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.

llvm-svn: 299515

1 files changed, 0 insertions, 1155 deletions

diff --git a/lld/ELF/LinkerScript.cpp b/lld/ELF/LinkerScript.cpp
index 1224f45958d..230a69d73fb 100644
--- a/lld/ELF/LinkerScript.cpp
+++ b/lld/ELF/LinkerScript.cpp
@@ -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 *addRegular(SymbolAssignment *Cmd) {
   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 Twine &Loc, StringRef PhdrName) {
   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();
-}