/*

* Copyright (c) Facebook, Inc. and its affiliates.

*

* This source code is licensed under the MIT license found in the

* LICENSE file in the root directory of this source tree.

*/

#include "hermes/SourceMap/SourceMap.h"

using namespace hermes;

namespace hermes {

llvh::Optional<SourceMapTextLocation> SourceMap::getLocationForAddress(

uint32_t line,

uint32_t column) const {

auto seg = this->getSegmentForAddress(line, column);

// Unmapped location

if (!seg.hasValue() || !seg->representedLocation.hasValue()) {

return llvh::None;

}

// parseSegment() should have validated this.

assert(

(size_t)seg->representedLocation->sourceIndex < sources_.size() &&

"SourceIndex is out-of-range.");

std::string fileName =

getSourceFullPath(seg->representedLocation->sourceIndex);

return SourceMapTextLocation{

std::move(fileName),

(uint32_t)seg->representedLocation->lineIndex + 1,

(uint32_t)seg->representedLocation->columnIndex + 1};

}

llvh::Optional<SourceMap::Segment> SourceMap::getSegmentForAddress(

uint32_t line,

uint32_t column) const {

if (line == 0 || line > lines_.size()) {

return llvh::None;

}

// line is 1-based.

uint32_t lineIndex = line - 1;

auto &segments = lines_[lineIndex];

if (segments.empty()) {

return llvh::None;

}

assert(column >= 1 && "the column argument to this function is 1-based");

uint32_t columnIndex = column - 1;

// Algorithm: we wanted to locate the segment covering

// the needle(`column`) -- segment.generatedColumn <= column.

// We achieve it by binary searching the first sentinel

// segment strictly greater than needle(`column`) and then move backward

// one slot.

auto segIter = std::upper_bound(

segments.begin(),

segments.end(),

columnIndex,

[](uint32_t column, const Segment &seg) {

return column < (uint32_t)seg.generatedColumn;

});

// The found sentinel segment is the first one. No covering segment.

if (segIter == segments.begin()) {

return llvh::None;

}

// Move back one slot.

const Segment &target =

segIter == segments.end() ? segments.back() : *(--segIter);

return target;

}

} // namespace hermes