[lld] r323579 - Add the /order option.
Rui Ueyama via llvm-commits
llvm-commits at lists.llvm.org
Fri Jan 26 16:34:47 PST 2018
Author: ruiu
Date: Fri Jan 26 16:34:46 2018
New Revision: 323579
URL: http://llvm.org/viewvc/llvm-project?rev=323579&view=rev
Log:
Add the /order option.
With the /order option, you can give an order file. An order file
contains symbol names, one per line, and the linker places comdat
sections in that given order. The option is used often to optimize
an output binary for (in particular, startup) speed by improving
locality.
Differential Revision: https://reviews.llvm.org/D42598
Added:
lld/trunk/test/COFF/Inputs/order.yaml
lld/trunk/test/COFF/order-i386.test
lld/trunk/test/COFF/order.test
Modified:
lld/trunk/COFF/Config.h
lld/trunk/COFF/Driver.cpp
lld/trunk/COFF/Options.td
lld/trunk/COFF/Writer.cpp
Modified: lld/trunk/COFF/Config.h
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/COFF/Config.h?rev=323579&r1=323578&r2=323579&view=diff
==============================================================================
--- lld/trunk/COFF/Config.h (original)
+++ lld/trunk/COFF/Config.h Fri Jan 26 16:34:46 2018
@@ -10,6 +10,7 @@
#ifndef LLD_COFF_CONFIG_H
#define LLD_COFF_CONFIG_H
+#include "llvm/ADT/StringMap.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/Object/COFF.h"
#include "llvm/Support/CachePruning.h"
@@ -153,6 +154,9 @@ struct Configuration {
// Used for /alternatename.
std::map<StringRef, StringRef> AlternateNames;
+ // Used for /order.
+ llvm::StringMap<int> Order;
+
// Used for /lldmap.
std::string MapFile;
Modified: lld/trunk/COFF/Driver.cpp
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/COFF/Driver.cpp?rev=323579&r1=323578&r2=323579&view=diff
==============================================================================
--- lld/trunk/COFF/Driver.cpp (original)
+++ lld/trunk/COFF/Driver.cpp Fri Jan 26 16:34:46 2018
@@ -14,6 +14,7 @@
#include "SymbolTable.h"
#include "Symbols.h"
#include "Writer.h"
+#include "lld/Common/Args.h"
#include "lld/Common/Driver.h"
#include "lld/Common/ErrorHandler.h"
#include "lld/Common/Memory.h"
@@ -756,6 +757,33 @@ bool LinkerDriver::run() {
return DidWork;
}
+// Parse an /order file. If an option is given, the linker places
+// COMDAT sections in the same order as their names appear in the
+// given file.
+static void parseOrderFile(StringRef Arg) {
+ // For some reason, the MSVC linker requires a filename to be
+ // preceded by "@".
+ if (!Arg.startswith("@")) {
+ error("malformed /order option: '@' missing");
+ return;
+ }
+
+ // Open a file.
+ StringRef Path = Arg.substr(1);
+ std::unique_ptr<MemoryBuffer> MB = CHECK(
+ MemoryBuffer::getFile(Path, -1, false, true), "could not open " + Path);
+
+ // Parse a file. An order file contains one symbol per line.
+ // All symbols that were not present in a given order file are
+ // considered to have the lowest priority 0 and are placed at
+ // end of an output section.
+ for (std::string S : args::getLines(MB->getMemBufferRef())) {
+ if (Config->Machine == I386 && !isDecorated(S))
+ S = "_" + S;
+ Config->Order[S] = INT_MIN + Config->Order.size();
+ }
+}
+
void LinkerDriver::link(ArrayRef<const char *> ArgsArr) {
// If the first command line argument is "/lib", link.exe acts like lib.exe.
// We call our own implementation of lib.exe that understands bitcode files.
@@ -1160,6 +1188,10 @@ void LinkerDriver::link(ArrayRef<const c
}
}
+ // Handle /order
+ if (auto *Arg = Args.getLastArg(OPT_order))
+ parseOrderFile(Arg->getValue());
+
// Handle /export
for (auto *Arg : Args.filtered(OPT_export)) {
Export E = parseExport(Arg->getValue());
Modified: lld/trunk/COFF/Options.td
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/COFF/Options.td?rev=323579&r1=323578&r2=323579&view=diff
==============================================================================
--- lld/trunk/COFF/Options.td (original)
+++ lld/trunk/COFF/Options.td Fri Jan 26 16:34:46 2018
@@ -42,6 +42,7 @@ def merge : P<"merge", "Combine sectio
def mllvm : P<"mllvm", "Options to pass to LLVM">;
def nodefaultlib : P<"nodefaultlib", "Remove a default library">;
def opt : P<"opt", "Control optimizations">;
+def order : P<"order", "Put functions in order">;
def out : P<"out", "Path to file to write output">;
def pdb : P<"pdb", "PDB file path">;
def section : P<"section", "Specify section attributes">;
Modified: lld/trunk/COFF/Writer.cpp
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/COFF/Writer.cpp?rev=323579&r1=323578&r2=323579&view=diff
==============================================================================
--- lld/trunk/COFF/Writer.cpp (original)
+++ lld/trunk/COFF/Writer.cpp Fri Jan 26 16:34:46 2018
@@ -348,6 +348,21 @@ static StringRef getOutputSection(String
return It->second;
}
+// For /order.
+static void sortBySectionOrder(std::vector<Chunk *> &Chunks) {
+ auto GetPriority = [](const Chunk *C) {
+ if (auto *Sec = dyn_cast<SectionChunk>(C))
+ if (Sec->Sym)
+ return Config->Order.lookup(Sec->Sym->getName());
+ return 0;
+ };
+
+ std::stable_sort(Chunks.begin(), Chunks.end(),
+ [=](const Chunk *A, const Chunk *B) {
+ return GetPriority(A) < GetPriority(B);
+ });
+}
+
// Create output section objects and add them to OutputSections.
void Writer::createSections() {
// First, bin chunks by name.
@@ -362,6 +377,11 @@ void Writer::createSections() {
Map[C->getSectionName()].push_back(C);
}
+ // Process an /order option.
+ if (!Config->Order.empty())
+ for (auto &Pair : Map)
+ sortBySectionOrder(Pair.second);
+
// Then create an OutputSection for each section.
// '$' and all following characters in input section names are
// discarded when determining output section. So, .text$foo
Added: lld/trunk/test/COFF/Inputs/order.yaml
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/test/COFF/Inputs/order.yaml?rev=323579&view=auto
==============================================================================
--- lld/trunk/test/COFF/Inputs/order.yaml (added)
+++ lld/trunk/test/COFF/Inputs/order.yaml Fri Jan 26 16:34:46 2018
@@ -0,0 +1,76 @@
+--- !COFF
+header:
+ Machine: IMAGE_FILE_MACHINE_AMD64
+ Characteristics: [ ]
+sections:
+ - Name: .text
+ Characteristics: [ IMAGE_SCN_CNT_CODE, IMAGE_SCN_LNK_COMDAT, IMAGE_SCN_MEM_EXECUTE, IMAGE_SCN_MEM_READ ]
+ Alignment: 16
+ SectionData: C3
+ - Name: .text
+ Characteristics: [ IMAGE_SCN_CNT_CODE, IMAGE_SCN_LNK_COMDAT, IMAGE_SCN_MEM_EXECUTE, IMAGE_SCN_MEM_READ ]
+ Alignment: 16
+ SectionData: C3
+ - Name: .text
+ Characteristics: [ IMAGE_SCN_CNT_CODE, IMAGE_SCN_LNK_COMDAT, IMAGE_SCN_MEM_EXECUTE, IMAGE_SCN_MEM_READ ]
+ Alignment: 16
+ SectionData: C3
+symbols:
+ - Name: .text
+ Value: 0
+ SectionNumber: 1
+ SimpleType: IMAGE_SYM_TYPE_NULL
+ ComplexType: IMAGE_SYM_DTYPE_NULL
+ StorageClass: IMAGE_SYM_CLASS_STATIC
+ SectionDefinition:
+ Length: 1
+ NumberOfRelocations: 0
+ NumberOfLinenumbers: 0
+ CheckSum: 0
+ Number: 1
+ Selection: IMAGE_COMDAT_SELECT_NODUPLICATES
+ - Name: unrelated2
+ Value: 0
+ SectionNumber: 1
+ SimpleType: IMAGE_SYM_TYPE_NULL
+ ComplexType: IMAGE_SYM_DTYPE_FUNCTION
+ StorageClass: IMAGE_SYM_CLASS_EXTERNAL
+ - Name: .text
+ Value: 0
+ SectionNumber: 2
+ SimpleType: IMAGE_SYM_TYPE_NULL
+ ComplexType: IMAGE_SYM_DTYPE_NULL
+ StorageClass: IMAGE_SYM_CLASS_STATIC
+ SectionDefinition:
+ Length: 2
+ NumberOfRelocations: 0
+ NumberOfLinenumbers: 0
+ CheckSum: 0
+ Number: 1
+ Selection: IMAGE_COMDAT_SELECT_NODUPLICATES
+ - Name: fn4
+ Value: 0
+ SectionNumber: 2
+ SimpleType: IMAGE_SYM_TYPE_NULL
+ ComplexType: IMAGE_SYM_DTYPE_FUNCTION
+ StorageClass: IMAGE_SYM_CLASS_EXTERNAL
+ - Name: .text
+ Value: 0
+ SectionNumber: 3
+ SimpleType: IMAGE_SYM_TYPE_NULL
+ ComplexType: IMAGE_SYM_DTYPE_NULL
+ StorageClass: IMAGE_SYM_CLASS_STATIC
+ SectionDefinition:
+ Length: 1
+ NumberOfRelocations: 0
+ NumberOfLinenumbers: 0
+ CheckSum: 0
+ Number: 3
+ Selection: IMAGE_COMDAT_SELECT_NODUPLICATES
+ - Name: fn1
+ Value: 0
+ SectionNumber: 3
+ SimpleType: IMAGE_SYM_TYPE_NULL
+ ComplexType: IMAGE_SYM_DTYPE_FUNCTION
+ StorageClass: IMAGE_SYM_CLASS_EXTERNAL
+...
Added: lld/trunk/test/COFF/order-i386.test
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/test/COFF/order-i386.test?rev=323579&view=auto
==============================================================================
--- lld/trunk/test/COFF/order-i386.test (added)
+++ lld/trunk/test/COFF/order-i386.test Fri Jan 26 16:34:46 2018
@@ -0,0 +1,69 @@
+# RUN: yaml2obj < %s > %t.obj
+
+# RUN: echo fn1 > %t.order
+# RUN: echo fn2 >> %t.order
+
+# RUN: lld-link -entry:fn1 -subsystem:console -opt:noref %t.obj \
+# RUN: -lldmap:- -out:%t.exe -order:@%t.order | FileCheck %s
+# CHECK: fn1
+# CHECK: fn2
+
+# RUN: lld-link -entry:fn1 -subsystem:console -opt:noref %t.obj \
+# RUN: -lldmap:- -out:%t.exe | FileCheck -check-prefix=DEFAULT %s
+# DEFAULT: fn2
+# DEFAULT: fn1
+
+--- !COFF
+header:
+ Machine: IMAGE_FILE_MACHINE_I386
+ Characteristics: [ ]
+sections:
+ - Name: '.text'
+ Characteristics: [ IMAGE_SCN_CNT_CODE, IMAGE_SCN_LNK_COMDAT, IMAGE_SCN_MEM_EXECUTE, IMAGE_SCN_MEM_READ ]
+ Alignment: 16
+ SectionData: CC
+ - Name: '.text'
+ Characteristics: [ IMAGE_SCN_CNT_CODE, IMAGE_SCN_LNK_COMDAT, IMAGE_SCN_MEM_EXECUTE, IMAGE_SCN_MEM_READ ]
+ Alignment: 16
+ SectionData: CC
+symbols:
+ - Name: '.text'
+ Value: 0
+ SectionNumber: 1
+ SimpleType: IMAGE_SYM_TYPE_NULL
+ ComplexType: IMAGE_SYM_DTYPE_NULL
+ StorageClass: IMAGE_SYM_CLASS_STATIC
+ SectionDefinition:
+ Length: 1
+ NumberOfRelocations: 0
+ NumberOfLinenumbers: 0
+ CheckSum: 0
+ Number: 0
+ Selection: IMAGE_COMDAT_SELECT_NODUPLICATES
+ - Name: '.text'
+ Value: 0
+ SectionNumber: 2
+ SimpleType: IMAGE_SYM_TYPE_NULL
+ ComplexType: IMAGE_SYM_DTYPE_NULL
+ StorageClass: IMAGE_SYM_CLASS_STATIC
+ SectionDefinition:
+ Length: 1
+ NumberOfRelocations: 0
+ NumberOfLinenumbers: 0
+ CheckSum: 0
+ Number: 0
+ Selection: IMAGE_COMDAT_SELECT_NODUPLICATES
+ - Name: _fn2
+ Value: 0
+ SectionNumber: 1
+ SimpleType: IMAGE_SYM_TYPE_NULL
+ ComplexType: IMAGE_SYM_DTYPE_FUNCTION
+ StorageClass: IMAGE_SYM_CLASS_EXTERNAL
+ - Name: _fn1
+ Value: 0
+ SectionNumber: 2
+ SimpleType: IMAGE_SYM_TYPE_NULL
+ ComplexType: IMAGE_SYM_DTYPE_FUNCTION
+ StorageClass: IMAGE_SYM_CLASS_EXTERNAL
+...
+
Added: lld/trunk/test/COFF/order.test
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/test/COFF/order.test?rev=323579&view=auto
==============================================================================
--- lld/trunk/test/COFF/order.test (added)
+++ lld/trunk/test/COFF/order.test Fri Jan 26 16:34:46 2018
@@ -0,0 +1,102 @@
+# RUN: yaml2obj < %s > %t1.obj
+# RUN: yaml2obj < %p/Inputs/order.yaml > %t2.obj
+
+# RUN: echo fn1 > %t.order
+# RUN: echo fn2 >> %t.order
+# RUN: echo fn3 >> %t.order
+# RUN: echo fn4 >> %t.order
+
+# RUN: lld-link -entry:fn1 -subsystem:console -opt:noref -debug %t1.obj %t2.obj \
+# RUN: -lldmap:- -out:%t.exe -order:@%t.order | FileCheck %s
+# CHECK: fn1
+# CHECK: fn2
+# CHECK: fn3
+# CHECK: fn4
+# CHECK: unrelated1
+# CHECK: unrelated2
+
+# RUN: lld-link -entry:fn1 -subsystem:console -opt:noref -debug %t1.obj %t2.obj \
+# RUN: -lldmap:- -out:%t.exe | FileCheck -check-prefix=DEFAULT %s
+# DEFAULT: fn2
+# DEFAULT: fn3
+# DEFAULT: unrelated1
+# DEFAULT: unrelated2
+# DEFAULT: fn4
+# DEFAULT: fn1
+
+--- !COFF
+header:
+ Machine: IMAGE_FILE_MACHINE_AMD64
+ Characteristics: [ ]
+sections:
+ - Name: .text
+ Characteristics: [ IMAGE_SCN_CNT_CODE, IMAGE_SCN_LNK_COMDAT, IMAGE_SCN_MEM_EXECUTE, IMAGE_SCN_MEM_READ ]
+ Alignment: 16
+ SectionData: C3
+ - Name: .text
+ Characteristics: [ IMAGE_SCN_CNT_CODE, IMAGE_SCN_LNK_COMDAT, IMAGE_SCN_MEM_EXECUTE, IMAGE_SCN_MEM_READ ]
+ Alignment: 16
+ SectionData: C3
+ - Name: .text
+ Characteristics: [ IMAGE_SCN_CNT_CODE, IMAGE_SCN_LNK_COMDAT, IMAGE_SCN_MEM_EXECUTE, IMAGE_SCN_MEM_READ ]
+ Alignment: 16
+ SectionData: C3
+symbols:
+ - Name: .text
+ Value: 0
+ SectionNumber: 1
+ SimpleType: IMAGE_SYM_TYPE_NULL
+ ComplexType: IMAGE_SYM_DTYPE_NULL
+ StorageClass: IMAGE_SYM_CLASS_STATIC
+ SectionDefinition:
+ Length: 1
+ NumberOfRelocations: 0
+ NumberOfLinenumbers: 0
+ CheckSum: 0
+ Number: 1
+ Selection: IMAGE_COMDAT_SELECT_NODUPLICATES
+ - Name: fn2
+ Value: 0
+ SectionNumber: 1
+ SimpleType: IMAGE_SYM_TYPE_NULL
+ ComplexType: IMAGE_SYM_DTYPE_FUNCTION
+ StorageClass: IMAGE_SYM_CLASS_EXTERNAL
+ - Name: .text
+ Value: 0
+ SectionNumber: 2
+ SimpleType: IMAGE_SYM_TYPE_NULL
+ ComplexType: IMAGE_SYM_DTYPE_NULL
+ StorageClass: IMAGE_SYM_CLASS_STATIC
+ SectionDefinition:
+ Length: 1
+ NumberOfRelocations: 0
+ NumberOfLinenumbers: 0
+ CheckSum: 0
+ Number: 2
+ Selection: IMAGE_COMDAT_SELECT_NODUPLICATES
+ - Name: fn3
+ Value: 0
+ SectionNumber: 2
+ SimpleType: IMAGE_SYM_TYPE_NULL
+ ComplexType: IMAGE_SYM_DTYPE_FUNCTION
+ StorageClass: IMAGE_SYM_CLASS_EXTERNAL
+ - Name: .text
+ Value: 0
+ SectionNumber: 3
+ SimpleType: IMAGE_SYM_TYPE_NULL
+ ComplexType: IMAGE_SYM_DTYPE_NULL
+ StorageClass: IMAGE_SYM_CLASS_STATIC
+ SectionDefinition:
+ Length: 1
+ NumberOfRelocations: 0
+ NumberOfLinenumbers: 0
+ CheckSum: 0
+ Number: 3
+ Selection: IMAGE_COMDAT_SELECT_NODUPLICATES
+ - Name: unrelated1
+ Value: 0
+ SectionNumber: 3
+ SimpleType: IMAGE_SYM_TYPE_NULL
+ ComplexType: IMAGE_SYM_DTYPE_FUNCTION
+ StorageClass: IMAGE_SYM_CLASS_EXTERNAL
+...
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