include/llvm/Support/SourceMgr.h

   1 //===- SourceMgr.h - Manager for Source Buffers & Diagnostics ---*- 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 // This file declares the SMDiagnostic and SourceMgr classes.  This
  10 // provides a simple substrate for diagnostics, #include handling, and other low
  11 // level things for simple parsers.
  12 //
  13 //===----------------------------------------------------------------------===//
  14
  15 #ifndef LLVM_SUPPORT_SOURCEMGR_H
  16 #define LLVM_SUPPORT_SOURCEMGR_H
  17
  18 #include "llvm/ADT/ArrayRef.h"
  19 #include "llvm/ADT/None.h"
  20 #include "llvm/ADT/PointerUnion.h"
  21 #include "llvm/ADT/SmallVector.h"
  22 #include "llvm/ADT/StringRef.h"
  23 #include "llvm/ADT/Twine.h"
  24 #include "llvm/Support/MemoryBuffer.h"
  25 #include "llvm/Support/SMLoc.h"
  26 #include <algorithm>
  27 #include <cassert>
  28 #include <memory>
  29 #include <string>
  30 #include <utility>
  31 #include <vector>
  32
  33 namespace llvm {
  34
  35 class raw_ostream;
  36 class SMDiagnostic;
  37 class SMFixIt;
  38
  39 /// This owns the files read by a parser, handles include stacks,
  40 /// and handles diagnostic wrangling.
  41 class SourceMgr {
  42 public:
  43   enum DiagKind {
  44     DK_Error,
  45     DK_Warning,
  46     DK_Remark,
  47     DK_Note,
  48   };
  49
  50   /// Clients that want to handle their own diagnostics in a custom way can
  51   /// register a function pointer+context as a diagnostic handler.
  52   /// It gets called each time PrintMessage is invoked.
  53   using DiagHandlerTy = void (*)(const SMDiagnostic &, void *Context);
  54
  55 private:
  56   struct SrcBuffer {
  57     /// The memory buffer for the file.
  58     std::unique_ptr<MemoryBuffer> Buffer;
  59
  60     /// Helper type for OffsetCache below: since we're storing many offsets
  61     /// into relatively small files (often smaller than 2^8 or 2^16 bytes),
  62     /// we select the offset vector element type dynamically based on the
  63     /// size of Buffer.
  64     using VariableSizeOffsets = PointerUnion4<std::vector<uint8_t> *,
  65                                               std::vector<uint16_t> *,
  66                                               std::vector<uint32_t> *,
  67                                               std::vector<uint64_t> *>;
  68
  69     /// Vector of offsets into Buffer at which there are line-endings
  70     /// (lazily populated). Once populated, the '\n' that marks the end of
  71     /// line number N from [1..] is at Buffer[OffsetCache[N-1]]. Since
  72     /// these offsets are in sorted (ascending) order, they can be
  73     /// binary-searched for the first one after any given offset (eg. an
  74     /// offset corresponding to a particular SMLoc).
  75     mutable VariableSizeOffsets OffsetCache;
  76
  77     /// Populate \c OffsetCache and look up a given \p Ptr in it, assuming
  78     /// it points somewhere into \c Buffer. The static type parameter \p T
  79     /// must be an unsigned integer type from uint{8,16,32,64}_t large
  80     /// enough to store offsets inside \c Buffer.
  81     template<typename T>
  82     unsigned getLineNumber(const char *Ptr) const;
  83
  84     /// This is the location of the parent include, or null if at the top level.
  85     SMLoc IncludeLoc;
  86
  87     SrcBuffer() = default;
  88     SrcBuffer(SrcBuffer &&);
  89     SrcBuffer(const SrcBuffer &) = delete;
  90     SrcBuffer &operator=(const SrcBuffer &) = delete;
  91     ~SrcBuffer();
  92   };
  93
  94   /// This is all of the buffers that we are reading from.
  95   std::vector<SrcBuffer> Buffers;
  96
  97   // This is the list of directories we should search for include files in.
  98   std::vector<std::string> IncludeDirectories;
  99
 100   DiagHandlerTy DiagHandler = nullptr;
 101   void *DiagContext = nullptr;
 102
 103   bool isValidBufferID(unsigned i) const { return i && i <= Buffers.size(); }
 104
 105 public:
 106   SourceMgr() = default;
 107   SourceMgr(const SourceMgr &) = delete;
 108   SourceMgr &operator=(const SourceMgr &) = delete;
 109   SourceMgr(SourceMgr &&) = default;
 110   SourceMgr &operator=(SourceMgr &&) = default;
 111   ~SourceMgr() = default;
 112
 113   void setIncludeDirs(const std::vector<std::string> &Dirs) {
 114     IncludeDirectories = Dirs;
 115   }
 116
 117   /// Specify a diagnostic handler to be invoked every time PrintMessage is
 118   /// called. \p Ctx is passed into the handler when it is invoked.
 119   void setDiagHandler(DiagHandlerTy DH, void *Ctx = nullptr) {
 120     DiagHandler = DH;
 121     DiagContext = Ctx;
 122   }
 123
 124   DiagHandlerTy getDiagHandler() const { return DiagHandler; }
 125   void *getDiagContext() const { return DiagContext; }
 126
 127   const SrcBuffer &getBufferInfo(unsigned i) const {
 128     assert(isValidBufferID(i));
 129     return Buffers[i - 1];
 130   }
 131
 132   const MemoryBuffer *getMemoryBuffer(unsigned i) const {
 133     assert(isValidBufferID(i));
 134     return Buffers[i - 1].Buffer.get();
 135   }
 136
 137   unsigned getNumBuffers() const {
 138     return Buffers.size();
 139   }
 140
 141   unsigned getMainFileID() const {
 142     assert(getNumBuffers());
 143     return 1;
 144   }
 145
 146   SMLoc getParentIncludeLoc(unsigned i) const {
 147     assert(isValidBufferID(i));
 148     return Buffers[i - 1].IncludeLoc;
 149   }
 150
 151   /// Add a new source buffer to this source manager. This takes ownership of
 152   /// the memory buffer.
 153   unsigned AddNewSourceBuffer(std::unique_ptr<MemoryBuffer> F,
 154                               SMLoc IncludeLoc) {
 155     SrcBuffer NB;
 156     NB.Buffer = std::move(F);
 157     NB.IncludeLoc = IncludeLoc;
 158     Buffers.push_back(std::move(NB));
 159     return Buffers.size();
 160   }
 161
 162   /// Search for a file with the specified name in the current directory or in
 163   /// one of the IncludeDirs.
 164   ///
 165   /// If no file is found, this returns 0, otherwise it returns the buffer ID
 166   /// of the stacked file. The full path to the included file can be found in
 167   /// \p IncludedFile.
 168   unsigned AddIncludeFile(const std::string &Filename, SMLoc IncludeLoc,
 169                           std::string &IncludedFile);
 170
 171   /// Return the ID of the buffer containing the specified location.
 172   ///
 173   /// 0 is returned if the buffer is not found.
 174   unsigned FindBufferContainingLoc(SMLoc Loc) const;
 175
 176   /// Find the line number for the specified location in the specified file.
 177   /// This is not a fast method.
 178   unsigned FindLineNumber(SMLoc Loc, unsigned BufferID = 0) const {
 179     return getLineAndColumn(Loc, BufferID).first;
 180   }
 181
 182   /// Find the line and column number for the specified location in the
 183   /// specified file. This is not a fast method.
 184   std::pair<unsigned, unsigned> getLineAndColumn(SMLoc Loc,
 185                                                  unsigned BufferID = 0) const;
 186
 187   /// Emit a message about the specified location with the specified string.
 188   ///
 189   /// \param ShowColors Display colored messages if output is a terminal and
 190   /// the default error handler is used.
 191   void PrintMessage(raw_ostream &OS, SMLoc Loc, DiagKind Kind,
 192                     const Twine &Msg,
 193                     ArrayRef<SMRange> Ranges = None,
 194                     ArrayRef<SMFixIt> FixIts = None,
 195                     bool ShowColors = true) const;
 196
 197   /// Emits a diagnostic to llvm::errs().
 198   void PrintMessage(SMLoc Loc, DiagKind Kind, const Twine &Msg,
 199                     ArrayRef<SMRange> Ranges = None,
 200                     ArrayRef<SMFixIt> FixIts = None,
 201                     bool ShowColors = true) const;
 202
 203   /// Emits a manually-constructed diagnostic to the given output stream.
 204   ///
 205   /// \param ShowColors Display colored messages if output is a terminal and
 206   /// the default error handler is used.
 207   void PrintMessage(raw_ostream &OS, const SMDiagnostic &Diagnostic,
 208                     bool ShowColors = true) const;
 209
 210   /// Return an SMDiagnostic at the specified location with the specified
 211   /// string.
 212   ///
 213   /// \param Msg If non-null, the kind of message (e.g., "error") which is
 214   /// prefixed to the message.
 215   SMDiagnostic GetMessage(SMLoc Loc, DiagKind Kind, const Twine &Msg,
 216                           ArrayRef<SMRange> Ranges = None,
 217                           ArrayRef<SMFixIt> FixIts = None) const;
 218
 219   /// Prints the names of included files and the line of the file they were
 220   /// included from. A diagnostic handler can use this before printing its
 221   /// custom formatted message.
 222   ///
 223   /// \param IncludeLoc The location of the include.
 224   /// \param OS the raw_ostream to print on.
 225   void PrintIncludeStack(SMLoc IncludeLoc, raw_ostream &OS) const;
 226 };
 227
 228 /// Represents a single fixit, a replacement of one range of text with another.
 229 class SMFixIt {
 230   SMRange Range;
 231
 232   std::string Text;
 233
 234 public:
 235   // FIXME: Twine.str() is not very efficient.
 236   SMFixIt(SMLoc Loc, const Twine &Insertion)
 237     : Range(Loc, Loc), Text(Insertion.str()) {
 238     assert(Loc.isValid());
 239   }
 240
 241   // FIXME: Twine.str() is not very efficient.
 242   SMFixIt(SMRange R, const Twine &Replacement)
 243     : Range(R), Text(Replacement.str()) {
 244     assert(R.isValid());
 245   }
 246
 247   StringRef getText() const { return Text; }
 248   SMRange getRange() const { return Range; }
 249
 250   bool operator<(const SMFixIt &Other) const {
 251     if (Range.Start.getPointer() != Other.Range.Start.getPointer())
 252       return Range.Start.getPointer() < Other.Range.Start.getPointer();
 253     if (Range.End.getPointer() != Other.Range.End.getPointer())
 254       return Range.End.getPointer() < Other.Range.End.getPointer();
 255     return Text < Other.Text;
 256   }
 257 };
 258
 259 /// Instances of this class encapsulate one diagnostic report, allowing
 260 /// printing to a raw_ostream as a caret diagnostic.
 261 class SMDiagnostic {
 262   const SourceMgr *SM = nullptr;
 263   SMLoc Loc;
 264   std::string Filename;
 265   int LineNo = 0;
 266   int ColumnNo = 0;
 267   SourceMgr::DiagKind Kind = SourceMgr::DK_Error;
 268   std::string Message, LineContents;
 269   std::vector<std::pair<unsigned, unsigned>> Ranges;
 270   SmallVector<SMFixIt, 4> FixIts;
 271
 272 public:
 273   // Null diagnostic.
 274   SMDiagnostic() = default;
 275   // Diagnostic with no location (e.g. file not found, command line arg error).
 276   SMDiagnostic(StringRef filename, SourceMgr::DiagKind Knd, StringRef Msg)
 277     : Filename(filename), LineNo(-1), ColumnNo(-1), Kind(Knd), Message(Msg) {}
 278
 279   // Diagnostic with a location.
 280   SMDiagnostic(const SourceMgr &sm, SMLoc L, StringRef FN,
 281                int Line, int Col, SourceMgr::DiagKind Kind,
 282                StringRef Msg, StringRef LineStr,
 283                ArrayRef<std::pair<unsigned,unsigned>> Ranges,
 284                ArrayRef<SMFixIt> FixIts = None);
 285
 286   const SourceMgr *getSourceMgr() const { return SM; }
 287   SMLoc getLoc() const { return Loc; }
 288   StringRef getFilename() const { return Filename; }
 289   int getLineNo() const { return LineNo; }
 290   int getColumnNo() const { return ColumnNo; }
 291   SourceMgr::DiagKind getKind() const { return Kind; }
 292   StringRef getMessage() const { return Message; }
 293   StringRef getLineContents() const { return LineContents; }
 294   ArrayRef<std::pair<unsigned, unsigned>> getRanges() const { return Ranges; }
 295
 296   void addFixIt(const SMFixIt &Hint) {
 297     FixIts.push_back(Hint);
 298   }
 299
 300   ArrayRef<SMFixIt> getFixIts() const {
 301     return FixIts;
 302   }
 303
 304   void print(const char *ProgName, raw_ostream &S, bool ShowColors = true,
 305              bool ShowKindLabel = true) const;
 306 };
 307
 308 } // end namespace llvm
 309
 310 #endif // LLVM_SUPPORT_SOURCEMGR_H