[llvm] r255546 - Print the eh_frame section in MachoDump.
Pete Cooper via llvm-commits
llvm-commits at lists.llvm.org
Mon Dec 14 13:39:27 PST 2015
Author: pete
Date: Mon Dec 14 15:39:27 2015
New Revision: 255546
URL: http://llvm.org/viewvc/llvm-project?rev=255546&view=rev
Log:
Print the eh_frame section in MachoDump.
This is the start of work to dump the contents of the eh_frame section.
It currently emits CIE entries. FDE entries will come later.
It also needs improved error checking which will follow soon.
http://reviews.llvm.org/D15502
Reviewed by Kevin Enderby and Lang Hames.
Added:
llvm/trunk/test/tools/llvm-objdump/Inputs/eh_frame.macho-arm64
llvm/trunk/test/tools/llvm-objdump/eh_frame-arm64.test
Modified:
llvm/trunk/tools/llvm-objdump/MachODump.cpp
Added: llvm/trunk/test/tools/llvm-objdump/Inputs/eh_frame.macho-arm64
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/tools/llvm-objdump/Inputs/eh_frame.macho-arm64?rev=255546&view=auto
==============================================================================
Binary files llvm/trunk/test/tools/llvm-objdump/Inputs/eh_frame.macho-arm64 (added) and llvm/trunk/test/tools/llvm-objdump/Inputs/eh_frame.macho-arm64 Mon Dec 14 15:39:27 2015 differ
Added: llvm/trunk/test/tools/llvm-objdump/eh_frame-arm64.test
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/tools/llvm-objdump/eh_frame-arm64.test?rev=255546&view=auto
==============================================================================
--- llvm/trunk/test/tools/llvm-objdump/eh_frame-arm64.test (added)
+++ llvm/trunk/test/tools/llvm-objdump/eh_frame-arm64.test Mon Dec 14 15:39:27 2015
@@ -0,0 +1,18 @@
+# RUN: llvm-objdump -unwind-info %p/Inputs/eh_frame.macho-arm64 2>/dev/null | FileCheck %s
+
+# CHECK: Contents of __eh_frame section:
+# CHECK: CIE:
+# CHECK: Length: 16
+# CHECK: CIE ID: 0
+# CHECK: Version: 1
+# CHECK: Augmentation String: zR
+# CHECK: Code Alignment Factor: 1
+# CHECK: Data Alignment Factor: -8
+# CHECK: Return Address Register: 30
+# CHECK: Augmentation Data Length: 1
+# CHECK: FDE Address Pointer Encoding: 16
+# CHECK: Instructions:
+# CHECK: 0c 1f 00
+# CHECK: FDE:
+# CHECK: Length: 32
+# CHECK: e4 ff ff ff ff ff ff ff 20 00 00 00 00 00 00 00 00 48 0e 10 9e 01 9d 02 00 00 00 00
Modified: llvm/trunk/tools/llvm-objdump/MachODump.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/tools/llvm-objdump/MachODump.cpp?rev=255546&r1=255545&r2=255546&view=diff
==============================================================================
--- llvm/trunk/tools/llvm-objdump/MachODump.cpp (original)
+++ llvm/trunk/tools/llvm-objdump/MachODump.cpp Mon Dec 14 15:39:27 2015
@@ -13,6 +13,7 @@
#include "llvm-objdump.h"
#include "llvm-c/Disassembler.h"
+#include "llvm/ADT/Optional.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/ADT/StringExtras.h"
#include "llvm/ADT/Triple.h"
@@ -6750,6 +6751,184 @@ static void printMachOUnwindInfoSection(
}
}
+static unsigned getSizeForEncoding(bool is64Bit,
+ unsigned symbolEncoding) {
+ unsigned format = symbolEncoding & 0x0f;
+ switch (format) {
+ default: llvm_unreachable("Unknown Encoding");
+ case dwarf::DW_EH_PE_absptr:
+ case dwarf::DW_EH_PE_signed:
+ return is64Bit ? 8 : 4;
+ case dwarf::DW_EH_PE_udata2:
+ case dwarf::DW_EH_PE_sdata2:
+ return 2;
+ case dwarf::DW_EH_PE_udata4:
+ case dwarf::DW_EH_PE_sdata4:
+ return 4;
+ case dwarf::DW_EH_PE_udata8:
+ case dwarf::DW_EH_PE_sdata8:
+ return 8;
+ }
+}
+
+static void printMachOEHFrameSection(const MachOObjectFile *Obj,
+ std::map<uint64_t, SymbolRef> &Symbols,
+ const SectionRef &EHFrame) {
+ if (!Obj->isLittleEndian()) {
+ outs() << "warning: cannot handle big endian __eh_frame section\n";
+ return;
+ }
+
+ bool is64Bit = Obj->is64Bit();
+
+ outs() << "Contents of __eh_frame section:\n";
+
+ StringRef Contents;
+ EHFrame.getContents(Contents);
+
+
+ //===----------------------------------
+ // Entry header
+ //===----------------------------------
+
+ for (const char *Pos = Contents.data(), *End = Contents.end(); Pos != End; ) {
+
+ uint64_t Length = readNext<uint32_t>(Pos);
+ if (Length == 0xffffffff)
+ Length = readNext<uint64_t>(Pos);
+
+ // Save the Pos so that we can check the length we encoded against what we
+ // end up decoding.
+ const char *PosAfterLength = Pos;
+ const char *EntryEndPos = PosAfterLength + Length;
+
+ assert(EntryEndPos <= End &&
+ "__eh_frame entry length exceeds section size");
+
+ uint32_t ID = readNext<uint32_t>(Pos);
+ if (ID == 0) {
+ // This is a CIE.
+
+ uint32_t Version = readNext<uint8_t>(Pos);
+
+ // Parse a null terminated augmentation string
+ SmallString<8> AugmentationString;
+ for (uint8_t Char = readNext<uint8_t>(Pos); Char;
+ Char = readNext<uint8_t>(Pos))
+ AugmentationString.push_back(Char);
+
+ // Optionally parse the EH data if the augmentation string says it's there.
+ Optional<uint64_t> EHData;
+ if (StringRef(AugmentationString).count("eh"))
+ EHData = is64Bit ? readNext<uint64_t>(Pos) : readNext<uint32_t>(Pos);
+
+ unsigned ULEBByteCount;
+ uint64_t CodeAlignmentFactor = decodeULEB128((const uint8_t *)Pos,
+ &ULEBByteCount);
+ Pos += ULEBByteCount;
+
+ int64_t DataAlignmentFactor = decodeSLEB128((const uint8_t *)Pos,
+ &ULEBByteCount);
+ Pos += ULEBByteCount;
+
+ uint32_t ReturnAddressRegister = readNext<uint8_t>(Pos);
+
+ Optional<uint64_t> AugmentationLength;
+ Optional<uint32_t> LSDAPointerEncoding;
+ Optional<uint32_t> PersonalityEncoding;
+ Optional<uint64_t> Personality;
+ Optional<uint32_t> FDEPointerEncoding;
+ if (!AugmentationString.empty() && AugmentationString.front() == 'z') {
+ AugmentationLength = decodeULEB128((const uint8_t *)Pos,
+ &ULEBByteCount);
+ Pos += ULEBByteCount;
+
+ // Walk the augmentation string to get all the augmentation data.
+ for (unsigned i = 1, e = AugmentationString.size(); i != e; ++i) {
+ char Char = AugmentationString[i];
+ switch (Char) {
+ case 'e':
+ assert((i + 1) != e && AugmentationString[i + 1] == 'h' &&
+ "Expected 'eh' in augmentation string");
+ break;
+ case 'L':
+ assert(!LSDAPointerEncoding && "Duplicate LSDA encoding");
+ LSDAPointerEncoding = readNext<uint8_t>(Pos);
+ break;
+ case 'P': {
+ assert(!Personality && "Duplicate personality");
+ PersonalityEncoding = readNext<uint8_t>(Pos);
+ switch (getSizeForEncoding(is64Bit, *PersonalityEncoding)) {
+ case 2:
+ Personality = readNext<uint16_t>(Pos);
+ break;
+ case 4:
+ Personality = readNext<uint32_t>(Pos);
+ break;
+ case 8:
+ Personality = readNext<uint64_t>(Pos);
+ break;
+ default:
+ llvm_unreachable("Illegal data size");
+ }
+ break;
+ }
+ case 'R':
+ assert(!FDEPointerEncoding && "Duplicate FDE encoding");
+ FDEPointerEncoding = readNext<uint8_t>(Pos);
+ break;
+ case 'z':
+ llvm_unreachable("'z' must be first in the augmentation string");
+ }
+ }
+ }
+
+ outs() << "CIE:\n";
+ outs() << " Length: " << Length << "\n";
+ outs() << " CIE ID: " << ID << "\n";
+ outs() << " Version: " << Version << "\n";
+ outs() << " Augmentation String: " << AugmentationString << "\n";
+ if (EHData)
+ outs() << " EHData: " << *EHData << "\n";
+ outs() << " Code Alignment Factor: " << CodeAlignmentFactor << "\n";
+ outs() << " Data Alignment Factor: " << DataAlignmentFactor << "\n";
+ outs() << " Return Address Register: " << ReturnAddressRegister << "\n";
+ if (AugmentationLength) {
+ outs() << " Augmentation Data Length: " << *AugmentationLength << "\n";
+ if (LSDAPointerEncoding) {
+ outs() << " FDE LSDA Pointer Encoding: "
+ << *LSDAPointerEncoding << "\n";
+ }
+ if (Personality) {
+ outs() << " Personality Encoding: " << *PersonalityEncoding << "\n";
+ outs() << " Personality: " << *Personality << "\n";
+ }
+ if (FDEPointerEncoding) {
+ outs() << " FDE Address Pointer Encoding: "
+ << *FDEPointerEncoding << "\n";
+ }
+ }
+ // FIXME: Handle instructions.
+ // For now just emit some bytes
+ outs() << " Instructions:\n ";
+ dumpBytes(makeArrayRef((const uint8_t*)Pos, (const uint8_t*)EntryEndPos),
+ outs());
+ outs() << "\n";
+ Pos = EntryEndPos;
+ continue;
+ }
+ // This is an FDE.
+ outs() << "FDE:\n";
+ outs() << " Length: " << Length << "\n";
+ outs() << " ";
+ dumpBytes(makeArrayRef((const uint8_t*)Pos, (const uint8_t*)EntryEndPos),
+ outs());
+ outs() << "\n";
+ Pos = EntryEndPos;
+
+ }
+}
+
void llvm::printMachOUnwindInfo(const MachOObjectFile *Obj) {
std::map<uint64_t, SymbolRef> Symbols;
for (const SymbolRef &SymRef : Obj->symbols()) {
@@ -6771,7 +6950,7 @@ void llvm::printMachOUnwindInfo(const Ma
else if (SectName == "__unwind_info")
printMachOUnwindInfoSection(Obj, Symbols, Section);
else if (SectName == "__eh_frame")
- outs() << "llvm-objdump: warning: unhandled __eh_frame section\n";
+ printMachOEHFrameSection(Obj, Symbols, Section);
}
}
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