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() = default;
 110
 111   void setIncludeDirs(const std::vector<std::string> &Dirs) {
 112     IncludeDirectories = Dirs;
 113   }
 114
 115   /// Specify a diagnostic handler to be invoked every time PrintMessage is
 116   /// called. \p Ctx is passed into the handler when it is invoked.
 117   void setDiagHandler(DiagHandlerTy DH, void *Ctx = nullptr) {
 118     DiagHandler = DH;
 119     DiagContext = Ctx;
 120   }
 121
 122   DiagHandlerTy getDiagHandler() const { return DiagHandler; }
 123   void *getDiagContext() const { return DiagContext; }
 124
 125   const SrcBuffer &getBufferInfo(unsigned i) const {
 126     assert(isValidBufferID(i));
 127     return Buffers[i - 1];
 128   }
 129
 130   const MemoryBuffer *getMemoryBuffer(unsigned i) const {
 131     assert(isValidBufferID(i));
 132     return Buffers[i - 1].Buffer.get();
 133   }
 134
 135   unsigned getNumBuffers() const {
 136     return Buffers.size();
 137   }
 138
 139   unsigned getMainFileID() const {
 140     assert(getNumBuffers());
 141     return 1;
 142   }
 143
 144   SMLoc getParentIncludeLoc(unsigned i) const {
 145     assert(isValidBufferID(i));
 146     return Buffers[i - 1].IncludeLoc;
 147   }
 148
 149   /// Add a new source buffer to this source manager. This takes ownership of
 150   /// the memory buffer.
 151   unsigned AddNewSourceBuffer(std::unique_ptr<MemoryBuffer> F,
 152                               SMLoc IncludeLoc) {
 153     SrcBuffer NB;
 154     NB.Buffer = std::move(F);
 155     NB.IncludeLoc = IncludeLoc;
 156     Buffers.push_back(std::move(NB));
 157     return Buffers.size();
 158   }
 159
 160   /// Search for a file with the specified name in the current directory or in
 161   /// one of the IncludeDirs.
 162   ///
 163   /// If no file is found, this returns 0, otherwise it returns the buffer ID
 164   /// of the stacked file. The full path to the included file can be found in
 165   /// \p IncludedFile.
 166   unsigned AddIncludeFile(const std::string &Filename, SMLoc IncludeLoc,
 167                           std::string &IncludedFile);
 168
 169   /// Return the ID of the buffer containing the specified location.
 170   ///
 171   /// 0 is returned if the buffer is not found.
 172   unsigned FindBufferContainingLoc(SMLoc Loc) const;
 173
 174   /// Find the line number for the specified location in the specified file.
 175   /// This is not a fast method.
 176   unsigned FindLineNumber(SMLoc Loc, unsigned BufferID = 0) const {
 177     return getLineAndColumn(Loc, BufferID).first;
 178   }
 179
 180   /// Find the line and column number for the specified location in the
 181   /// specified file. This is not a fast method.
 182   std::pair<unsigned, unsigned> getLineAndColumn(SMLoc Loc,
 183                                                  unsigned BufferID = 0) const;
 184
 185   /// Emit a message about the specified location with the specified string.
 186   ///
 187   /// \param ShowColors Display colored messages if output is a terminal and
 188   /// the default error handler is used.
 189   void PrintMessage(raw_ostream &OS, SMLoc Loc, DiagKind Kind,
 190                     const Twine &Msg,
 191                     ArrayRef<SMRange> Ranges = None,
 192                     ArrayRef<SMFixIt> FixIts = None,
 193                     bool ShowColors = true) const;
 194
 195   /// Emits a diagnostic to llvm::errs().
 196   void PrintMessage(SMLoc Loc, DiagKind Kind, const Twine &Msg,
 197                     ArrayRef<SMRange> Ranges = None,
 198                     ArrayRef<SMFixIt> FixIts = None,
 199                     bool ShowColors = true) const;
 200
 201   /// Emits a manually-constructed diagnostic to the given output stream.
 202   ///
 203   /// \param ShowColors Display colored messages if output is a terminal and
 204   /// the default error handler is used.
 205   void PrintMessage(raw_ostream &OS, const SMDiagnostic &Diagnostic,
 206                     bool ShowColors = true) const;
 207
 208   /// Return an SMDiagnostic at the specified location with the specified
 209   /// string.
 210   ///
 211   /// \param Msg If non-null, the kind of message (e.g., "error") which is
 212   /// prefixed to the message.
 213   SMDiagnostic GetMessage(SMLoc Loc, DiagKind Kind, const Twine &Msg,
 214                           ArrayRef<SMRange> Ranges = None,
 215                           ArrayRef<SMFixIt> FixIts = None) const;
 216
 217   /// Prints the names of included files and the line of the file they were
 218   /// included from. A diagnostic handler can use this before printing its
 219   /// custom formatted message.
 220   ///
 221   /// \param IncludeLoc The location of the include.
 222   /// \param OS the raw_ostream to print on.
 223   void PrintIncludeStack(SMLoc IncludeLoc, raw_ostream &OS) const;
 224 };
 225
 226 /// Represents a single fixit, a replacement of one range of text with another.
 227 class SMFixIt {
 228   SMRange Range;
 229
 230   std::string Text;
 231
 232 public:
 233   // FIXME: Twine.str() is not very efficient.
 234   SMFixIt(SMLoc Loc, const Twine &Insertion)
 235     : Range(Loc, Loc), Text(Insertion.str()) {
 236     assert(Loc.isValid());
 237   }
 238
 239   // FIXME: Twine.str() is not very efficient.
 240   SMFixIt(SMRange R, const Twine &Replacement)
 241     : Range(R), Text(Replacement.str()) {
 242     assert(R.isValid());
 243   }
 244
 245   StringRef getText() const { return Text; }
 246   SMRange getRange() const { return Range; }
 247
 248   bool operator<(const SMFixIt &Other) const {
 249     if (Range.Start.getPointer() != Other.Range.Start.getPointer())
 250       return Range.Start.getPointer() < Other.Range.Start.getPointer();
 251     if (Range.End.getPointer() != Other.Range.End.getPointer())
 252       return Range.End.getPointer() < Other.Range.End.getPointer();
 253     return Text < Other.Text;
 254   }
 255 };
 256
 257 /// Instances of this class encapsulate one diagnostic report, allowing
 258 /// printing to a raw_ostream as a caret diagnostic.
 259 class SMDiagnostic {
 260   const SourceMgr *SM = nullptr;
 261   SMLoc Loc;
 262   std::string Filename;
 263   int LineNo = 0;
 264   int ColumnNo = 0;
 265   SourceMgr::DiagKind Kind = SourceMgr::DK_Error;
 266   std::string Message, LineContents;
 267   std::vector<std::pair<unsigned, unsigned>> Ranges;
 268   SmallVector<SMFixIt, 4> FixIts;
 269
 270 public:
 271   // Null diagnostic.
 272   SMDiagnostic() = default;
 273   // Diagnostic with no location (e.g. file not found, command line arg error).
 274   SMDiagnostic(StringRef filename, SourceMgr::DiagKind Knd, StringRef Msg)
 275     : Filename(filename), LineNo(-1), ColumnNo(-1), Kind(Knd), Message(Msg) {}
 276
 277   // Diagnostic with a location.
 278   SMDiagnostic(const SourceMgr &sm, SMLoc L, StringRef FN,
 279                int Line, int Col, SourceMgr::DiagKind Kind,
 280                StringRef Msg, StringRef LineStr,
 281                ArrayRef<std::pair<unsigned,unsigned>> Ranges,
 282                ArrayRef<SMFixIt> FixIts = None);
 283
 284   const SourceMgr *getSourceMgr() const { return SM; }
 285   SMLoc getLoc() const { return Loc; }
 286   StringRef getFilename() const { return Filename; }
 287   int getLineNo() const { return LineNo; }
 288   int getColumnNo() const { return ColumnNo; }
 289   SourceMgr::DiagKind getKind() const { return Kind; }
 290   StringRef getMessage() const { return Message; }
 291   StringRef getLineContents() const { return LineContents; }
 292   ArrayRef<std::pair<unsigned, unsigned>> getRanges() const { return Ranges; }
 293
 294   void addFixIt(const SMFixIt &Hint) {
 295     FixIts.push_back(Hint);
 296   }
 297
 298   ArrayRef<SMFixIt> getFixIts() const {
 299     return FixIts;
 300   }
 301
 302   void print(const char *ProgName, raw_ostream &S, bool ShowColors = true,
 303              bool ShowKindLabel = true) const;
 304 };
 305
 306 } // end namespace llvm
 307
 308 #endif // LLVM_SUPPORT_SOURCEMGR_H