[llvm-bugs] [Bug 27714] New: clang trunk r261461+ fails to compile on some platforms (including Snow Leopard) due to strnlen usage

[via llvm-bugs]

https://llvm.org/bugs/show_bug.cgi?id=27714

            Bug ID: 27714
           Summary: clang trunk r261461+ fails to compile on some
                    platforms (including Snow Leopard) due to strnlen
                    usage
           Product: clang
           Version: unspecified
          Hardware: PC
                OS: All
            Status: NEW
          Severity: normal
          Priority: P
         Component: -New Bugs
          Assignee: unassignedclangbugs at nondot.org
          Reporter: jeremyhu at apple.com
                CC: llvm-bugs at lists.llvm.org
    Classification: Unclassified

strnlen() is used unconditionally, but it is not available on all supported
platforms.

trunk/tools/clang/lib/Lex/HeaderMap.cpp:158:18: error: use of undeclared
identifier 'strnlen'
  unsigned Len = strnlen(Data, MaxLen);
                 ^
1 error generated.

---

Regression introduced by:

commit 839cd13b65d802f06276ff88d234419c38a44199
Author: Duncan P. N. Exon Smith <dexonsmith at apple.com>
Date:   Sun Feb 21 00:14:36 2016 +0000

    Lex: Never overflow the file in HeaderMap::lookupFilename()

    If a header map file is corrupt, the strings in the string table may not
    be null-terminated.  The logic here previously relied on `MemoryBuffer`
    always being null-terminated, but this isn't actually guaranteed by the
    class AFAICT.  Moreover, we're seeing a lot of crash traces at calls to
    `strlen()` inside of `lookupFilename()`, so something is going wrong
    there.

    Instead, use `strnlen()` to get the length, and check for corruption.

    Also remove code paths that could call `StringRef(nullptr)`.  r261459
    made these rather obvious (although they'd been there all along).

    git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@261461
91177308-0d34-0410-b5e6-96231b3b80d8

-- 
You are receiving this mail because:
You are on the CC list for the bug.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.llvm.org/pipermail/llvm-bugs/attachments/20160511/6bb3bdd7/attachment.html>