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// Copyright 2020 The Tint Authors.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
#include "src/tint/source.h"
#include <algorithm>
#include <string_view>
#include <utility>
#include "src/tint/utils/unicode.h"
namespace tint {
namespace {
bool ParseLineBreak(std::string_view str, size_t i, bool* is_line_break, size_t* line_break_size) {
// See https://www.w3.org/TR/WGSL/#blankspace
auto* utf8 = reinterpret_cast<const uint8_t*>(&str[i]);
auto [cp, n] = utils::utf8::Decode(utf8, str.size() - i);
if (n == 0) {
return false;
}
static const auto kLF = utils::CodePoint(0x000A); // line feed
static const auto kVTab = utils::CodePoint(0x000B); // vertical tab
static const auto kFF = utils::CodePoint(0x000C); // form feed
static const auto kNL = utils::CodePoint(0x0085); // next line
static const auto kCR = utils::CodePoint(0x000D); // carriage return
static const auto kLS = utils::CodePoint(0x2028); // line separator
static const auto kPS = utils::CodePoint(0x2029); // parargraph separator
if (cp == kLF || cp == kVTab || cp == kFF || cp == kNL || cp == kPS || cp == kLS) {
*is_line_break = true;
*line_break_size = n;
return true;
}
// Handle CRLF as one line break, and CR alone as one line break
if (cp == kCR) {
*is_line_break = true;
*line_break_size = n;
if (auto next_i = i + n; next_i < str.size()) {
auto* next_utf8 = reinterpret_cast<const uint8_t*>(&str[next_i]);
auto [next_cp, next_n] = utils::utf8::Decode(next_utf8, str.size() - next_i);
if (next_n == 0) {
return false;
}
if (next_cp == kLF) {
// CRLF as one break
*line_break_size = n + next_n;
}
}
return true;
}
*is_line_break = false;
return true;
}
std::vector<std::string_view> SplitLines(std::string_view str) {
std::vector<std::string_view> lines;
size_t lineStart = 0;
for (size_t i = 0; i < str.size();) {
bool is_line_break{};
size_t line_break_size{};
// We don't handle decode errors from ParseLineBreak. Instead, we rely on
// the Lexer to do so.
ParseLineBreak(str, i, &is_line_break, &line_break_size);
if (is_line_break) {
lines.push_back(str.substr(lineStart, i - lineStart));
i += line_break_size;
lineStart = i;
} else {
++i;
}
}
if (lineStart < str.size()) {
lines.push_back(str.substr(lineStart));
}
return lines;
}
std::vector<std::string_view> CopyRelativeStringViews(const std::vector<std::string_view>& src_list,
const std::string_view& src_view,
const std::string_view& dst_view) {
std::vector<std::string_view> out(src_list.size());
for (size_t i = 0; i < src_list.size(); i++) {
auto offset = static_cast<size_t>(&src_list[i].front() - &src_view.front());
auto count = src_list[i].length();
out[i] = dst_view.substr(offset, count);
}
return out;
}
} // namespace
Source::FileContent::FileContent(const std::string& body) : data(body), lines(SplitLines(data)) {}
Source::FileContent::FileContent(const FileContent& rhs)
: data(rhs.data), lines(CopyRelativeStringViews(rhs.lines, rhs.data, data)) {}
Source::FileContent::~FileContent() = default;
Source::File::~File() = default;
utils::StringStream& operator<<(utils::StringStream& out, const Source& source) {
auto rng = source.range;
if (source.file) {
out << source.file->path << ":";
}
if (rng.begin.line) {
out << rng.begin.line << ":";
if (rng.begin.column) {
out << rng.begin.column;
}
if (source.file) {
out << std::endl << std::endl;
auto repeat = [&](char c, size_t n) {
while (n--) {
out << c;
}
};
for (size_t line = rng.begin.line; line <= rng.end.line; line++) {
if (line < source.file->content.lines.size() + 1) {
auto len = source.file->content.lines[line - 1].size();
out << source.file->content.lines[line - 1];
out << std::endl;
if (line == rng.begin.line && line == rng.end.line) {
// Single line
repeat(' ', rng.begin.column - 1);
repeat('^', std::max<size_t>(rng.end.column - rng.begin.column, 1));
} else if (line == rng.begin.line) {
// Start of multi-line
repeat(' ', rng.begin.column - 1);
repeat('^', len - (rng.begin.column - 1));
} else if (line == rng.end.line) {
// End of multi-line
repeat('^', rng.end.column - 1);
} else {
// Middle of multi-line
repeat('^', len);
}
out << std::endl;
}
}
}
}
return out;
}
} // namespace tint