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authorMichael J. Spencer <bigcheesegs@gmail.com>2013-01-04 20:36:28 +0000
committerMichael J. Spencer <bigcheesegs@gmail.com>2013-01-04 20:36:28 +0000
commit4d9c5397b4a3be747bdb73f1d24c3fdbaaf438fe (patch)
tree4caf73a9a9994c1aa9d6f82f8cf356b760a268ed /lib/Object
parente13f441e002b95bb64d883d173f6aff9615556fd (diff)
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[Object][ELF] Add a maximum alignment. This is used by createELFObjectFile to create a properly aligned reader.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@171520 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'lib/Object')
-rw-r--r--lib/Object/ELFObjectFile.cpp34
1 files changed, 28 insertions, 6 deletions
diff --git a/lib/Object/ELFObjectFile.cpp b/lib/Object/ELFObjectFile.cpp
index 663b84e..2c8c1b1 100644
--- a/lib/Object/ELFObjectFile.cpp
+++ b/lib/Object/ELFObjectFile.cpp
@@ -12,6 +12,7 @@
//===----------------------------------------------------------------------===//
#include "llvm/Object/ELF.h"
+#include "llvm/Support/MathExtras.h"
namespace llvm {
@@ -22,16 +23,37 @@ ObjectFile *ObjectFile::createELFObjectFile(MemoryBuffer *Object) {
std::pair<unsigned char, unsigned char> Ident = getElfArchType(Object);
error_code ec;
+ std::size_t MaxAlignment =
+ 1ULL << CountTrailingZeros_64(uintptr_t(Object->getBufferStart()));
+
if (Ident.first == ELF::ELFCLASS32 && Ident.second == ELF::ELFDATA2LSB)
- return new ELFObjectFile<support::little, false>(Object, ec);
+ if (MaxAlignment >= 4)
+ return new ELFObjectFile<support::little, 4, false>(Object, ec);
+ else if (MaxAlignment >= 2)
+ return new ELFObjectFile<support::little, 2, false>(Object, ec);
+ else
+ llvm_unreachable("Invalid alignment for ELF file!");
else if (Ident.first == ELF::ELFCLASS32 && Ident.second == ELF::ELFDATA2MSB)
- return new ELFObjectFile<support::big, false>(Object, ec);
+ if (MaxAlignment >= 4)
+ return new ELFObjectFile<support::big, 4, false>(Object, ec);
+ else if (MaxAlignment >= 2)
+ return new ELFObjectFile<support::big, 2, false>(Object, ec);
+ else
+ llvm_unreachable("Invalid alignment for ELF file!");
else if (Ident.first == ELF::ELFCLASS64 && Ident.second == ELF::ELFDATA2MSB)
- return new ELFObjectFile<support::big, true>(Object, ec);
+ if (MaxAlignment >= 8)
+ return new ELFObjectFile<support::big, 8, true>(Object, ec);
+ else if (MaxAlignment >= 2)
+ return new ELFObjectFile<support::big, 2, true>(Object, ec);
+ else
+ llvm_unreachable("Invalid alignment for ELF file!");
else if (Ident.first == ELF::ELFCLASS64 && Ident.second == ELF::ELFDATA2LSB) {
- ELFObjectFile<support::little, true> *result =
- new ELFObjectFile<support::little, true>(Object, ec);
- return result;
+ if (MaxAlignment >= 8)
+ return new ELFObjectFile<support::little, 8, true>(Object, ec);
+ else if (MaxAlignment >= 2)
+ return new ELFObjectFile<support::little, 2, true>(Object, ec);
+ else
+ llvm_unreachable("Invalid alignment for ELF file!");
}
report_fatal_error("Buffer is not an ELF object file!");