caio/clang-p2996
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

[llvm] Win x64 Unwind V2 2/n: Support dumping UOP_Epilog (#110338)

Browse Source 
Adds support to objdump and readobj for reading the `UOP_Epilog` entries
of Windows x64 unwind v2.

`UOP_Epilog` has a weird format:

The first `UOP_Epilog` in the unwind data is the "header":
* The least-significant bit of `OpInfo` is the "At End" flag, which
signifies that there is an epilog at the very end of the associated
function.
* `CodeOffset` is the length each epilog described by the current unwind
information (all epilogs have the same length).

Any subsequent `UOP_Epilog` represents another epilog for the current
function, where `OpInfo` and `CodeOffset` are combined to a 12-bit value
which is the offset of the beginning of the epilog from the end of the
current function. If the offset is 0, then this entry is actually
padding and can be ignored.
This commit is contained in:
Daniel Paoliello
2025-01-13 16:53:42 -08:00
committed by GitHub
parent 1515caf7a5
commit 2201164477
6 changed files with 273 additions and 31 deletions
Download Patch File Download Diff File Expand all files Collapse all files

5
llvm/include/llvm/Support/Win64EH.h
View File

@@ -124,6 +124,11 @@ union UnwindCode {
uint8_t getOpInfo() const {
return (u.UnwindOpAndOpInfo >> 4) & 0x0F;
}
/// Gets the offset for an UOP_Epilog unwind code.
uint32_t getEpilogOffset() const {
assert(getUnwindOp() == UOP_Epilog);
return (getOpInfo() << 8) | static_cast<uint32_t>(u.CodeOffset);
}
};
enum {

175
llvm/test/tools/llvm-objdump/COFF/win64-unwindv2.yaml Normal file
View File

@@ -0,0 +1,175 @@
# RUN: yaml2obj %s -o %t.exe
# RUN: llvm-objdump --unwind-info %t.exe | FileCheck %s
# CHECK-LABEL: Unwind info:
# CHECK-EMPTY:
# CHECK-NEXT: Function Table:
# CHECK-NEXT: Start Address: 0x1010
# CHECK-NEXT: End Address: 0x1017
# CHECK-NEXT: Unwind Info Address: 0x2000
# CHECK-NEXT: Version: 2
# CHECK-NEXT: Flags: 0
# CHECK-NEXT: Size of prolog: 4
# CHECK-NEXT: Number of Codes: 3
# CHECK-NEXT: No frame pointer used
# CHECK-NEXT: Unwind Codes:
# CHECK-NEXT: 0x01: UOP_Epilog atend=yes, length=0x1
# CHECK-NEXT: 0x0b: UOP_Epilog offset=0xB
# CHECK-NEXT: 0x04: UOP_AllocSmall 72
# CHECK-EMPTY:
# CHECK-NEXT: Function Table:
# CHECK-NEXT: Start Address: 0x1020
# CHECK-NEXT: End Address: 0x105c
# CHECK-NEXT: Unwind Info Address: 0x200c
# CHECK-NEXT: Version: 1
# CHECK-NEXT: Flags: 3 UNW_ExceptionHandler UNW_TerminateHandler
# CHECK-NEXT: Size of prolog: 4
# CHECK-NEXT: Number of Codes: 1
# CHECK-NEXT: No frame pointer used
# CHECK-NEXT: Unwind Codes:
# CHECK-NEXT: 0x04: UOP_AllocSmall 56
--- !COFF
OptionalHeader:
AddressOfEntryPoint: 4128
ImageBase: 5368709120
SectionAlignment: 4096
FileAlignment: 512
MajorOperatingSystemVersion: 6
MinorOperatingSystemVersion: 0
MajorImageVersion: 0
MinorImageVersion: 0
MajorSubsystemVersion: 6
MinorSubsystemVersion: 0
Subsystem: IMAGE_SUBSYSTEM_WINDOWS_CUI
DLLCharacteristics: [ IMAGE_DLL_CHARACTERISTICS_HIGH_ENTROPY_VA, IMAGE_DLL_CHARACTERISTICS_DYNAMIC_BASE, IMAGE_DLL_CHARACTERISTICS_NX_COMPAT, IMAGE_DLL_CHARACTERISTICS_TERMINAL_SERVER_AWARE ]
SizeOfStackReserve: 1048576
SizeOfStackCommit: 4096
SizeOfHeapReserve: 1048576
SizeOfHeapCommit: 4096
ExportTable:
RelativeVirtualAddress: 0
Size: 0
ImportTable:
RelativeVirtualAddress: 0
Size: 0
ResourceTable:
RelativeVirtualAddress: 0
Size: 0
ExceptionTable:
RelativeVirtualAddress: 12288
Size: 24
CertificateTable:
RelativeVirtualAddress: 0
Size: 0
BaseRelocationTable:
RelativeVirtualAddress: 0
Size: 0
Debug:
RelativeVirtualAddress: 0
Size: 0
Architecture:
RelativeVirtualAddress: 0
Size: 0
GlobalPtr:
RelativeVirtualAddress: 0
Size: 0
TlsTable:
RelativeVirtualAddress: 0
Size: 0
LoadConfigTable:
RelativeVirtualAddress: 0
Size: 0
BoundImport:
RelativeVirtualAddress: 0
Size: 0
IAT:
RelativeVirtualAddress: 0
Size: 0
DelayImportDescriptor:
RelativeVirtualAddress: 0
Size: 0
ClrRuntimeHeader:
RelativeVirtualAddress: 0
Size: 0
header:
Machine: IMAGE_FILE_MACHINE_AMD64
Characteristics: [ IMAGE_FILE_EXECUTABLE_IMAGE, IMAGE_FILE_LARGE_ADDRESS_AWARE ]
sections:
- Name: .text
Characteristics: [ IMAGE_SCN_CNT_CODE, IMAGE_SCN_MEM_EXECUTE, IMAGE_SCN_MEM_READ ]
VirtualAddress: 4096
VirtualSize: 8
SectionData: 00000000
- Name: .xdata
Characteristics: [ IMAGE_SCN_CNT_INITIALIZED_DATA, IMAGE_SCN_MEM_READ ]
VirtualAddress: 8192
VirtualSize: 40
SectionData: 0204030001160B0604820000190401000462000070100000FFFF010804051E0009330000
- Name: .pdata
Characteristics: [ IMAGE_SCN_CNT_INITIALIZED_DATA, IMAGE_SCN_MEM_READ ]
VirtualAddress: 12288
VirtualSize: 24
SectionData: 101000001710000000200000201000005C1000000C200000
symbols:
- Name: .text
Value: 0
SectionNumber: 1
SimpleType: IMAGE_SYM_TYPE_NULL
ComplexType: IMAGE_SYM_DTYPE_NULL
StorageClass: IMAGE_SYM_CLASS_STATIC
- Name: .xdata
Value: 0
SectionNumber: 2
SimpleType: IMAGE_SYM_TYPE_NULL
ComplexType: IMAGE_SYM_DTYPE_NULL
StorageClass: IMAGE_SYM_CLASS_STATIC
- Name: .pdata
Value: 0
SectionNumber: 3
SimpleType: IMAGE_SYM_TYPE_NULL
ComplexType: IMAGE_SYM_DTYPE_NULL
StorageClass: IMAGE_SYM_CLASS_STATIC
- Name: other
Value: 0
SectionNumber: 1
SimpleType: IMAGE_SYM_TYPE_NULL
ComplexType: IMAGE_SYM_DTYPE_FUNCTION
StorageClass: IMAGE_SYM_CLASS_EXTERNAL
- Name: _ZN4RAIID2Ev
Value: 16
SectionNumber: 1
SimpleType: IMAGE_SYM_TYPE_NULL
ComplexType: IMAGE_SYM_DTYPE_FUNCTION
StorageClass: IMAGE_SYM_CLASS_EXTERNAL
- Name: entry
Value: 32
SectionNumber: 1
SimpleType: IMAGE_SYM_TYPE_NULL
ComplexType: IMAGE_SYM_DTYPE_FUNCTION
StorageClass: IMAGE_SYM_CLASS_EXTERNAL
- Name: _ZN4RAIID1Ev
Value: 16
SectionNumber: 1
SimpleType: IMAGE_SYM_TYPE_NULL
ComplexType: IMAGE_SYM_DTYPE_NULL
StorageClass: IMAGE_SYM_CLASS_EXTERNAL
- Name: _Unwind_Resume
Value: 96
SectionNumber: 1
SimpleType: IMAGE_SYM_TYPE_NULL
ComplexType: IMAGE_SYM_DTYPE_FUNCTION
StorageClass: IMAGE_SYM_CLASS_EXTERNAL
- Name: __gxx_personality_seh0
Value: 112
SectionNumber: 1
SimpleType: IMAGE_SYM_TYPE_NULL
ComplexType: IMAGE_SYM_DTYPE_FUNCTION
StorageClass: IMAGE_SYM_CLASS_EXTERNAL
- Name: GCC_except_table2
Value: 20
SectionNumber: 2
SimpleType: IMAGE_SYM_TYPE_NULL
ComplexType: IMAGE_SYM_DTYPE_NULL
StorageClass: IMAGE_SYM_CLASS_STATIC
...

71
llvm/test/tools/llvm-readobj/COFF/unwind-x86_64-image.yaml
View File

@@ -1,26 +1,47 @@
# RUN: yaml2obj %s -o %t.exe
# RUN: llvm-readobj --unwind %t.exe | FileCheck %s
# CHECK: RuntimeFunction {
# CHECK: StartAddress: entry (0x140001020)
# CHECK-NEXT: EndAddress: (0x14000105C)
# CHECK-NEXT: UnwindInfoAddress: (0x140002008)
# CHECK-NEXT: UnwindInfo {
# CHECK-NEXT: Version: 1
# CHECK-NEXT: Flags [ (0x3)
# CHECK-NEXT: ExceptionHandler (0x1)
# CHECK-NEXT: TerminateHandler (0x2)
# CHECK-NEXT: ]
# CHECK-NEXT: PrologSize: 4
# CHECK-NEXT: FrameRegister: -
# CHECK-NEXT: FrameOffset: -
# CHECK-NEXT: UnwindCodeCount: 1
# CHECK-NEXT: UnwindCodes [
# CHECK-NEXT: 0x04: ALLOC_SMALL size=56
# CHECK-NEXT: ]
# CHECK-NEXT: Handler: __gxx_personality_seh0 (0x140001070)
# CHECK-LABEL: UnwindInformation [
# CHECK-NEXT: RuntimeFunction {
# CHECK-NEXT: StartAddress: _ZN4RAIID2Ev (0x140001010)
# CHECK-NEXT: EndAddress: (0x140001017)
# CHECK-NEXT: UnwindInfoAddress: .xdata (0x140002000)
# CHECK-NEXT: UnwindInfo {
# CHECK-NEXT: Version: 2
# CHECK-NEXT: Flags [ (0x0)
# CHECK-NEXT: ]
# CHECK-NEXT: PrologSize: 4
# CHECK-NEXT: FrameRegister: -
# CHECK-NEXT: FrameOffset: -
# CHECK-NEXT: UnwindCodeCount: 3
# CHECK-NEXT: UnwindCodes [
# CHECK-NEXT: 0x01: EPILOG atend=yes, length=0x1
# CHECK-NEXT: 0x0B: EPILOG offset=0xB
# CHECK-NEXT: 0x04: ALLOC_SMALL size=72
# CHECK-NEXT: ]
# CHECK-NEXT: }
# CHECK-NEXT: }
# CHECK-NEXT: }
# CHECK-NEXT: RuntimeFunction {
# CHECK-NEXT: StartAddress: entry (0x140001020)
# CHECK-NEXT: EndAddress: (0x14000105C)
# CHECK-NEXT: UnwindInfoAddress: (0x14000200C)
# CHECK-NEXT: UnwindInfo {
# CHECK-NEXT: Version: 1
# CHECK-NEXT: Flags [ (0x3)
# CHECK-NEXT: ExceptionHandler (0x1)
# CHECK-NEXT: TerminateHandler (0x2)
# CHECK-NEXT: ]
# CHECK-NEXT: PrologSize: 4
# CHECK-NEXT: FrameRegister: -
# CHECK-NEXT: FrameOffset: -
# CHECK-NEXT: UnwindCodeCount: 1
# CHECK-NEXT: UnwindCodes [
# CHECK-NEXT: 0x04: ALLOC_SMALL size=56
# CHECK-NEXT: ]
# CHECK-NEXT: Handler: __gxx_personality_seh0 (0x140001070)
# CHECK-NEXT: }
# CHECK-NEXT: }
# CHECK-NEXT: ]
--- !COFF
OptionalHeader:
@@ -92,18 +113,18 @@ sections:
- Name: .text
Characteristics: [ IMAGE_SCN_CNT_CODE, IMAGE_SCN_MEM_EXECUTE, IMAGE_SCN_MEM_READ ]
VirtualAddress: 4096
VirtualSize: 113
SectionData: C3662E0F1F8400000000000F1F4400005048890C2458C3660F1F8400000000004883EC38E8D7FFFFFFE900000000488D4C2430E8D8FFFFFF904883C438C3488944242889542424488D4C2430E8BFFFFFFF488B4C2428E805000000CC0F1F4000C3662E0F1F8400000000000F1F440000C3
- Name: .rdata
VirtualSize: 8
SectionData: 00000000
- Name: .xdata
Characteristics: [ IMAGE_SCN_CNT_INITIALIZED_DATA, IMAGE_SCN_MEM_READ ]
VirtualAddress: 8192
VirtualSize: 32
SectionData: 0101010001020000190401000462000070100000FFFF010804051E0009330000
VirtualSize: 40
SectionData: 0204030001160B0604820000190401000462000070100000FFFF010804051E0009330000
- Name: .pdata
Characteristics: [ IMAGE_SCN_CNT_INITIALIZED_DATA, IMAGE_SCN_MEM_READ ]
VirtualAddress: 12288
VirtualSize: 24
SectionData: 101000001710000000200000201000005C10000008200000
SectionData: 101000001710000000200000201000005C1000000C200000
symbols:
- Name: .text
Value: 0

24
llvm/tools/llvm-objdump/COFFDump.cpp
View File

@@ -240,10 +240,10 @@ static unsigned getNumUsedSlots(const UnwindCode &UnwindCode) {
case UOP_AllocSmall:
case UOP_SetFPReg:
case UOP_PushMachFrame:
case UOP_Epilog:
return 1;
case UOP_SaveNonVol:
case UOP_SaveXMM128:
case UOP_Epilog:
return 2;
case UOP_SaveNonVolBig:
case UOP_SaveXMM128Big:
@@ -257,7 +257,7 @@ static unsigned getNumUsedSlots(const UnwindCode &UnwindCode) {
// Prints one unwind code. Because an unwind code can occupy up to 3 slots in
// the unwind codes array, this function requires that the correct number of
// slots is provided.
static void printUnwindCode(ArrayRef<UnwindCode> UCs) {
static void printUnwindCode(ArrayRef<UnwindCode> UCs, bool &SeenFirstEpilog) {
assert(UCs.size() >= getNumUsedSlots(UCs[0]));
outs() << format(" 0x%02x: ", unsigned(UCs[0].u.CodeOffset))
<< getUnwindCodeTypeName(UCs[0].getUnwindOp());
@@ -301,11 +301,29 @@ static void printUnwindCode(ArrayRef<UnwindCode> UCs) {
outs() << " " << (UCs[0].getOpInfo() ? "w/o" : "w")
<< " error code";
break;
case UOP_Epilog:
if (SeenFirstEpilog) {
uint32_t Offset = UCs[0].getEpilogOffset();
if (Offset == 0) {
outs() << " padding";
} else {
outs() << " offset=" << format("0x%X", Offset);
}
} else {
SeenFirstEpilog = true;
bool AtEnd = (UCs[0].getOpInfo() & 0x1) != 0;
uint32_t Length = UCs[0].u.CodeOffset;
outs() << " atend=" << (AtEnd ? "yes" : "no")
<< ", length=" << format("0x%X", Length);
}
break;
}
outs() << "\n";
}
static void printAllUnwindCodes(ArrayRef<UnwindCode> UCs) {
bool SeenFirstEpilog = false;
for (const UnwindCode *I = UCs.begin(), *E = UCs.end(); I < E; ) {
unsigned UsedSlots = getNumUsedSlots(*I);
if (UsedSlots > UCs.size()) {
@@ -316,7 +334,7 @@ static void printAllUnwindCodes(ArrayRef<UnwindCode> UCs) {
<< " remaining in buffer";
return ;
}
printUnwindCode(ArrayRef(I, E));
printUnwindCode(ArrayRef(I, E), SeenFirstEpilog);
I += UsedSlots;
}
}

26
llvm/tools/llvm-readobj/Win64EHDumper.cpp
View File

@@ -65,6 +65,8 @@ static StringRef getUnwindCodeTypeName(uint8_t Code) {
case UOP_SaveXMM128: return "SAVE_XMM128";
case UOP_SaveXMM128Big: return "SAVE_XMM128_FAR";
case UOP_PushMachFrame: return "PUSH_MACHFRAME";
case UOP_Epilog:
return "EPILOG";
}
}
@@ -99,6 +101,7 @@ static unsigned getNumUsedSlots(const UnwindCode &UnwindCode) {
case UOP_AllocSmall:
case UOP_SetFPReg:
case UOP_PushMachFrame:
case UOP_Epilog:
return 1;
case UOP_SaveNonVol:
case UOP_SaveXMM128:
@@ -254,7 +257,8 @@ void Dumper::printRuntimeFunctionEntry(const Context &Ctx,
// Prints one unwind code. Because an unwind code can occupy up to 3 slots in
// the unwind codes array, this function requires that the correct number of
// slots is provided.
void Dumper::printUnwindCode(const UnwindInfo& UI, ArrayRef<UnwindCode> UC) {
void Dumper::printUnwindCode(const UnwindInfo &UI, ArrayRef<UnwindCode> UC,
bool &SeenFirstEpilog) {
assert(UC.size() >= getNumUsedSlots(UC[0]));
SW.startLine() << format("0x%02X: ", unsigned(UC[0].u.CodeOffset))
@@ -306,6 +310,23 @@ void Dumper::printUnwindCode(const UnwindInfo& UI, ArrayRef<UnwindCode> UC) {
case UOP_PushMachFrame:
OS << " errcode=" << (UC[0].getOpInfo() == 0 ? "no" : "yes");
break;
case UOP_Epilog:
if (SeenFirstEpilog) {
uint32_t Offset = UC[0].getEpilogOffset();
if (Offset == 0) {
OS << " padding";
} else {
OS << " offset=" << format("0x%X", Offset);
}
} else {
SeenFirstEpilog = true;
bool AtEnd = (UC[0].getOpInfo() & 0x1) != 0;
uint32_t Length = UC[0].u.CodeOffset;
OS << " atend=" << (AtEnd ? "yes" : "no")
<< ", length=" << format("0x%X", Length);
}
break;
}
OS << "\n";
@@ -330,6 +351,7 @@ void Dumper::printUnwindInfo(const Context &Ctx, const coff_section *Section,
{
ListScope UCS(SW, "UnwindCodes");
ArrayRef<UnwindCode> UC(&UI.UnwindCodes[0], UI.NumCodes);
bool SeenFirstEpilog = false;
for (const UnwindCode *UCI = UC.begin(), *UCE = UC.end(); UCI < UCE; ++UCI) {
unsigned UsedSlots = getNumUsedSlots(*UCI);
if (UsedSlots > UC.size()) {
@@ -337,7 +359,7 @@ void Dumper::printUnwindInfo(const Context &Ctx, const coff_section *Section,
return;
}
printUnwindCode(UI, ArrayRef(UCI, UCE));
printUnwindCode(UI, ArrayRef(UCI, UCE), SeenFirstEpilog);
UCI = UCI + UsedSlots - 1;
}
}

3
llvm/tools/llvm-readobj/Win64EHDumper.h
View File

@@ -44,7 +44,8 @@ private:
const object::coff_section *Section,
uint64_t SectionOffset,
const RuntimeFunction &RF);
void printUnwindCode(const UnwindInfo& UI, ArrayRef<UnwindCode> UC);
void printUnwindCode(const UnwindInfo &UI, ArrayRef<UnwindCode> UC,
bool &SeenFirstEpilog);
void printUnwindInfo(const Context &Ctx, const object::coff_section *Section,
off_t Offset, const UnwindInfo &UI);
void printRuntimeFunction(const Context &Ctx,