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ObjectFile: parse EABI Attributes

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This adds basic parsing of the EABI attributes section.  This section contains
additional information about the target for which the file was built.  Attempt
to infer additional architecture information from that section.

llvm-svn: 267291
This commit is contained in:
Saleem Abdulrasool
2016-04-23 16:00:15 +00:00
parent 66b0a87ae8
commit d2d1504805
2 changed files with 104 additions and 0 deletions
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100
lldb/source/Plugins/ObjectFile/ELF/ObjectFileELF.cpp
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@@ -31,6 +31,7 @@
#include "llvm/ADT/PointerUnion.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/Support/ARMBuildAttributes.h"
#include "llvm/Support/MathExtras.h"
#define CASE_AND_STREAM(s, def, width) \
@@ -1516,6 +1517,93 @@ ObjectFileELF::RefineModuleDetailsFromNote (lldb_private::DataExtractor &data, l
return error;
}
void
ObjectFileELF::ParseARMAttributes(DataExtractor &data, uint64_t length, ArchSpec &arch_spec)
{
lldb::offset_t Offset = 0;
uint8_t FormatVersion = data.GetU8(&Offset);
if (FormatVersion != llvm::ARMBuildAttrs::Format_Version)
return;
Offset = Offset + sizeof(uint32_t); // Section Length
llvm::StringRef VendorName = data.GetCStr(&Offset);
if (VendorName != "aeabi")
return;
if (arch_spec.GetTriple().getEnvironment() == llvm::Triple::UnknownEnvironment)
arch_spec.GetTriple().setEnvironment(llvm::Triple::EABI);
while (Offset < length)
{
uint8_t Tag = data.GetU8(&Offset);
uint32_t Size = data.GetU32(&Offset);
if (Tag != llvm::ARMBuildAttrs::File || Size == 0)
continue;
while (Offset < length)
{
uint64_t Tag = data.GetULEB128(&Offset);
switch (Tag)
{
default:
if (Tag < 32)
data.GetULEB128(&Offset);
else if (Tag % 2 == 0)
data.GetULEB128(&Offset);
else
data.GetCStr(&Offset);
break;
case llvm::ARMBuildAttrs::CPU_raw_name:
case llvm::ARMBuildAttrs::CPU_name:
data.GetCStr(&Offset);
break;
case llvm::ARMBuildAttrs::THUMB_ISA_use:
{
uint64_t ThumbISA = data.GetULEB128(&Offset);
// NOTE: ignore ThumbISA == llvm::ARMBuildAttrs::AllowThumbDerived
// since that derives it based on the architecutre/profile
if (ThumbISA == llvm::ARMBuildAttrs::AllowThumb32)
if (arch_spec.GetTriple().getArch() == llvm::Triple::UnknownArch ||
arch_spec.GetTriple().getArch() == llvm::Triple::arm)
arch_spec.GetTriple().setArch(llvm::Triple::thumb);
break;
}
case llvm::ARMBuildAttrs::ABI_VFP_args:
{
uint64_t VFPArgs = data.GetULEB128(&Offset);
if (VFPArgs == llvm::ARMBuildAttrs::BaseAAPCS)
{
if (arch_spec.GetTriple().getEnvironment() == llvm::Triple::UnknownEnvironment ||
arch_spec.GetTriple().getEnvironment() == llvm::Triple::EABIHF)
arch_spec.GetTriple().setEnvironment(llvm::Triple::EABI);
arch_spec.SetFlags(ArchSpec::eARM_abi_soft_float);
}
else if (VFPArgs == llvm::ARMBuildAttrs::HardFPAAPCS)
{
if (arch_spec.GetTriple().getEnvironment() == llvm::Triple::UnknownEnvironment ||
arch_spec.GetTriple().getEnvironment() == llvm::Triple::EABI)
arch_spec.GetTriple().setEnvironment(llvm::Triple::EABIHF);
arch_spec.SetFlags(ArchSpec::eARM_abi_hard_float);
}
break;
}
}
}
}
}
//----------------------------------------------------------------------
// GetSectionHeaderInfo
@@ -1648,6 +1736,18 @@ ObjectFileELF::GetSectionHeaderInfo(SectionHeaderColl &section_headers,
arch_spec.SetFlags (arch_flags);
}
if (arch_spec.GetMachine() == llvm::Triple::arm || arch_spec.GetMachine() == llvm::Triple::thumb)
{
DataExtractor data;
if (sheader.sh_type != SHT_ARM_ATTRIBUTES)
continue;
if (section_size == 0 || set_data(data, sheader.sh_offset, section_size) != section_size)
continue;
ParseARMAttributes(data, section_size, arch_spec);
}
if (name == g_sect_name_gnu_debuglink)
{
DataExtractor data;