클랜 ++
방금이 재미있는 버그를 발견했습니다.
#include <iostream>
#include <string>
#include <sstream>
#include <fstream>
std::stringstream prog;
constexpr unsigned c_strlen( char const* str, unsigned count = 0 )
{
return ('\0' == str[0]) ? count : c_strlen(str+1, count+1);
}
template < char t_c, char... tt_c >
struct rec_eval
{
static void eval()
{
rec_eval<t_c>::eval();
rec_eval < tt_c... > :: eval ();
}
};
template < char t_c >
struct rec_eval < t_c >
{
static void eval() {
switch(t_c) {
case '+':
prog<<"++t[i];";
break;
case '-':
prog<<"--t[i];";
break;
case '>':
prog<<"++i;";
break;
case '<':
prog<<"--i;";
break;
case '[':
prog<<"while(t[i]){";
break;
case ']':
prog<<"}";
break;
case '.':
prog<<"putc(t[i],stdout);";
break;
case ',':
prog<<"t[i]=getchar();";
break;
}
}
};
template < char... tt_c >
struct exploded_string
{
static void eval()
{
rec_eval < tt_c... > :: eval();
}
};
template < typename T_StrProvider, unsigned t_len, char... tt_c >
struct explode_impl
{
using result =
typename explode_impl < T_StrProvider, t_len-1,
T_StrProvider::str()[t_len-1],
tt_c... > :: result;
};
template < typename T_StrProvider, char... tt_c >
struct explode_impl < T_StrProvider, 0, tt_c... >
{
using result = exploded_string < tt_c... >;
};
template < typename T_StrProvider >
using explode =
typename explode_impl < T_StrProvider,
c_strlen(T_StrProvider::str()) > :: result;
int main(int argc, char** argv)
{
if(argc < 2) return 1;
prog << "#include <stdio.h>\n#include <stdlib.h>\nint main(){unsigned char* t=calloc(";
prog << (1 << sizeof(unsigned short));
prog << ",sizeof(unsigned short));unsigned short i=0;";
struct my_str_provider
{
constexpr static char const* str() { return "++++[>+++++<-]>+++[[>+>+<<-]>++++++[<+>-]+++++++++[<++++++++++>-]>[<+>-]<-]+++>+++++++++[<+++++++++>-]>++++++[<++++++++>-]<--[>+>+<<-]>>[<<+>>-]<-->>++++[<++++++++>-]++++++++++>+++++++++[>+++++++++++<-]>[[>+>+>+<<<-]>[<+>-]>>[[>+>+<<-]>>[<<+>>-]<[<->-[<->-[<->-[<->-[<->-[<->-[<->-[<->-[<->-[<<<+>---------->->[-]]]]]]]]]]]<]<<[>>++++++++++++[<++++<++++>>-]<<[.[-]>]<<]>[<++++++[>++++++++<-]>.[-]]<<<<<.<<<<<.[<]>>>>>>>>>.<<<<<..>>>>>>>>.>>>>>>>.[>]>[>+>+<<-]>[<+>-]>[-[[-]+++++++++[<+++++++++++++>-]<--.[-]>]]<<<<<.[<]>>>>>>>>>.>>>>>>>>>.[>]<<.<<<<<.<<<..[<]>>>>>>.[>]<<.[<]>>>>>>>>>.>.[>]<<.[<]>>>>.>>>>>>>>>>>>.>>>.[>]<<.[<]>.[>]<<<<<<.<<<<<<<<<<<..[>]<<<.>.[>]>[>+>+>+<<<-]>[<+>-]>>[[>+>+<<-]>>[<<+>>-]<[<->-[<->-[<->-[<->-[<->-[<->-[<->-[<->-[<->-[<<<+>---------->->[-]]]]]]]]]]]<]<<[>>++++++++++++[<++++<++++>>-]<<[.[-]>]<<]>[<++++++[>++++++++<-]>.[-]]<<<<<.<<<<<.[<]>>>>>>>>>.<<<<<..>>>>>>>>.>>>>>>>.[>]>[>+>+<<-]>[<+>-]>[-[[-]+++++++++[<+++++++++++++>-]<--.[-]>]]<<<<<.[<]>>>>>>>>>.>>>>>>>>>.[>]<<.<<<<<.<<<..[<]>>>>>>.[>]<<<<.>>>.<<<<.<.<<<<<<<<<<.>>>>>>.[>]<<.[<]>>>>>>>>>.>.>>>>>>>>>.[>]<<.<<<<<<<.[<]>>>>>>>>>.[<]>.>>>>>>>>>.[>]<<.<<<<.<<<<<<<<<<<<<.[>]<<<<<<<<<.[>]<<.[<]>>>>>>>>.[>]<<<<<<.[<]>>>>>..[>]<<.<<<<<<<<<<<<.[<]>>>>.[>]<<.<<<<.[<]>>>>>>.>>>.<<<<<<.>>>>>>>.>>>>>>>>>>.[>]<<<.>.>>>-[>+>+>+<<<-]>[<+>-]>>[[>+>+<<-]>>[<<+>>-]<[<->-[<->-[<->-[<->-[<->-[<->-[<->-[<->-[<->-[<<<+>---------->->[-]]]]]]]]]]]<]<<[>>++++++++++++[<++++<++++>>-]<<[.[-]>]<<]>[<++++++[>++++++++<-]>.[-]]<<[>+>+<<-]>[<+>-]+>[<->[-]]<[-<<<[<]>>>>>>>>>>.<.[>]<<.[<]>>>>>>>>>>>.<<.<<<.[>]<<<<<<<<<<.[>]>>]<<<<.<<<<<.[<]>>>>>>>>>.<<<<<..>>>>>>>>.>>>>>>>.[>]>[>+>+<<-]>[<+>-]+>[<->-[<+>[-]]]<[++++++++[>+++++++++++++<-]>--.[-]<]<<<<.[<]>>>>>>>>>.>>>>>>>>>.[>]<<.<<<<<.<<<..[<]>>>>>>.[>]<<.[<]>>>>>>>>>.>.[>]<<.[<]>>>>.>>>>>>>>>>>>.>>>.[>]<<.[<]>.[>]<<<<<<.<<<<<<<<<<<..[>]<<<<.>>>..>>]"; }
};
auto my_str = explode < my_str_provider >{};
my_str.eval();
prog << "}";
std::ofstream ofs(argv[1]);
if(!ofs) return 2;
ofs << prog.str() << std::endl;
ofs.close();
return 0;
}
목표는 템플릿 메타 프로그래밍을 사용하여 대부분의 작업을 수행하는 Brainfuck을 C로 변환하는 것입니다. 이 코드는 Hello World와 같은 작은 Brainfuck 프로그램에서 작동하지만 99 병으로 실행하려고 할 때 ...
$ clang++ -std=c++11 -fconstexpr-depth=1000 bf_static.cpp
clang: error: unable to execute command: Segmentation fault (core dumped)
clang: error: clang frontend command failed due to signal (use -v to see invocation)
clang version 3.5.2 (tags/RELEASE_352/final)
Target: i386-pc-windows-cygnus
Thread model: posix
clang: note: diagnostic msg: PLEASE submit a bug report to http://llvm.org/bugs/ and include the crash backtrace, preprocessed source, and associated run script.
clang: note: diagnostic msg:
********************
PLEASE ATTACH THE FOLLOWING FILES TO THE BUG REPORT:
Preprocessed source(s) and associated run script(s) are located at:
clang: note: diagnostic msg: /tmp/bf_static-afa982.cpp
clang: note: diagnostic msg: /tmp/bf_static-afa982.sh
clang: note: diagnostic msg:
********************
약 2 분 후에 GCC에서 성공적으로 컴파일되지만 링크하면 다른 문제가 발생합니다 ...
/usr/lib/gcc/i686-pc-cygwin/4.9.3/../../../../i686-pc-cygwin/bin/as: /tmp/cc0W7cJu.o:
section .eh_frame$_ZN8rec_eval<giant mangled name removed>: string table overflow at offset 10004228
/tmp/cc3JeiMp.s: Assembler messages:
/tmp/cc3JeiMp.s: Fatal error: can't close /tmp/cc0W7cJu.o: File too big
죄송합니다.
