220 lines · cpp
1//===-- lib/Parser/source.cpp ---------------------------------------------===//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-exception6//7//===----------------------------------------------------------------------===//8 9#include "flang/Parser/source.h"10#include "flang/Common/idioms.h"11#include "flang/Parser/char-buffer.h"12#include "flang/Parser/characters.h"13#include "llvm/Support/Errno.h"14#include "llvm/Support/FileSystem.h"15#include "llvm/Support/Path.h"16#include "llvm/Support/raw_ostream.h"17#include <algorithm>18#include <cstring>19#include <memory>20#include <string>21#include <vector>22 23namespace Fortran::parser {24 25SourceFile::~SourceFile() { Close(); }26 27void SourceFile::RecordLineStarts() {28 if (std::size_t chars{bytes()}; chars > 0) {29 origins_.emplace(1, SourcePositionOrigin{path_, 1});30 const char *source{content().data()};31 CHECK(source[chars - 1] == '\n' && "missing ultimate newline");32 std::size_t at{0};33 do { // "at" is always at the beginning of a source line34 lineStart_.push_back(at);35 at = reinterpret_cast<const char *>(36 std::memchr(source + at, '\n', chars - at)) -37 source + 1;38 } while (at < chars);39 CHECK(at == chars);40 lineStart_.shrink_to_fit();41 }42}43 44// Check for a Unicode byte order mark (BOM).45// Module files all have one; so can source files.46void SourceFile::IdentifyPayload() {47 llvm::StringRef content{buf_->getBufferStart(), buf_->getBufferSize()};48 constexpr llvm::StringLiteral UTF8_BOM{"\xef\xbb\xbf"};49 if (content.starts_with(UTF8_BOM)) {50 bom_end_ = UTF8_BOM.size();51 encoding_ = Encoding::UTF_8;52 }53}54 55std::string DirectoryName(std::string path) {56 llvm::SmallString<128> pathBuf{path};57 llvm::sys::path::remove_filename(pathBuf);58 return pathBuf.str().str();59}60 61std::optional<std::string> LocateSourceFile(62 std::string name, const std::list<std::string> &searchPath) {63 if (name == "-" || llvm::sys::path::is_absolute(name)) {64 return name;65 }66 for (const std::string &dir : searchPath) {67 llvm::SmallString<128> path{dir};68 llvm::sys::path::append(path, name);69 bool isDir{false};70 auto er = llvm::sys::fs::is_directory(path, isDir);71 if (!er && !isDir) {72 return path.str().str();73 }74 }75 return std::nullopt;76}77 78std::vector<std::string> LocateSourceFileAll(79 std::string name, const std::vector<std::string> &searchPath) {80 if (name == "-" || llvm::sys::path::is_absolute(name)) {81 return {name};82 }83 std::vector<std::string> result;84 for (const std::string &dir : searchPath) {85 llvm::SmallString<128> path{dir};86 llvm::sys::path::append(path, name);87 bool isDir{false};88 auto er = llvm::sys::fs::is_directory(path, isDir);89 if (!er && !isDir) {90 result.emplace_back(path.str().str());91 }92 }93 return result;94}95 96std::size_t RemoveCarriageReturns(llvm::MutableArrayRef<char> buf) {97 std::size_t wrote{0};98 char *buffer{buf.data()};99 char *p{buf.data()};100 std::size_t bytes = buf.size();101 while (bytes > 0) {102 void *vp{static_cast<void *>(p)};103 void *crvp{std::memchr(vp, '\r', bytes)};104 char *crcp{static_cast<char *>(crvp)};105 if (!crcp) {106 std::memmove(buffer + wrote, p, bytes);107 wrote += bytes;108 break;109 }110 std::size_t chunk = crcp - p;111 auto advance{chunk + 1};112 if (chunk + 1 >= bytes || crcp[1] == '\n') {113 // CR followed by LF or EOF: omit114 } else if ((chunk == 0 && p == buf.data()) || crcp[-1] == '\n') {115 // CR preceded by LF or BOF: omit116 } else {117 // CR in line: retain118 ++chunk;119 }120 std::memmove(buffer + wrote, p, chunk);121 wrote += chunk;122 p += advance;123 bytes -= advance;124 }125 return wrote;126}127 128bool SourceFile::Open(std::string path, llvm::raw_ostream &error) {129 Close();130 path_ = path;131 std::string errorPath{"'"s + path_ + "'"};132 auto bufOr{llvm::WritableMemoryBuffer::getFile(path)};133 if (!bufOr) {134 auto err = bufOr.getError();135 error << "Could not open " << errorPath << ": " << err.message();136 return false;137 }138 buf_ = std::move(bufOr.get());139 ReadFile();140 return true;141}142 143bool SourceFile::ReadStandardInput(llvm::raw_ostream &error) {144 Close();145 path_ = "standard input";146 auto buf_or = llvm::MemoryBuffer::getSTDIN();147 if (!buf_or) {148 auto err = buf_or.getError();149 error << err.message();150 return false;151 }152 auto inbuf = std::move(buf_or.get());153 buf_ =154 llvm::WritableMemoryBuffer::getNewUninitMemBuffer(inbuf->getBufferSize());155 llvm::copy(inbuf->getBuffer(), buf_->getBufferStart());156 ReadFile();157 return true;158}159 160void SourceFile::ReadFile() {161 buf_end_ = RemoveCarriageReturns(buf_->getBuffer());162 if (content().size() == 0 || content().back() != '\n') {163 // Don't bother to copy if we have spare memory164 if (content().size() >= buf_->getBufferSize()) {165 auto tmp_buf{llvm::WritableMemoryBuffer::getNewUninitMemBuffer(166 content().size() + 1)};167 llvm::copy(content(), tmp_buf->getBufferStart());168 buf_ = std::move(tmp_buf);169 }170 buf_end_++;171 buf_->getBuffer()[buf_end_ - 1] = '\n';172 }173 IdentifyPayload();174 RecordLineStarts();175}176 177void SourceFile::Close() {178 path_.clear();179 buf_.reset();180 distinctPaths_.clear();181 origins_.clear();182}183 184SourcePosition SourceFile::GetSourcePosition(std::size_t at) const {185 CHECK(at < bytes());186 auto it{llvm::upper_bound(lineStart_, at)};187 auto trueLineNumber{std::distance(lineStart_.begin(), it - 1) + 1};188 auto ub{origins_.upper_bound(trueLineNumber)};189 auto column{static_cast<int>(at - lineStart_[trueLineNumber - 1] + 1)};190 if (ub == origins_.begin()) {191 return {*this, path_, static_cast<int>(trueLineNumber), column,192 static_cast<int>(trueLineNumber)};193 } else {194 --ub;195 const SourcePositionOrigin &origin{ub->second};196 auto lineNumber{197 trueLineNumber - ub->first + static_cast<std::size_t>(origin.line)};198 return {*this, origin.path, static_cast<int>(lineNumber), column,199 static_cast<int>(trueLineNumber)};200 }201}202 203const std::string &SourceFile::SavePath(std::string &&path) {204 return *distinctPaths_.emplace(std::move(path)).first;205}206 207void SourceFile::LineDirective(208 int trueLineNumber, const std::string &path, int lineNumber) {209 origins_.emplace(trueLineNumber, SourcePositionOrigin{path, lineNumber});210}211 212llvm::raw_ostream &SourceFile::Dump(llvm::raw_ostream &o) const {213 o << "SourceFile '" << path_ << "'\n";214 for (const auto &[at, spo] : origins_) {215 o << " origin_[" << at << "] -> '" << spo.path << "' " << spo.line << '\n';216 }217 return o;218}219} // namespace Fortran::parser220