[lld] r270706 - ELF: Handle empty CIE augmentation string

[Ed Maste via llvm-commits]

Author: emaste
Date: Wed May 25 09:45:28 2016
New Revision: 270706

URL: http://llvm.org/viewvc/llvm-project?rev=270706&view=rev
Log:
ELF: Handle empty CIE augmentation string

"A zero length string indicates that no augmentation data is present."

The FreeBSD/mips toolchain (GCC 4.2.1) generates .debug_frame sections
containing CIE records that have an empty augmentation string.

Differential Revision: http://reviews.llvm.org/D19928

Added:
    lld/trunk/test/ELF/Inputs/no-augmentation.o   (with props)
    lld/trunk/test/ELF/no-augmentation.test
Modified:
    lld/trunk/ELF/EhFrame.cpp

Modified: lld/trunk/ELF/EhFrame.cpp
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/ELF/EhFrame.cpp?rev=270706&r1=270705&r2=270706&view=diff
==============================================================================
--- lld/trunk/ELF/EhFrame.cpp (original)
+++ lld/trunk/ELF/EhFrame.cpp Wed May 25 09:45:28 2016
@@ -111,7 +111,7 @@ template <class ELFT> uint8_t getFdeEnco
   if (Version != 1 && Version != 3)
     fatal("FDE version 1 or 3 expected, but got " + Twine((unsigned)Version));
 
-  const unsigned char *AugEnd = std::find(D.begin() + 1, D.end(), '\0');
+  const unsigned char *AugEnd = std::find(D.begin(), D.end(), '\0');
   if (AugEnd == D.end())
     fatal("corrupted CIE");
   StringRef Aug(reinterpret_cast<const char *>(D.begin()), AugEnd - D.begin());

Added: lld/trunk/test/ELF/Inputs/no-augmentation.o
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/test/ELF/Inputs/no-augmentation.o?rev=270706&view=auto
==============================================================================
Binary file - no diff available.

Propchange: lld/trunk/test/ELF/Inputs/no-augmentation.o
------------------------------------------------------------------------------
    svn:mime-type = application/x-object

Added: lld/trunk/test/ELF/no-augmentation.test
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/test/ELF/no-augmentation.test?rev=270706&view=auto
==============================================================================
--- lld/trunk/test/ELF/no-augmentation.test (added)
+++ lld/trunk/test/ELF/no-augmentation.test Wed May 25 09:45:28 2016
@@ -0,0 +1,10 @@
+// RUN: llvm-mc -filetype=obj -triple=mips64-unknown-freebsd %s -o %t.o
+// RUN: ld.lld --eh-frame-hdr %t.o %p/Inputs/no-augmentation.o -o %t \
+// RUN:   | FileCheck -allow-empty %s
+
+// REQUIRES: mips
+
+// CHECK-NOT: corrupted or unsupported CIE information
+
+.global __start
+__start: