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
  21 class ScriptLexer {
  22 protected:
  23   struct Buffer {
  24     // The remaining content to parse and the filename.
  25     StringRef s, filename;
  26     const char *begin = nullptr;
  27     size_t lineNumber = 1;
  28     // True if the script is opened as an absolute path under the --sysroot
  29     // directory.
  30     bool isUnderSysroot = false;
  31
  32     Buffer() = default;
  33     Buffer(MemoryBufferRef mb);
  34   };
  35   // The current buffer and parent buffers due to INCLUDE.
  36   Buffer curBuf;
  37   SmallVector<Buffer, 0> buffers;
  38
  39   // Used to detect INCLUDE() cycles.
  40   llvm::DenseSet<StringRef> activeFilenames;
  41
  42   struct Token {
  43     StringRef str;
  44     explicit operator bool() const { return !str.empty(); }
  45     operator StringRef() const { return str; }
  46   };
  47
  48   // The token before the last next().
  49   StringRef prevTok;
  50   // Rules for what is a token are different when we are in an expression.
  51   // curTok holds the cached return value of peek() and is invalid when the
  52   // expression state changes.
  53   StringRef curTok;
  54   size_t prevTokLine = 1;
  55   // The inExpr state when curTok is cached.
  56   bool curTokState = false;
  57   bool eof = false;
  58
  59 public:
  60   explicit ScriptLexer(MemoryBufferRef mb);
  61
  62   void setError(const Twine &msg);
  63   void lex();
  64   StringRef skipSpace(StringRef s);
  65   bool atEOF();
  66   StringRef next();
  67   StringRef peek();
  68   void skip();
  69   bool consume(StringRef tok);
  70   void expect(StringRef expect);
  71   Token till(StringRef tok);
  72   std::string getCurrentLocation();
  73   MemoryBufferRef getCurrentMB();
  74
  75   std::vector<MemoryBufferRef> mbs;
  76   bool inExpr = false;
  77
  78 private:
  79   StringRef getLine();
  80   size_t getColumnNumber();
  81 };
  82
  83 } // namespace lld::elf
  84
  85 #endif