llvm/lib/System/Unix, branch release_26

Merge 80863 from mainline.

2009-09-04T19:52:18Z

Improve llvm::getHostTriple for some cases where the LLVM_HOSTTRIPLE is not reliable. git-svn-id: https://llvm.org/svn/llvm-project/llvm/branches/release_26@81033 91177308-0d34-0410-b5e6-96231b3b80d8

Get rid of a helgrind warning. If this is _actually_ a performance problem,

2009-08-19T21:48:34Z

we can find a way to cache the answer that isn't racy. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@79472 91177308-0d34-0410-b5e6-96231b3b80d8

Add locking around signal handler registration.

2009-08-17T17:07:22Z

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@79254 91177308-0d34-0410-b5e6-96231b3b80d8

Fix a bunch of namespace pollution.

2009-08-07T01:32:21Z

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@78363 91177308-0d34-0410-b5e6-96231b3b80d8

Minor code simplification.

2009-08-05T20:16:55Z

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@78239 91177308-0d34-0410-b5e6-96231b3b80d8

Update a comment to reflect the current code.

2009-08-05T17:32:39Z

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@78215 91177308-0d34-0410-b5e6-96231b3b80d8

Remove needless uses of std::flush in the parent process after a

2009-08-05T00:17:00Z

fork call. This eliminates a need for . Also remove needless fsync calls. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@78131 91177308-0d34-0410-b5e6-96231b3b80d8

Use _exit rather than exit in the child process after a failed exec.

2009-08-05T00:09:12Z

Add a comment explaining why. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@78128 91177308-0d34-0410-b5e6-96231b3b80d8

Follow Unix behavior and return 127 if the command is not found,

2009-08-04T23:15:49Z

and 126 if it is not executable. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@78120 91177308-0d34-0410-b5e6-96231b3b80d8

When exec() fails, return 127 instead of errno; the parent process has no way to

2009-08-04T20:32:25Z

distinguish that the result is errno, so it can't use it to provide more information about the error (it also exposes the numeric value of errno). git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@78098 91177308-0d34-0410-b5e6-96231b3b80d8