[llvm-commits] [llvm] r123962 - in /llvm/trunk: include/llvm/Object/ObjectFile.h lib/Object/COFFObjectFile.cpp lib/Object/ELFObjectFile.cpp
Michael J. Spencer
bigcheesegs at gmail.com
Thu Jan 20 18:27:02 PST 2011
Author: mspencer
Date: Thu Jan 20 20:27:02 2011
New Revision: 123962
URL: http://llvm.org/viewvc/llvm-project?rev=123962&view=rev
Log:
Object: Fix type punned pointer issues by making DataRefImpl a union and using intptr_t.
Modified:
llvm/trunk/include/llvm/Object/ObjectFile.h
llvm/trunk/lib/Object/COFFObjectFile.cpp
llvm/trunk/lib/Object/ELFObjectFile.cpp
Modified: llvm/trunk/include/llvm/Object/ObjectFile.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/Object/ObjectFile.h?rev=123962&r1=123961&r2=123962&view=diff
==============================================================================
--- llvm/trunk/include/llvm/Object/ObjectFile.h (original)
+++ llvm/trunk/include/llvm/Object/ObjectFile.h Thu Jan 20 20:27:02 2011
@@ -16,6 +16,7 @@
#include "llvm/ADT/StringRef.h"
#include "llvm/Support/DataTypes.h"
+#include <cstring>
namespace llvm {
@@ -25,7 +26,19 @@
namespace object {
class ObjectFile;
-typedef uint64_t DataRefImpl;
+
+union DataRefImpl {
+ struct {
+ uint32_t a, b;
+ } d;
+ intptr_t p;
+};
+
+static bool operator ==(const DataRefImpl &a, const DataRefImpl &b) {
+ // Check bitwise identical. This is the only legal way to compare a union w/o
+ // knowing which member is in use.
+ return std::memcmp(&a, &b, sizeof(DataRefImpl)) == 0;
+}
/// SymbolRef - This is a value type class that represents a single symbol in
/// the list of symbols in the object file.
Modified: llvm/trunk/lib/Object/COFFObjectFile.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Object/COFFObjectFile.cpp?rev=123962&r1=123961&r2=123962&view=diff
==============================================================================
--- llvm/trunk/lib/Object/COFFObjectFile.cpp (original)
+++ llvm/trunk/lib/Object/COFFObjectFile.cpp Thu Jan 20 20:27:02 2011
@@ -128,13 +128,14 @@
} // end namespace
SymbolRef COFFObjectFile::getSymbolNext(DataRefImpl Symb) const {
- const coff_symbol *symb = *reinterpret_cast<const coff_symbol**>(&Symb);
+ const coff_symbol *symb = reinterpret_cast<const coff_symbol*>(Symb.p);
symb += 1 + symb->NumberOfAuxSymbols;
- return SymbolRef(DataRefImpl(symb), this);
+ Symb.p = reinterpret_cast<intptr_t>(symb);
+ return SymbolRef(Symb, this);
}
StringRef COFFObjectFile::getSymbolName(DataRefImpl Symb) const {
- const coff_symbol *symb = *reinterpret_cast<const coff_symbol**>(&Symb);
+ const coff_symbol *symb = reinterpret_cast<const coff_symbol*>(Symb.p);
// Check for string table entry. First 4 bytes are 0.
if (symb->Name.Offset.Zeroes == 0) {
uint32_t Offset = symb->Name.Offset.Offset;
@@ -149,7 +150,7 @@
}
uint64_t COFFObjectFile::getSymbolAddress(DataRefImpl Symb) const {
- const coff_symbol *symb = *reinterpret_cast<const coff_symbol**>(&Symb);
+ const coff_symbol *symb = reinterpret_cast<const coff_symbol*>(Symb.p);
const coff_section *Section = getSection(symb->SectionNumber);
char Type = getSymbolNMTypeChar(Symb);
if (Type == 'U' || Type == 'w')
@@ -163,7 +164,7 @@
// FIXME: Return the correct size. This requires looking at all the symbols
// in the same section as this symbol, and looking for either the next
// symbol, or the end of the section.
- const coff_symbol *symb = *reinterpret_cast<const coff_symbol**>(&Symb);
+ const coff_symbol *symb = reinterpret_cast<const coff_symbol*>(Symb.p);
const coff_section *Section = getSection(symb->SectionNumber);
char Type = getSymbolNMTypeChar(Symb);
if (Type == 'U' || Type == 'w')
@@ -174,7 +175,7 @@
}
char COFFObjectFile::getSymbolNMTypeChar(DataRefImpl Symb) const {
- const coff_symbol *symb = *reinterpret_cast<const coff_symbol**>(&Symb);
+ const coff_symbol *symb = reinterpret_cast<const coff_symbol*>(Symb.p);
char ret = StringSwitch<char>(getSymbolName(Symb))
.StartsWith(".debug", 'N')
.StartsWith(".sxdata", 'N')
@@ -236,13 +237,14 @@
}
SectionRef COFFObjectFile::getSectionNext(DataRefImpl Sec) const {
- const coff_section *sec = *reinterpret_cast<const coff_section**>(&Sec);
+ const coff_section *sec = reinterpret_cast<const coff_section*>(Sec.p);
sec += 1;
- return SectionRef(DataRefImpl(sec), this);
+ Sec.p = reinterpret_cast<intptr_t>(sec);
+ return SectionRef(Sec, this);
}
StringRef COFFObjectFile::getSectionName(DataRefImpl Sec) const {
- const coff_section *sec = *reinterpret_cast<const coff_section**>(&Sec);
+ const coff_section *sec = reinterpret_cast<const coff_section*>(Sec.p);
StringRef name;
if (sec->Name[7] == 0)
// Null terminated, let ::strlen figure out the length.
@@ -263,23 +265,23 @@
}
uint64_t COFFObjectFile::getSectionAddress(DataRefImpl Sec) const {
- const coff_section *sec = *reinterpret_cast<const coff_section**>(&Sec);
+ const coff_section *sec = reinterpret_cast<const coff_section*>(Sec.p);
return sec->VirtualAddress;
}
uint64_t COFFObjectFile::getSectionSize(DataRefImpl Sec) const {
- const coff_section *sec = *reinterpret_cast<const coff_section**>(&Sec);
+ const coff_section *sec = reinterpret_cast<const coff_section*>(Sec.p);
return sec->SizeOfRawData;
}
StringRef COFFObjectFile::getSectionContents(DataRefImpl Sec) const {
- const coff_section *sec = *reinterpret_cast<const coff_section**>(&Sec);
+ const coff_section *sec = reinterpret_cast<const coff_section*>(Sec.p);
return StringRef(reinterpret_cast<const char *>(base + sec->PointerToRawData),
sec->SizeOfRawData);
}
bool COFFObjectFile::isSectionText(DataRefImpl Sec) const {
- const coff_section *sec = *reinterpret_cast<const coff_section**>(&Sec);
+ const coff_section *sec = reinterpret_cast<const coff_section*>(Sec.p);
return sec->Characteristics & COFF::IMAGE_SCN_CNT_CODE;
}
@@ -300,29 +302,32 @@
}
ObjectFile::symbol_iterator COFFObjectFile::begin_symbols() const {
- return symbol_iterator(
- SymbolRef(DataRefImpl(SymbolTable), this));
+ DataRefImpl ret;
+ ret.p = reinterpret_cast<intptr_t>(SymbolTable);
+ return symbol_iterator(SymbolRef(ret, this));
}
ObjectFile::symbol_iterator COFFObjectFile::end_symbols() const {
// The symbol table ends where the string table begins.
- return symbol_iterator(
- SymbolRef(DataRefImpl(StringTable), this));
+ DataRefImpl ret;
+ ret.p = reinterpret_cast<intptr_t>(StringTable);
+ return symbol_iterator(SymbolRef(ret, this));
}
ObjectFile::section_iterator COFFObjectFile::begin_sections() const {
- return section_iterator(
- SectionRef(DataRefImpl(SectionTable), this));
+ DataRefImpl ret;
+ ret.p = reinterpret_cast<intptr_t>(SectionTable);
+ return section_iterator(SectionRef(ret, this));
}
ObjectFile::section_iterator COFFObjectFile::end_sections() const {
- return section_iterator(
- SectionRef(
- DataRefImpl((void *)(SectionTable + Header->NumberOfSections)), this));
+ DataRefImpl ret;
+ ret.p = reinterpret_cast<intptr_t>(SectionTable + Header->NumberOfSections);
+ return section_iterator(SectionRef(ret, this));
}
uint8_t COFFObjectFile::getBytesInAddress() const {
- return 4;
+ return getArch() == Triple::x86_64 ? 8 : 4;
}
StringRef COFFObjectFile::getFileFormatName() const {
Modified: llvm/trunk/lib/Object/ELFObjectFile.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Object/ELFObjectFile.cpp?rev=123962&r1=123961&r2=123962&view=diff
==============================================================================
--- llvm/trunk/lib/Object/ELFObjectFile.cpp (original)
+++ llvm/trunk/lib/Object/ELFObjectFile.cpp Thu Jan 20 20:27:02 2011
@@ -128,8 +128,7 @@
unsigned getEntityCount() const {
if (sh_entsize == 0)
return 0;
- else
- return sh_size / sh_entsize;
+ return sh_size / sh_entsize;
}
};
}
@@ -177,14 +176,6 @@
}
namespace {
-struct ELFDataRefImpl {
- uint32_t SymbolIndex;
- uint16_t SymbolTableSectionIndex;
- uint16_t Unused;
-};
-}
-
-namespace {
template<support::endianness target_endianness, bool is64Bits>
class ELFObjectFile : public ObjectFile {
LLVM_ELF_IMPORT_TYPES(target_endianness, is64Bits)
@@ -261,10 +252,8 @@
template<support::endianness target_endianness, bool is64Bits>
void ELFObjectFile<target_endianness, is64Bits>
::validateSymbol(DataRefImpl Symb) const {
- const ELFDataRefImpl SymbolData = *reinterpret_cast<ELFDataRefImpl *>(&Symb);
const Elf_Sym *symb = getSymbol(Symb);
- const Elf_Shdr *SymbolTableSection =
- SymbolTableSections[SymbolData.SymbolTableSectionIndex];
+ const Elf_Shdr *SymbolTableSection = SymbolTableSections[Symb.d.b];
// FIXME: We really need to do proper error handling in the case of an invalid
// input file. Because we don't use exceptions, I think we'll just pass
// an error object around.
@@ -283,20 +272,18 @@
SymbolRef ELFObjectFile<target_endianness, is64Bits>
::getSymbolNext(DataRefImpl Symb) const {
validateSymbol(Symb);
- ELFDataRefImpl &SymbolData = *reinterpret_cast<ELFDataRefImpl *>(&Symb);
- const Elf_Shdr *SymbolTableSection =
- SymbolTableSections[SymbolData.SymbolTableSectionIndex];
+ const Elf_Shdr *SymbolTableSection = SymbolTableSections[Symb.d.b];
- ++SymbolData.SymbolIndex;
+ ++Symb.d.a;
// Check to see if we are at the end of this symbol table.
- if (SymbolData.SymbolIndex >= SymbolTableSection->getEntityCount()) {
+ if (Symb.d.a >= SymbolTableSection->getEntityCount()) {
// We are at the end. If there are other symbol tables, jump to them.
- ++SymbolData.SymbolTableSectionIndex;
- SymbolData.SymbolIndex = 1; // The 0th symbol in ELF is fake.
+ ++Symb.d.b;
+ Symb.d.a = 1; // The 0th symbol in ELF is fake.
// Otherwise return the terminator.
- if (SymbolData.SymbolTableSectionIndex >= SymbolTableSections.size()) {
- SymbolData.SymbolIndex = std::numeric_limits<uint32_t>::max();
- SymbolData.SymbolTableSectionIndex = std::numeric_limits<uint32_t>::max();
+ if (Symb.d.b >= SymbolTableSections.size()) {
+ Symb.d.a = std::numeric_limits<uint32_t>::max();
+ Symb.d.b = std::numeric_limits<uint32_t>::max();
}
}
@@ -426,40 +413,37 @@
template<support::endianness target_endianness, bool is64Bits>
SectionRef ELFObjectFile<target_endianness, is64Bits>
::getSectionNext(DataRefImpl Sec) const {
- const uint8_t *sec = *reinterpret_cast<const uint8_t **>(&Sec);
+ const uint8_t *sec = reinterpret_cast<const uint8_t *>(Sec.p);
sec += Header->e_shentsize;
- return SectionRef(DataRefImpl(sec), this);
+ Sec.p = reinterpret_cast<intptr_t>(sec);
+ return SectionRef(Sec, this);
}
template<support::endianness target_endianness, bool is64Bits>
StringRef ELFObjectFile<target_endianness, is64Bits>
::getSectionName(DataRefImpl Sec) const {
- const Elf_Shdr *sec =
- *reinterpret_cast<const Elf_Shdr **>(&Sec);
+ const Elf_Shdr *sec = reinterpret_cast<const Elf_Shdr *>(Sec.p);
return StringRef(getString(dot_shstrtab_sec, sec->sh_name));
}
template<support::endianness target_endianness, bool is64Bits>
uint64_t ELFObjectFile<target_endianness, is64Bits>
::getSectionAddress(DataRefImpl Sec) const {
- const Elf_Shdr *sec =
- *reinterpret_cast<const Elf_Shdr **>(&Sec);
+ const Elf_Shdr *sec = reinterpret_cast<const Elf_Shdr *>(Sec.p);
return sec->sh_addr;
}
template<support::endianness target_endianness, bool is64Bits>
uint64_t ELFObjectFile<target_endianness, is64Bits>
::getSectionSize(DataRefImpl Sec) const {
- const Elf_Shdr *sec =
- *reinterpret_cast<const Elf_Shdr **>(&Sec);
+ const Elf_Shdr *sec = reinterpret_cast<const Elf_Shdr *>(Sec.p);
return sec->sh_size;
}
template<support::endianness target_endianness, bool is64Bits>
StringRef ELFObjectFile<target_endianness, is64Bits>
::getSectionContents(DataRefImpl Sec) const {
- const Elf_Shdr *sec =
- *reinterpret_cast<const Elf_Shdr **>(&Sec);
+ const Elf_Shdr *sec = reinterpret_cast<const Elf_Shdr *>(Sec.p);
const char *start = (char*)base + sec->sh_offset;
return StringRef(start, sec->sh_size);
}
@@ -467,8 +451,7 @@
template<support::endianness target_endianness, bool is64Bits>
bool ELFObjectFile<target_endianness, is64Bits>
::isSectionText(DataRefImpl Sec) const {
- const Elf_Shdr *sec =
- *reinterpret_cast<const Elf_Shdr **>(&Sec);
+ const Elf_Shdr *sec = reinterpret_cast<const Elf_Shdr *>(Sec.p);
if (sec->sh_flags & ELF::SHF_EXECINSTR)
return true;
return false;
@@ -538,49 +521,49 @@
template<support::endianness target_endianness, bool is64Bits>
ObjectFile::symbol_iterator ELFObjectFile<target_endianness, is64Bits>
::begin_symbols() const {
- ELFDataRefImpl SymbolData;
+ DataRefImpl SymbolData;
memset(&SymbolData, 0, sizeof(SymbolData));
if (SymbolTableSections.size() == 0) {
- SymbolData.SymbolIndex = std::numeric_limits<uint32_t>::max();
- SymbolData.SymbolTableSectionIndex = std::numeric_limits<uint32_t>::max();
+ SymbolData.d.a = std::numeric_limits<uint32_t>::max();
+ SymbolData.d.b = std::numeric_limits<uint32_t>::max();
} else {
- SymbolData.SymbolIndex = 1; // The 0th symbol in ELF is fake.
- SymbolData.SymbolTableSectionIndex = 0;
+ SymbolData.d.a = 1; // The 0th symbol in ELF is fake.
+ SymbolData.d.b = 0;
}
- return symbol_iterator(
- SymbolRef(DataRefImpl(*reinterpret_cast<DataRefImpl*>(&SymbolData)), this));
+ return symbol_iterator(SymbolRef(SymbolData, this));
}
template<support::endianness target_endianness, bool is64Bits>
ObjectFile::symbol_iterator ELFObjectFile<target_endianness, is64Bits>
::end_symbols() const {
- ELFDataRefImpl SymbolData;
+ DataRefImpl SymbolData;
memset(&SymbolData, 0, sizeof(SymbolData));
- SymbolData.SymbolIndex = std::numeric_limits<uint32_t>::max();
- SymbolData.SymbolTableSectionIndex = std::numeric_limits<uint32_t>::max();
- return symbol_iterator(
- SymbolRef(DataRefImpl(*reinterpret_cast<DataRefImpl*>(&SymbolData)), this));
+ SymbolData.d.a = std::numeric_limits<uint32_t>::max();
+ SymbolData.d.b = std::numeric_limits<uint32_t>::max();
+ return symbol_iterator(SymbolRef(SymbolData, this));
}
template<support::endianness target_endianness, bool is64Bits>
ObjectFile::section_iterator ELFObjectFile<target_endianness, is64Bits>
::begin_sections() const {
- return section_iterator(
- SectionRef(DataRefImpl(base + Header->e_shoff), this));
+ DataRefImpl ret;
+ ret.p = reinterpret_cast<intptr_t>(base + Header->e_shoff);
+ return section_iterator(SectionRef(ret, this));
}
template<support::endianness target_endianness, bool is64Bits>
ObjectFile::section_iterator ELFObjectFile<target_endianness, is64Bits>
::end_sections() const {
- return section_iterator(
- SectionRef(DataRefImpl(base
- + Header->e_shoff
- + (Header->e_shentsize * Header->e_shnum)), this));
+ DataRefImpl ret;
+ ret.p = reinterpret_cast<intptr_t>(base
+ + Header->e_shoff
+ + (Header->e_shentsize * Header->e_shnum));
+ return section_iterator(SectionRef(ret, this));
}
template<support::endianness target_endianness, bool is64Bits>
uint8_t ELFObjectFile<target_endianness, is64Bits>::getBytesInAddress() const {
- return 4;
+ return is64Bits ? 8 : 4;
}
template<support::endianness target_endianness, bool is64Bits>
@@ -626,20 +609,17 @@
template<support::endianness target_endianness, bool is64Bits>
const typename ELFObjectFile<target_endianness, is64Bits>::Elf_Sym *
ELFObjectFile<target_endianness, is64Bits>::getSymbol(DataRefImpl Symb) const {
- const ELFDataRefImpl SymbolData = *reinterpret_cast<ELFDataRefImpl *>(&Symb);
- const Elf_Shdr *sec =
- SymbolTableSections[SymbolData.SymbolTableSectionIndex];
+ const Elf_Shdr *sec = SymbolTableSections[Symb.d.b];
return reinterpret_cast<const Elf_Sym *>(
base
+ sec->sh_offset
- + (SymbolData.SymbolIndex * sec->sh_entsize));
+ + (Symb.d.a * sec->sh_entsize));
}
template<support::endianness target_endianness, bool is64Bits>
const typename ELFObjectFile<target_endianness, is64Bits>::Elf_Shdr *
ELFObjectFile<target_endianness, is64Bits>::getSection(DataRefImpl Symb) const {
- const ELFDataRefImpl SymbolData = *reinterpret_cast<ELFDataRefImpl *>(&Symb);
- const Elf_Shdr *sec = getSection(SymbolData.SymbolTableSectionIndex);
+ const Elf_Shdr *sec = getSection(Symb.d.b);
if (sec->sh_type != ELF::SHT_SYMTAB)
// FIXME: Proper error handling.
report_fatal_error("Invalid symbol table section!");
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