COFF: migrate def parser from LLD to LLVM [1/2]

This is split up into two commits.
The will create the DEF parser in LLVM.
Check the following commit to see the removal from LLD

Reviewers: ruiu

Differential Revision: https://reviews.llvm.org/D32689

llvm-svn: 303490

1 files changed, 319 insertions, 0 deletions

diff --git a/llvm/lib/Object/COFFModuleDefinition.cpp b/llvm/lib/Object/COFFModuleDefinition.cpp
new file mode 100644
index 00000000000..5af12a807d3
--- /dev/null
+++ b/llvm/lib/Object/COFFModuleDefinition.cpp
@@ -0,0 +1,319 @@
+//===--- COFFModuleDefinition.cpp - Simple DEF parser ---------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// Windows-specific.
+// A parser for the module-definition file (.def file).
+//
+// The format of module-definition files are described in this document:
+// https://msdn.microsoft.com/en-us/library/28d6s79h.aspx
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/Object/COFFModuleDefinition.h"
+#include "llvm/ADT/StringRef.h"
+#include "llvm/ADT/StringSwitch.h"
+#include "llvm/Object/COFF.h"
+#include "llvm/Object/COFFImportFile.h"
+#include "llvm/Object/Error.h"
+#include "llvm/Support/Error.h"
+#include "llvm/Support/raw_ostream.h"
+
+using namespace llvm::COFF;
+using namespace llvm;
+
+namespace llvm {
+namespace object {
+
+enum Kind {
+  Unknown,
+  Eof,
+  Identifier,
+  Comma,
+  Equal,
+  KwBase,
+  KwConstant,
+  KwData,
+  KwExports,
+  KwHeapsize,
+  KwLibrary,
+  KwName,
+  KwNoname,
+  KwPrivate,
+  KwStacksize,
+  KwVersion,
+};
+
+struct Token {
+  explicit Token(Kind T = Unknown, StringRef S = "") : K(T), Value(S) {}
+  Kind K;
+  StringRef Value;
+};
+
+static bool isDecorated(StringRef Sym) {
+  return Sym.startswith("_") || Sym.startswith("@") || Sym.startswith("?");
+}
+
+static Error createError(const Twine &Err) {
+  return make_error<StringError>(Err.getSingleStringRef(),
+                                 object_error::parse_failed);
+}
+
+class Lexer {
+public:
+  Lexer(StringRef S) : Buf(S) {}
+
+  Token lex() {
+    Buf = Buf.trim();
+    if (Buf.empty())
+      return Token(Eof);
+
+    switch (Buf[0]) {
+    case '\0':
+      return Token(Eof);
+    case ';': {
+      size_t End = Buf.find('\n');
+      Buf = (End == Buf.npos) ? "" : Buf.drop_front(End);
+      return lex();
+    }
+    case '=':
+      Buf = Buf.drop_front();
+      return Token(Equal, "=");
+    case ',':
+      Buf = Buf.drop_front();
+      return Token(Comma, ",");
+    case '"': {
+      StringRef S;
+      std::tie(S, Buf) = Buf.substr(1).split('"');
+      return Token(Identifier, S);
+    }
+    default: {
+      size_t End = Buf.find_first_of("=,\r\n \t\v");
+      StringRef Word = Buf.substr(0, End);
+      Kind K = llvm::StringSwitch<Kind>(Word)
+                   .Case("BASE", KwBase)
+                   .Case("CONSTANT", KwConstant)
+                   .Case("DATA", KwData)
+                   .Case("EXPORTS", KwExports)
+                   .Case("HEAPSIZE", KwHeapsize)
+                   .Case("LIBRARY", KwLibrary)
+                   .Case("NAME", KwName)
+                   .Case("NONAME", KwNoname)
+                   .Case("PRIVATE", KwPrivate)
+                   .Case("STACKSIZE", KwStacksize)
+                   .Case("VERSION", KwVersion)
+                   .Default(Identifier);
+      Buf = (End == Buf.npos) ? "" : Buf.drop_front(End);
+      return Token(K, Word);
+    }
+    }
+  }
+
+private:
+  StringRef Buf;
+};
+
+class Parser {
+public:
+  explicit Parser(StringRef S, MachineTypes M) : Lex(S), Machine(M) {}
+
+  Expected<COFFModuleDefinition> parse() {
+    do {
+      if (Error Err = parseOne())
+        return std::move(Err);
+    } while (Tok.K != Eof);
+    return Info;
+  }
+
+private:
+  void read() {
+    if (Stack.empty()) {
+      Tok = Lex.lex();
+      return;
+    }
+    Tok = Stack.back();
+    Stack.pop_back();
+  }
+
+  Error readAsInt(uint64_t *I) {
+    read();
+    if (Tok.K != Identifier || Tok.Value.getAsInteger(10, *I))
+      return createError("integer expected");
+    return Error::success();
+  }
+
+  Error expect(Kind Expected, StringRef Msg) {
+    read();
+    if (Tok.K != Expected)
+      return createError(Msg);
+    return Error::success();
+  }
+
+  void unget() { Stack.push_back(Tok); }
+
+  Error parseOne() {
+    read();
+    switch (Tok.K) {
+    case Eof:
+      return Error::success();
+    case KwExports:
+      for (;;) {
+        read();
+        if (Tok.K != Identifier) {
+          unget();
+          return Error::success();
+        }
+        if (Error Err = parseExport())
+          return Err;
+      }
+    case KwHeapsize:
+      return parseNumbers(&Info.HeapReserve, &Info.HeapCommit);
+    case KwStacksize:
+      return parseNumbers(&Info.StackReserve, &Info.StackCommit);
+    case KwLibrary:
+    case KwName: {
+      bool IsDll = Tok.K == KwLibrary; // Check before parseName.
+      std::string Name;
+      if (Error Err = parseName(&Name, &Info.ImageBase))
+        return Err;
+      // Append the appropriate file extension if not already present.
+      StringRef Ext = IsDll ? ".dll" : ".exe";
+      if (!StringRef(Name).endswith_lower(Ext))
+        Name += Ext;
+
+      // Set the output file, but don't override /out if it was already passed.
+      if (Info.OutputFile.empty())
+        Info.OutputFile = Name;
+      return Error::success();
+    }
+    case KwVersion:
+      return parseVersion(&Info.MajorImageVersion, &Info.MinorImageVersion);
+    default:
+      return createError("unknown directive: " + Tok.Value);
+    }
+  }
+
+  Error parseExport() {
+    COFFShortExport E;
+    E.Name = Tok.Value;
+    read();
+    if (Tok.K == Equal) {
+      read();
+      if (Tok.K != Identifier)
+        return createError("identifier expected, but got " + Tok.Value);
+      E.ExtName = E.Name;
+      E.Name = Tok.Value;
+    } else {
+      unget();
+    }
+
+    if (Machine == IMAGE_FILE_MACHINE_I386) {
+      if (!isDecorated(E.Name))
+        E.Name = (std::string("_").append(E.Name));
+      if (!E.ExtName.empty() && !isDecorated(E.ExtName))
+        E.ExtName = (std::string("_").append(E.ExtName));
+    }
+
+    for (;;) {
+      read();
+      if (Tok.K == Identifier && Tok.Value[0] == '@') {
+        Tok.Value.drop_front().getAsInteger(10, E.Ordinal);
+        read();
+        if (Tok.K == KwNoname) {
+          E.Noname = true;
+        } else {
+          unget();
+        }
+        continue;
+      }
+      if (Tok.K == KwData) {
+        E.Data = true;
+        continue;
+      }
+      if (Tok.K == KwConstant) {
+        E.Constant = true;
+        continue;
+      }
+      if (Tok.K == KwPrivate) {
+        E.Private = true;
+        continue;
+      }
+      unget();
+      Info.Exports.push_back(E);
+      return Error::success();
+    }
+  }
+
+  // HEAPSIZE/STACKSIZE reserve[,commit]
+  Error parseNumbers(uint64_t *Reserve, uint64_t *Commit) {
+    if (Error Err = readAsInt(Reserve))
+      return Err;
+    read();
+    if (Tok.K != Comma) {
+      unget();
+      Commit = nullptr;
+      return Error::success();
+    }
+    if (Error Err = readAsInt(Commit))
+      return Err;
+    return Error::success();
+  }
+
+  // NAME outputPath [BASE=address]
+  Error parseName(std::string *Out, uint64_t *Baseaddr) {
+    read();
+    if (Tok.K == Identifier) {
+      *Out = Tok.Value;
+    } else {
+      *Out = "";
+      unget();
+      return Error::success();
+    }
+    read();
+    if (Tok.K == KwBase) {
+      if (Error Err = expect(Equal, "'=' expected"))
+        return Err;
+      if (Error Err = readAsInt(Baseaddr))
+        return Err;
+    } else {
+      unget();
+      *Baseaddr = 0;
+    }
+    return Error::success();
+  }
+
+  // VERSION major[.minor]
+  Error parseVersion(uint32_t *Major, uint32_t *Minor) {
+    read();
+    if (Tok.K != Identifier)
+      return createError("identifier expected, but got " + Tok.Value);
+    StringRef V1, V2;
+    std::tie(V1, V2) = Tok.Value.split('.');
+    if (V1.getAsInteger(10, *Major))
+      return createError("integer expected, but got " + Tok.Value);
+    if (V2.empty())
+      *Minor = 0;
+    else if (V2.getAsInteger(10, *Minor))
+      return createError("integer expected, but got " + Tok.Value);
+    return Error::success();
+  }
+
+  Lexer Lex;
+  Token Tok;
+  std::vector<Token> Stack;
+  MachineTypes Machine;
+  COFFModuleDefinition Info;
+};
+
+Expected<COFFModuleDefinition> parseCOFFModuleDefinition(MemoryBufferRef MB,
+                                                         MachineTypes Machine) {
+  return Parser(MB.getBuffer(), Machine).parse();
+}
+
+} // namespace object
+} // namespace llvm