[llvm] 814dffa - [llvm-objcopy][MachO] Support LC_LINKER_OPTIMIZATION_HINT load command
Fangrui Song via llvm-commits
llvm-commits at lists.llvm.org
Tue Jun 29 18:48:01 PDT 2021
Author: Fangrui Song
Date: 2021-06-29T18:47:55-07:00
New Revision: 814dffa4b7edb36d3b05c6b96591330e33a82204
URL: https://github.com/llvm/llvm-project/commit/814dffa4b7edb36d3b05c6b96591330e33a82204
DIFF: https://github.com/llvm/llvm-project/commit/814dffa4b7edb36d3b05c6b96591330e33a82204.diff
LOG: [llvm-objcopy][MachO] Support LC_LINKER_OPTIMIZATION_HINT load command
The load command is currently specific to arm64 and holds information
for instruction rewriting, e.g. converting a GOT load to an ADR to
compute a local address.
(On ELF the information is usually conveyed by relocations, e.g.
R_X86_64_REX_GOTPCRELX, R_PPC64_TOC16_HA)
Reviewed By: alexander-shaposhnikov
Differential Revision: https://reviews.llvm.org/D104968
Added:
llvm/test/tools/llvm-objcopy/MachO/lc-linker-optimization-hint.s
Modified:
llvm/tools/llvm-objcopy/MachO/MachOLayoutBuilder.cpp
llvm/tools/llvm-objcopy/MachO/MachOReader.cpp
llvm/tools/llvm-objcopy/MachO/MachOReader.h
llvm/tools/llvm-objcopy/MachO/MachOWriter.cpp
llvm/tools/llvm-objcopy/MachO/MachOWriter.h
llvm/tools/llvm-objcopy/MachO/Object.cpp
llvm/tools/llvm-objcopy/MachO/Object.h
Removed:
################################################################################
diff --git a/llvm/test/tools/llvm-objcopy/MachO/lc-linker-optimization-hint.s b/llvm/test/tools/llvm-objcopy/MachO/lc-linker-optimization-hint.s
new file mode 100644
index 0000000000000..2c2ec6f7be935
--- /dev/null
+++ b/llvm/test/tools/llvm-objcopy/MachO/lc-linker-optimization-hint.s
@@ -0,0 +1,25 @@
+# REQUIRES: aarch64-registered-target
+## Test that we can copy LC_LINKER_OPTIMIZATION_HINT.
+
+# RUN: llvm-mc -filetype=obj -triple=arm64-apple-darwin %s -o %t.o
+# RUN: llvm-objdump --macho --link-opt-hints - < %t.o > %tloh.txt
+# RUN: FileCheck --input-file=%tloh.txt %s
+
+# CHECK: Linker optimiztion hints (8 total bytes)
+# CHECK-NEXT: identifier 7 AdrpAdd
+
+# RUN: llvm-objcopy %t.o %t.copy.o
+# RUN: llvm-objdump --macho --link-opt-hints - < %t.copy.o |
diff %tloh.txt -
+
+.text
+.align 2
+_test:
+L1:
+ adrp x0, _foo at PAGE
+L2:
+ add x0, x0, _foo at PAGEOFF
+.loh AdrpAdd L1, L2
+
+.data
+_foo:
+ .long 0
diff --git a/llvm/tools/llvm-objcopy/MachO/MachOLayoutBuilder.cpp b/llvm/tools/llvm-objcopy/MachO/MachOLayoutBuilder.cpp
index 8dc4259418400..6ed21806fe5ed 100644
--- a/llvm/tools/llvm-objcopy/MachO/MachOLayoutBuilder.cpp
+++ b/llvm/tools/llvm-objcopy/MachO/MachOLayoutBuilder.cpp
@@ -251,7 +251,10 @@ Error MachOLayoutBuilder::layoutTail(uint64_t Offset) {
uint64_t StartOfFunctionStarts = StartOfExportTrie + O.Exports.Trie.size();
uint64_t StartOfDataInCode =
StartOfFunctionStarts + O.FunctionStarts.Data.size();
- uint64_t StartOfSymbols = StartOfDataInCode + O.DataInCode.Data.size();
+ uint64_t StartOfLinkerOptimizationHint =
+ StartOfDataInCode + O.DataInCode.Data.size();
+ uint64_t StartOfSymbols =
+ StartOfLinkerOptimizationHint + O.LinkerOptimizationHint.Data.size();
uint64_t StartOfIndirectSymbols =
StartOfSymbols + NListSize * O.SymTable.Symbols.size();
uint64_t StartOfSymbolStrings =
@@ -320,6 +323,11 @@ Error MachOLayoutBuilder::layoutTail(uint64_t Offset) {
MLC.linkedit_data_command_data.dataoff = StartOfDataInCode;
MLC.linkedit_data_command_data.datasize = O.DataInCode.Data.size();
break;
+ case MachO::LC_LINKER_OPTIMIZATION_HINT:
+ MLC.linkedit_data_command_data.dataoff = StartOfLinkerOptimizationHint;
+ MLC.linkedit_data_command_data.datasize =
+ O.LinkerOptimizationHint.Data.size();
+ break;
case MachO::LC_FUNCTION_STARTS:
MLC.linkedit_data_command_data.dataoff = StartOfFunctionStarts;
MLC.linkedit_data_command_data.datasize = O.FunctionStarts.Data.size();
@@ -355,7 +363,6 @@ Error MachOLayoutBuilder::layoutTail(uint64_t Offset) {
// LC_ENCRYPT_INFO/LC_ENCRYPTION_INFO_64 need to be adjusted.
case MachO::LC_ENCRYPTION_INFO:
case MachO::LC_ENCRYPTION_INFO_64:
- case MachO::LC_LINKER_OPTIMIZATION_HINT:
case MachO::LC_LOAD_DYLINKER:
case MachO::LC_MAIN:
case MachO::LC_RPATH:
diff --git a/llvm/tools/llvm-objcopy/MachO/MachOReader.cpp b/llvm/tools/llvm-objcopy/MachO/MachOReader.cpp
index da47e4bc61f25..7d1c29b42c2e4 100644
--- a/llvm/tools/llvm-objcopy/MachO/MachOReader.cpp
+++ b/llvm/tools/llvm-objcopy/MachO/MachOReader.cpp
@@ -151,6 +151,9 @@ Error MachOReader::readLoadCommands(Object &O) const {
case MachO::LC_DATA_IN_CODE:
O.DataInCodeCommandIndex = O.LoadCommands.size();
break;
+ case MachO::LC_LINKER_OPTIMIZATION_HINT:
+ O.LinkerOptimizationHintCommandIndex = O.LoadCommands.size();
+ break;
case MachO::LC_FUNCTION_STARTS:
O.FunctionStartsCommandIndex = O.LoadCommands.size();
break;
@@ -276,6 +279,11 @@ void MachOReader::readDataInCodeData(Object &O) const {
return readLinkData(O, O.DataInCodeCommandIndex, O.DataInCode);
}
+void MachOReader::readLinkerOptimizationHint(Object &O) const {
+ return readLinkData(O, O.LinkerOptimizationHintCommandIndex,
+ O.LinkerOptimizationHint);
+}
+
void MachOReader::readFunctionStartsData(Object &O) const {
return readLinkData(O, O.FunctionStartsCommandIndex, O.FunctionStarts);
}
@@ -330,6 +338,7 @@ Expected<std::unique_ptr<Object>> MachOReader::create() const {
readExportInfo(*Obj);
readCodeSignature(*Obj);
readDataInCodeData(*Obj);
+ readLinkerOptimizationHint(*Obj);
readFunctionStartsData(*Obj);
readIndirectSymbolTable(*Obj);
readSwiftVersion(*Obj);
diff --git a/llvm/tools/llvm-objcopy/MachO/MachOReader.h b/llvm/tools/llvm-objcopy/MachO/MachOReader.h
index b446e02865e57..ca3a0214cb6d3 100644
--- a/llvm/tools/llvm-objcopy/MachO/MachOReader.h
+++ b/llvm/tools/llvm-objcopy/MachO/MachOReader.h
@@ -39,6 +39,7 @@ class MachOReader : public Reader {
void readLinkData(Object &O, Optional<size_t> LCIndex, LinkData &LD) const;
void readCodeSignature(Object &O) const;
void readDataInCodeData(Object &O) const;
+ void readLinkerOptimizationHint(Object &O) const;
void readFunctionStartsData(Object &O) const;
void readIndirectSymbolTable(Object &O) const;
void readSwiftVersion(Object &O) const;
diff --git a/llvm/tools/llvm-objcopy/MachO/MachOWriter.cpp b/llvm/tools/llvm-objcopy/MachO/MachOWriter.cpp
index 24a9d28dfbd96..295098ed41183 100644
--- a/llvm/tools/llvm-objcopy/MachO/MachOWriter.cpp
+++ b/llvm/tools/llvm-objcopy/MachO/MachOWriter.cpp
@@ -107,6 +107,16 @@ size_t MachOWriter::totalSize() const {
LinkEditDataCommand.datasize);
}
+ if (O.LinkerOptimizationHintCommandIndex) {
+ const MachO::linkedit_data_command &LinkEditDataCommand =
+ O.LoadCommands[*O.LinkerOptimizationHintCommandIndex]
+ .MachOLoadCommand.linkedit_data_command_data;
+
+ if (LinkEditDataCommand.dataoff)
+ Ends.push_back(LinkEditDataCommand.dataoff +
+ LinkEditDataCommand.datasize);
+ }
+
if (O.FunctionStartsCommandIndex) {
const MachO::linkedit_data_command &LinkEditDataCommand =
O.LoadCommands[*O.FunctionStartsCommandIndex]
@@ -421,6 +431,11 @@ void MachOWriter::writeDataInCodeData() {
return writeLinkData(O.DataInCodeCommandIndex, O.DataInCode);
}
+void MachOWriter::writeLinkerOptimizationHint() {
+ return writeLinkData(O.LinkerOptimizationHintCommandIndex,
+ O.LinkerOptimizationHint);
+}
+
void MachOWriter::writeFunctionStartsData() {
return writeLinkData(O.FunctionStartsCommandIndex, O.FunctionStarts);
}
@@ -490,6 +505,16 @@ void MachOWriter::writeTail() {
&MachOWriter::writeDataInCodeData);
}
+ if (O.LinkerOptimizationHintCommandIndex) {
+ const MachO::linkedit_data_command &LinkEditDataCommand =
+ O.LoadCommands[*O.LinkerOptimizationHintCommandIndex]
+ .MachOLoadCommand.linkedit_data_command_data;
+
+ if (LinkEditDataCommand.dataoff)
+ Queue.emplace_back(LinkEditDataCommand.dataoff,
+ &MachOWriter::writeLinkerOptimizationHint);
+ }
+
if (O.FunctionStartsCommandIndex) {
const MachO::linkedit_data_command &LinkEditDataCommand =
O.LoadCommands[*O.FunctionStartsCommandIndex]
diff --git a/llvm/tools/llvm-objcopy/MachO/MachOWriter.h b/llvm/tools/llvm-objcopy/MachO/MachOWriter.h
index 24d36712a2a69..c8c06d644e9f7 100644
--- a/llvm/tools/llvm-objcopy/MachO/MachOWriter.h
+++ b/llvm/tools/llvm-objcopy/MachO/MachOWriter.h
@@ -48,6 +48,7 @@ class MachOWriter {
void writeLinkData(Optional<size_t> LCIndex, const LinkData &LD);
void writeCodeSignatureData();
void writeDataInCodeData();
+ void writeLinkerOptimizationHint();
void writeFunctionStartsData();
void writeTail();
diff --git a/llvm/tools/llvm-objcopy/MachO/Object.cpp b/llvm/tools/llvm-objcopy/MachO/Object.cpp
index c82dae6d98ada..b4f98fa84cb59 100644
--- a/llvm/tools/llvm-objcopy/MachO/Object.cpp
+++ b/llvm/tools/llvm-objcopy/MachO/Object.cpp
@@ -46,6 +46,9 @@ void Object::updateLoadCommandIndexes() {
case MachO::LC_DATA_IN_CODE:
DataInCodeCommandIndex = Index;
break;
+ case MachO::LC_LINKER_OPTIMIZATION_HINT:
+ LinkerOptimizationHintCommandIndex = Index;
+ break;
case MachO::LC_FUNCTION_STARTS:
FunctionStartsCommandIndex = Index;
break;
diff --git a/llvm/tools/llvm-objcopy/MachO/Object.h b/llvm/tools/llvm-objcopy/MachO/Object.h
index 978bd80e97b39..207502e2241b8 100644
--- a/llvm/tools/llvm-objcopy/MachO/Object.h
+++ b/llvm/tools/llvm-objcopy/MachO/Object.h
@@ -313,6 +313,7 @@ struct Object {
ExportInfo Exports;
IndirectSymbolTable IndirectSymTable;
LinkData DataInCode;
+ LinkData LinkerOptimizationHint;
LinkData FunctionStarts;
LinkData CodeSignature;
@@ -328,6 +329,8 @@ struct Object {
Optional<size_t> DySymTabCommandIndex;
/// The index LC_DATA_IN_CODE load comamnd if present.
Optional<size_t> DataInCodeCommandIndex;
+ /// The index of LC_LINKER_OPTIMIZATIN_HINT load comamnd if present.
+ Optional<size_t> LinkerOptimizationHintCommandIndex;
/// The index LC_FUNCTION_STARTS load comamnd if present.
Optional<size_t> FunctionStartsCommandIndex;
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