laurenthuberdeau
commented
2 months ago Add pnut mode to do only expansion of #include
I must be missing something: what could it do other than expansion?
I didn't have enough space to give a meaningful title to the commit but the description has more information:
Using the
DEBUG_EXPAND_INCLUDESoption makes Pnut read the input file, tokenize it (reading files included in the process), and then output the characters as they are read.This gives a very accurate view of the total lines that are read by Pnut and allows us to compute the size of pnut.c for different backends.
As an example, giving the following program to Pnut compiled with DEBUG_EXPAND_INCLUDES:
// Some comment
#include "file.c"
// And now we include another file, this time in a #if block
#if 1
#include "other_file.c"
#endif
#if 0
#include "conditional_file.c"
#endif
void main() {
...
}will produce:
// Some comment
#include "file.c" // INCLUDED
[Content of file.c]
// And now we include another file, this time in a #if block
#if 1
#include "other_file.c" // INCLUDED
[Content of file.c]
#endif
#if 0
#include "conditional_file.c"
#endif
void main() {
...
}And then by removing the lines ending in // INCLUDED, we get a valid C file where active #include directives are replaced by the content of the file they include.
This is used by the analysis/measure-file-size.sh script to compute the size of the source code used by the different pnut compilers we have (pnut-sh, pnut-exe):
➜ ./analysis/measure-file-size.sh
########## pnut-sh ##########
By file:
3251 10551 81401 pnut.c
2510 12257 99333 sh.c
918 4004 36919 sh-runtime.c
6679 26812 217653 total
By file (without comments or blank lines):
2443 7656 63766 build/measure/pnut.c
1950 8658 77587 build/measure/sh.c
861 3802 35480 build/measure/sh-runtime.c
5254 20116 176833 total
Expanded includes:
6679 26808 217615 build/measure/pnut-sh.c
7171 31257 230897 build/measure/pnut-sh.sh
Ratio (Original): 7171/6679 = 1.073
Ratio (Cleaned): 7171/5254 = 1.364
########## pnut-i386_linux ##########
By file:
3251 10551 81401 pnut.c
707 3181 23341 x86.c
2213 7884 65691 exe.c
103 564 4896 elf.c
6274 22180 175329 total
By file (without comments or blank lines):
2443 7656 63766 build/measure/pnut.c
441 1158 9348 build/measure/x86.c
1766 5941 54394 build/measure/exe.c
80 188 2125 build/measure/elf.c
4730 14943 129633 total
Expanded includes:
6274 22174 175280 build/measure/pnut-i386_linux.c
6131 25368 178213 build/measure/pnut-i386_linux.sh
Ratio (Original): 6131/6274 = .977
Ratio (Cleaned): 6131/4730 = 1.296
I must be missing something: what could it do other than expansion?