lld/ELF/ScriptLexer.h

   1 //===- ScriptLexer.h --------------------------------------------*- C++ -*-===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8
   9 #ifndef LLD_ELF_SCRIPT_LEXER_H
  10 #define LLD_ELF_SCRIPT_LEXER_H
  11
  12 #include "lld/Common/LLVM.h"
  13 #include "llvm/ADT/DenseSet.h"
  14 #include "llvm/ADT/SmallVector.h"
  15 #include "llvm/ADT/StringRef.h"
  16 #include "llvm/Support/MemoryBufferRef.h"
  17 #include <vector>
  18
  19 namespace lld::elf {
  20 struct Ctx;
  21
  22 class ScriptLexer {
  23 protected:
  24   struct Buffer {
  25     // The remaining content to parse and the filename.
  26     StringRef s, filename;
  27     const char *begin = nullptr;
  28     size_t lineNumber = 1;
  29     // True if the script is opened as an absolute path under the --sysroot
  30     // directory.
  31     bool isUnderSysroot = false;
  32
  33     Buffer() = default;
  34     Buffer(Ctx &ctx, MemoryBufferRef mb);
  35   };
  36   Ctx &ctx;
  37   // The current buffer and parent buffers due to INCLUDE.
  38   Buffer curBuf;
  39   SmallVector<Buffer, 0> buffers;
  40
  41   // Used to detect INCLUDE() cycles.
  42   llvm::DenseSet<StringRef> activeFilenames;
  43
  44   struct Token {
  45     StringRef str;
  46     explicit operator bool() const { return !str.empty(); }
  47     operator StringRef() const { return str; }
  48   };
  49
  50   // The token before the last next().
  51   StringRef prevTok;
  52   // Rules for what is a token are different when we are in an expression.
  53   // curTok holds the cached return value of peek() and is invalid when the
  54   // expression state changes.
  55   StringRef curTok;
  56   size_t prevTokLine = 1;
  57   // The inExpr state when curTok is cached.
  58   bool curTokState = false;
  59   bool eof = false;
  60
  61 public:
  62   explicit ScriptLexer(Ctx &ctx, MemoryBufferRef mb);
  63
  64   void setError(const Twine &msg);
  65   void lex();
  66   StringRef skipSpace(StringRef s);
  67   bool atEOF();
  68   StringRef next();
  69   StringRef peek();
  70   void skip();
  71   bool consume(StringRef tok);
  72   void expect(StringRef expect);
  73   Token till(StringRef tok);
  74   std::string getCurrentLocation();
  75   MemoryBufferRef getCurrentMB();
  76
  77   std::vector<MemoryBufferRef> mbs;
  78   bool inExpr = false;
  79
  80 private:
  81   StringRef getLine();
  82   size_t getColumnNumber();
  83 };
  84
  85 } // namespace lld::elf
  86
  87 #endif