ELF: Template LinkerScript class.
Originally, linker scripts were basically an alternative way to specify
options to the command line options. But as we add more features to hanlde
symbols and sections, many member functions needed to be templated.
Now most the members are templated. It is probably time to template the
entire class.
Previously, LinkerScript is an executor of the linker script as well as
a storage of linker script configurations. This is not suitable to template
the class because when we are reading linker script files, we don't know
the ELF type yet, so we can't instantiate ELF-templated classes.
In this patch, I defined a new class, ScriptConfiguration, to store
linker script configurations. ScriptParser writes parse results to it,
and LinkerScript uses them.
Differential Revision: http://reviews.llvm.org/D19302
llvm-svn: 266908
diff --git a/lld/ELF/Driver.cpp b/lld/ELF/Driver.cpp
index c71cfca..f72fa3d 100644
--- a/lld/ELF/Driver.cpp
+++ b/lld/ELF/Driver.cpp
@@ -36,12 +36,14 @@
bool elf::link(ArrayRef<const char *> Args, raw_ostream &Error) {
HasError = false;
ErrorOS = &Error;
+
Configuration C;
LinkerDriver D;
- LinkerScript LS;
+ ScriptConfiguration SC;
Config = &C;
Driver = &D;
- Script = &LS;
+ ScriptConfig = &SC;
+
Driver->main(Args);
return !HasError;
}
@@ -108,7 +110,7 @@
switch (identify_magic(MBRef.getBuffer())) {
case file_magic::unknown:
- Script->read(MBRef);
+ readLinkerScript(MBRef);
return;
case file_magic::archive:
if (WholeArchive) {
@@ -415,8 +417,11 @@
template <class ELFT> void LinkerDriver::link(opt::InputArgList &Args) {
SymbolTable<ELFT> Symtab;
+
std::unique_ptr<TargetInfo> TI(createTarget());
Target = TI.get();
+ LinkerScript<ELFT> LS;
+ Script<ELFT>::X = &LS;
Config->Rela = ELFT::Is64Bits;
diff --git a/lld/ELF/LinkerScript.cpp b/lld/ELF/LinkerScript.cpp
index 9a47ee6..1000856 100644
--- a/lld/ELF/LinkerScript.cpp
+++ b/lld/ELF/LinkerScript.cpp
@@ -33,7 +33,7 @@
using namespace lld;
using namespace lld::elf;
-LinkerScript *elf::Script;
+ScriptConfiguration *elf::ScriptConfig;
static uint64_t getInteger(StringRef S) {
uint64_t V;
@@ -147,25 +147,26 @@
}
template <class ELFT>
-SectionRule *LinkerScript::find(InputSectionBase<ELFT> *S) {
- for (SectionRule &R : Sections)
+SectionRule *LinkerScript<ELFT>::find(InputSectionBase<ELFT> *S) {
+ for (SectionRule &R : Opt.Sections)
if (R.match(S))
return &R;
return nullptr;
}
template <class ELFT>
-StringRef LinkerScript::getOutputSection(InputSectionBase<ELFT> *S) {
+StringRef LinkerScript<ELFT>::getOutputSection(InputSectionBase<ELFT> *S) {
SectionRule *R = find(S);
return R ? R->Dest : "";
}
template <class ELFT>
-bool LinkerScript::isDiscarded(InputSectionBase<ELFT> *S) {
+bool LinkerScript<ELFT>::isDiscarded(InputSectionBase<ELFT> *S) {
return getOutputSection(S) == "/DISCARD/";
}
-template <class ELFT> bool LinkerScript::shouldKeep(InputSectionBase<ELFT> *S) {
+template <class ELFT>
+bool LinkerScript<ELFT>::shouldKeep(InputSectionBase<ELFT> *S) {
SectionRule *R = find(S);
return R && R->Keep;
}
@@ -180,7 +181,7 @@
}
template <class ELFT>
-void LinkerScript::assignAddresses(
+void LinkerScript<ELFT>::assignAddresses(
std::vector<OutputSectionBase<ELFT> *> &Sections) {
typedef typename ELFT::uint uintX_t;
@@ -191,9 +192,9 @@
// https://sourceware.org/binutils/docs/ld/Orphan-Sections.html#Orphan-Sections.
for (OutputSectionBase<ELFT> *Sec : Sections) {
StringRef Name = Sec->getName();
- auto I = std::find(SectionOrder.begin(), SectionOrder.end(), Name);
- if (I == SectionOrder.end())
- Commands.push_back({SectionKind, {}, Name});
+ auto I = std::find(Opt.SectionOrder.begin(), Opt.SectionOrder.end(), Name);
+ if (I == Opt.SectionOrder.end())
+ Opt.Commands.push_back({SectionKind, {}, Name});
}
// Assign addresses as instructed by linker script SECTIONS sub-commands.
@@ -201,7 +202,7 @@
uintX_t VA =
Out<ELFT>::ElfHeader->getSize() + Out<ELFT>::ProgramHeaders->getSize();
- for (SectionsCommand &Cmd : Commands) {
+ for (SectionsCommand &Cmd : Opt.Commands) {
if (Cmd.Kind == ExprKind) {
VA = evaluate(Cmd.Expr, VA);
continue;
@@ -228,9 +229,10 @@
}
}
-ArrayRef<uint8_t> LinkerScript::getFiller(StringRef Name) {
- auto I = Filler.find(Name);
- if (I == Filler.end())
+template <class ELFT>
+ArrayRef<uint8_t> LinkerScript<ELFT>::getFiller(StringRef Name) {
+ auto I = Opt.Filler.find(Name);
+ if (I == Opt.Filler.end())
return {};
return I->second;
}
@@ -238,10 +240,11 @@
// A compartor to sort output sections. Returns -1 or 1 if both
// A and B are mentioned in linker scripts. Otherwise, returns 0
// to use the default rule which is implemented in Writer.cpp.
-int LinkerScript::compareSections(StringRef A, StringRef B) {
- auto E = SectionOrder.end();
- auto I = std::find(SectionOrder.begin(), E, A);
- auto J = std::find(SectionOrder.begin(), E, B);
+template <class ELFT>
+int LinkerScript<ELFT>::compareSections(StringRef A, StringRef B) {
+ auto E = Opt.SectionOrder.end();
+ auto I = std::find(Opt.SectionOrder.begin(), E, A);
+ auto J = std::find(Opt.SectionOrder.begin(), E, B);
if (I == E || J == E)
return 0;
return I < J ? -1 : 1;
@@ -275,12 +278,11 @@
return matchStr(SectionPattern, S->getSectionName());
}
-class elf::ScriptParser final : public elf::ScriptParserBase {
+class elf::ScriptParser : public ScriptParserBase {
typedef void (ScriptParser::*Handler)();
public:
- ScriptParser(BumpPtrAllocator *A, StringRef S, bool B)
- : ScriptParserBase(S), Saver(*A), IsUnderSysroot(B) {}
+ ScriptParser(StringRef S, bool B) : ScriptParserBase(S), IsUnderSysroot(B) {}
void run() override;
@@ -303,8 +305,9 @@
void readOutputSectionDescription();
void readSectionPatterns(StringRef OutSec, bool Keep);
- StringSaver Saver;
const static StringMap<Handler> Cmd;
+ ScriptConfiguration &Opt = *ScriptConfig;
+ StringSaver Saver = {ScriptConfig->Alloc};
bool IsUnderSysroot;
};
@@ -460,7 +463,7 @@
}
void ScriptParser::readSections() {
- Script->DoLayout = true;
+ Opt.DoLayout = true;
expect("{");
while (!Error && !skip("}")) {
StringRef Tok = peek();
@@ -474,14 +477,14 @@
void ScriptParser::readSectionPatterns(StringRef OutSec, bool Keep) {
expect("(");
while (!Error && !skip(")"))
- Script->Sections.emplace_back(OutSec, next(), Keep);
+ Opt.Sections.emplace_back(OutSec, next(), Keep);
}
void ScriptParser::readLocationCounterValue() {
expect(".");
expect("=");
- Script->Commands.push_back({ExprKind, {}, ""});
- SectionsCommand &Cmd = Script->Commands.back();
+ Opt.Commands.push_back({ExprKind, {}, ""});
+ SectionsCommand &Cmd = Opt.Commands.back();
while (!Error) {
StringRef Tok = next();
if (Tok == ";")
@@ -494,8 +497,8 @@
void ScriptParser::readOutputSectionDescription() {
StringRef OutSec = next();
- Script->SectionOrder.push_back(OutSec);
- Script->Commands.push_back({SectionKind, {}, OutSec});
+ Opt.SectionOrder.push_back(OutSec);
+ Opt.Commands.push_back({SectionKind, {}, OutSec});
expect(":");
expect("{");
while (!Error && !skip("}")) {
@@ -518,7 +521,7 @@
return;
}
Tok = Tok.substr(3);
- Script->Filler[OutSec] = parseHex(Tok);
+ Opt.Filler[OutSec] = parseHex(Tok);
next();
}
}
@@ -532,32 +535,13 @@
return false;
}
-// Entry point. The other functions or classes are private to this file.
-void LinkerScript::read(MemoryBufferRef MB) {
+// Entry point.
+void elf::readLinkerScript(MemoryBufferRef MB) {
StringRef Path = MB.getBufferIdentifier();
- ScriptParser(&Alloc, MB.getBuffer(), isUnderSysroot(Path)).run();
+ ScriptParser(MB.getBuffer(), isUnderSysroot(Path)).run();
}
-template StringRef LinkerScript::getOutputSection(InputSectionBase<ELF32LE> *);
-template StringRef LinkerScript::getOutputSection(InputSectionBase<ELF32BE> *);
-template StringRef LinkerScript::getOutputSection(InputSectionBase<ELF64LE> *);
-template StringRef LinkerScript::getOutputSection(InputSectionBase<ELF64BE> *);
-
-template bool LinkerScript::isDiscarded(InputSectionBase<ELF32LE> *);
-template bool LinkerScript::isDiscarded(InputSectionBase<ELF32BE> *);
-template bool LinkerScript::isDiscarded(InputSectionBase<ELF64LE> *);
-template bool LinkerScript::isDiscarded(InputSectionBase<ELF64BE> *);
-
-template bool LinkerScript::shouldKeep(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> *> &);
+template class elf::LinkerScript<ELF32LE>;
+template class elf::LinkerScript<ELF32BE>;
+template class elf::LinkerScript<ELF64LE>;
+template class elf::LinkerScript<ELF64BE>;
diff --git a/lld/ELF/LinkerScript.h b/lld/ELF/LinkerScript.h
index 2deae33..bdc217e 100644
--- a/lld/ELF/LinkerScript.h
+++ b/lld/ELF/LinkerScript.h
@@ -19,6 +19,10 @@
namespace lld {
namespace elf {
+// Parses a linker script. Calling this function updates
+// Config and ScriptConfig.
+void readLinkerScript(MemoryBufferRef MB);
+
class ScriptParser;
template <class ELFT> class InputSectionBase;
template <class ELFT> class OutputSectionBase;
@@ -52,28 +56,8 @@
StringRef SectionName;
};
-// This is a runner of the linker script.
-class LinkerScript {
- friend class ScriptParser;
-
-public:
- // Parses a linker script. Calling this function may update
- // this object and Config.
- void read(MemoryBufferRef MB);
-
- template <class ELFT> StringRef getOutputSection(InputSectionBase<ELFT> *S);
- 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 DoLayout = false;
-
-private:
- template <class ELFT> SectionRule *find(InputSectionBase<ELFT> *S);
-
+// ScriptConfiguration holds linker script parse results.
+struct ScriptConfiguration {
// SECTIONS commands.
std::vector<SectionRule> Sections;
@@ -86,10 +70,33 @@
// Used to assign addresses to sections.
std::vector<SectionsCommand> Commands;
+ bool DoLayout = false;
+
llvm::BumpPtrAllocator Alloc;
};
-extern LinkerScript *Script;
+extern ScriptConfiguration *ScriptConfig;
+
+// This is a runner of the linker script.
+template <class ELFT> class LinkerScript {
+public:
+ StringRef getOutputSection(InputSectionBase<ELFT> *S);
+ ArrayRef<uint8_t> getFiller(StringRef Name);
+ bool isDiscarded(InputSectionBase<ELFT> *S);
+ bool shouldKeep(InputSectionBase<ELFT> *S);
+ void assignAddresses(std::vector<OutputSectionBase<ELFT> *> &S);
+ int compareSections(StringRef A, StringRef B);
+
+private:
+ SectionRule *find(InputSectionBase<ELFT> *S);
+
+ ScriptConfiguration &Opt = *ScriptConfig;
+};
+
+// Variable template is a C++14 feature, so we can't template
+// a global variable. Use a struct to workaround.
+template <class ELFT> struct Script { static LinkerScript<ELFT> *X; };
+template <class ELFT> LinkerScript<ELFT> *Script<ELFT>::X;
} // namespace elf
} // namespace lld
diff --git a/lld/ELF/MarkLive.cpp b/lld/ELF/MarkLive.cpp
index ade0dce..155fe3f 100644
--- a/lld/ELF/MarkLive.cpp
+++ b/lld/ELF/MarkLive.cpp
@@ -126,7 +126,7 @@
for (const std::unique_ptr<ObjectFile<ELFT>> &F : Symtab->getObjectFiles())
for (InputSectionBase<ELFT> *Sec : F->getSections())
if (Sec && Sec != &InputSection<ELFT>::Discarded)
- if (isReserved(Sec) || Script->shouldKeep<ELFT>(Sec))
+ if (isReserved(Sec) || Script<ELFT>::X->shouldKeep(Sec))
Enqueue(Sec);
// Mark all reachable sections.
diff --git a/lld/ELF/OutputSections.cpp b/lld/ELF/OutputSections.cpp
index acbdd31..9052aec 100644
--- a/lld/ELF/OutputSections.cpp
+++ b/lld/ELF/OutputSections.cpp
@@ -908,7 +908,7 @@
}
template <class ELFT> void OutputSection<ELFT>::writeTo(uint8_t *Buf) {
- ArrayRef<uint8_t> Filler = Script->getFiller(this->Name);
+ ArrayRef<uint8_t> Filler = Script<ELFT>::X->getFiller(this->Name);
if (!Filler.empty())
fill(Buf, this->getSize(), Filler);
if (Config->Threads) {
diff --git a/lld/ELF/Writer.cpp b/lld/ELF/Writer.cpp
index 5d98ff7..8fb71c5 100644
--- a/lld/ELF/Writer.cpp
+++ b/lld/ELF/Writer.cpp
@@ -220,8 +220,8 @@
} else {
createPhdrs();
fixHeaders();
- if (Script->DoLayout) {
- Script->assignAddresses(OutputSections);
+ if (ScriptConfig->DoLayout) {
+ Script<ELFT>::X->assignAddresses(OutputSections);
} else {
fixSectionAlignments();
assignAddresses();
@@ -776,7 +776,7 @@
OutputSectionBase<ELFT> *B) {
typedef typename ELFT::uint uintX_t;
- int Comp = Script->compareSections(A->getName(), B->getName());
+ int Comp = Script<ELFT>::X->compareSections(A->getName(), B->getName());
if (Comp != 0)
return Comp < 0;
@@ -918,7 +918,7 @@
template <class ELFT>
StringRef Writer<ELFT>::getOutputSectionName(InputSectionBase<ELFT> *S) const {
- StringRef Dest = Script->getOutputSection<ELFT>(S);
+ StringRef Dest = Script<ELFT>::X->getOutputSection(S);
if (!Dest.empty())
return Dest;
@@ -943,7 +943,7 @@
template <class ELFT>
bool Writer<ELFT>::isDiscarded(InputSectionBase<ELFT> *S) const {
return !S || S == &InputSection<ELFT>::Discarded || !S->Live ||
- Script->isDiscarded(S);
+ Script<ELFT>::X->isDiscarded(S);
}
template <class ELFT>
@@ -1545,7 +1545,7 @@
// 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->DoLayout ? 0 : Target->getVAStart();
+ uintX_t BaseVA = ScriptConfig->DoLayout ? 0 : Target->getVAStart();
Out<ELFT>::ElfHeader->setVA(BaseVA);
Out<ELFT>::ElfHeader->setFileOffset(0);
uintX_t Off = Out<ELFT>::ElfHeader->getSize();