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//===-- ResourceScriptCppFilter.cpp ----------------------------*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===---------------------------------------------------------------------===//
//
// This file implements an interface defined in ResourceScriptCppFilter.h.
//
//===---------------------------------------------------------------------===//
#include "ResourceScriptCppFilter.h"
#include "llvm/ADT/StringExtras.h"
#include <vector>
using namespace llvm;
namespace {
class Filter {
public:
explicit Filter(StringRef Input) : Data(Input), DataLength(Input.size()) {}
std::string run();
private:
// Parse the line, returning whether the line should be included in
// the output.
bool parseLine(StringRef Line);
bool streamEof() const;
StringRef Data;
size_t DataLength;
size_t Pos = 0;
bool Outputting = true;
};
std::string Filter::run() {
std::vector<StringRef> Output;
while (!streamEof() && Pos != StringRef::npos) {
size_t LineStart = Pos;
Pos = Data.find_first_of("\r\n", Pos);
Pos = Data.find_first_not_of("\r\n", Pos);
StringRef Line = Data.take_front(Pos).drop_front(LineStart);
if (parseLine(Line))
Output.push_back(Line);
}
return llvm::join(Output, "");
}
bool Filter::parseLine(StringRef Line) {
Line = Line.ltrim();
if (!Line.consume_front("#")) {
// A normal content line, filtered according to the current mode.
return Outputting;
}
// Found a preprocessing directive line. From here on, we always return
// false since the preprocessing directives should be filtered out.
Line.consume_front("line");
if (!Line.startswith(" "))
return false; // Not a line directive (pragma etc).
// #line 123 "path/file.h"
// # 123 "path/file.h" 1
Line =
Line.ltrim(); // There could be multiple spaces after the #line directive
size_t N;
if (Line.consumeInteger(10, N)) // Returns true to signify an error
return false;
Line = Line.ltrim();
if (!Line.consume_front("\""))
return false; // Malformed line, no quote found.
// Split the string at the last quote (in case the path name had
// escaped quotes as well).
Line = Line.rsplit('"').first;
StringRef Ext = Line.rsplit('.').second;
if (Ext.equals_lower("h") || Ext.equals_lower("c")) {
Outputting = false;
} else {
Outputting = true;
}
return false;
}
bool Filter::streamEof() const { return Pos == DataLength; }
} // anonymous namespace
namespace llvm {
std::string filterCppOutput(StringRef Input) { return Filter(Input).run(); }
} // namespace llvm