[MacPorts] #53226: gcc5 @5.4: error: 'std::log2' has not been declared

[MacPorts]

#53226: gcc5 @5.4: error: 'std::log2' has not been declared
-----------------------+----------------------
  Reporter:  noloader  |      Owner:  mww@…
      Type:  defect    |     Status:  assigned
  Priority:  Normal    |  Milestone:
 Component:  ports     |    Version:  2.3.5
Resolution:            |   Keywords:  powerpc
      Port:  gcc5      |
-----------------------+----------------------

Comment (by kencu):

 some more data - from an Intel 10.5 machine. Same issue on the Intel
 machine, and also same issue with clang++. So it's looking more like a
 10.5 issue than anything else, at the moment - not specific to gcc, and
 not specific to PPC. The `llrint` missing definitions you noted are a
 recognized issue with systems < 10.7, btw, see
 <https://github.com/jeremyhu/libcxx/commit/720feba4874d4ca3131753dc31af127e3c509c36>
 {{{
 $ cat math.cxx
 #include <cmath>
 #include <stdio.h>
 int main(int argc, char* argv[])
 {
     int i = 1000;
     double b = std::log2(i);
     printf("%f \n",b);

     double d = std::log2(2.3456789f);
     printf("%f \n",d);
     return 0;
 }
 }}}

 {{{
 $ g++ --version
 i686-apple-darwin9-llvm-g++-4.2 (GCC) 4.2.1 (Based on Apple Inc. build
 5555) (LLVM build 2064.3)
 Copyright (C) 2007 Free Software Foundation, Inc.
 This is free software; see the source for copying conditions.  There is NO
 warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR
 PURPOSE.
 }}}
 {{{
 $ g++ -o math.intel math.cxx
 math.cxx: In function ‘int main(int, char**)’:
 math.cxx:6: error: ‘log2’ is not a member of ‘std’
 math.cxx:9: error: ‘log2’ is not a member of ‘std’
 }}}

 {{{
 $ clang++ --version
 clang version 3.7.1 (tags/RELEASE_371/final)
 Target: i686-apple-darwin9.8.0
 Thread model: posix
 }}}
 {{{
 $ clang++ -o math.intel math.cxx
 math.cxx:6:16: error: no member named 'log2' in namespace 'std'; did you
 mean simply 'log2'?
     double b = std::log2(i);
                ^~~~~~~~~
                log2
 /usr/include/architecture/i386/math.h:316:15: note: 'log2' declared here
 extern double log2 ( double );
               ^
 math.cxx:9:16: error: no member named 'log2' in namespace 'std'; did you
 mean simply 'log2'?
     double d = std::log2(2.3456789f);
                ^~~~~~~~~
                log2
 /usr/include/architecture/i386/math.h:316:15: note: 'log2' declared here
 extern double log2 ( double );
               ^
 }}}

--
Ticket URL: <https://trac.macports.org/ticket/53226#comment:5>
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