llvm/tools/llvm-rc/ResourceScriptCppFilter.h
Martin Storsjo d5e933640f [llvm-rc] Handle C preprocessor output
When preprocessing resource scripts (which can easily be done outside
of llvm-rc), included headers can leave behind C declarations (despite
preprocessing with -DRC_INVOKED), that can't be parsed by a resource
compiler.

This is handled in all of rc.exe, by parsing the preprocessor output
line markers and ignoring content from files named *.h and *.c,
documented at [1].

In addition to this filtering, strip out any other preprocessor directive
that is left behind (like pragmas) which also can't be handled by the
tokenizer.

The added test uses both standard #line markers (supported by rc.exe) and
GNU style extended line markers, thus this test doesn't pass with rc.exe,
but passes with GNU windres. (Windres on the other hand doesn't filter
out files named *.c, only *.h.)

Differential Revision: https://reviews.llvm.org/D46579

[1] https://msdn.microsoft.com/en-us/library/windows/desktop/aa381033(v=vs.85).aspx

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@331903 91177308-0d34-0410-b5e6-96231b3b80d8
2018-05-09 18:21:03 +00:00

36 lines
1.2 KiB
C++

//===-- ResourceScriptCppFilter.h ------------------------------*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===---------------------------------------------------------------------===//
//
// This filters the input to llvm-rc for preprocessor markers, removing
// preprocessing directives that a preprocessor can output or leave behind.
//
// It also filters out any contribution from files named *.h or *.c, based
// on preprocessor line markers. When preprocessing RC files, the included
// headers can leave behind C declarations, that RC doesn't understand.
// Rc.exe simply discards anything that comes from files named *.h or *.h.
//
// https://msdn.microsoft.com/en-us/library/windows/desktop/aa381033(v=vs.85).aspx
//
//===---------------------------------------------------------------------===//
#ifndef LLVM_TOOLS_LLVMRC_RESOURCESCRIPTCPPFILTER_H
#define LLVM_TOOLS_LLVMRC_RESOURCESCRIPTCPPFILTER_H
#include "llvm/ADT/StringRef.h"
#include <string>
namespace llvm {
std::string filterCppOutput(StringRef Input);
} // namespace llvm
#endif