Re: question about linker

On 03/12/2024 21:51, Bart wrote:

On 03/12/2024 14:34, David Brown wrote:

On 02/12/2024 22:53, Bart wrote:

 

For the project-specific code, rather than libraries, SDK, etc.:
>
-----------------------------------------------------------------------
Language             files          blank        comment           code
-----------------------------------------------------------------------
C++                     39           2217           1020          11820
C/C++ Header            44           1078            798           2696
C                        3            259            237           1152
-----------------------------------------------------------------------
SUM:                    86           3554           2055          15668
------------------------------------------------------------------------
>

 

Not that it really matters, but a typical build for my project takes about 1 to 3 seconds.

 I don't really know what they means, because I don't know is involved, and what is being missed out.
 So, to get an idea of how long gcc really takes (or would take on my machine), I set up a comparable test. I took an 800-line C program, and duplicated it in 200 separate files f1.c to f200.c, for a total line count of 167Kloc.
 gcc took 30 to 90 seconds to create an EXE using -O0 and -O2.
 Under WSL, it took 18 to 54 seconds 'real time' (to .o files; it can't link due to Win32 imports).
 Tiny C took 0.64 seconds.
 My two C compilers were rubbish so I won't report those timings (the newer one only works a file at a time anyway so needs invoking 200 times).

The timing from one was about 9 seconds when it was generating 200 .obj files, before I tweaked things to allow an EXE to be created (by using 'static' in each file to avoid clashes).
If I also include my original compiler when I strived to make multiple files more efficient, then timings on Windows are:
   mm   0.53 seconds  (Non-C test inputs)
   tcc  0.64 seconds
   bcc  1    second
   mcc  3    seconds
   cc   5    seconds (to produce 200 .obj files)
   gcc 32    seconds (-O0, v.14.1; the WSL timing was for 9.4)
The original 93 seconds for gcc-O2 was for a test using non-static functions and generating 200 .o files. I reran it for EXE using -O0 but not with -O2.
If I do so now, gcc-O2 takes 18 seconds, but it produces a too-small EXE file. Presumably it is largely discarding the 199 modules that comprise only static functions.
So that timing is erroneous.