#include "Config.h"
#include "Driver.h"
#include "InputSection.h"
-#include "OutputSections.h"
#include "ScriptParser.h"
#include "SymbolTable.h"
-#include "llvm/Support/ELF.h"
#include "llvm/Support/FileSystem.h"
#include "llvm/Support/MemoryBuffer.h"
#include "llvm/Support/Path.h"
#include "llvm/Support/StringSaver.h"
using namespace llvm;
-using namespace llvm::ELF;
using namespace llvm::object;
using namespace lld;
using namespace lld::elf;
LinkerScript *elf::Script;
-static uint64_t getInteger(StringRef S) {
- uint64_t V;
- if (S.getAsInteger(0, V)) {
- error("malformed number: " + S);
- return 0;
- }
- return V;
-}
-
-// Evaluates the expression given by list of tokens.
-uint64_t LinkerScript::evaluate(std::vector<StringRef> &Tokens,
- uint64_t LocCounter) {
- uint64_t Result = 0;
- for (size_t I = 0, E = Tokens.size(); I < E; ++I) {
- // Each second token should be '+' as this is the
- // only operator we support now.
- if (I % 2 == 1) {
- if (Tokens[I] == "+")
- continue;
- error("error in location counter expression");
- return 0;
- }
-
- StringRef Tok = Tokens[I];
- if (Tok == ".")
- Result += LocCounter;
- else
- Result += getInteger(Tok);
- }
- return Result;
-}
-
template <class ELFT>
SectionRule *LinkerScript::find(InputSectionBase<ELFT> *S) {
for (SectionRule &R : Sections)
return R && R->Keep;
}
-// This method finalizes the Locations list. Adds neccesary locations for
-// orphan sections, what prepares it for futher use without
-// changes in LinkerScript::assignAddresses().
-template <class ELFT>
-void LinkerScript::fixupLocations(std::vector<OutputSectionBase<ELFT> *> &S) {
- // Orphan sections are sections present in the input files which
- // are not explicitly placed into the output file by the linker
- // script. We place orphan sections at end of file. Other linkers places
- // them using some heuristics as described in
- // https://sourceware.org/binutils/docs/ld/Orphan-Sections.html#Orphan-Sections.
- for (OutputSectionBase<ELFT> *Sec : S) {
- StringRef Name = Sec->getName();
- auto I = std::find(SectionOrder.begin(), SectionOrder.end(), Name);
- if (I == SectionOrder.end())
- Locations.push_back({Command::Section, {}, {Name}});
- }
-}
-
-template <class ELFT>
-void LinkerScript::assignAddresses(std::vector<OutputSectionBase<ELFT> *> &S) {
- typedef typename ELFT::uint uintX_t;
-
- Script->fixupLocations(S);
-
- uintX_t ThreadBssOffset = 0;
- uintX_t VA =
- Out<ELFT>::ElfHeader->getSize() + Out<ELFT>::ProgramHeaders->getSize();
-
- for (LocationNode &Node : Locations) {
- if (Node.Type == Command::Expr) {
- VA = evaluate(Node.Expr, VA);
- continue;
- }
-
- auto I =
- std::find_if(S.begin(), S.end(), [&](OutputSectionBase<ELFT> *Sec) {
- return Sec->getName() == Node.SectionName;
- });
- if (I == S.end())
- continue;
-
- OutputSectionBase<ELFT> *Sec = *I;
- uintX_t Align = Sec->getAlign();
- if ((Sec->getFlags() & SHF_TLS) && Sec->getType() == SHT_NOBITS) {
- uintX_t TVA = VA + ThreadBssOffset;
- TVA = alignTo(TVA, Align);
- Sec->setVA(TVA);
- ThreadBssOffset = TVA - VA + Sec->getSize();
- continue;
- }
-
- if (Sec->getFlags() & SHF_ALLOC) {
- VA = alignTo(VA, Align);
- Sec->setVA(VA);
- VA += Sec->getSize();
- continue;
- }
- }
-}
-
ArrayRef<uint8_t> LinkerScript::getFiller(StringRef Name) {
auto I = Filler.find(Name);
if (I == Filler.end())
void readSearchDir();
void readSections();
- void readLocationCounterValue();
void readOutputSectionDescription();
void readSectionPatterns(StringRef OutSec, bool Keep);
void ScriptParser::readSections() {
expect("{");
- while (!Error && !skip("}")) {
- StringRef Tok = peek();
- if (Tok == ".")
- readLocationCounterValue();
- else
- readOutputSectionDescription();
- }
+ while (!Error && !skip("}"))
+ readOutputSectionDescription();
}
void ScriptParser::readSectionPatterns(StringRef OutSec, bool Keep) {
Script->Sections.emplace_back(OutSec, next(), Keep);
}
-void ScriptParser::readLocationCounterValue() {
- expect(".");
- expect("=");
- Script->Locations.push_back({Command::Expr, {}, {}});
- LocationNode &Node = Script->Locations.back();
- while (!Error) {
- StringRef Tok = next();
- if (Tok == ";")
- break;
- Node.Expr.push_back(Tok);
- }
- if (Node.Expr.empty())
- error("error in location counter expression");
-}
-
void ScriptParser::readOutputSectionDescription() {
StringRef OutSec = next();
Script->SectionOrder.push_back(OutSec);
- Script->Locations.push_back({Command::Section, {}, {OutSec}});
expect(":");
expect("{");
while (!Error && !skip("}")) {
void LinkerScript::read(MemoryBufferRef MB) {
StringRef Path = MB.getBufferIdentifier();
ScriptParser(&Alloc, MB.getBuffer(), isUnderSysroot(Path)).run();
- Exists = true;
}
template StringRef LinkerScript::getOutputSection(InputSectionBase<ELF32LE> *);
template bool LinkerScript::shouldKeep(InputSectionBase<ELF32BE> *);
template bool LinkerScript::shouldKeep(InputSectionBase<ELF64LE> *);
template bool LinkerScript::shouldKeep(InputSectionBase<ELF64BE> *);
-
-template void
-LinkerScript::assignAddresses(std::vector<OutputSectionBase<ELF32LE> *> &);
-template void
-LinkerScript::assignAddresses(std::vector<OutputSectionBase<ELF32BE> *> &);
-template void
-LinkerScript::assignAddresses(std::vector<OutputSectionBase<ELF64LE> *> &);
-template void
-LinkerScript::assignAddresses(std::vector<OutputSectionBase<ELF64BE> *> &);
class ScriptParser;
template <class ELFT> class InputSectionBase;
-template <class ELFT> class OutputSectionBase;
// This class represents each rule in SECTIONS command.
class SectionRule {
StringRef SectionPattern;
};
-// This enum represents what we can observe in SECTIONS tag of script:
-// Expr is a location counter change, like ". = . + 0x1000"
-// Section is a description of output section, like ".data :..."
-enum class Command { Expr, Section };
-
-struct LocationNode {
- Command Type;
- std::vector<StringRef> Expr;
- StringRef SectionName;
-};
-
// This is a runner of the linker script.
class LinkerScript {
friend class ScriptParser;
ArrayRef<uint8_t> getFiller(StringRef Name);
template <class ELFT> bool isDiscarded(InputSectionBase<ELFT> *S);
template <class ELFT> bool shouldKeep(InputSectionBase<ELFT> *S);
- template <class ELFT>
- void assignAddresses(std::vector<OutputSectionBase<ELFT> *> &S);
int compareSections(StringRef A, StringRef B);
- bool Exists = false;
-
private:
- template <class ELFT>
- void fixupLocations(std::vector<OutputSectionBase<ELFT> *> &);
- uint64_t evaluate(std::vector<StringRef> &Tokens, uint64_t LocCounter);
template <class ELFT> SectionRule *find(InputSectionBase<ELFT> *S);
// SECTIONS commands.
// Section fill attribute for each section.
llvm::StringMap<std::vector<uint8_t>> Filler;
- // Used to assign addresses to sections.
- std::vector<LocationNode> Locations;
-
llvm::BumpPtrAllocator Alloc;
};
} else {
createPhdrs();
fixHeaders();
- if (Script->Exists) {
- Script->assignAddresses(OutputSections);
- } else {
- fixSectionAlignments();
- assignAddresses();
- }
+ fixSectionAlignments();
+ assignAddresses();
assignFileOffsets();
setPhdrs();
fixAbsoluteSymbols();
// sections. These are special, we do not include them into output sections
// list, but have them to simplify the code.
template <class ELFT> void Writer<ELFT>::fixHeaders() {
- uintX_t BaseVA = Script->Exists ? 0 : Target->getVAStart();
- Out<ELFT>::ElfHeader->setVA(BaseVA);
+ Out<ELFT>::ElfHeader->setVA(Target->getVAStart());
Out<ELFT>::ElfHeader->setFileOffset(0);
uintX_t Off = Out<ELFT>::ElfHeader->getSize();
- Out<ELFT>::ProgramHeaders->setVA(Off + BaseVA);
+ Out<ELFT>::ProgramHeaders->setVA(Off + Target->getVAStart());
Out<ELFT>::ProgramHeaders->setFileOffset(Off);
}
// NOBSS-NEXT: SHF_ALLOC
// NOBSS-NEXT: SHF_WRITE
// NOBSS-NEXT: ]
-// NOBSS-NEXT: Address: 0x159
+// NOBSS-NEXT: Address: 0x12000
// NOBSS-NEXT: Offset:
// NOBSS-NEXT: Size: 2
// NOBSS: ]
// NOBSS: Symbols [
// NOBSS: Name: _end
-// NOBSS-NEXT: Value: 0x15B
+// NOBSS-NEXT: Value: 0x12002
// NOBSS: ]
// If the layout of the sections is changed, "_end" should point to the end of allocated address space.
// TEXTATEND-NEXT: SHF_ALLOC
// TEXTATEND-NEXT: SHF_EXECINSTR
// TEXTATEND-NEXT: ]
-// TEXTATEND-NEXT: Address: 0x160
+// TEXTATEND-NEXT: Address: 0x12000
// TEXTATEND-NEXT: Offset:
// TEXTATEND-NEXT: Size: 1
// TEXTATEND: ]
// TEXTATEND: Symbols [
// TEXTATEND: Name: _end
-// TEXTATEND-NEXT: Value: 0x161
+// TEXTATEND-NEXT: Value: 0x12001
// TEXTATEND: ]
.global _start,_end
+++ /dev/null
-# REQUIRES: x86
-# RUN: llvm-mc -filetype=obj -triple=x86_64-unknown-linux %s -o %t
-# RUN: echo "SECTIONS { \
-# RUN: . = 0x12341; \
-# RUN: .data : { *(.data) } \
-# RUN: . = . + 0x10000; \
-# RUN: .text : { *(.text) } \
-# RUN: }" > %t.script
-
-# RUN: ld.lld %t --script %t.script -o %t2
-# RUN: llvm-readobj -s %t2 | FileCheck %s
-
-# CHECK: Sections [
-# CHECK-NEXT: Section {
-# CHECK-NEXT: Index: 0
-# CHECK-NEXT: Name: (0)
-# CHECK-NEXT: Type: SHT_NULL
-# CHECK-NEXT: Flags [
-# CHECK-NEXT: ]
-# CHECK-NEXT: Address: 0x0
-# CHECK-NEXT: Offset: 0x0
-# CHECK-NEXT: Size: 0
-# CHECK-NEXT: Link: 0
-# CHECK-NEXT: Info: 0
-# CHECK-NEXT: AddressAlignment: 0
-# CHECK-NEXT: EntrySize: 0
-# CHECK-NEXT: }
-# CHECK-NEXT: Section {
-# CHECK-NEXT: Index: 1
-# CHECK-NEXT: Name: .data
-# CHECK-NEXT: Type: SHT_PROGBITS
-# CHECK-NEXT: Flags [
-# CHECK-NEXT: SHF_ALLOC
-# CHECK-NEXT: SHF_WRITE
-# CHECK-NEXT: ]
-# CHECK-NEXT: Address: 0x12341
-# CHECK-NEXT: Offset: 0x158
-# CHECK-NEXT: Size: 8
-# CHECK-NEXT: Link: 0
-# CHECK-NEXT: Info: 0
-# CHECK-NEXT: AddressAlignment: 1
-# CHECK-NEXT: EntrySize: 0
-# CHECK-NEXT: }
-# CHECK-NEXT: Section {
-# CHECK-NEXT: Index: 2
-# CHECK-NEXT: Name: .text
-# CHECK-NEXT: Type: SHT_PROGBITS
-# CHECK-NEXT: Flags [
-# CHECK-NEXT: SHF_ALLOC
-# CHECK-NEXT: SHF_EXECINSTR
-# CHECK-NEXT: ]
-# CHECK-NEXT: Address: 0x2234C
-# CHECK-NEXT: Offset: 0x160
-# CHECK-NEXT: Size: 1
-# CHECK-NEXT: Link: 0
-# CHECK-NEXT: Info: 0
-# CHECK-NEXT: AddressAlignment: 4
-# CHECK-NEXT: EntrySize: 0
-# CHECK-NEXT: }
-
-# RUN: echo "SECTIONS { \
-# RUN: . = 0x12Q41; \
-# RUN: }" > %t.script
-# RUN: not ld.lld %t --script %t.script -o %t2 2>&1 | \
-# RUN: FileCheck --check-prefix=NUMERR %s
-# NUMERR: malformed number: 0x12Q41
-
-.globl _start;
-_start:
-nop
-
-.section .data
-.quad 0
-
# SECGC: Sections:
# SECGC-NEXT: Idx Name Size Address Type
# SECGC-NEXT: 0 00000000 0000000000000000
-# SECGC-NEXT: 1 .text 00000007 0000000000000158 TEXT DATA
-# SECGC-NEXT: 2 .temp 00000004 000000000000015f DATA
+# SECGC-NEXT: 1 .text 00000007 0000000000011000 TEXT DATA
+# SECGC-NEXT: 2 .temp 00000004 0000000000012000 DATA
## Now apply KEEP command to preserve the section.
# RUN: echo "SECTIONS { \
# SECNOGC: Sections:
# SECNOGC-NEXT: Idx Name Size Address Type
# SECNOGC-NEXT: 0 00000000 0000000000000000
-# SECNOGC-NEXT: 1 .text 00000007 0000000000000158 TEXT DATA
-# SECNOGC-NEXT: 2 .keep 00000004 000000000000015f DATA
-# SECNOGC-NEXT: 3 .temp 00000004 0000000000000163 DATA
+# SECNOGC-NEXT: 1 .text 00000007 0000000000011000 TEXT DATA
+# SECNOGC-NEXT: 2 .keep 00000004 0000000000012000 DATA
+# SECNOGC-NEXT: 3 .temp 00000004 0000000000012004 DATA
## A section name matches two entries in the SECTIONS directive. The
## first one doesn't have KEEP, the second one does. If section that have
# KEEP-AT-FIRST: Sections:
# KEEP-AT-FIRST-NEXT: Idx Name Size Address Type
# KEEP-AT-FIRST-NEXT: 0 00000000 0000000000000000
-# KEEP-AT-FIRST-NEXT: 1 .keep 00000004 0000000000000120 DATA
-# KEEP-AT-FIRST-NEXT: 2 .temp 00000004 0000000000000124 DATA
-# KEEP-AT-FIRST-NEXT: 3 .text 00000007 0000000000000128 TEXT DATA
+# KEEP-AT-FIRST-NEXT: 1 .keep 00000004 0000000000010120 DATA
+# KEEP-AT-FIRST-NEXT: 2 .temp 00000004 0000000000010124 DATA
+# KEEP-AT-FIRST-NEXT: 3 .text 00000007 0000000000011000 TEXT DATA
# KEEP-AT-FIRST-NEXT: 4 .symtab 00000060 0000000000000000
# KEEP-AT-FIRST-NEXT: 5 .shstrtab 0000002d 0000000000000000
# KEEP-AT-FIRST-NEXT: 6 .strtab 00000012 0000000000000000
# KEEP-AT-SECOND: Sections:
# KEEP-AT-SECOND-NEXT: Idx Name Size Address Type
# KEEP-AT-SECOND-NEXT: 0 00000000 0000000000000000
-# KEEP-AT-SECOND-NEXT: 1 .temp 00000004 0000000000000120 DATA
-# KEEP-AT-SECOND-NEXT: 2 .text 00000007 0000000000000124 TEXT DATA
+# KEEP-AT-SECOND-NEXT: 1 .temp 00000004 0000000000010120 DATA
+# KEEP-AT-SECOND-NEXT: 2 .text 00000007 0000000000011000 TEXT DATA
# KEEP-AT-SECOND-NEXT: 3 .symtab 00000048 0000000000000000
# KEEP-AT-SECOND-NEXT: 4 .shstrtab 00000027 0000000000000000
# KEEP-AT-SECOND-NEXT: 5 .strtab 0000000d 0000000000000000
+++ /dev/null
-# REQUIRES: x86
-# RUN: llvm-mc -filetype=obj -triple=x86_64-unknown-linux %s -o %t
-
-# RUN: echo "" > %t.script
-# RUN: ld.lld -o %t1 --script %t.script %t
-# RUN: llvm-objdump -section-headers %t1 | FileCheck %s
-# CHECK: Sections:
-# CHECK-NEXT: Idx Name Size Address Type
-# CHECK-NEXT: 0 00000000 0000000000000000
-# CHECK-NEXT: 1 .foo 00000004 0000000000000120 DATA
-# CHECK-NEXT: 2 .boo 00000004 0000000000000124 DATA
-# CHECK-NEXT: 3 .text 00000001 0000000000000128 TEXT DATA
-
-.global _start
-_start:
- nop
-
-.section .foo, "a"
-foo:
- .long 0
-
-.section .boo, "a"
-boo:
- .long 0
# SEC-DEFAULT: Sections:
# SEC-DEFAULT-NEXT: Idx Name Size Address Type
# SEC-DEFAULT-NEXT: 0 00000000 0000000000000000
-# SEC-DEFAULT-NEXT: 1 .text 00000008 0000000000000120 TEXT DATA
-# SEC-DEFAULT-NEXT: 2 .abcd 00000004 0000000000000128 TEXT DATA
-# SEC-DEFAULT-NEXT: 3 .ad 00000004 000000000000012c TEXT DATA
-# SEC-DEFAULT-NEXT: 4 .ag 00000004 0000000000000130 TEXT DATA
+# SEC-DEFAULT-NEXT: 1 .text 00000008 0000000000011000 TEXT DATA
+# SEC-DEFAULT-NEXT: 2 .abcd 00000004 0000000000011008 TEXT DATA
+# SEC-DEFAULT-NEXT: 3 .ad 00000004 000000000001100c TEXT DATA
+# SEC-DEFAULT-NEXT: 4 .ag 00000004 0000000000011010 TEXT DATA
# SEC-DEFAULT-NEXT: 5 .symtab 00000030 0000000000000000
# SEC-DEFAULT-NEXT: 6 .shstrtab 0000002f 0000000000000000
# SEC-DEFAULT-NEXT: 7 .strtab 00000008 0000000000000000
# SEC-ALL: Sections:
# SEC-ALL-NEXT: Idx Name Size Address Type
# SEC-ALL-NEXT: 0 00000000 0000000000000000
-# SEC-ALL-NEXT: 1 .text 0000000c 0000000000000120 TEXT DATA
-# SEC-ALL-NEXT: 2 .ad 00000004 000000000000012c TEXT DATA
-# SEC-ALL-NEXT: 3 .ag 00000004 0000000000000130 TEXT DATA
+# SEC-ALL-NEXT: 1 .text 0000000c 0000000000011000 TEXT DATA
+# SEC-ALL-NEXT: 2 .ad 00000004 000000000001100c TEXT DATA
+# SEC-ALL-NEXT: 3 .ag 00000004 0000000000011010 TEXT DATA
# SEC-ALL-NEXT: 4 .symtab 00000030 0000000000000000
# SEC-ALL-NEXT: 5 .shstrtab 00000029 0000000000000000
# SEC-ALL-NEXT: 6 .strtab 00000008 0000000000000000
# SEC-NO: Sections:
# SEC-NO-NEXT: Idx Name Size Address Type
# SEC-NO-NEXT: 0 00000000 0000000000000000
-# SEC-NO-NEXT: 1 .text 00000014 0000000000000120 TEXT DATA
+# SEC-NO-NEXT: 1 .text 00000014 0000000000011000 TEXT DATA
# SEC-NO-NEXT: 2 .symtab 00000030 0000000000000000
# SEC-NO-NEXT: 3 .shstrtab 00000021 0000000000000000
# SEC-NO-NEXT: 4 .strtab 00000008 0000000000000000