[llvm] r215437 - llvm-objdump: print contents of MachO __unwind_info sections
Tim Northover
tnorthover at apple.com
Tue Aug 12 04:53:00 PDT 2014
Author: tnorthover
Date: Tue Aug 12 06:52:59 2014
New Revision: 215437
URL: http://llvm.org/viewvc/llvm-project?rev=215437&view=rev
Log:
llvm-objdump: print contents of MachO __unwind_info sections
Added:
llvm/trunk/test/tools/llvm-objdump/Inputs/unwind-info.macho-arm64 (with props)
llvm/trunk/test/tools/llvm-objdump/Inputs/unwind-info.macho-x86_64 (with props)
llvm/trunk/test/tools/llvm-objdump/macho-unwind-info-arm64.test
llvm/trunk/test/tools/llvm-objdump/macho-unwind-info-x86_64.test
Modified:
llvm/trunk/tools/llvm-objdump/MachODump.cpp
Added: llvm/trunk/test/tools/llvm-objdump/Inputs/unwind-info.macho-arm64
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/tools/llvm-objdump/Inputs/unwind-info.macho-arm64?rev=215437&view=auto
==============================================================================
Binary files llvm/trunk/test/tools/llvm-objdump/Inputs/unwind-info.macho-arm64 (added) and llvm/trunk/test/tools/llvm-objdump/Inputs/unwind-info.macho-arm64 Tue Aug 12 06:52:59 2014 differ
Propchange: llvm/trunk/test/tools/llvm-objdump/Inputs/unwind-info.macho-arm64
------------------------------------------------------------------------------
svn:executable = *
Added: llvm/trunk/test/tools/llvm-objdump/Inputs/unwind-info.macho-x86_64
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/tools/llvm-objdump/Inputs/unwind-info.macho-x86_64?rev=215437&view=auto
==============================================================================
Binary files llvm/trunk/test/tools/llvm-objdump/Inputs/unwind-info.macho-x86_64 (added) and llvm/trunk/test/tools/llvm-objdump/Inputs/unwind-info.macho-x86_64 Tue Aug 12 06:52:59 2014 differ
Propchange: llvm/trunk/test/tools/llvm-objdump/Inputs/unwind-info.macho-x86_64
------------------------------------------------------------------------------
svn:executable = *
Added: llvm/trunk/test/tools/llvm-objdump/macho-unwind-info-arm64.test
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/tools/llvm-objdump/macho-unwind-info-arm64.test?rev=215437&view=auto
==============================================================================
--- llvm/trunk/test/tools/llvm-objdump/macho-unwind-info-arm64.test (added)
+++ llvm/trunk/test/tools/llvm-objdump/macho-unwind-info-arm64.test Tue Aug 12 06:52:59 2014
@@ -0,0 +1,28 @@
+# RUN: llvm-objdump -unwind-info %p/Inputs/unwind-info.macho-arm64 2>/dev/null | FileCheck %s
+
+# The 2nd level index here is "regular", including all offsets & encodings in
+# full.
+
+# CHECK: Contents of __unwind_info section:
+# CHECK: Version: 0x1
+# CHECK: Common encodings array section offset: 0x1c
+# CHECK: Number of common encodings in array: 0x2
+# CHECK: Personality function array section offset: 0x24
+# CHECK: Number of personality functions in array: 0x1
+# CHECK: Index array section offset: 0x28
+# CHECK: Number of indices in array: 0x2
+# CHECK: Common encodings: (count = 2)
+# CHECK: encoding[0]: 0x04000000
+# CHECK: encoding[1]: 0x54000000
+# CHECK: Personality functions: (count = 1)
+# CHECK: personality[1]: 0x00008008
+# CHECK: Top level indices: (count = 2)
+# CHECK: [0]: function offset=0x00007d64, 2nd level page offset=0x00000050, LSDA offset=0x00000040
+# CHECK: [1]: function offset=0x00007eb5, 2nd level page offset=0x00000000, LSDA offset=0x00000050
+# CHECK: LSDA descriptors:
+# CHECK: [0]: function offset=0x00007d90, LSDA offset=0x00007f44
+# CHECK: [1]: function offset=0x00007e10, LSDA offset=0x00007f6c
+# CHECK: Second level indices:
+# CHECK: Second level index[0]: offset in section=0x00000050, base function offset=0x00007d64
+# CHECK: [0]: function offset=0x00007d90, encoding=0x78563412
+# CHECK: [1]: function offset=0x00007e10, encoding=0x21436587
Added: llvm/trunk/test/tools/llvm-objdump/macho-unwind-info-x86_64.test
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/tools/llvm-objdump/macho-unwind-info-x86_64.test?rev=215437&view=auto
==============================================================================
--- llvm/trunk/test/tools/llvm-objdump/macho-unwind-info-x86_64.test (added)
+++ llvm/trunk/test/tools/llvm-objdump/macho-unwind-info-x86_64.test Tue Aug 12 06:52:59 2014
@@ -0,0 +1,29 @@
+# RUN: llvm-objdump -unwind-info %p/Inputs/unwind-info.macho-x86_64 2>/dev/null | FileCheck %s
+
+# The 2nd level index in this file is in compressed form, referring to both
+# common and packed encodings.
+
+# CHECK:Contents of __unwind_info section:
+# CHECK: Version: 0x1
+# CHECK: Common encodings array section offset: 0x1c
+# CHECK: Number of common encodings in array: 0x2
+# CHECK: Personality function array section offset: 0x24
+# CHECK: Number of personality functions in array: 0x1
+# CHECK: Index array section offset: 0x28
+# CHECK: Number of indices in array: 0x2
+# CHECK: Common encodings: (count = 2)
+# CHECK: encoding[0]: 0x01000000
+# CHECK: encoding[1]: 0x51000000
+# CHECK: Personality functions: (count = 1)
+# CHECK: personality[1]: 0x00001018
+# CHECK: Top level indices: (count = 2)
+# CHECK: [0]: function offset=0x00000d70, 2nd level page offset=0x00000050, LSDA offset=0x00000040
+# CHECK: [1]: function offset=0x00000eab, 2nd level page offset=0x00000000, LSDA offset=0x00000050
+# CHECK: LSDA descriptors:
+# CHECK: [0]: function offset=0x00000db0, LSDA offset=0x00000f0c
+# CHECK: [1]: function offset=0x00000e20, LSDA offset=0x00000f34
+# CHECK: Second level indices:
+# CHECK: Second level index[0]: offset in section=0x00000050, base function offset=0x00000d70
+# CHECK: [0]: function offset=0x00000d70, encoding[0]=0x01000000
+# CHECK: [1]: function offset=0x00000db0, encoding[1]=0x51000000
+# CHECK: [2]: function offset=0x00000e20, encoding[2]=0x01234567
Modified: llvm/trunk/tools/llvm-objdump/MachODump.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/tools/llvm-objdump/MachODump.cpp?rev=215437&r1=215436&r2=215437&view=diff
==============================================================================
--- llvm/trunk/tools/llvm-objdump/MachODump.cpp (original)
+++ llvm/trunk/tools/llvm-objdump/MachODump.cpp Tue Aug 12 06:52:59 2014
@@ -471,7 +471,22 @@ static void DisassembleInputMachO2(Strin
}
}
+
+//===----------------------------------------------------------------------===//
+// __compact_unwind section dumping
+//===----------------------------------------------------------------------===//
+
namespace {
+
+template <typename T> static uint64_t readNext(const char *&Buf) {
+ using llvm::support::little;
+ using llvm::support::unaligned;
+
+ uint64_t Val = support::endian::read<T, little, unaligned>(Buf);
+ Buf += sizeof(T);
+ return Val;
+ }
+
struct CompactUnwindEntry {
uint32_t OffsetInSection;
@@ -494,16 +509,6 @@ struct CompactUnwindEntry {
}
private:
- template<typename T>
- static uint64_t readNext(const char *&Buf) {
- using llvm::support::little;
- using llvm::support::unaligned;
-
- uint64_t Val = support::endian::read<T, little, unaligned>(Buf);
- Buf += sizeof(T);
- return Val;
- }
-
template<typename UIntPtr>
void read(const char *Buf) {
FunctionAddr = readNext<UIntPtr>(Buf);
@@ -665,6 +670,239 @@ printMachOCompactUnwindSection(const Mac
}
}
+//===----------------------------------------------------------------------===//
+// __unwind_info section dumping
+//===----------------------------------------------------------------------===//
+
+static void printRegularSecondLevelUnwindPage(const char *PageStart) {
+ const char *Pos = PageStart;
+ uint32_t Kind = readNext<uint32_t>(Pos);
+ (void)Kind;
+ assert(Kind == 2 && "kind for a regular 2nd level index should be 2");
+
+ uint16_t EntriesStart = readNext<uint16_t>(Pos);
+ uint16_t NumEntries = readNext<uint16_t>(Pos);
+
+ Pos = PageStart + EntriesStart;
+ for (unsigned i = 0; i < NumEntries; ++i) {
+ uint32_t FunctionOffset = readNext<uint32_t>(Pos);
+ uint32_t Encoding = readNext<uint32_t>(Pos);
+
+ outs() << " [" << i << "]: "
+ << "function offset="
+ << format("0x%08" PRIx32, FunctionOffset) << ", "
+ << "encoding="
+ << format("0x%08" PRIx32, Encoding)
+ << '\n';
+ }
+}
+
+static void printCompressedSecondLevelUnwindPage(
+ const char *PageStart, uint32_t FunctionBase,
+ const SmallVectorImpl<uint32_t> &CommonEncodings) {
+ const char *Pos = PageStart;
+ uint32_t Kind = readNext<uint32_t>(Pos);
+ (void)Kind;
+ assert(Kind == 3 && "kind for a compressed 2nd level index should be 3");
+
+ uint16_t EntriesStart = readNext<uint16_t>(Pos);
+ uint16_t NumEntries = readNext<uint16_t>(Pos);
+
+ uint16_t EncodingsStart = readNext<uint16_t>(Pos);
+ readNext<uint16_t>(Pos);
+ auto PageEncodings = (support::ulittle32_t *)(PageStart + EncodingsStart);
+
+ Pos = PageStart + EntriesStart;
+ for (unsigned i = 0; i < NumEntries; ++i) {
+ uint32_t Entry = readNext<uint32_t>(Pos);
+ uint32_t FunctionOffset = FunctionBase + (Entry & 0xffffff);
+ uint32_t EncodingIdx = Entry >> 24;
+
+ uint32_t Encoding;
+ if (EncodingIdx < CommonEncodings.size())
+ Encoding = CommonEncodings[EncodingIdx];
+ else
+ Encoding = PageEncodings[EncodingIdx - CommonEncodings.size()];
+
+ outs() << " [" << i << "]: "
+ << "function offset="
+ << format("0x%08" PRIx32, FunctionOffset) << ", "
+ << "encoding[" << EncodingIdx << "]="
+ << format("0x%08" PRIx32, Encoding)
+ << '\n';
+ }
+}
+
+static void
+printMachOUnwindInfoSection(const MachOObjectFile *Obj,
+ std::map<uint64_t, SymbolRef> &Symbols,
+ const SectionRef &UnwindInfo) {
+
+ assert(Obj->isLittleEndian() &&
+ "There should not be a big-endian .o with __unwind_info");
+
+ outs() << "Contents of __unwind_info section:\n";
+
+ StringRef Contents;
+ UnwindInfo.getContents(Contents);
+ const char *Pos = Contents.data();
+
+ //===----------------------------------
+ // Section header
+ //===----------------------------------
+
+ uint32_t Version = readNext<uint32_t>(Pos);
+ outs() << " Version: "
+ << format("0x%" PRIx32, Version) << '\n';
+ assert(Version == 1 && "only understand version 1");
+
+ uint32_t CommonEncodingsStart = readNext<uint32_t>(Pos);
+ outs() << " Common encodings array section offset: "
+ << format("0x%" PRIx32, CommonEncodingsStart) << '\n';
+ uint32_t NumCommonEncodings = readNext<uint32_t>(Pos);
+ outs() << " Number of common encodings in array: "
+ << format("0x%" PRIx32, NumCommonEncodings) << '\n';
+
+ uint32_t PersonalitiesStart = readNext<uint32_t>(Pos);
+ outs() << " Personality function array section offset: "
+ << format("0x%" PRIx32, PersonalitiesStart) << '\n';
+ uint32_t NumPersonalities = readNext<uint32_t>(Pos);
+ outs() << " Number of personality functions in array: "
+ << format("0x%" PRIx32, NumPersonalities) << '\n';
+
+ uint32_t IndicesStart = readNext<uint32_t>(Pos);
+ outs() << " Index array section offset: "
+ << format("0x%" PRIx32, IndicesStart) << '\n';
+ uint32_t NumIndices = readNext<uint32_t>(Pos);
+ outs() << " Number of indices in array: "
+ << format("0x%" PRIx32, NumIndices) << '\n';
+
+ //===----------------------------------
+ // A shared list of common encodings
+ //===----------------------------------
+
+ // These occupy indices in the range [0, N] whenever an encoding is referenced
+ // from a compressed 2nd level index table. In practice the linker only
+ // creates ~128 of these, so that indices are available to embed encodings in
+ // the 2nd level index.
+
+ SmallVector<uint32_t, 64> CommonEncodings;
+ outs() << " Common encodings: (count = " << NumCommonEncodings << ")\n";
+ Pos = Contents.data() + CommonEncodingsStart;
+ for (unsigned i = 0; i < NumCommonEncodings; ++i) {
+ uint32_t Encoding = readNext<uint32_t>(Pos);
+ CommonEncodings.push_back(Encoding);
+
+ outs() << " encoding[" << i << "]: " << format("0x%08" PRIx32, Encoding)
+ << '\n';
+ }
+
+
+ //===----------------------------------
+ // Personality functions used in this executable
+ //===----------------------------------
+
+ // There should be only a handful of these (one per source language,
+ // roughly). Particularly since they only get 2 bits in the compact encoding.
+
+ outs() << " Personality functions: (count = " << NumPersonalities << ")\n";
+ Pos = Contents.data() + PersonalitiesStart;
+ for (unsigned i = 0; i < NumPersonalities; ++i) {
+ uint32_t PersonalityFn = readNext<uint32_t>(Pos);
+ outs() << " personality[" << i + 1
+ << "]: " << format("0x%08" PRIx32, PersonalityFn) << '\n';
+ }
+
+ //===----------------------------------
+ // The level 1 index entries
+ //===----------------------------------
+
+ // These specify an approximate place to start searching for the more detailed
+ // information, sorted by PC.
+
+ struct IndexEntry {
+ uint32_t FunctionOffset;
+ uint32_t SecondLevelPageStart;
+ uint32_t LSDAStart;
+ };
+
+ SmallVector<IndexEntry, 4> IndexEntries;
+
+ outs() << " Top level indices: (count = " << NumIndices << ")\n";
+ Pos = Contents.data() + IndicesStart;
+ for (unsigned i = 0; i < NumIndices; ++i) {
+ IndexEntry Entry;
+
+ Entry.FunctionOffset = readNext<uint32_t>(Pos);
+ Entry.SecondLevelPageStart = readNext<uint32_t>(Pos);
+ Entry.LSDAStart = readNext<uint32_t>(Pos);
+ IndexEntries.push_back(Entry);
+
+ outs() << " [" << i << "]: "
+ << "function offset="
+ << format("0x%08" PRIx32, Entry.FunctionOffset) << ", "
+ << "2nd level page offset="
+ << format("0x%08" PRIx32, Entry.SecondLevelPageStart) << ", "
+ << "LSDA offset="
+ << format("0x%08" PRIx32, Entry.LSDAStart) << '\n';
+ }
+
+
+ //===----------------------------------
+ // Next come the LSDA tables
+ //===----------------------------------
+
+ // The LSDA layout is rather implicit: it's a contiguous array of entries from
+ // the first top-level index's LSDAOffset to the last (sentinel).
+
+ outs() << " LSDA descriptors:\n";
+ Pos = Contents.data() + IndexEntries[0].LSDAStart;
+ int NumLSDAs = (IndexEntries.back().LSDAStart - IndexEntries[0].LSDAStart) /
+ (2 * sizeof(uint32_t));
+ for (int i = 0; i < NumLSDAs; ++i) {
+ uint32_t FunctionOffset = readNext<uint32_t>(Pos);
+ uint32_t LSDAOffset = readNext<uint32_t>(Pos);
+ outs() << " [" << i << "]: "
+ << "function offset="
+ << format("0x%08" PRIx32, FunctionOffset) << ", "
+ << "LSDA offset="
+ << format("0x%08" PRIx32, LSDAOffset) << '\n';
+ }
+
+ //===----------------------------------
+ // Finally, the 2nd level indices
+ //===----------------------------------
+
+ // Generally these are 4K in size, and have 2 possible forms:
+ // + Regular stores up to 511 entries with disparate encodings
+ // + Compressed stores up to 1021 entries if few enough compact encoding
+ // values are used.
+ outs() << " Second level indices:\n";
+ for (unsigned i = 0; i < IndexEntries.size() - 1; ++i) {
+ // The final sentinel top-level index has no associated 2nd level page
+ if (IndexEntries[i].SecondLevelPageStart == 0)
+ break;
+
+ outs() << " Second level index[" << i << "]: "
+ << "offset in section="
+ << format("0x%08" PRIx32, IndexEntries[i].SecondLevelPageStart)
+ << ", "
+ << "base function offset="
+ << format("0x%08" PRIx32, IndexEntries[i].FunctionOffset) << '\n';
+
+ Pos = Contents.data() + IndexEntries[i].SecondLevelPageStart;
+ uint32_t Kind = *(support::ulittle32_t *)Pos;
+ if (Kind == 2)
+ printRegularSecondLevelUnwindPage(Pos);
+ else if (Kind == 3)
+ printCompressedSecondLevelUnwindPage(Pos, IndexEntries[i].FunctionOffset,
+ CommonEncodings);
+ else
+ llvm_unreachable("Do not know how to print this kind of 2nd level page");
+
+ }
+}
+
void llvm::printMachOUnwindInfo(const MachOObjectFile *Obj) {
std::map<uint64_t, SymbolRef> Symbols;
for (const SymbolRef &SymRef : Obj->symbols()) {
@@ -686,7 +924,7 @@ void llvm::printMachOUnwindInfo(const Ma
if (SectName == "__compact_unwind")
printMachOCompactUnwindSection(Obj, Symbols, Section);
else if (SectName == "__unwind_info")
- outs() << "llvm-objdump: warning: unhandled __unwind_info section\n";
+ printMachOUnwindInfoSection(Obj, Symbols, Section);
else if (SectName == "__eh_frame")
outs() << "llvm-objdump: warning: unhandled __eh_frame section\n";
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