aboutsummaryrefslogtreecommitdiff
path: root/flang/lib/Parser/source.cpp
blob: ae834dc241652958c656cd86bd2ca26475e5598e (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
//===-- lib/Parser/source.cpp ---------------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//

#include "flang/Parser/source.h"
#include "flang/Common/idioms.h"
#include "flang/Parser/char-buffer.h"
#include "flang/Parser/characters.h"
#include "llvm/Support/Errno.h"
#include "llvm/Support/FileSystem.h"
#include "llvm/Support/Path.h"
#include "llvm/Support/raw_ostream.h"
#include <algorithm>
#include <cstring>
#include <memory>
#include <string>
#include <vector>

namespace Fortran::parser {

SourceFile::~SourceFile() { Close(); }

void SourceFile::RecordLineStarts() {
  if (std::size_t chars{bytes()}; chars > 0) {
    origins_.emplace(1, SourcePositionOrigin{path_, 1});
    const char *source{content().data()};
    CHECK(source[chars - 1] == '\n' && "missing ultimate newline");
    std::size_t at{0};
    do { // "at" is always at the beginning of a source line
      lineStart_.push_back(at);
      at = reinterpret_cast<const char *>(
               std::memchr(source + at, '\n', chars - at)) -
          source + 1;
    } while (at < chars);
    CHECK(at == chars);
    lineStart_.shrink_to_fit();
  }
}

// Check for a Unicode byte order mark (BOM).
// Module files all have one; so can source files.
void SourceFile::IdentifyPayload() {
  llvm::StringRef content{buf_->getBufferStart(), buf_->getBufferSize()};
  constexpr llvm::StringLiteral UTF8_BOM{"\xef\xbb\xbf"};
  if (content.starts_with(UTF8_BOM)) {
    bom_end_ = UTF8_BOM.size();
    encoding_ = Encoding::UTF_8;
  }
}

std::string DirectoryName(std::string path) {
  llvm::SmallString<128> pathBuf{path};
  llvm::sys::path::remove_filename(pathBuf);
  return pathBuf.str().str();
}

std::optional<std::string> LocateSourceFile(
    std::string name, const std::list<std::string> &searchPath) {
  if (name == "-" || llvm::sys::path::is_absolute(name)) {
    return name;
  }
  for (const std::string &dir : searchPath) {
    llvm::SmallString<128> path{dir};
    llvm::sys::path::append(path, name);
    bool isDir{false};
    auto er = llvm::sys::fs::is_directory(path, isDir);
    if (!er && !isDir) {
      return path.str().str();
    }
  }
  return std::nullopt;
}

std::vector<std::string> LocateSourceFileAll(
    std::string name, const std::vector<std::string> &searchPath) {
  if (name == "-" || llvm::sys::path::is_absolute(name)) {
    return {name};
  }
  std::vector<std::string> result;
  for (const std::string &dir : searchPath) {
    llvm::SmallString<128> path{dir};
    llvm::sys::path::append(path, name);
    bool isDir{false};
    auto er = llvm::sys::fs::is_directory(path, isDir);
    if (!er && !isDir) {
      result.emplace_back(path.str().str());
    }
  }
  return result;
}

std::size_t RemoveCarriageReturns(llvm::MutableArrayRef<char> buf) {
  std::size_t wrote{0};
  char *buffer{buf.data()};
  char *p{buf.data()};
  std::size_t bytes = buf.size();
  while (bytes > 0) {
    void *vp{static_cast<void *>(p)};
    void *crvp{std::memchr(vp, '\r', bytes)};
    char *crcp{static_cast<char *>(crvp)};
    if (!crcp) {
      std::memmove(buffer + wrote, p, bytes);
      wrote += bytes;
      break;
    }
    std::size_t chunk = crcp - p;
    auto advance{chunk + 1};
    if (chunk + 1 >= bytes || crcp[1] == '\n') {
      // CR followed by LF or EOF: omit
    } else if ((chunk == 0 && p == buf.data()) || crcp[-1] == '\n') {
      // CR preceded by LF or BOF: omit
    } else {
      // CR in line: retain
      ++chunk;
    }
    std::memmove(buffer + wrote, p, chunk);
    wrote += chunk;
    p += advance;
    bytes -= advance;
  }
  return wrote;
}

bool SourceFile::Open(std::string path, llvm::raw_ostream &error) {
  Close();
  path_ = path;
  std::string errorPath{"'"s + path_ + "'"};
  auto bufOr{llvm::WritableMemoryBuffer::getFile(path)};
  if (!bufOr) {
    auto err = bufOr.getError();
    error << "Could not open " << errorPath << ": " << err.message();
    return false;
  }
  buf_ = std::move(bufOr.get());
  ReadFile();
  return true;
}

bool SourceFile::ReadStandardInput(llvm::raw_ostream &error) {
  Close();
  path_ = "standard input";
  auto buf_or = llvm::MemoryBuffer::getSTDIN();
  if (!buf_or) {
    auto err = buf_or.getError();
    error << err.message();
    return false;
  }
  auto inbuf = std::move(buf_or.get());
  buf_ =
      llvm::WritableMemoryBuffer::getNewUninitMemBuffer(inbuf->getBufferSize());
  llvm::copy(inbuf->getBuffer(), buf_->getBufferStart());
  ReadFile();
  return true;
}

void SourceFile::ReadFile() {
  buf_end_ = RemoveCarriageReturns(buf_->getBuffer());
  if (content().size() == 0 || content().back() != '\n') {
    // Don't bother to copy if we have spare memory
    if (content().size() >= buf_->getBufferSize()) {
      auto tmp_buf{llvm::WritableMemoryBuffer::getNewUninitMemBuffer(
          content().size() + 1)};
      llvm::copy(content(), tmp_buf->getBufferStart());
      buf_ = std::move(tmp_buf);
    }
    buf_end_++;
    buf_->getBuffer()[buf_end_ - 1] = '\n';
  }
  IdentifyPayload();
  RecordLineStarts();
}

void SourceFile::Close() {
  path_.clear();
  buf_.reset();
  distinctPaths_.clear();
  origins_.clear();
}

SourcePosition SourceFile::GetSourcePosition(std::size_t at) const {
  CHECK(at < bytes());
  auto it{llvm::upper_bound(lineStart_, at)};
  auto trueLineNumber{std::distance(lineStart_.begin(), it - 1) + 1};
  auto ub{origins_.upper_bound(trueLineNumber)};
  auto column{static_cast<int>(at - lineStart_[trueLineNumber - 1] + 1)};
  if (ub == origins_.begin()) {
    return {*this, path_, static_cast<int>(trueLineNumber), column,
        static_cast<int>(trueLineNumber)};
  } else {
    --ub;
    const SourcePositionOrigin &origin{ub->second};
    auto lineNumber{
        trueLineNumber - ub->first + static_cast<std::size_t>(origin.line)};
    return {*this, origin.path, static_cast<int>(lineNumber), column,
        static_cast<int>(trueLineNumber)};
  }
}

const std::string &SourceFile::SavePath(std::string &&path) {
  return *distinctPaths_.emplace(std::move(path)).first;
}

void SourceFile::LineDirective(
    int trueLineNumber, const std::string &path, int lineNumber) {
  origins_.emplace(trueLineNumber, SourcePositionOrigin{path, lineNumber});
}

llvm::raw_ostream &SourceFile::Dump(llvm::raw_ostream &o) const {
  o << "SourceFile '" << path_ << "'\n";
  for (const auto &[at, spo] : origins_) {
    o << "  origin_[" << at << "] -> '" << spo.path << "' " << spo.line << '\n';
  }
  return o;
}
} // namespace Fortran::parser