Clang vs GCC para mi proyecto de desarrollo de Linux

 C Programming >> Programación C >  >> Tags >> Clang
Clang vs GCC para mi proyecto de desarrollo de Linux


Estoy en la universidad y para un proyecto estamos usando C. Hemos explorado GCC y Clang, y Clang parece ser mucho más fácil de usar que GCC. Como resultado, me pregunto cuáles son las ventajas o desventajas de usar clang, en lugar de GCC, para desarrollar en C y C++ en Linux.


En mi caso, esto se usaría para programas de nivel de estudiante, no para producción.


Si uso Clang, ¿debo depurar con GDB y usar GNU Make, o usar otro depurador y hacer la utilidad?


Respuestas:


EDITAR:


Los muchachos de gcc realmente mejoraron la experiencia de diagnóstico en gcc (competencia ah). Crearon una página wiki para mostrarlo aquí. gcc 4.8 ahora también tiene diagnósticos bastante buenos (gcc 4.9x soporte de color agregado). Clang todavía está a la cabeza, pero la brecha se está cerrando.



Original:


Para los estudiantes, recomendaría incondicionalmente a Clang.


El rendimiento en términos de código generado entre gcc y Clang ahora no está claro (aunque creo que gcc 4.7 todavía lleva la delantera, aún no he visto puntos de referencia concluyentes), pero que los estudiantes aprendan no importa de todos modos.


Por otro lado, los diagnósticos extremadamente claros de Clang son definitivamente más fáciles de interpretar para los principiantes.


Considere este fragmento simple:


#include <string>
#include <iostream>
struct Student {
std::string surname;
std::string givenname;
}
std::ostream& operator<<(std::ostream& out, Student const& s) {
return out << "{" << s.surname << ", " << s.givenname << "}";
}
int main() {
Student me = { "Doe", "John" };
std::cout << me << "\n";
}

Notarás de inmediato que falta el punto y coma después de la definición del Student clase, ¿verdad :) ?


Bueno, gcc también lo nota, de alguna manera:


prog.cpp:9: error: expected initializer before ‘&’ token
prog.cpp: In function ‘int main()’:
prog.cpp:15: error: no match for ‘operator<<’ in ‘std::cout << me’
/usr/lib/gcc/i686-pc-linux-gnu/4.3.4/include/g++-v4/ostream:112: note: candidates are: std::basic_ostream<_CharT, _Traits>& std::basic_ostream<_CharT, _Traits>::operator<<(std::basic_ostream<_CharT, _Traits>& (*)(std::basic_ostream<_CharT, _Traits>&)) [with _CharT = char, _Traits = std::char_traits<char>]
/usr/lib/gcc/i686-pc-linux-gnu/4.3.4/include/g++-v4/ostream:121: note: std::basic_ostream<_CharT, _Traits>& std::basic_ostream<_CharT, _Traits>::operator<<(std::basic_ios<_CharT, _Traits>& (*)(std::basic_ios<_CharT, _Traits>&)) [with _CharT = char, _Traits = std::char_traits<char>]
/usr/lib/gcc/i686-pc-linux-gnu/4.3.4/include/g++-v4/ostream:131: note: std::basic_ostream<_CharT, _Traits>& std::basic_ostream<_CharT, _Traits>::operator<<(std::ios_base& (*)(std::ios_base&)) [with _CharT = char, _Traits = std::char_traits<char>]
/usr/lib/gcc/i686-pc-linux-gnu/4.3.4/include/g++-v4/ostream:169: note: std::basic_ostream<_CharT, _Traits>& std::basic_ostream<_CharT, _Traits>::operator<<(long int) [with _CharT = char, _Traits = std::char_traits<char>]
/usr/lib/gcc/i686-pc-linux-gnu/4.3.4/include/g++-v4/ostream:173: note: std::basic_ostream<_CharT, _Traits>& std::basic_ostream<_CharT, _Traits>::operator<<(long unsigned int) [with _CharT = char, _Traits = std::char_traits<char>]
/usr/lib/gcc/i686-pc-linux-gnu/4.3.4/include/g++-v4/ostream:177: note: std::basic_ostream<_CharT, _Traits>& std::basic_ostream<_CharT, _Traits>::operator<<(bool) [with _CharT = char, _Traits = std::char_traits<char>]
/usr/lib/gcc/i686-pc-linux-gnu/4.3.4/include/g++-v4/bits/ostream.tcc:97: note: std::basic_ostream<_CharT, _Traits>& std::basic_ostream<_CharT, _Traits>::operator<<(short int) [with _CharT = char, _Traits = std::char_traits<char>]
/usr/lib/gcc/i686-pc-linux-gnu/4.3.4/include/g++-v4/ostream:184: note: std::basic_ostream<_CharT, _Traits>& std::basic_ostream<_CharT, _Traits>::operator<<(short unsigned int) [with _CharT = char, _Traits = std::char_traits<char>]
/usr/lib/gcc/i686-pc-linux-gnu/4.3.4/include/g++-v4/bits/ostream.tcc:111: note: std::basic_ostream<_CharT, _Traits>& std::basic_ostream<_CharT, _Traits>::operator<<(int) [with _CharT = char, _Traits = std::char_traits<char>]
/usr/lib/gcc/i686-pc-linux-gnu/4.3.4/include/g++-v4/ostream:195: note: std::basic_ostream<_CharT, _Traits>& std::basic_ostream<_CharT, _Traits>::operator<<(unsigned int) [with _CharT = char, _Traits = std::char_traits<char>]
/usr/lib/gcc/i686-pc-linux-gnu/4.3.4/include/g++-v4/ostream:204: note: std::basic_ostream<_CharT, _Traits>& std::basic_ostream<_CharT, _Traits>::operator<<(long long int) [with _CharT = char, _Traits = std::char_traits<char>]
/usr/lib/gcc/i686-pc-linux-gnu/4.3.4/include/g++-v4/ostream:208: note: std::basic_ostream<_CharT, _Traits>& std::basic_ostream<_CharT, _Traits>::operator<<(long long unsigned int) [with _CharT = char, _Traits = std::char_traits<char>]
/usr/lib/gcc/i686-pc-linux-gnu/4.3.4/include/g++-v4/ostream:213: note: std::basic_ostream<_CharT, _Traits>& std::basic_ostream<_CharT, _Traits>::operator<<(double) [with _CharT = char, _Traits = std::char_traits<char>]
/usr/lib/gcc/i686-pc-linux-gnu/4.3.4/include/g++-v4/ostream:217: note: std::basic_ostream<_CharT, _Traits>& std::basic_ostream<_CharT, _Traits>::operator<<(float) [with _CharT = char, _Traits = std::char_traits<char>]
/usr/lib/gcc/i686-pc-linux-gnu/4.3.4/include/g++-v4/ostream:225: note: std::basic_ostream<_CharT, _Traits>& std::basic_ostream<_CharT, _Traits>::operator<<(long double) [with _CharT = char, _Traits = std::char_traits<char>]
/usr/lib/gcc/i686-pc-linux-gnu/4.3.4/include/g++-v4/ostream:229: note: std::basic_ostream<_CharT, _Traits>& std::basic_ostream<_CharT, _Traits>::operator<<(const void*) [with _CharT = char, _Traits = std::char_traits<char>]
/usr/lib/gcc/i686-pc-linux-gnu/4.3.4/include/g++-v4/bits/ostream.tcc:125: note: std::basic_ostream<_CharT, _Traits>& std::basic_ostream<_CharT, _Traits>::operator<<(std::basic_streambuf<_CharT, _Traits>*) [with _CharT = char, _Traits = std::char_traits<char>]

Y Clang tampoco protagoniza exactamente aquí, pero aún así:


/tmp/webcompile/_25327_1.cc:9:6: error: redefinition of 'ostream' as different kind of symbol
std::ostream& operator<<(std::ostream& out, Student const& s) {
^
In file included from /tmp/webcompile/_25327_1.cc:1:
In file included from /usr/include/c++/4.3/string:49:
In file included from /usr/include/c++/4.3/bits/localefwd.h:47:
/usr/include/c++/4.3/iosfwd:134:33: note: previous definition is here
typedef basic_ostream<char> ostream; ///< @isiosfwd
^
/tmp/webcompile/_25327_1.cc:9:13: error: expected ';' after top level declarator
std::ostream& operator<<(std::ostream& out, Student const& s) {
^
;
2 errors generated.

Elijo a propósito un ejemplo que desencadena un mensaje de error poco claro (procedente de una ambigüedad en la gramática) en lugar de los ejemplos típicos de "Oh, Dios mío, Clang lee mi mente". Aún así, notamos que Clang evita la avalancha de errores. No hay necesidad de asustar a los estudiantes.


Algunas respuestas de código


#include <string>
#include <iostream>
struct Student { std::string surname;
std::string givenname;
} std::ostream&
operator<<(std::ostream&
out, Student const&
s) { return out <<
"{" <<
s.surname <<
", " <<
s.givenname <<
"}";
} int main() { Student me = { "Doe", "John" };
std::cout <<
me <<
"\n";
}
prog.cpp:9: error: expected initializer before ‘&’ token prog.cpp: In function ‘int main()’: prog.cpp:15: error: no match for ‘operator<<’ in ‘std::cout <<
me’ /usr/lib/gcc/i686-pc-linux-gnu/4.3.4/include/g++-v4/ostream:112: note: candidates are: std::basic_ostream<_CharT, _Traits>&
std::basic_ostream<_CharT, _Traits>::operator<<(std::basic_ostream<_CharT, _Traits>&
(*)(std::basic_ostream<_CharT, _Traits>&)) [with _CharT = char, _Traits = std::char_traits<char>] /usr/lib/gcc/i686-pc-linux-gnu/4.3.4/include/g++-v4/ostream:121: note:
std::basic_ostream<_CharT, _Traits>&
std::basic_ostream<_CharT, _Traits>::operator<<(std::basic_ios<_CharT, _Traits>&
(*)(std::basic_ios<_CharT, _Traits>&)) [with _CharT = char, _Traits = std::char_traits<char>] /usr/lib/gcc/i686-pc-linux-gnu/4.3.4/include/g++-v4/ostream:131: note:
std::basic_ostream<_CharT, _Traits>&
std::basic_ostream<_CharT, _Traits>::operator<<(std::ios_base&
(*)(std::ios_base&)) [with _CharT = char, _Traits = std::char_traits<char>] /usr/lib/gcc/i686-pc-linux-gnu/4.3.4/include/g++-v4/ostream:169: note:
std::basic_ostream<_CharT, _Traits>&
std::basic_ostream<_CharT, _Traits>::operator<<(long int) [with _CharT = char, _Traits = std::char_traits<char>] /usr/lib/gcc/i686-pc-linux-gnu/4.3.4/include/g++-v4/ostream:173: note:
std::basic_ostream<_CharT, _Traits>&
std::basic_ostream<_CharT, _Traits>::operator<<(long unsigned int) [with _CharT = char, _Traits = std::char_traits<char>] /usr/lib/gcc/i686-pc-linux-gnu/4.3.4/include/g++-v4/ostream:177: note:
std::basic_ostream<_CharT, _Traits>&
std::basic_ostream<_CharT, _Traits>::operator<<(bool) [with _CharT = char, _Traits = std::char_traits<char>] /usr/lib/gcc/i686-pc-linux-gnu/4.3.4/include/g++-v4/bits/ostream.tcc:97: note:
std::basic_ostream<_CharT, _Traits>&
std::basic_ostream<_CharT, _Traits>::operator<<(short int) [with _CharT = char, _Traits = std::char_traits<char>] /usr/lib/gcc/i686-pc-linux-gnu/4.3.4/include/g++-v4/ostream:184: note:
std::basic_ostream<_CharT, _Traits>&
std::basic_ostream<_CharT, _Traits>::operator<<(short unsigned int) [with _CharT = char, _Traits = std::char_traits<char>] /usr/lib/gcc/i686-pc-linux-gnu/4.3.4/include/g++-v4/bits/ostream.tcc:111: note:
std::basic_ostream<_CharT, _Traits>&
std::basic_ostream<_CharT, _Traits>::operator<<(int) [with _CharT = char, _Traits = std::char_traits<char>] /usr/lib/gcc/i686-pc-linux-gnu/4.3.4/include/g++-v4/ostream:195: note:
std::basic_ostream<_CharT, _Traits>&
std::basic_ostream<_CharT, _Traits>::operator<<(unsigned int) [with _CharT = char, _Traits = std::char_traits<char>] /usr/lib/gcc/i686-pc-linux-gnu/4.3.4/include/g++-v4/ostream:204: note:
std::basic_ostream<_CharT, _Traits>&
std::basic_ostream<_CharT, _Traits>::operator<<(long long int) [with _CharT = char, _Traits = std::char_traits<char>] /usr/lib/gcc/i686-pc-linux-gnu/4.3.4/include/g++-v4/ostream:208: note:
std::basic_ostream<_CharT, _Traits>&
std::basic_ostream<_CharT, _Traits>::operator<<(long long unsigned int) [with _CharT = char, _Traits = std::char_traits<char>] /usr/lib/gcc/i686-pc-linux-gnu/4.3.4/include/g++-v4/ostream:213: note:
std::basic_ostream<_CharT, _Traits>&
std::basic_ostream<_CharT, _Traits>::operator<<(double) [with _CharT = char, _Traits = std::char_traits<char>] /usr/lib/gcc/i686-pc-linux-gnu/4.3.4/include/g++-v4/ostream:217: note:
std::basic_ostream<_CharT, _Traits>&
std::basic_ostream<_CharT, _Traits>::operator<<(float) [with _CharT = char, _Traits = std::char_traits<char>] /usr/lib/gcc/i686-pc-linux-gnu/4.3.4/include/g++-v4/ostream:225: note:
std::basic_ostream<_CharT, _Traits>&
std::basic_ostream<_CharT, _Traits>::operator<<(long double) [with _CharT = char, _Traits = std::char_traits<char>] /usr/lib/gcc/i686-pc-linux-gnu/4.3.4/include/g++-v4/ostream:229: note:
std::basic_ostream<_CharT, _Traits>&
std::basic_ostream<_CharT, _Traits>::operator<<(const void*) [with _CharT = char, _Traits = std::char_traits<char>] /usr/lib/gcc/i686-pc-linux-gnu/4.3.4/include/g++-v4/bits/ostream.tcc:125: note:
std::basic_ostream<_CharT, _Traits>&
std::basic_ostream<_CharT, _Traits>::operator<<(std::basic_streambuf<_CharT, _Traits>*) [with _CharT = char, _Traits = std::char_traits<char>]
/tmp/webcompile/_25327_1.cc:9:6: error: redefinition of 'ostream' as different kind of symbol std::ostream&
operator<<(std::ostream&
out, Student const&
s) {
^ In file included from /tmp/webcompile/_25327_1.cc:1: In file included from /usr/include/c++/4.3/string:49: In file included from /usr/include/c++/4.3/bits/localefwd.h:47: /usr/include/c++/4.3/iosfwd:134:33: note: previous definition is here typedef basic_ostream<char>
ostream;
///<
@isiosfwd
^ /tmp/webcompile/_25327_1.cc:9:13: error: expected ';' after top level declarator std::ostream&
operator<<(std::ostream&
out, Student const&
s) { ^ ;
2 errors generated.
main() {
puts("Hello, world!");
}