cmath does not work with clang -std=c++0x or -std=c++93

[llvmbot]

Bugzilla Link	9205
Resolution	WORKSFORME
Resolved on	Apr 01, 2011 07:34
Version	unspecified
OS	All
Reporter	LLVM Bugzilla Contributor

Extended Description

A simple:

#include

does not work on mac os x 10.6, with clang -std=c++0x or clang -std=c++93. It works fine with -std=gnu++0x and -std=gnu++93.

I had assumed that -std=c++0x was the 'natural' extension to get c++0x support. I can see I should probably be using gnu++0x. That is an unfortunate choice of naming (but probably clang's fault).

[llvmbot]

This is AFAIK a bug in Apple's math.h headers. See http://lists.cs.uiuc.edu/pipermail/cfe-dev/2010-August/010176.html:

| I had to add an additional tweak to the cmath header for OSX when
| building with Clang with -std=c++0x, as that flag disables the GNU
| extensions mode and defines STRICT_ANSI, and the current math.h
| headers with OSX/iOS (Xcode 3.2.3) don't bring in a number of the C99
| math functions when STRICT_ANSI is defined.

I solved the problem by changing the buggy math.h on my system.

You are correct that 'c++0x' is used to enable C++0x support. Clang works as expected here.

@​Howard: Close this bug? (after filing a radar for math.h)

[llvmbot]

Closed. Bug has been filed (and fixed) for math.h on OS X.