[lld] r299515 - Move the parser for the linker script to a separate file.
Rui Ueyama via llvm-commits
llvm-commits at lists.llvm.org
Tue Apr 4 22:07:40 PDT 2017
Author: ruiu
Date: Wed Apr 5 00:07:39 2017
New Revision: 299515
URL: http://llvm.org/viewvc/llvm-project?rev=299515&view=rev
Log:
Move the parser for the linker script to a separate file.
LinkerScript.cpp contains both the linker script processor and the
linker script parser. I put both into a single file, but the file grown
too large, so it's time to put them into two different files.
Added:
lld/trunk/ELF/ScriptParser.cpp
lld/trunk/ELF/ScriptParser.h
Modified:
lld/trunk/ELF/CMakeLists.txt
lld/trunk/ELF/Driver.cpp
lld/trunk/ELF/LinkerScript.cpp
lld/trunk/ELF/LinkerScript.h
Modified: lld/trunk/ELF/CMakeLists.txt
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/ELF/CMakeLists.txt?rev=299515&r1=299514&r2=299515&view=diff
==============================================================================
--- lld/trunk/ELF/CMakeLists.txt (original)
+++ lld/trunk/ELF/CMakeLists.txt Wed Apr 5 00:07:39 2017
@@ -24,6 +24,7 @@ add_lld_library(lldELF
OutputSections.cpp
Relocations.cpp
ScriptLexer.cpp
+ ScriptParser.cpp
Strings.cpp
SymbolTable.cpp
Symbols.cpp
Modified: lld/trunk/ELF/Driver.cpp
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/ELF/Driver.cpp?rev=299515&r1=299514&r2=299515&view=diff
==============================================================================
--- lld/trunk/ELF/Driver.cpp (original)
+++ lld/trunk/ELF/Driver.cpp Wed Apr 5 00:07:39 2017
@@ -33,6 +33,7 @@
#include "LinkerScript.h"
#include "Memory.h"
#include "OutputSections.h"
+#include "ScriptParser.h"
#include "Strings.h"
#include "SymbolTable.h"
#include "Target.h"
Modified: lld/trunk/ELF/LinkerScript.cpp
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/ELF/LinkerScript.cpp?rev=299515&r1=299514&r2=299515&view=diff
==============================================================================
--- lld/trunk/ELF/LinkerScript.cpp (original)
+++ lld/trunk/ELF/LinkerScript.cpp Wed Apr 5 00:07:39 2017
@@ -13,27 +13,21 @@
#include "LinkerScript.h"
#include "Config.h"
-#include "Driver.h"
#include "InputSection.h"
#include "Memory.h"
#include "OutputSections.h"
-#include "ScriptLexer.h"
#include "Strings.h"
#include "SymbolTable.h"
#include "Symbols.h"
#include "SyntheticSections.h"
-#include "Target.h"
#include "Writer.h"
#include "llvm/ADT/STLExtras.h"
-#include "llvm/ADT/SmallString.h"
#include "llvm/ADT/StringRef.h"
-#include "llvm/ADT/StringSwitch.h"
#include "llvm/Support/Casting.h"
#include "llvm/Support/ELF.h"
#include "llvm/Support/Endian.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/FileSystem.h"
-#include "llvm/Support/MathExtras.h"
#include "llvm/Support/Path.h"
#include <algorithm>
#include <cassert>
@@ -41,9 +35,7 @@
#include <cstdint>
#include <iterator>
#include <limits>
-#include <memory>
#include <string>
-#include <tuple>
#include <vector>
using namespace llvm;
@@ -67,58 +59,6 @@ uint64_t ExprValue::getSecAddr() const {
return 0;
}
-// Some operations only support one non absolute value. Move the
-// absolute one to the right hand side for convenience.
-static void moveAbsRight(ExprValue &A, ExprValue &B) {
- if (A.isAbsolute())
- std::swap(A, B);
- if (!B.isAbsolute())
- error("At least one side of the expression must be absolute");
-}
-
-static ExprValue add(ExprValue A, ExprValue B) {
- moveAbsRight(A, B);
- return {A.Sec, A.ForceAbsolute, A.Val + B.getValue()};
-}
-
-static ExprValue sub(ExprValue A, ExprValue B) {
- return {A.Sec, A.Val - B.getValue()};
-}
-
-static ExprValue mul(ExprValue A, ExprValue B) {
- return A.getValue() * B.getValue();
-}
-
-static ExprValue div(ExprValue A, ExprValue B) {
- if (uint64_t BV = B.getValue())
- return A.getValue() / BV;
- error("division by zero");
- return 0;
-}
-
-static ExprValue leftShift(ExprValue A, ExprValue B) {
- return A.getValue() << B.getValue();
-}
-
-static ExprValue rightShift(ExprValue A, ExprValue B) {
- return A.getValue() >> B.getValue();
-}
-
-static ExprValue bitAnd(ExprValue A, ExprValue B) {
- moveAbsRight(A, B);
- return {A.Sec, A.ForceAbsolute,
- (A.getValue() & B.getValue()) - A.getSecAddr()};
-}
-
-static ExprValue bitOr(ExprValue A, ExprValue B) {
- moveAbsRight(A, B);
- return {A.Sec, A.ForceAbsolute,
- (A.getValue() | B.getValue()) - A.getSecAddr()};
-}
-
-static ExprValue bitNot(ExprValue A) { return ~A.getValue(); }
-static ExprValue minus(ExprValue A) { return -A.getValue(); }
-
template <class ELFT> static SymbolBody *addRegular(SymbolAssignment *Cmd) {
Symbol *Sym;
uint8_t Visibility = Cmd->Hidden ? STV_HIDDEN : STV_DEFAULT;
@@ -133,15 +73,6 @@ template <class ELFT> static SymbolBody
return Sym->body();
}
-static bool isUnderSysroot(StringRef Path) {
- if (Config->Sysroot == "")
- return false;
- for (; !Path.empty(); Path = sys::path::parent_path(Path))
- if (sys::fs::equivalent(Config->Sysroot, Path))
- return true;
- return false;
-}
-
OutputSection *LinkerScript::getOutputSection(const Twine &Loc,
StringRef Name) {
for (OutputSection *Sec : *OutputSections)
@@ -1025,1089 +956,3 @@ size_t LinkerScript::getPhdrIndex(const
error(Loc + ": section header '" + PhdrName + "' is not listed in PHDRS");
return 0;
}
-
-class elf::ScriptParser final : ScriptLexer {
-public:
- ScriptParser(MemoryBufferRef MB)
- : ScriptLexer(MB),
- IsUnderSysroot(isUnderSysroot(MB.getBufferIdentifier())) {}
-
- void readLinkerScript();
- void readVersionScript();
- void readDynamicList();
-
-private:
- void addFile(StringRef Path);
-
- void readAsNeeded();
- void readEntry();
- void readExtern();
- void readGroup();
- void readInclude();
- void readMemory();
- void readOutput();
- void readOutputArch();
- void readOutputFormat();
- void readPhdrs();
- void readSearchDir();
- void readSections();
- void readVersion();
- void readVersionScriptCommand();
-
- SymbolAssignment *readAssignment(StringRef Name);
- BytesDataCommand *readBytesDataCommand(StringRef Tok);
- uint32_t readFill();
- OutputSectionCommand *readOutputSectionDescription(StringRef OutSec);
- uint32_t readOutputSectionFiller(StringRef Tok);
- std::vector<StringRef> readOutputSectionPhdrs();
- InputSectionDescription *readInputSectionDescription(StringRef Tok);
- StringMatcher readFilePatterns();
- std::vector<SectionPattern> readInputSectionsList();
- InputSectionDescription *readInputSectionRules(StringRef FilePattern);
- unsigned readPhdrType();
- SortSectionPolicy readSortKind();
- SymbolAssignment *readProvideHidden(bool Provide, bool Hidden);
- SymbolAssignment *readProvideOrAssignment(StringRef Tok);
- void readSort();
- Expr readAssert();
-
- uint64_t readMemoryAssignment(StringRef, StringRef, StringRef);
- std::pair<uint32_t, uint32_t> readMemoryAttributes();
-
- Expr readExpr();
- Expr readExpr1(Expr Lhs, int MinPrec);
- StringRef readParenLiteral();
- Expr readPrimary();
- Expr readTernary(Expr Cond);
- Expr readParenExpr();
-
- // For parsing version script.
- std::vector<SymbolVersion> readVersionExtern();
- void readAnonymousDeclaration();
- void readVersionDeclaration(StringRef VerStr);
-
- std::pair<std::vector<SymbolVersion>, std::vector<SymbolVersion>>
- readSymbols();
-
- bool IsUnderSysroot;
-};
-
-void ScriptParser::readDynamicList() {
- expect("{");
- readAnonymousDeclaration();
- if (!atEOF())
- setError("EOF expected, but got " + next());
-}
-
-void ScriptParser::readVersionScript() {
- readVersionScriptCommand();
- if (!atEOF())
- setError("EOF expected, but got " + next());
-}
-
-void ScriptParser::readVersionScriptCommand() {
- if (consume("{")) {
- readAnonymousDeclaration();
- return;
- }
-
- while (!atEOF() && !Error && peek() != "}") {
- StringRef VerStr = next();
- if (VerStr == "{") {
- setError("anonymous version definition is used in "
- "combination with other version definitions");
- return;
- }
- expect("{");
- readVersionDeclaration(VerStr);
- }
-}
-
-void ScriptParser::readVersion() {
- expect("{");
- readVersionScriptCommand();
- expect("}");
-}
-
-void ScriptParser::readLinkerScript() {
- while (!atEOF()) {
- StringRef Tok = next();
- if (Tok == ";")
- continue;
-
- if (Tok == "ASSERT") {
- Script->Opt.Commands.push_back(make<AssertCommand>(readAssert()));
- } else if (Tok == "ENTRY") {
- readEntry();
- } else if (Tok == "EXTERN") {
- readExtern();
- } else if (Tok == "GROUP" || Tok == "INPUT") {
- readGroup();
- } else if (Tok == "INCLUDE") {
- readInclude();
- } else if (Tok == "MEMORY") {
- readMemory();
- } else if (Tok == "OUTPUT") {
- readOutput();
- } else if (Tok == "OUTPUT_ARCH") {
- readOutputArch();
- } else if (Tok == "OUTPUT_FORMAT") {
- readOutputFormat();
- } else if (Tok == "PHDRS") {
- readPhdrs();
- } else if (Tok == "SEARCH_DIR") {
- readSearchDir();
- } else if (Tok == "SECTIONS") {
- readSections();
- } else if (Tok == "VERSION") {
- readVersion();
- } else if (SymbolAssignment *Cmd = readProvideOrAssignment(Tok)) {
- Script->Opt.Commands.push_back(Cmd);
- } else {
- setError("unknown directive: " + Tok);
- }
- }
-}
-
-void ScriptParser::addFile(StringRef S) {
- if (IsUnderSysroot && S.startswith("/")) {
- SmallString<128> PathData;
- StringRef Path = (Config->Sysroot + S).toStringRef(PathData);
- if (sys::fs::exists(Path)) {
- Driver->addFile(Saver.save(Path));
- return;
- }
- }
-
- if (sys::path::is_absolute(S)) {
- Driver->addFile(S);
- } else if (S.startswith("=")) {
- if (Config->Sysroot.empty())
- Driver->addFile(S.substr(1));
- else
- Driver->addFile(Saver.save(Config->Sysroot + "/" + S.substr(1)));
- } else if (S.startswith("-l")) {
- Driver->addLibrary(S.substr(2));
- } else if (sys::fs::exists(S)) {
- Driver->addFile(S);
- } else {
- if (Optional<std::string> Path = findFromSearchPaths(S))
- Driver->addFile(Saver.save(*Path));
- else
- setError("unable to find " + S);
- }
-}
-
-void ScriptParser::readAsNeeded() {
- expect("(");
- bool Orig = Config->AsNeeded;
- Config->AsNeeded = true;
- while (!Error && !consume(")"))
- addFile(unquote(next()));
- Config->AsNeeded = Orig;
-}
-
-void ScriptParser::readEntry() {
- // -e <symbol> takes predecence over ENTRY(<symbol>).
- expect("(");
- StringRef Tok = next();
- if (Config->Entry.empty())
- Config->Entry = Tok;
- expect(")");
-}
-
-void ScriptParser::readExtern() {
- expect("(");
- while (!Error && !consume(")"))
- Config->Undefined.push_back(next());
-}
-
-void ScriptParser::readGroup() {
- expect("(");
- while (!Error && !consume(")")) {
- StringRef Tok = next();
- if (Tok == "AS_NEEDED")
- readAsNeeded();
- else
- addFile(unquote(Tok));
- }
-}
-
-void ScriptParser::readInclude() {
- StringRef Tok = unquote(next());
-
- // https://sourceware.org/binutils/docs/ld/File-Commands.html:
- // The file will be searched for in the current directory, and in any
- // directory specified with the -L option.
- if (sys::fs::exists(Tok)) {
- if (Optional<MemoryBufferRef> MB = readFile(Tok))
- tokenize(*MB);
- return;
- }
- if (Optional<std::string> Path = findFromSearchPaths(Tok)) {
- if (Optional<MemoryBufferRef> MB = readFile(*Path))
- tokenize(*MB);
- return;
- }
- setError("cannot open " + Tok);
-}
-
-void ScriptParser::readOutput() {
- // -o <file> takes predecence over OUTPUT(<file>).
- expect("(");
- StringRef Tok = next();
- if (Config->OutputFile.empty())
- Config->OutputFile = unquote(Tok);
- expect(")");
-}
-
-void ScriptParser::readOutputArch() {
- // OUTPUT_ARCH is ignored for now.
- expect("(");
- while (!Error && !consume(")"))
- skip();
-}
-
-void ScriptParser::readOutputFormat() {
- // Error checking only for now.
- expect("(");
- skip();
- StringRef Tok = next();
- if (Tok == ")")
- return;
- if (Tok != ",") {
- setError("unexpected token: " + Tok);
- return;
- }
- skip();
- expect(",");
- skip();
- expect(")");
-}
-
-void ScriptParser::readPhdrs() {
- expect("{");
- while (!Error && !consume("}")) {
- StringRef Tok = next();
- Script->Opt.PhdrsCommands.push_back(
- {Tok, PT_NULL, false, false, UINT_MAX, nullptr});
- PhdrsCommand &PhdrCmd = Script->Opt.PhdrsCommands.back();
-
- PhdrCmd.Type = readPhdrType();
- do {
- Tok = next();
- if (Tok == ";")
- break;
- if (Tok == "FILEHDR")
- PhdrCmd.HasFilehdr = true;
- else if (Tok == "PHDRS")
- PhdrCmd.HasPhdrs = true;
- else if (Tok == "AT")
- PhdrCmd.LMAExpr = readParenExpr();
- else if (Tok == "FLAGS") {
- expect("(");
- // Passing 0 for the value of dot is a bit of a hack. It means that
- // we accept expressions like ".|1".
- PhdrCmd.Flags = readExpr()().getValue();
- expect(")");
- } else
- setError("unexpected header attribute: " + Tok);
- } while (!Error);
- }
-}
-
-void ScriptParser::readSearchDir() {
- expect("(");
- StringRef Tok = next();
- if (!Config->Nostdlib)
- Config->SearchPaths.push_back(unquote(Tok));
- expect(")");
-}
-
-void ScriptParser::readSections() {
- Script->Opt.HasSections = true;
- // -no-rosegment is used to avoid placing read only non-executable sections in
- // their own segment. We do the same if SECTIONS command is present in linker
- // script. See comment for computeFlags().
- Config->SingleRoRx = true;
-
- expect("{");
- while (!Error && !consume("}")) {
- StringRef Tok = next();
- BaseCommand *Cmd = readProvideOrAssignment(Tok);
- if (!Cmd) {
- if (Tok == "ASSERT")
- Cmd = make<AssertCommand>(readAssert());
- else
- Cmd = readOutputSectionDescription(Tok);
- }
- Script->Opt.Commands.push_back(Cmd);
- }
-}
-
-static int precedence(StringRef Op) {
- return StringSwitch<int>(Op)
- .Cases("*", "/", 5)
- .Cases("+", "-", 4)
- .Cases("<<", ">>", 3)
- .Cases("<", "<=", ">", ">=", "==", "!=", 2)
- .Cases("&", "|", 1)
- .Default(-1);
-}
-
-StringMatcher ScriptParser::readFilePatterns() {
- std::vector<StringRef> V;
- while (!Error && !consume(")"))
- V.push_back(next());
- return StringMatcher(V);
-}
-
-SortSectionPolicy ScriptParser::readSortKind() {
- if (consume("SORT") || consume("SORT_BY_NAME"))
- return SortSectionPolicy::Name;
- if (consume("SORT_BY_ALIGNMENT"))
- return SortSectionPolicy::Alignment;
- if (consume("SORT_BY_INIT_PRIORITY"))
- return SortSectionPolicy::Priority;
- if (consume("SORT_NONE"))
- return SortSectionPolicy::None;
- return SortSectionPolicy::Default;
-}
-
-// Method reads a list of sequence of excluded files and section globs given in
-// a following form: ((EXCLUDE_FILE(file_pattern+))? section_pattern+)+
-// Example: *(.foo.1 EXCLUDE_FILE (*a.o) .foo.2 EXCLUDE_FILE (*b.o) .foo.3)
-// The semantics of that is next:
-// * Include .foo.1 from every file.
-// * Include .foo.2 from every file but a.o
-// * Include .foo.3 from every file but b.o
-std::vector<SectionPattern> ScriptParser::readInputSectionsList() {
- std::vector<SectionPattern> Ret;
- while (!Error && peek() != ")") {
- StringMatcher ExcludeFilePat;
- if (consume("EXCLUDE_FILE")) {
- expect("(");
- ExcludeFilePat = readFilePatterns();
- }
-
- std::vector<StringRef> V;
- while (!Error && peek() != ")" && peek() != "EXCLUDE_FILE")
- V.push_back(next());
-
- if (!V.empty())
- Ret.push_back({std::move(ExcludeFilePat), StringMatcher(V)});
- else
- setError("section pattern is expected");
- }
- return Ret;
-}
-
-// Reads contents of "SECTIONS" directive. That directive contains a
-// list of glob patterns for input sections. The grammar is as follows.
-//
-// <patterns> ::= <section-list>
-// | <sort> "(" <section-list> ")"
-// | <sort> "(" <sort> "(" <section-list> ")" ")"
-//
-// <sort> ::= "SORT" | "SORT_BY_NAME" | "SORT_BY_ALIGNMENT"
-// | "SORT_BY_INIT_PRIORITY" | "SORT_NONE"
-//
-// <section-list> is parsed by readInputSectionsList().
-InputSectionDescription *
-ScriptParser::readInputSectionRules(StringRef FilePattern) {
- auto *Cmd = make<InputSectionDescription>(FilePattern);
- expect("(");
-
- while (!Error && !consume(")")) {
- SortSectionPolicy Outer = readSortKind();
- SortSectionPolicy Inner = SortSectionPolicy::Default;
- std::vector<SectionPattern> V;
- if (Outer != SortSectionPolicy::Default) {
- expect("(");
- Inner = readSortKind();
- if (Inner != SortSectionPolicy::Default) {
- expect("(");
- V = readInputSectionsList();
- expect(")");
- } else {
- V = readInputSectionsList();
- }
- expect(")");
- } else {
- V = readInputSectionsList();
- }
-
- for (SectionPattern &Pat : V) {
- Pat.SortInner = Inner;
- Pat.SortOuter = Outer;
- }
-
- std::move(V.begin(), V.end(), std::back_inserter(Cmd->SectionPatterns));
- }
- return Cmd;
-}
-
-InputSectionDescription *
-ScriptParser::readInputSectionDescription(StringRef Tok) {
- // Input section wildcard can be surrounded by KEEP.
- // https://sourceware.org/binutils/docs/ld/Input-Section-Keep.html#Input-Section-Keep
- if (Tok == "KEEP") {
- expect("(");
- StringRef FilePattern = next();
- InputSectionDescription *Cmd = readInputSectionRules(FilePattern);
- expect(")");
- Script->Opt.KeptSections.push_back(Cmd);
- return Cmd;
- }
- return readInputSectionRules(Tok);
-}
-
-void ScriptParser::readSort() {
- expect("(");
- expect("CONSTRUCTORS");
- expect(")");
-}
-
-Expr ScriptParser::readAssert() {
- expect("(");
- Expr E = readExpr();
- expect(",");
- StringRef Msg = unquote(next());
- expect(")");
- return [=] {
- if (!E().getValue())
- error(Msg);
- return Script->getDot();
- };
-}
-
-// Reads a FILL(expr) command. We handle the FILL command as an
-// alias for =fillexp section attribute, which is different from
-// what GNU linkers do.
-// https://sourceware.org/binutils/docs/ld/Output-Section-Data.html
-uint32_t ScriptParser::readFill() {
- expect("(");
- uint32_t V = readOutputSectionFiller(next());
- expect(")");
- expect(";");
- return V;
-}
-
-OutputSectionCommand *
-ScriptParser::readOutputSectionDescription(StringRef OutSec) {
- OutputSectionCommand *Cmd = make<OutputSectionCommand>(OutSec);
- Cmd->Location = getCurrentLocation();
-
- // Read an address expression.
- // https://sourceware.org/binutils/docs/ld/Output-Section-Address.html#Output-Section-Address
- if (peek() != ":")
- Cmd->AddrExpr = readExpr();
-
- expect(":");
-
- if (consume("AT"))
- Cmd->LMAExpr = readParenExpr();
- if (consume("ALIGN"))
- Cmd->AlignExpr = readParenExpr();
- if (consume("SUBALIGN"))
- Cmd->SubalignExpr = readParenExpr();
-
- // Parse constraints.
- if (consume("ONLY_IF_RO"))
- Cmd->Constraint = ConstraintKind::ReadOnly;
- if (consume("ONLY_IF_RW"))
- Cmd->Constraint = ConstraintKind::ReadWrite;
- expect("{");
-
- while (!Error && !consume("}")) {
- StringRef Tok = next();
- if (Tok == ";") {
- // Empty commands are allowed. Do nothing here.
- } else if (SymbolAssignment *Assignment = readProvideOrAssignment(Tok)) {
- Cmd->Commands.push_back(Assignment);
- } else if (BytesDataCommand *Data = readBytesDataCommand(Tok)) {
- Cmd->Commands.push_back(Data);
- } else if (Tok == "ASSERT") {
- Cmd->Commands.push_back(make<AssertCommand>(readAssert()));
- expect(";");
- } else if (Tok == "CONSTRUCTORS") {
- // CONSTRUCTORS is a keyword to make the linker recognize C++ ctors/dtors
- // by name. This is for very old file formats such as ECOFF/XCOFF.
- // For ELF, we should ignore.
- } else if (Tok == "FILL") {
- Cmd->Filler = readFill();
- } else if (Tok == "SORT") {
- readSort();
- } else if (peek() == "(") {
- Cmd->Commands.push_back(readInputSectionDescription(Tok));
- } else {
- setError("unknown command " + Tok);
- }
- }
-
- if (consume(">"))
- Cmd->MemoryRegionName = next();
-
- Cmd->Phdrs = readOutputSectionPhdrs();
-
- if (consume("="))
- Cmd->Filler = readOutputSectionFiller(next());
- else if (peek().startswith("="))
- Cmd->Filler = readOutputSectionFiller(next().drop_front());
-
- // Consume optional comma following output section command.
- consume(",");
-
- return Cmd;
-}
-
-// Read "=<number>" where <number> is an octal/decimal/hexadecimal number.
-// https://sourceware.org/binutils/docs/ld/Output-Section-Fill.html
-//
-// ld.gold is not fully compatible with ld.bfd. ld.bfd handles
-// hexstrings as blobs of arbitrary sizes, while ld.gold handles them
-// as 32-bit big-endian values. We will do the same as ld.gold does
-// because it's simpler than what ld.bfd does.
-uint32_t ScriptParser::readOutputSectionFiller(StringRef Tok) {
- uint32_t V;
- if (!Tok.getAsInteger(0, V))
- return V;
- setError("invalid filler expression: " + Tok);
- return 0;
-}
-
-SymbolAssignment *ScriptParser::readProvideHidden(bool Provide, bool Hidden) {
- expect("(");
- SymbolAssignment *Cmd = readAssignment(next());
- Cmd->Provide = Provide;
- Cmd->Hidden = Hidden;
- expect(")");
- expect(";");
- return Cmd;
-}
-
-SymbolAssignment *ScriptParser::readProvideOrAssignment(StringRef Tok) {
- SymbolAssignment *Cmd = nullptr;
- if (peek() == "=" || peek() == "+=") {
- Cmd = readAssignment(Tok);
- expect(";");
- } else if (Tok == "PROVIDE") {
- Cmd = readProvideHidden(true, false);
- } else if (Tok == "HIDDEN") {
- Cmd = readProvideHidden(false, true);
- } else if (Tok == "PROVIDE_HIDDEN") {
- Cmd = readProvideHidden(true, true);
- }
- return Cmd;
-}
-
-SymbolAssignment *ScriptParser::readAssignment(StringRef Name) {
- StringRef Op = next();
- assert(Op == "=" || Op == "+=");
- Expr E = readExpr();
- if (Op == "+=") {
- std::string Loc = getCurrentLocation();
- E = [=] { return add(Script->getSymbolValue(Loc, Name), E()); };
- }
- return make<SymbolAssignment>(Name, E, getCurrentLocation());
-}
-
-// This is an operator-precedence parser to parse a linker
-// script expression.
-Expr ScriptParser::readExpr() {
- // Our lexer is context-aware. Set the in-expression bit so that
- // they apply different tokenization rules.
- bool Orig = InExpr;
- InExpr = true;
- Expr E = readExpr1(readPrimary(), 0);
- InExpr = Orig;
- return E;
-}
-
-static Expr combine(StringRef Op, Expr L, Expr R) {
- if (Op == "*")
- return [=] { return mul(L(), R()); };
- if (Op == "/") {
- return [=] { return div(L(), R()); };
- }
- if (Op == "+")
- return [=] { return add(L(), R()); };
- if (Op == "-")
- return [=] { return sub(L(), R()); };
- if (Op == "<<")
- return [=] { return leftShift(L(), R()); };
- if (Op == ">>")
- return [=] { return rightShift(L(), R()); };
- if (Op == "<")
- return [=] { return L().getValue() < R().getValue(); };
- if (Op == ">")
- return [=] { return L().getValue() > R().getValue(); };
- if (Op == ">=")
- return [=] { return L().getValue() >= R().getValue(); };
- if (Op == "<=")
- return [=] { return L().getValue() <= R().getValue(); };
- if (Op == "==")
- return [=] { return L().getValue() == R().getValue(); };
- if (Op == "!=")
- return [=] { return L().getValue() != R().getValue(); };
- if (Op == "&")
- return [=] { return bitAnd(L(), R()); };
- if (Op == "|")
- return [=] { return bitOr(L(), R()); };
- llvm_unreachable("invalid operator");
-}
-
-// This is a part of the operator-precedence parser. This function
-// assumes that the remaining token stream starts with an operator.
-Expr ScriptParser::readExpr1(Expr Lhs, int MinPrec) {
- while (!atEOF() && !Error) {
- // Read an operator and an expression.
- if (consume("?"))
- return readTernary(Lhs);
- StringRef Op1 = peek();
- if (precedence(Op1) < MinPrec)
- break;
- skip();
- Expr Rhs = readPrimary();
-
- // Evaluate the remaining part of the expression first if the
- // next operator has greater precedence than the previous one.
- // For example, if we have read "+" and "3", and if the next
- // operator is "*", then we'll evaluate 3 * ... part first.
- while (!atEOF()) {
- StringRef Op2 = peek();
- if (precedence(Op2) <= precedence(Op1))
- break;
- Rhs = readExpr1(Rhs, precedence(Op2));
- }
-
- Lhs = combine(Op1, Lhs, Rhs);
- }
- return Lhs;
-}
-
-uint64_t static getConstant(StringRef S) {
- if (S == "COMMONPAGESIZE")
- return Target->PageSize;
- if (S == "MAXPAGESIZE")
- return Config->MaxPageSize;
- error("unknown constant: " + S);
- return 0;
-}
-
-// Parses Tok as an integer. Returns true if successful.
-// It recognizes hexadecimal (prefixed with "0x" or suffixed with "H")
-// and decimal numbers. Decimal numbers may have "K" (kilo) or
-// "M" (mega) prefixes.
-static bool readInteger(StringRef Tok, uint64_t &Result) {
- // Negative number
- if (Tok.startswith("-")) {
- if (!readInteger(Tok.substr(1), Result))
- return false;
- Result = -Result;
- return true;
- }
-
- // Hexadecimal
- if (Tok.startswith_lower("0x"))
- return !Tok.substr(2).getAsInteger(16, Result);
- if (Tok.endswith_lower("H"))
- return !Tok.drop_back().getAsInteger(16, Result);
-
- // Decimal
- int Suffix = 1;
- if (Tok.endswith_lower("K")) {
- Suffix = 1024;
- Tok = Tok.drop_back();
- } else if (Tok.endswith_lower("M")) {
- Suffix = 1024 * 1024;
- Tok = Tok.drop_back();
- }
- if (Tok.getAsInteger(10, Result))
- return false;
- Result *= Suffix;
- return true;
-}
-
-BytesDataCommand *ScriptParser::readBytesDataCommand(StringRef Tok) {
- int Size = StringSwitch<unsigned>(Tok)
- .Case("BYTE", 1)
- .Case("SHORT", 2)
- .Case("LONG", 4)
- .Case("QUAD", 8)
- .Default(-1);
- if (Size == -1)
- return nullptr;
-
- return make<BytesDataCommand>(readParenExpr(), Size);
-}
-
-StringRef ScriptParser::readParenLiteral() {
- expect("(");
- StringRef Tok = next();
- expect(")");
- return Tok;
-}
-
-Expr ScriptParser::readPrimary() {
- if (peek() == "(")
- return readParenExpr();
-
- StringRef Tok = next();
- std::string Location = getCurrentLocation();
-
- if (Tok == "~") {
- Expr E = readPrimary();
- return [=] { return bitNot(E()); };
- }
- if (Tok == "-") {
- Expr E = readPrimary();
- return [=] { return minus(E()); };
- }
-
- // Built-in functions are parsed here.
- // https://sourceware.org/binutils/docs/ld/Builtin-Functions.html.
- if (Tok == "ABSOLUTE") {
- Expr Inner = readParenExpr();
- return [=] {
- ExprValue I = Inner();
- I.ForceAbsolute = true;
- return I;
- };
- }
- if (Tok == "ADDR") {
- StringRef Name = readParenLiteral();
- return [=]() -> ExprValue {
- return {Script->getOutputSection(Location, Name), 0};
- };
- }
- if (Tok == "ALIGN") {
- expect("(");
- Expr E = readExpr();
- if (consume(",")) {
- Expr E2 = readExpr();
- expect(")");
- return [=] { return alignTo(E().getValue(), E2().getValue()); };
- }
- expect(")");
- return [=] { return alignTo(Script->getDot(), E().getValue()); };
- }
- if (Tok == "ALIGNOF") {
- StringRef Name = readParenLiteral();
- return [=] { return Script->getOutputSection(Location, Name)->Alignment; };
- }
- if (Tok == "ASSERT")
- return readAssert();
- if (Tok == "CONSTANT") {
- StringRef Name = readParenLiteral();
- return [=] { return getConstant(Name); };
- }
- if (Tok == "DATA_SEGMENT_ALIGN") {
- expect("(");
- Expr E = readExpr();
- expect(",");
- readExpr();
- expect(")");
- return [=] { return alignTo(Script->getDot(), E().getValue()); };
- }
- if (Tok == "DATA_SEGMENT_END") {
- expect("(");
- expect(".");
- expect(")");
- return [] { return Script->getDot(); };
- }
- if (Tok == "DATA_SEGMENT_RELRO_END") {
- // GNU linkers implements more complicated logic to handle
- // DATA_SEGMENT_RELRO_END. We instead ignore the arguments and
- // just align to the next page boundary for simplicity.
- expect("(");
- readExpr();
- expect(",");
- readExpr();
- expect(")");
- return [] { return alignTo(Script->getDot(), Target->PageSize); };
- }
- if (Tok == "DEFINED") {
- StringRef Name = readParenLiteral();
- return [=] { return Script->isDefined(Name) ? 1 : 0; };
- }
- if (Tok == "LOADADDR") {
- StringRef Name = readParenLiteral();
- return [=] { return Script->getOutputSection(Location, Name)->getLMA(); };
- }
- if (Tok == "SEGMENT_START") {
- expect("(");
- skip();
- expect(",");
- Expr E = readExpr();
- expect(")");
- return [=] { return E(); };
- }
- if (Tok == "SIZEOF") {
- StringRef Name = readParenLiteral();
- return [=] { return Script->getOutputSectionSize(Name); };
- }
- if (Tok == "SIZEOF_HEADERS")
- return [=] { return elf::getHeaderSize(); };
-
- // Tok is a literal number.
- uint64_t V;
- if (readInteger(Tok, V))
- return [=] { return V; };
-
- // Tok is a symbol name.
- if (Tok != ".") {
- if (!isValidCIdentifier(Tok))
- setError("malformed number: " + Tok);
- Script->Opt.UndefinedSymbols.push_back(Tok);
- }
- return [=] { return Script->getSymbolValue(Location, Tok); };
-}
-
-Expr ScriptParser::readTernary(Expr Cond) {
- Expr L = readExpr();
- expect(":");
- Expr R = readExpr();
- return [=] { return Cond().getValue() ? L() : R(); };
-}
-
-Expr ScriptParser::readParenExpr() {
- expect("(");
- Expr E = readExpr();
- expect(")");
- return E;
-}
-
-std::vector<StringRef> ScriptParser::readOutputSectionPhdrs() {
- std::vector<StringRef> Phdrs;
- while (!Error && peek().startswith(":")) {
- StringRef Tok = next();
- Phdrs.push_back((Tok.size() == 1) ? next() : Tok.substr(1));
- }
- return Phdrs;
-}
-
-// Read a program header type name. The next token must be a
-// name of a program header type or a constant (e.g. "0x3").
-unsigned ScriptParser::readPhdrType() {
- StringRef Tok = next();
- uint64_t Val;
- if (readInteger(Tok, Val))
- return Val;
-
- unsigned Ret = StringSwitch<unsigned>(Tok)
- .Case("PT_NULL", PT_NULL)
- .Case("PT_LOAD", PT_LOAD)
- .Case("PT_DYNAMIC", PT_DYNAMIC)
- .Case("PT_INTERP", PT_INTERP)
- .Case("PT_NOTE", PT_NOTE)
- .Case("PT_SHLIB", PT_SHLIB)
- .Case("PT_PHDR", PT_PHDR)
- .Case("PT_TLS", PT_TLS)
- .Case("PT_GNU_EH_FRAME", PT_GNU_EH_FRAME)
- .Case("PT_GNU_STACK", PT_GNU_STACK)
- .Case("PT_GNU_RELRO", PT_GNU_RELRO)
- .Case("PT_OPENBSD_RANDOMIZE", PT_OPENBSD_RANDOMIZE)
- .Case("PT_OPENBSD_WXNEEDED", PT_OPENBSD_WXNEEDED)
- .Case("PT_OPENBSD_BOOTDATA", PT_OPENBSD_BOOTDATA)
- .Default(-1);
-
- if (Ret == (unsigned)-1) {
- setError("invalid program header type: " + Tok);
- return PT_NULL;
- }
- return Ret;
-}
-
-// Reads an anonymous version declaration.
-void ScriptParser::readAnonymousDeclaration() {
- std::vector<SymbolVersion> Locals;
- std::vector<SymbolVersion> Globals;
- std::tie(Locals, Globals) = readSymbols();
-
- for (SymbolVersion V : Locals) {
- if (V.Name == "*")
- Config->DefaultSymbolVersion = VER_NDX_LOCAL;
- else
- Config->VersionScriptLocals.push_back(V);
- }
-
- for (SymbolVersion V : Globals)
- Config->VersionScriptGlobals.push_back(V);
-
- expect(";");
-}
-
-// Reads a non-anonymous version definition,
-// e.g. "VerStr { global: foo; bar; local: *; };".
-void ScriptParser::readVersionDeclaration(StringRef VerStr) {
- // Read a symbol list.
- std::vector<SymbolVersion> Locals;
- std::vector<SymbolVersion> Globals;
- std::tie(Locals, Globals) = readSymbols();
-
- for (SymbolVersion V : Locals) {
- if (V.Name == "*")
- Config->DefaultSymbolVersion = VER_NDX_LOCAL;
- else
- Config->VersionScriptLocals.push_back(V);
- }
-
- // Create a new version definition and add that to the global symbols.
- VersionDefinition Ver;
- Ver.Name = VerStr;
- Ver.Globals = Globals;
-
- // User-defined version number starts from 2 because 0 and 1 are
- // reserved for VER_NDX_LOCAL and VER_NDX_GLOBAL, respectively.
- Ver.Id = Config->VersionDefinitions.size() + 2;
- Config->VersionDefinitions.push_back(Ver);
-
- // Each version may have a parent version. For example, "Ver2"
- // defined as "Ver2 { global: foo; local: *; } Ver1;" has "Ver1"
- // as a parent. This version hierarchy is, probably against your
- // instinct, purely for hint; the runtime doesn't care about it
- // at all. In LLD, we simply ignore it.
- if (peek() != ";")
- skip();
- expect(";");
-}
-
-// Reads a list of symbols, e.g. "{ global: foo; bar; local: *; };".
-std::pair<std::vector<SymbolVersion>, std::vector<SymbolVersion>>
-ScriptParser::readSymbols() {
- std::vector<SymbolVersion> Locals;
- std::vector<SymbolVersion> Globals;
- std::vector<SymbolVersion> *V = &Globals;
-
- while (!Error) {
- if (consume("}"))
- break;
- if (consumeLabel("local")) {
- V = &Locals;
- continue;
- }
- if (consumeLabel("global")) {
- V = &Globals;
- continue;
- }
-
- if (consume("extern")) {
- std::vector<SymbolVersion> Ext = readVersionExtern();
- V->insert(V->end(), Ext.begin(), Ext.end());
- } else {
- StringRef Tok = next();
- V->push_back({unquote(Tok), false, hasWildcard(Tok)});
- }
- expect(";");
- }
- return {Locals, Globals};
-}
-
-// Reads an "extern C++" directive, e.g.,
-// "extern "C++" { ns::*; "f(int, double)"; };"
-std::vector<SymbolVersion> ScriptParser::readVersionExtern() {
- StringRef Tok = next();
- bool IsCXX = Tok == "\"C++\"";
- if (!IsCXX && Tok != "\"C\"")
- setError("Unknown language");
- expect("{");
-
- std::vector<SymbolVersion> Ret;
- while (!Error && peek() != "}") {
- StringRef Tok = next();
- bool HasWildcard = !Tok.startswith("\"") && hasWildcard(Tok);
- Ret.push_back({unquote(Tok), IsCXX, HasWildcard});
- expect(";");
- }
-
- expect("}");
- return Ret;
-}
-
-uint64_t ScriptParser::readMemoryAssignment(StringRef S1, StringRef S2,
- StringRef S3) {
- if (!(consume(S1) || consume(S2) || consume(S3))) {
- setError("expected one of: " + S1 + ", " + S2 + ", or " + S3);
- return 0;
- }
- expect("=");
-
- // TODO: Fully support constant expressions.
- uint64_t Val;
- if (!readInteger(next(), Val))
- setError("nonconstant expression for " + S1);
- return Val;
-}
-
-// Parse the MEMORY command as specified in:
-// https://sourceware.org/binutils/docs/ld/MEMORY.html
-//
-// MEMORY { name [(attr)] : ORIGIN = origin, LENGTH = len ... }
-void ScriptParser::readMemory() {
- expect("{");
- while (!Error && !consume("}")) {
- StringRef Name = next();
-
- uint32_t Flags = 0;
- uint32_t NegFlags = 0;
- if (consume("(")) {
- std::tie(Flags, NegFlags) = readMemoryAttributes();
- expect(")");
- }
- expect(":");
-
- uint64_t Origin = readMemoryAssignment("ORIGIN", "org", "o");
- expect(",");
- uint64_t Length = readMemoryAssignment("LENGTH", "len", "l");
-
- // Add the memory region to the region map (if it doesn't already exist).
- auto It = Script->Opt.MemoryRegions.find(Name);
- if (It != Script->Opt.MemoryRegions.end())
- setError("region '" + Name + "' already defined");
- else
- Script->Opt.MemoryRegions[Name] = {Name, Origin, Length,
- Origin, Flags, NegFlags};
- }
-}
-
-// This function parses the attributes used to match against section
-// flags when placing output sections in a memory region. These flags
-// are only used when an explicit memory region name is not used.
-std::pair<uint32_t, uint32_t> ScriptParser::readMemoryAttributes() {
- uint32_t Flags = 0;
- uint32_t NegFlags = 0;
- bool Invert = false;
-
- for (char C : next().lower()) {
- uint32_t Flag = 0;
- if (C == '!')
- Invert = !Invert;
- else if (C == 'w')
- Flag = SHF_WRITE;
- else if (C == 'x')
- Flag = SHF_EXECINSTR;
- else if (C == 'a')
- Flag = SHF_ALLOC;
- else if (C != 'r')
- setError("invalid memory region attribute");
-
- if (Invert)
- NegFlags |= Flag;
- else
- Flags |= Flag;
- }
- return {Flags, NegFlags};
-}
-
-void elf::readLinkerScript(MemoryBufferRef MB) {
- ScriptParser(MB).readLinkerScript();
-}
-
-void elf::readVersionScript(MemoryBufferRef MB) {
- ScriptParser(MB).readVersionScript();
-}
-
-void elf::readDynamicList(MemoryBufferRef MB) {
- ScriptParser(MB).readDynamicList();
-}
Modified: lld/trunk/ELF/LinkerScript.h
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/ELF/LinkerScript.h?rev=299515&r1=299514&r2=299515&view=diff
==============================================================================
--- lld/trunk/ELF/LinkerScript.h (original)
+++ lld/trunk/ELF/LinkerScript.h Wed Apr 5 00:07:39 2017
@@ -57,15 +57,6 @@ struct ExprValue {
// Later, we evaluate the expression by calling the function.
typedef std::function<ExprValue()> Expr;
-// Parses a linker script. Calling this function updates
-// Config and ScriptConfig.
-void readLinkerScript(MemoryBufferRef MB);
-
-// Parses a version script.
-void readVersionScript(MemoryBufferRef MB);
-
-void readDynamicList(MemoryBufferRef MB);
-
// This enum is used to implement linker script SECTIONS command.
// https://sourceware.org/binutils/docs/ld/SECTIONS.html#SECTIONS
enum SectionsCommandKind {
Added: lld/trunk/ELF/ScriptParser.cpp
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/ELF/ScriptParser.cpp?rev=299515&view=auto
==============================================================================
--- lld/trunk/ELF/ScriptParser.cpp (added)
+++ lld/trunk/ELF/ScriptParser.cpp Wed Apr 5 00:07:39 2017
@@ -0,0 +1,1184 @@
+//===- ScriptParser.cpp ---------------------------------------------------===//
+//
+// The LLVM Linker
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "ScriptParser.h"
+#include "Config.h"
+#include "Driver.h"
+#include "InputSection.h"
+#include "LinkerScript.h"
+#include "Memory.h"
+#include "OutputSections.h"
+#include "ScriptLexer.h"
+#include "Symbols.h"
+#include "Target.h"
+#include "llvm/ADT/SmallString.h"
+#include "llvm/ADT/StringRef.h"
+#include "llvm/ADT/StringSwitch.h"
+#include "llvm/Support/Casting.h"
+#include "llvm/Support/ELF.h"
+#include "llvm/Support/ErrorHandling.h"
+#include "llvm/Support/FileSystem.h"
+#include "llvm/Support/Path.h"
+#include <cassert>
+#include <limits>
+#include <vector>
+
+using namespace llvm;
+using namespace llvm::ELF;
+using namespace lld;
+using namespace lld::elf;
+
+static bool isUnderSysroot(StringRef Path);
+
+class elf::ScriptParser final : ScriptLexer {
+public:
+ ScriptParser(MemoryBufferRef MB)
+ : ScriptLexer(MB),
+ IsUnderSysroot(isUnderSysroot(MB.getBufferIdentifier())) {}
+
+ void readLinkerScript();
+ void readVersionScript();
+ void readDynamicList();
+
+private:
+ void addFile(StringRef Path);
+
+ void readAsNeeded();
+ void readEntry();
+ void readExtern();
+ void readGroup();
+ void readInclude();
+ void readMemory();
+ void readOutput();
+ void readOutputArch();
+ void readOutputFormat();
+ void readPhdrs();
+ void readSearchDir();
+ void readSections();
+ void readVersion();
+ void readVersionScriptCommand();
+
+ SymbolAssignment *readAssignment(StringRef Name);
+ BytesDataCommand *readBytesDataCommand(StringRef Tok);
+ uint32_t readFill();
+ OutputSectionCommand *readOutputSectionDescription(StringRef OutSec);
+ uint32_t readOutputSectionFiller(StringRef Tok);
+ std::vector<StringRef> readOutputSectionPhdrs();
+ InputSectionDescription *readInputSectionDescription(StringRef Tok);
+ StringMatcher readFilePatterns();
+ std::vector<SectionPattern> readInputSectionsList();
+ InputSectionDescription *readInputSectionRules(StringRef FilePattern);
+ unsigned readPhdrType();
+ SortSectionPolicy readSortKind();
+ SymbolAssignment *readProvideHidden(bool Provide, bool Hidden);
+ SymbolAssignment *readProvideOrAssignment(StringRef Tok);
+ void readSort();
+ Expr readAssert();
+
+ uint64_t readMemoryAssignment(StringRef, StringRef, StringRef);
+ std::pair<uint32_t, uint32_t> readMemoryAttributes();
+
+ Expr readExpr();
+ Expr readExpr1(Expr Lhs, int MinPrec);
+ StringRef readParenLiteral();
+ Expr readPrimary();
+ Expr readTernary(Expr Cond);
+ Expr readParenExpr();
+
+ // For parsing version script.
+ std::vector<SymbolVersion> readVersionExtern();
+ void readAnonymousDeclaration();
+ void readVersionDeclaration(StringRef VerStr);
+
+ std::pair<std::vector<SymbolVersion>, std::vector<SymbolVersion>>
+ readSymbols();
+
+ bool IsUnderSysroot;
+};
+
+static bool isUnderSysroot(StringRef Path) {
+ if (Config->Sysroot == "")
+ return false;
+ for (; !Path.empty(); Path = sys::path::parent_path(Path))
+ if (sys::fs::equivalent(Config->Sysroot, Path))
+ return true;
+ return false;
+}
+
+// Some operations only support one non absolute value. Move the
+// absolute one to the right hand side for convenience.
+static void moveAbsRight(ExprValue &A, ExprValue &B) {
+ if (A.isAbsolute())
+ std::swap(A, B);
+ if (!B.isAbsolute())
+ error("At least one side of the expression must be absolute");
+}
+
+static ExprValue add(ExprValue A, ExprValue B) {
+ moveAbsRight(A, B);
+ return {A.Sec, A.ForceAbsolute, A.Val + B.getValue()};
+}
+
+static ExprValue sub(ExprValue A, ExprValue B) {
+ return {A.Sec, A.Val - B.getValue()};
+}
+
+static ExprValue mul(ExprValue A, ExprValue B) {
+ return A.getValue() * B.getValue();
+}
+
+static ExprValue div(ExprValue A, ExprValue B) {
+ if (uint64_t BV = B.getValue())
+ return A.getValue() / BV;
+ error("division by zero");
+ return 0;
+}
+
+static ExprValue leftShift(ExprValue A, ExprValue B) {
+ return A.getValue() << B.getValue();
+}
+
+static ExprValue rightShift(ExprValue A, ExprValue B) {
+ return A.getValue() >> B.getValue();
+}
+
+static ExprValue bitAnd(ExprValue A, ExprValue B) {
+ moveAbsRight(A, B);
+ return {A.Sec, A.ForceAbsolute,
+ (A.getValue() & B.getValue()) - A.getSecAddr()};
+}
+
+static ExprValue bitOr(ExprValue A, ExprValue B) {
+ moveAbsRight(A, B);
+ return {A.Sec, A.ForceAbsolute,
+ (A.getValue() | B.getValue()) - A.getSecAddr()};
+}
+
+static ExprValue bitNot(ExprValue A) { return ~A.getValue(); }
+static ExprValue minus(ExprValue A) { return -A.getValue(); }
+
+void ScriptParser::readDynamicList() {
+ expect("{");
+ readAnonymousDeclaration();
+ if (!atEOF())
+ setError("EOF expected, but got " + next());
+}
+
+void ScriptParser::readVersionScript() {
+ readVersionScriptCommand();
+ if (!atEOF())
+ setError("EOF expected, but got " + next());
+}
+
+void ScriptParser::readVersionScriptCommand() {
+ if (consume("{")) {
+ readAnonymousDeclaration();
+ return;
+ }
+
+ while (!atEOF() && !Error && peek() != "}") {
+ StringRef VerStr = next();
+ if (VerStr == "{") {
+ setError("anonymous version definition is used in "
+ "combination with other version definitions");
+ return;
+ }
+ expect("{");
+ readVersionDeclaration(VerStr);
+ }
+}
+
+void ScriptParser::readVersion() {
+ expect("{");
+ readVersionScriptCommand();
+ expect("}");
+}
+
+void ScriptParser::readLinkerScript() {
+ while (!atEOF()) {
+ StringRef Tok = next();
+ if (Tok == ";")
+ continue;
+
+ if (Tok == "ASSERT") {
+ Script->Opt.Commands.push_back(make<AssertCommand>(readAssert()));
+ } else if (Tok == "ENTRY") {
+ readEntry();
+ } else if (Tok == "EXTERN") {
+ readExtern();
+ } else if (Tok == "GROUP" || Tok == "INPUT") {
+ readGroup();
+ } else if (Tok == "INCLUDE") {
+ readInclude();
+ } else if (Tok == "MEMORY") {
+ readMemory();
+ } else if (Tok == "OUTPUT") {
+ readOutput();
+ } else if (Tok == "OUTPUT_ARCH") {
+ readOutputArch();
+ } else if (Tok == "OUTPUT_FORMAT") {
+ readOutputFormat();
+ } else if (Tok == "PHDRS") {
+ readPhdrs();
+ } else if (Tok == "SEARCH_DIR") {
+ readSearchDir();
+ } else if (Tok == "SECTIONS") {
+ readSections();
+ } else if (Tok == "VERSION") {
+ readVersion();
+ } else if (SymbolAssignment *Cmd = readProvideOrAssignment(Tok)) {
+ Script->Opt.Commands.push_back(Cmd);
+ } else {
+ setError("unknown directive: " + Tok);
+ }
+ }
+}
+
+void ScriptParser::addFile(StringRef S) {
+ if (IsUnderSysroot && S.startswith("/")) {
+ SmallString<128> PathData;
+ StringRef Path = (Config->Sysroot + S).toStringRef(PathData);
+ if (sys::fs::exists(Path)) {
+ Driver->addFile(Saver.save(Path));
+ return;
+ }
+ }
+
+ if (sys::path::is_absolute(S)) {
+ Driver->addFile(S);
+ } else if (S.startswith("=")) {
+ if (Config->Sysroot.empty())
+ Driver->addFile(S.substr(1));
+ else
+ Driver->addFile(Saver.save(Config->Sysroot + "/" + S.substr(1)));
+ } else if (S.startswith("-l")) {
+ Driver->addLibrary(S.substr(2));
+ } else if (sys::fs::exists(S)) {
+ Driver->addFile(S);
+ } else {
+ if (Optional<std::string> Path = findFromSearchPaths(S))
+ Driver->addFile(Saver.save(*Path));
+ else
+ setError("unable to find " + S);
+ }
+}
+
+void ScriptParser::readAsNeeded() {
+ expect("(");
+ bool Orig = Config->AsNeeded;
+ Config->AsNeeded = true;
+ while (!Error && !consume(")"))
+ addFile(unquote(next()));
+ Config->AsNeeded = Orig;
+}
+
+void ScriptParser::readEntry() {
+ // -e <symbol> takes predecence over ENTRY(<symbol>).
+ expect("(");
+ StringRef Tok = next();
+ if (Config->Entry.empty())
+ Config->Entry = Tok;
+ expect(")");
+}
+
+void ScriptParser::readExtern() {
+ expect("(");
+ while (!Error && !consume(")"))
+ Config->Undefined.push_back(next());
+}
+
+void ScriptParser::readGroup() {
+ expect("(");
+ while (!Error && !consume(")")) {
+ StringRef Tok = next();
+ if (Tok == "AS_NEEDED")
+ readAsNeeded();
+ else
+ addFile(unquote(Tok));
+ }
+}
+
+void ScriptParser::readInclude() {
+ StringRef Tok = unquote(next());
+
+ // https://sourceware.org/binutils/docs/ld/File-Commands.html:
+ // The file will be searched for in the current directory, and in any
+ // directory specified with the -L option.
+ if (sys::fs::exists(Tok)) {
+ if (Optional<MemoryBufferRef> MB = readFile(Tok))
+ tokenize(*MB);
+ return;
+ }
+ if (Optional<std::string> Path = findFromSearchPaths(Tok)) {
+ if (Optional<MemoryBufferRef> MB = readFile(*Path))
+ tokenize(*MB);
+ return;
+ }
+ setError("cannot open " + Tok);
+}
+
+void ScriptParser::readOutput() {
+ // -o <file> takes predecence over OUTPUT(<file>).
+ expect("(");
+ StringRef Tok = next();
+ if (Config->OutputFile.empty())
+ Config->OutputFile = unquote(Tok);
+ expect(")");
+}
+
+void ScriptParser::readOutputArch() {
+ // OUTPUT_ARCH is ignored for now.
+ expect("(");
+ while (!Error && !consume(")"))
+ skip();
+}
+
+void ScriptParser::readOutputFormat() {
+ // Error checking only for now.
+ expect("(");
+ skip();
+ StringRef Tok = next();
+ if (Tok == ")")
+ return;
+ if (Tok != ",") {
+ setError("unexpected token: " + Tok);
+ return;
+ }
+ skip();
+ expect(",");
+ skip();
+ expect(")");
+}
+
+void ScriptParser::readPhdrs() {
+ expect("{");
+ while (!Error && !consume("}")) {
+ StringRef Tok = next();
+ Script->Opt.PhdrsCommands.push_back(
+ {Tok, PT_NULL, false, false, UINT_MAX, nullptr});
+ PhdrsCommand &PhdrCmd = Script->Opt.PhdrsCommands.back();
+
+ PhdrCmd.Type = readPhdrType();
+ do {
+ Tok = next();
+ if (Tok == ";")
+ break;
+ if (Tok == "FILEHDR")
+ PhdrCmd.HasFilehdr = true;
+ else if (Tok == "PHDRS")
+ PhdrCmd.HasPhdrs = true;
+ else if (Tok == "AT")
+ PhdrCmd.LMAExpr = readParenExpr();
+ else if (Tok == "FLAGS") {
+ expect("(");
+ // Passing 0 for the value of dot is a bit of a hack. It means that
+ // we accept expressions like ".|1".
+ PhdrCmd.Flags = readExpr()().getValue();
+ expect(")");
+ } else
+ setError("unexpected header attribute: " + Tok);
+ } while (!Error);
+ }
+}
+
+void ScriptParser::readSearchDir() {
+ expect("(");
+ StringRef Tok = next();
+ if (!Config->Nostdlib)
+ Config->SearchPaths.push_back(unquote(Tok));
+ expect(")");
+}
+
+void ScriptParser::readSections() {
+ Script->Opt.HasSections = true;
+ // -no-rosegment is used to avoid placing read only non-executable sections in
+ // their own segment. We do the same if SECTIONS command is present in linker
+ // script. See comment for computeFlags().
+ Config->SingleRoRx = true;
+
+ expect("{");
+ while (!Error && !consume("}")) {
+ StringRef Tok = next();
+ BaseCommand *Cmd = readProvideOrAssignment(Tok);
+ if (!Cmd) {
+ if (Tok == "ASSERT")
+ Cmd = make<AssertCommand>(readAssert());
+ else
+ Cmd = readOutputSectionDescription(Tok);
+ }
+ Script->Opt.Commands.push_back(Cmd);
+ }
+}
+
+static int precedence(StringRef Op) {
+ return StringSwitch<int>(Op)
+ .Cases("*", "/", 5)
+ .Cases("+", "-", 4)
+ .Cases("<<", ">>", 3)
+ .Cases("<", "<=", ">", ">=", "==", "!=", 2)
+ .Cases("&", "|", 1)
+ .Default(-1);
+}
+
+StringMatcher ScriptParser::readFilePatterns() {
+ std::vector<StringRef> V;
+ while (!Error && !consume(")"))
+ V.push_back(next());
+ return StringMatcher(V);
+}
+
+SortSectionPolicy ScriptParser::readSortKind() {
+ if (consume("SORT") || consume("SORT_BY_NAME"))
+ return SortSectionPolicy::Name;
+ if (consume("SORT_BY_ALIGNMENT"))
+ return SortSectionPolicy::Alignment;
+ if (consume("SORT_BY_INIT_PRIORITY"))
+ return SortSectionPolicy::Priority;
+ if (consume("SORT_NONE"))
+ return SortSectionPolicy::None;
+ return SortSectionPolicy::Default;
+}
+
+// Method reads a list of sequence of excluded files and section globs given in
+// a following form: ((EXCLUDE_FILE(file_pattern+))? section_pattern+)+
+// Example: *(.foo.1 EXCLUDE_FILE (*a.o) .foo.2 EXCLUDE_FILE (*b.o) .foo.3)
+// The semantics of that is next:
+// * Include .foo.1 from every file.
+// * Include .foo.2 from every file but a.o
+// * Include .foo.3 from every file but b.o
+std::vector<SectionPattern> ScriptParser::readInputSectionsList() {
+ std::vector<SectionPattern> Ret;
+ while (!Error && peek() != ")") {
+ StringMatcher ExcludeFilePat;
+ if (consume("EXCLUDE_FILE")) {
+ expect("(");
+ ExcludeFilePat = readFilePatterns();
+ }
+
+ std::vector<StringRef> V;
+ while (!Error && peek() != ")" && peek() != "EXCLUDE_FILE")
+ V.push_back(next());
+
+ if (!V.empty())
+ Ret.push_back({std::move(ExcludeFilePat), StringMatcher(V)});
+ else
+ setError("section pattern is expected");
+ }
+ return Ret;
+}
+
+// Reads contents of "SECTIONS" directive. That directive contains a
+// list of glob patterns for input sections. The grammar is as follows.
+//
+// <patterns> ::= <section-list>
+// | <sort> "(" <section-list> ")"
+// | <sort> "(" <sort> "(" <section-list> ")" ")"
+//
+// <sort> ::= "SORT" | "SORT_BY_NAME" | "SORT_BY_ALIGNMENT"
+// | "SORT_BY_INIT_PRIORITY" | "SORT_NONE"
+//
+// <section-list> is parsed by readInputSectionsList().
+InputSectionDescription *
+ScriptParser::readInputSectionRules(StringRef FilePattern) {
+ auto *Cmd = make<InputSectionDescription>(FilePattern);
+ expect("(");
+
+ while (!Error && !consume(")")) {
+ SortSectionPolicy Outer = readSortKind();
+ SortSectionPolicy Inner = SortSectionPolicy::Default;
+ std::vector<SectionPattern> V;
+ if (Outer != SortSectionPolicy::Default) {
+ expect("(");
+ Inner = readSortKind();
+ if (Inner != SortSectionPolicy::Default) {
+ expect("(");
+ V = readInputSectionsList();
+ expect(")");
+ } else {
+ V = readInputSectionsList();
+ }
+ expect(")");
+ } else {
+ V = readInputSectionsList();
+ }
+
+ for (SectionPattern &Pat : V) {
+ Pat.SortInner = Inner;
+ Pat.SortOuter = Outer;
+ }
+
+ std::move(V.begin(), V.end(), std::back_inserter(Cmd->SectionPatterns));
+ }
+ return Cmd;
+}
+
+InputSectionDescription *
+ScriptParser::readInputSectionDescription(StringRef Tok) {
+ // Input section wildcard can be surrounded by KEEP.
+ // https://sourceware.org/binutils/docs/ld/Input-Section-Keep.html#Input-Section-Keep
+ if (Tok == "KEEP") {
+ expect("(");
+ StringRef FilePattern = next();
+ InputSectionDescription *Cmd = readInputSectionRules(FilePattern);
+ expect(")");
+ Script->Opt.KeptSections.push_back(Cmd);
+ return Cmd;
+ }
+ return readInputSectionRules(Tok);
+}
+
+void ScriptParser::readSort() {
+ expect("(");
+ expect("CONSTRUCTORS");
+ expect(")");
+}
+
+Expr ScriptParser::readAssert() {
+ expect("(");
+ Expr E = readExpr();
+ expect(",");
+ StringRef Msg = unquote(next());
+ expect(")");
+ return [=] {
+ if (!E().getValue())
+ error(Msg);
+ return Script->getDot();
+ };
+}
+
+// Reads a FILL(expr) command. We handle the FILL command as an
+// alias for =fillexp section attribute, which is different from
+// what GNU linkers do.
+// https://sourceware.org/binutils/docs/ld/Output-Section-Data.html
+uint32_t ScriptParser::readFill() {
+ expect("(");
+ uint32_t V = readOutputSectionFiller(next());
+ expect(")");
+ expect(";");
+ return V;
+}
+
+OutputSectionCommand *
+ScriptParser::readOutputSectionDescription(StringRef OutSec) {
+ OutputSectionCommand *Cmd = make<OutputSectionCommand>(OutSec);
+ Cmd->Location = getCurrentLocation();
+
+ // Read an address expression.
+ // https://sourceware.org/binutils/docs/ld/Output-Section-Address.html#Output-Section-Address
+ if (peek() != ":")
+ Cmd->AddrExpr = readExpr();
+
+ expect(":");
+
+ if (consume("AT"))
+ Cmd->LMAExpr = readParenExpr();
+ if (consume("ALIGN"))
+ Cmd->AlignExpr = readParenExpr();
+ if (consume("SUBALIGN"))
+ Cmd->SubalignExpr = readParenExpr();
+
+ // Parse constraints.
+ if (consume("ONLY_IF_RO"))
+ Cmd->Constraint = ConstraintKind::ReadOnly;
+ if (consume("ONLY_IF_RW"))
+ Cmd->Constraint = ConstraintKind::ReadWrite;
+ expect("{");
+
+ while (!Error && !consume("}")) {
+ StringRef Tok = next();
+ if (Tok == ";") {
+ // Empty commands are allowed. Do nothing here.
+ } else if (SymbolAssignment *Assignment = readProvideOrAssignment(Tok)) {
+ Cmd->Commands.push_back(Assignment);
+ } else if (BytesDataCommand *Data = readBytesDataCommand(Tok)) {
+ Cmd->Commands.push_back(Data);
+ } else if (Tok == "ASSERT") {
+ Cmd->Commands.push_back(make<AssertCommand>(readAssert()));
+ expect(";");
+ } else if (Tok == "CONSTRUCTORS") {
+ // CONSTRUCTORS is a keyword to make the linker recognize C++ ctors/dtors
+ // by name. This is for very old file formats such as ECOFF/XCOFF.
+ // For ELF, we should ignore.
+ } else if (Tok == "FILL") {
+ Cmd->Filler = readFill();
+ } else if (Tok == "SORT") {
+ readSort();
+ } else if (peek() == "(") {
+ Cmd->Commands.push_back(readInputSectionDescription(Tok));
+ } else {
+ setError("unknown command " + Tok);
+ }
+ }
+
+ if (consume(">"))
+ Cmd->MemoryRegionName = next();
+
+ Cmd->Phdrs = readOutputSectionPhdrs();
+
+ if (consume("="))
+ Cmd->Filler = readOutputSectionFiller(next());
+ else if (peek().startswith("="))
+ Cmd->Filler = readOutputSectionFiller(next().drop_front());
+
+ // Consume optional comma following output section command.
+ consume(",");
+
+ return Cmd;
+}
+
+// Read "=<number>" where <number> is an octal/decimal/hexadecimal number.
+// https://sourceware.org/binutils/docs/ld/Output-Section-Fill.html
+//
+// ld.gold is not fully compatible with ld.bfd. ld.bfd handles
+// hexstrings as blobs of arbitrary sizes, while ld.gold handles them
+// as 32-bit big-endian values. We will do the same as ld.gold does
+// because it's simpler than what ld.bfd does.
+uint32_t ScriptParser::readOutputSectionFiller(StringRef Tok) {
+ uint32_t V;
+ if (!Tok.getAsInteger(0, V))
+ return V;
+ setError("invalid filler expression: " + Tok);
+ return 0;
+}
+
+SymbolAssignment *ScriptParser::readProvideHidden(bool Provide, bool Hidden) {
+ expect("(");
+ SymbolAssignment *Cmd = readAssignment(next());
+ Cmd->Provide = Provide;
+ Cmd->Hidden = Hidden;
+ expect(")");
+ expect(";");
+ return Cmd;
+}
+
+SymbolAssignment *ScriptParser::readProvideOrAssignment(StringRef Tok) {
+ SymbolAssignment *Cmd = nullptr;
+ if (peek() == "=" || peek() == "+=") {
+ Cmd = readAssignment(Tok);
+ expect(";");
+ } else if (Tok == "PROVIDE") {
+ Cmd = readProvideHidden(true, false);
+ } else if (Tok == "HIDDEN") {
+ Cmd = readProvideHidden(false, true);
+ } else if (Tok == "PROVIDE_HIDDEN") {
+ Cmd = readProvideHidden(true, true);
+ }
+ return Cmd;
+}
+
+SymbolAssignment *ScriptParser::readAssignment(StringRef Name) {
+ StringRef Op = next();
+ assert(Op == "=" || Op == "+=");
+ Expr E = readExpr();
+ if (Op == "+=") {
+ std::string Loc = getCurrentLocation();
+ E = [=] { return add(Script->getSymbolValue(Loc, Name), E()); };
+ }
+ return make<SymbolAssignment>(Name, E, getCurrentLocation());
+}
+
+// This is an operator-precedence parser to parse a linker
+// script expression.
+Expr ScriptParser::readExpr() {
+ // Our lexer is context-aware. Set the in-expression bit so that
+ // they apply different tokenization rules.
+ bool Orig = InExpr;
+ InExpr = true;
+ Expr E = readExpr1(readPrimary(), 0);
+ InExpr = Orig;
+ return E;
+}
+
+static Expr combine(StringRef Op, Expr L, Expr R) {
+ if (Op == "*")
+ return [=] { return mul(L(), R()); };
+ if (Op == "/") {
+ return [=] { return div(L(), R()); };
+ }
+ if (Op == "+")
+ return [=] { return add(L(), R()); };
+ if (Op == "-")
+ return [=] { return sub(L(), R()); };
+ if (Op == "<<")
+ return [=] { return leftShift(L(), R()); };
+ if (Op == ">>")
+ return [=] { return rightShift(L(), R()); };
+ if (Op == "<")
+ return [=] { return L().getValue() < R().getValue(); };
+ if (Op == ">")
+ return [=] { return L().getValue() > R().getValue(); };
+ if (Op == ">=")
+ return [=] { return L().getValue() >= R().getValue(); };
+ if (Op == "<=")
+ return [=] { return L().getValue() <= R().getValue(); };
+ if (Op == "==")
+ return [=] { return L().getValue() == R().getValue(); };
+ if (Op == "!=")
+ return [=] { return L().getValue() != R().getValue(); };
+ if (Op == "&")
+ return [=] { return bitAnd(L(), R()); };
+ if (Op == "|")
+ return [=] { return bitOr(L(), R()); };
+ llvm_unreachable("invalid operator");
+}
+
+// This is a part of the operator-precedence parser. This function
+// assumes that the remaining token stream starts with an operator.
+Expr ScriptParser::readExpr1(Expr Lhs, int MinPrec) {
+ while (!atEOF() && !Error) {
+ // Read an operator and an expression.
+ if (consume("?"))
+ return readTernary(Lhs);
+ StringRef Op1 = peek();
+ if (precedence(Op1) < MinPrec)
+ break;
+ skip();
+ Expr Rhs = readPrimary();
+
+ // Evaluate the remaining part of the expression first if the
+ // next operator has greater precedence than the previous one.
+ // For example, if we have read "+" and "3", and if the next
+ // operator is "*", then we'll evaluate 3 * ... part first.
+ while (!atEOF()) {
+ StringRef Op2 = peek();
+ if (precedence(Op2) <= precedence(Op1))
+ break;
+ Rhs = readExpr1(Rhs, precedence(Op2));
+ }
+
+ Lhs = combine(Op1, Lhs, Rhs);
+ }
+ return Lhs;
+}
+
+uint64_t static getConstant(StringRef S) {
+ if (S == "COMMONPAGESIZE")
+ return Target->PageSize;
+ if (S == "MAXPAGESIZE")
+ return Config->MaxPageSize;
+ error("unknown constant: " + S);
+ return 0;
+}
+
+// Parses Tok as an integer. Returns true if successful.
+// It recognizes hexadecimal (prefixed with "0x" or suffixed with "H")
+// and decimal numbers. Decimal numbers may have "K" (kilo) or
+// "M" (mega) prefixes.
+static bool readInteger(StringRef Tok, uint64_t &Result) {
+ // Negative number
+ if (Tok.startswith("-")) {
+ if (!readInteger(Tok.substr(1), Result))
+ return false;
+ Result = -Result;
+ return true;
+ }
+
+ // Hexadecimal
+ if (Tok.startswith_lower("0x"))
+ return !Tok.substr(2).getAsInteger(16, Result);
+ if (Tok.endswith_lower("H"))
+ return !Tok.drop_back().getAsInteger(16, Result);
+
+ // Decimal
+ int Suffix = 1;
+ if (Tok.endswith_lower("K")) {
+ Suffix = 1024;
+ Tok = Tok.drop_back();
+ } else if (Tok.endswith_lower("M")) {
+ Suffix = 1024 * 1024;
+ Tok = Tok.drop_back();
+ }
+ if (Tok.getAsInteger(10, Result))
+ return false;
+ Result *= Suffix;
+ return true;
+}
+
+BytesDataCommand *ScriptParser::readBytesDataCommand(StringRef Tok) {
+ int Size = StringSwitch<unsigned>(Tok)
+ .Case("BYTE", 1)
+ .Case("SHORT", 2)
+ .Case("LONG", 4)
+ .Case("QUAD", 8)
+ .Default(-1);
+ if (Size == -1)
+ return nullptr;
+
+ return make<BytesDataCommand>(readParenExpr(), Size);
+}
+
+StringRef ScriptParser::readParenLiteral() {
+ expect("(");
+ StringRef Tok = next();
+ expect(")");
+ return Tok;
+}
+
+Expr ScriptParser::readPrimary() {
+ if (peek() == "(")
+ return readParenExpr();
+
+ StringRef Tok = next();
+ std::string Location = getCurrentLocation();
+
+ if (Tok == "~") {
+ Expr E = readPrimary();
+ return [=] { return bitNot(E()); };
+ }
+ if (Tok == "-") {
+ Expr E = readPrimary();
+ return [=] { return minus(E()); };
+ }
+
+ // Built-in functions are parsed here.
+ // https://sourceware.org/binutils/docs/ld/Builtin-Functions.html.
+ if (Tok == "ABSOLUTE") {
+ Expr Inner = readParenExpr();
+ return [=] {
+ ExprValue I = Inner();
+ I.ForceAbsolute = true;
+ return I;
+ };
+ }
+ if (Tok == "ADDR") {
+ StringRef Name = readParenLiteral();
+ return [=]() -> ExprValue {
+ return {Script->getOutputSection(Location, Name), 0};
+ };
+ }
+ if (Tok == "ALIGN") {
+ expect("(");
+ Expr E = readExpr();
+ if (consume(",")) {
+ Expr E2 = readExpr();
+ expect(")");
+ return [=] { return alignTo(E().getValue(), E2().getValue()); };
+ }
+ expect(")");
+ return [=] { return alignTo(Script->getDot(), E().getValue()); };
+ }
+ if (Tok == "ALIGNOF") {
+ StringRef Name = readParenLiteral();
+ return [=] { return Script->getOutputSection(Location, Name)->Alignment; };
+ }
+ if (Tok == "ASSERT")
+ return readAssert();
+ if (Tok == "CONSTANT") {
+ StringRef Name = readParenLiteral();
+ return [=] { return getConstant(Name); };
+ }
+ if (Tok == "DATA_SEGMENT_ALIGN") {
+ expect("(");
+ Expr E = readExpr();
+ expect(",");
+ readExpr();
+ expect(")");
+ return [=] { return alignTo(Script->getDot(), E().getValue()); };
+ }
+ if (Tok == "DATA_SEGMENT_END") {
+ expect("(");
+ expect(".");
+ expect(")");
+ return [] { return Script->getDot(); };
+ }
+ if (Tok == "DATA_SEGMENT_RELRO_END") {
+ // GNU linkers implements more complicated logic to handle
+ // DATA_SEGMENT_RELRO_END. We instead ignore the arguments and
+ // just align to the next page boundary for simplicity.
+ expect("(");
+ readExpr();
+ expect(",");
+ readExpr();
+ expect(")");
+ return [] { return alignTo(Script->getDot(), Target->PageSize); };
+ }
+ if (Tok == "DEFINED") {
+ StringRef Name = readParenLiteral();
+ return [=] { return Script->isDefined(Name) ? 1 : 0; };
+ }
+ if (Tok == "LOADADDR") {
+ StringRef Name = readParenLiteral();
+ return [=] { return Script->getOutputSection(Location, Name)->getLMA(); };
+ }
+ if (Tok == "SEGMENT_START") {
+ expect("(");
+ skip();
+ expect(",");
+ Expr E = readExpr();
+ expect(")");
+ return [=] { return E(); };
+ }
+ if (Tok == "SIZEOF") {
+ StringRef Name = readParenLiteral();
+ return [=] { return Script->getOutputSectionSize(Name); };
+ }
+ if (Tok == "SIZEOF_HEADERS")
+ return [=] { return elf::getHeaderSize(); };
+
+ // Tok is a literal number.
+ uint64_t V;
+ if (readInteger(Tok, V))
+ return [=] { return V; };
+
+ // Tok is a symbol name.
+ if (Tok != ".") {
+ if (!isValidCIdentifier(Tok))
+ setError("malformed number: " + Tok);
+ Script->Opt.UndefinedSymbols.push_back(Tok);
+ }
+ return [=] { return Script->getSymbolValue(Location, Tok); };
+}
+
+Expr ScriptParser::readTernary(Expr Cond) {
+ Expr L = readExpr();
+ expect(":");
+ Expr R = readExpr();
+ return [=] { return Cond().getValue() ? L() : R(); };
+}
+
+Expr ScriptParser::readParenExpr() {
+ expect("(");
+ Expr E = readExpr();
+ expect(")");
+ return E;
+}
+
+std::vector<StringRef> ScriptParser::readOutputSectionPhdrs() {
+ std::vector<StringRef> Phdrs;
+ while (!Error && peek().startswith(":")) {
+ StringRef Tok = next();
+ Phdrs.push_back((Tok.size() == 1) ? next() : Tok.substr(1));
+ }
+ return Phdrs;
+}
+
+// Read a program header type name. The next token must be a
+// name of a program header type or a constant (e.g. "0x3").
+unsigned ScriptParser::readPhdrType() {
+ StringRef Tok = next();
+ uint64_t Val;
+ if (readInteger(Tok, Val))
+ return Val;
+
+ unsigned Ret = StringSwitch<unsigned>(Tok)
+ .Case("PT_NULL", PT_NULL)
+ .Case("PT_LOAD", PT_LOAD)
+ .Case("PT_DYNAMIC", PT_DYNAMIC)
+ .Case("PT_INTERP", PT_INTERP)
+ .Case("PT_NOTE", PT_NOTE)
+ .Case("PT_SHLIB", PT_SHLIB)
+ .Case("PT_PHDR", PT_PHDR)
+ .Case("PT_TLS", PT_TLS)
+ .Case("PT_GNU_EH_FRAME", PT_GNU_EH_FRAME)
+ .Case("PT_GNU_STACK", PT_GNU_STACK)
+ .Case("PT_GNU_RELRO", PT_GNU_RELRO)
+ .Case("PT_OPENBSD_RANDOMIZE", PT_OPENBSD_RANDOMIZE)
+ .Case("PT_OPENBSD_WXNEEDED", PT_OPENBSD_WXNEEDED)
+ .Case("PT_OPENBSD_BOOTDATA", PT_OPENBSD_BOOTDATA)
+ .Default(-1);
+
+ if (Ret == (unsigned)-1) {
+ setError("invalid program header type: " + Tok);
+ return PT_NULL;
+ }
+ return Ret;
+}
+
+// Reads an anonymous version declaration.
+void ScriptParser::readAnonymousDeclaration() {
+ std::vector<SymbolVersion> Locals;
+ std::vector<SymbolVersion> Globals;
+ std::tie(Locals, Globals) = readSymbols();
+
+ for (SymbolVersion V : Locals) {
+ if (V.Name == "*")
+ Config->DefaultSymbolVersion = VER_NDX_LOCAL;
+ else
+ Config->VersionScriptLocals.push_back(V);
+ }
+
+ for (SymbolVersion V : Globals)
+ Config->VersionScriptGlobals.push_back(V);
+
+ expect(";");
+}
+
+// Reads a non-anonymous version definition,
+// e.g. "VerStr { global: foo; bar; local: *; };".
+void ScriptParser::readVersionDeclaration(StringRef VerStr) {
+ // Read a symbol list.
+ std::vector<SymbolVersion> Locals;
+ std::vector<SymbolVersion> Globals;
+ std::tie(Locals, Globals) = readSymbols();
+
+ for (SymbolVersion V : Locals) {
+ if (V.Name == "*")
+ Config->DefaultSymbolVersion = VER_NDX_LOCAL;
+ else
+ Config->VersionScriptLocals.push_back(V);
+ }
+
+ // Create a new version definition and add that to the global symbols.
+ VersionDefinition Ver;
+ Ver.Name = VerStr;
+ Ver.Globals = Globals;
+
+ // User-defined version number starts from 2 because 0 and 1 are
+ // reserved for VER_NDX_LOCAL and VER_NDX_GLOBAL, respectively.
+ Ver.Id = Config->VersionDefinitions.size() + 2;
+ Config->VersionDefinitions.push_back(Ver);
+
+ // Each version may have a parent version. For example, "Ver2"
+ // defined as "Ver2 { global: foo; local: *; } Ver1;" has "Ver1"
+ // as a parent. This version hierarchy is, probably against your
+ // instinct, purely for hint; the runtime doesn't care about it
+ // at all. In LLD, we simply ignore it.
+ if (peek() != ";")
+ skip();
+ expect(";");
+}
+
+// Reads a list of symbols, e.g. "{ global: foo; bar; local: *; };".
+std::pair<std::vector<SymbolVersion>, std::vector<SymbolVersion>>
+ScriptParser::readSymbols() {
+ std::vector<SymbolVersion> Locals;
+ std::vector<SymbolVersion> Globals;
+ std::vector<SymbolVersion> *V = &Globals;
+
+ while (!Error) {
+ if (consume("}"))
+ break;
+ if (consumeLabel("local")) {
+ V = &Locals;
+ continue;
+ }
+ if (consumeLabel("global")) {
+ V = &Globals;
+ continue;
+ }
+
+ if (consume("extern")) {
+ std::vector<SymbolVersion> Ext = readVersionExtern();
+ V->insert(V->end(), Ext.begin(), Ext.end());
+ } else {
+ StringRef Tok = next();
+ V->push_back({unquote(Tok), false, hasWildcard(Tok)});
+ }
+ expect(";");
+ }
+ return {Locals, Globals};
+}
+
+// Reads an "extern C++" directive, e.g.,
+// "extern "C++" { ns::*; "f(int, double)"; };"
+std::vector<SymbolVersion> ScriptParser::readVersionExtern() {
+ StringRef Tok = next();
+ bool IsCXX = Tok == "\"C++\"";
+ if (!IsCXX && Tok != "\"C\"")
+ setError("Unknown language");
+ expect("{");
+
+ std::vector<SymbolVersion> Ret;
+ while (!Error && peek() != "}") {
+ StringRef Tok = next();
+ bool HasWildcard = !Tok.startswith("\"") && hasWildcard(Tok);
+ Ret.push_back({unquote(Tok), IsCXX, HasWildcard});
+ expect(";");
+ }
+
+ expect("}");
+ return Ret;
+}
+
+uint64_t ScriptParser::readMemoryAssignment(StringRef S1, StringRef S2,
+ StringRef S3) {
+ if (!(consume(S1) || consume(S2) || consume(S3))) {
+ setError("expected one of: " + S1 + ", " + S2 + ", or " + S3);
+ return 0;
+ }
+ expect("=");
+
+ // TODO: Fully support constant expressions.
+ uint64_t Val;
+ if (!readInteger(next(), Val))
+ setError("nonconstant expression for " + S1);
+ return Val;
+}
+
+// Parse the MEMORY command as specified in:
+// https://sourceware.org/binutils/docs/ld/MEMORY.html
+//
+// MEMORY { name [(attr)] : ORIGIN = origin, LENGTH = len ... }
+void ScriptParser::readMemory() {
+ expect("{");
+ while (!Error && !consume("}")) {
+ StringRef Name = next();
+
+ uint32_t Flags = 0;
+ uint32_t NegFlags = 0;
+ if (consume("(")) {
+ std::tie(Flags, NegFlags) = readMemoryAttributes();
+ expect(")");
+ }
+ expect(":");
+
+ uint64_t Origin = readMemoryAssignment("ORIGIN", "org", "o");
+ expect(",");
+ uint64_t Length = readMemoryAssignment("LENGTH", "len", "l");
+
+ // Add the memory region to the region map (if it doesn't already exist).
+ auto It = Script->Opt.MemoryRegions.find(Name);
+ if (It != Script->Opt.MemoryRegions.end())
+ setError("region '" + Name + "' already defined");
+ else
+ Script->Opt.MemoryRegions[Name] = {Name, Origin, Length,
+ Origin, Flags, NegFlags};
+ }
+}
+
+// This function parses the attributes used to match against section
+// flags when placing output sections in a memory region. These flags
+// are only used when an explicit memory region name is not used.
+std::pair<uint32_t, uint32_t> ScriptParser::readMemoryAttributes() {
+ uint32_t Flags = 0;
+ uint32_t NegFlags = 0;
+ bool Invert = false;
+
+ for (char C : next().lower()) {
+ uint32_t Flag = 0;
+ if (C == '!')
+ Invert = !Invert;
+ else if (C == 'w')
+ Flag = SHF_WRITE;
+ else if (C == 'x')
+ Flag = SHF_EXECINSTR;
+ else if (C == 'a')
+ Flag = SHF_ALLOC;
+ else if (C != 'r')
+ setError("invalid memory region attribute");
+
+ if (Invert)
+ NegFlags |= Flag;
+ else
+ Flags |= Flag;
+ }
+ return {Flags, NegFlags};
+}
+
+void elf::readLinkerScript(MemoryBufferRef MB) {
+ ScriptParser(MB).readLinkerScript();
+}
+
+void elf::readVersionScript(MemoryBufferRef MB) {
+ ScriptParser(MB).readVersionScript();
+}
+
+void elf::readDynamicList(MemoryBufferRef MB) {
+ ScriptParser(MB).readDynamicList();
+}
Added: lld/trunk/ELF/ScriptParser.h
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/ELF/ScriptParser.h?rev=299515&view=auto
==============================================================================
--- lld/trunk/ELF/ScriptParser.h (added)
+++ lld/trunk/ELF/ScriptParser.h Wed Apr 5 00:07:39 2017
@@ -0,0 +1,31 @@
+//===- ScriptParser.h -------------------------------------------*- C++ -*-===//
+//
+// The LLVM Linker
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLD_ELF_SCRIPT_PARSER_H
+#define LLD_ELF_SCRIPT_PARSER_H
+
+#include "lld/Core/LLVM.h"
+#include "llvm/Support/MemoryBuffer.h"
+
+namespace lld {
+namespace elf {
+
+// Parses a linker script. Calling this function updates
+// Config and ScriptConfig.
+void readLinkerScript(MemoryBufferRef MB);
+
+// Parses a version script.
+void readVersionScript(MemoryBufferRef MB);
+
+void readDynamicList(MemoryBufferRef MB);
+
+} // namespace elf
+} // namespace lld
+
+#endif
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