file, so that it can be re-included by any header and redo the #undefs. Let's do the same, no? > I'm almost tempted to make it #error not #warning, to teach people a lesson > ;-) Well, they will get an error if they use -Werror.
[Bug libstdc++/69782] [6 Regression] defining min() macro causes thousand of lines of error messages
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=69782 Jonathan Wakely changed: What|Removed |Added Status|UNCONFIRMED |ASSIGNED Last reconfirmed||2016-02-12 Assignee|unassigned at gcc dot gnu.org |redi at gcc dot gnu.org Ever confirmed|0 |1 --- Comment #2 from Jonathan Wakely --- This is undefined behaviour, really egregious undefined behaviour. The code compiled before because includes which does #undef min #undef max to remove the silly macro before doing anything else. Now that include those #undefs come too early to help. I assume clang does it by not having header guards in its __undef_min_max file, so that it can be re-included by any header and redo the #undefs. I'm almost tempted to make it #error not #warning, to teach people a lesson ;-)
[Bug libstdc++/69782] [6 Regression] defining min() macro causes thousand of lines of error messages
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=69782 Martin Sebor changed: What|Removed |Added CC||msebor at gcc dot gnu.org --- Comment #4 from Martin Sebor --- FWIW, while C++ doesn't allow programs to define min and max as macros, lots of C code does it. When that code happens to be in a header, including that header in a C++ program causes all kinds of grief. Sometimes, fixing the header is easy. Other times, for instance when the header is a system one, it can be less than trivial. A fairly easy way to avoid having to deal with the problem in libstdc++ is to enclose every call to min and max in public libstdc++ headers in parentheses: z = (min)(x, y).
[Bug libstdc++/69782] [6 Regression] defining min() macro causes thousand of lines of error messages
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=69782 --- Comment #6 from Jonathan Wakely --- (In reply to Jonathan Wakely from comment #5) > That doesn't help for std::numeric_limits::min() Martin corrected me, (numeric_limits::min)() will work.
[Bug libstdc++/69782] [6 Regression] defining min() macro causes thousand of lines of error messages
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=69782 --- Comment #5 from Jonathan Wakely --- (In reply to Martin Sebor from comment #4) > it can be less than trivial. A fairly easy way to avoid having to deal with > the problem in libstdc++ is to enclose every call to min and max in public > libstdc++ headers in parentheses: z = (min)(x, y). That doesn't help for std::numeric_limits::min()
