| 1 |
On Thu 29 Sep 2011 11:10:00 PM IST, Michael Mol wrote: |
| 2 |
> On Thu, Sep 29, 2011 at 1:27 PM, Nilesh Govindarajan |
| 3 |
> <contact@××××××××.com> wrote: |
| 4 |
>> Default function arguments in C are specified like this: |
| 5 |
>> |
| 6 |
>> int func(int a = 10) {} // just a dummy function |
| 7 |
>> |
| 8 |
>> Now I save that in a file called foo.c |
| 9 |
>> |
| 10 |
>> The above piece of code is valid in C as well as C++ |
| 11 |
>> |
| 12 |
>> Now see this: |
| 13 |
>> |
| 14 |
>> nilesh@Linux ~ $ cat /tmp/foo.c |
| 15 |
>> int func(int a = 1) {} |
| 16 |
>> nilesh@Linux ~ $ gcc /tmp/foo.c |
| 17 |
>> /tmp/foo.c:1:16: error: expected ‘;’, ‘,’ or ‘)’ before ‘=’ token |
| 18 |
>> nilesh@Linux ~ $ g++ /tmp/foo.c |
| 19 |
>> /usr/lib/gcc/x86_64-pc-linux-gnu/4.5.3/../../../../lib64/crt1.o: In |
| 20 |
>> function `_start': |
| 21 |
>> (.text+0x20): undefined reference to `main' |
| 22 |
>> collect2: ld returned 1 exit status |
| 23 |
>> nilesh@Linux ~ $ gcc -v |
| 24 |
>> Using built-in specs. |
| 25 |
>> COLLECT_GCC=/usr/x86_64-pc-linux-gnu/gcc-bin/4.5.3/gcc |
| 26 |
>> COLLECT_LTO_WRAPPER=/usr/libexec/gcc/x86_64-pc-linux-gnu/4.5.3/lto-wrapper |
| 27 |
>> Target: x86_64-pc-linux-gnu |
| 28 |
>> Configured with: |
| 29 |
>> /media/500GB/gentoo_portage/tmp/portage/sys-devel/gcc-4.5.3-r1/work/gcc-4.5.3/configure |
| 30 |
>> --prefix=/usr --bindir=/usr/x86_64-pc-linux-gnu/gcc-bin/4.5.3 |
| 31 |
>> --includedir=/usr/lib/gcc/x86_64-pc-linux-gnu/4.5.3/include |
| 32 |
>> --datadir=/usr/share/gcc-data/x86_64-pc-linux-gnu/4.5.3 |
| 33 |
>> --mandir=/usr/share/gcc-data/x86_64-pc-linux-gnu/4.5.3/man |
| 34 |
>> --infodir=/usr/share/gcc-data/x86_64-pc-linux-gnu/4.5.3/info |
| 35 |
>> --with-gxx-include-dir=/usr/lib/gcc/x86_64-pc-linux-gnu/4.5.3/include/g++-v4 |
| 36 |
>> --host=x86_64-pc-linux-gnu --build=x86_64-pc-linux-gnu --disable-altivec |
| 37 |
>> --disable-fixed-point --without-ppl --without-cloog --disable-lto |
| 38 |
>> --enable-nls --without-included-gettext --with-system-zlib |
| 39 |
>> --disable-werror --enable-secureplt --enable-multilib |
| 40 |
>> --enable-libmudflap --disable-libssp --enable-libgomp --enable-cld |
| 41 |
>> --with-python-dir=/share/gcc-data/x86_64-pc-linux-gnu/4.5.3/python |
| 42 |
>> --enable-checking=release --disable-libgcj |
| 43 |
>> --enable-languages=c,c++,fortran --enable-shared --enable-threads=posix |
| 44 |
>> --enable-__cxa_atexit --enable-clocale=gnu |
| 45 |
>> --with-bugurl=http://bugs.gentoo.org/ --with-pkgversion='Gentoo 4.5.3-r1 |
| 46 |
>> p1.0, pie-0.4.5' |
| 47 |
>> Thread model: posix |
| 48 |
>> gcc version 4.5.3 (Gentoo 4.5.3-r1 p1.0, pie-0.4.5) |
| 49 |
>> nilesh@Linux ~ $ g++ -v |
| 50 |
>> Using built-in specs. |
| 51 |
>> COLLECT_GCC=/usr/x86_64-pc-linux-gnu/gcc-bin/4.5.3/g++ |
| 52 |
>> COLLECT_LTO_WRAPPER=/usr/libexec/gcc/x86_64-pc-linux-gnu/4.5.3/lto-wrapper |
| 53 |
>> Target: x86_64-pc-linux-gnu |
| 54 |
>> Configured with: |
| 55 |
>> /media/500GB/gentoo_portage/tmp/portage/sys-devel/gcc-4.5.3-r1/work/gcc-4.5.3/configure |
| 56 |
>> --prefix=/usr --bindir=/usr/x86_64-pc-linux-gnu/gcc-bin/4.5.3 |
| 57 |
>> --includedir=/usr/lib/gcc/x86_64-pc-linux-gnu/4.5.3/include |
| 58 |
>> --datadir=/usr/share/gcc-data/x86_64-pc-linux-gnu/4.5.3 |
| 59 |
>> --mandir=/usr/share/gcc-data/x86_64-pc-linux-gnu/4.5.3/man |
| 60 |
>> --infodir=/usr/share/gcc-data/x86_64-pc-linux-gnu/4.5.3/info |
| 61 |
>> --with-gxx-include-dir=/usr/lib/gcc/x86_64-pc-linux-gnu/4.5.3/include/g++-v4 |
| 62 |
>> --host=x86_64-pc-linux-gnu --build=x86_64-pc-linux-gnu --disable-altivec |
| 63 |
>> --disable-fixed-point --without-ppl --without-cloog --disable-lto |
| 64 |
>> --enable-nls --without-included-gettext --with-system-zlib |
| 65 |
>> --disable-werror --enable-secureplt --enable-multilib |
| 66 |
>> --enable-libmudflap --disable-libssp --enable-libgomp --enable-cld |
| 67 |
>> --with-python-dir=/share/gcc-data/x86_64-pc-linux-gnu/4.5.3/python |
| 68 |
>> --enable-checking=release --disable-libgcj |
| 69 |
>> --enable-languages=c,c++,fortran --enable-shared --enable-threads=posix |
| 70 |
>> --enable-__cxa_atexit --enable-clocale=gnu |
| 71 |
>> --with-bugurl=http://bugs.gentoo.org/ --with-pkgversion='Gentoo 4.5.3-r1 |
| 72 |
>> p1.0, pie-0.4.5' |
| 73 |
>> Thread model: posix |
| 74 |
>> gcc version 4.5.3 (Gentoo 4.5.3-r1 p1.0, pie-0.4.5) |
| 75 |
>> |
| 76 |
>> Why is this happening? O_o |
| 77 |
> |
| 78 |
> First guess, you need an int main() function, or you need to tell gcc |
| 79 |
> not to look for one. |
| 80 |
> |
| 81 |
> |
| 82 |
|
| 83 |
Syntax error doesn't depend on existence of main. I just posted this as |
| 84 |
a snippet, I'd been working on one of my practical programs and |
| 85 |
spotted this problem with a function I'd just made. And yeah, my |
| 86 |
program had main(). |
| 87 |
|
| 88 |
-- |
| 89 |
Nilesh Govindarajan |
| 90 |
http://nileshgr.com |
Archives