Will the string defined by a statement like:
#define CADENA "stringy string\n"
be duplicated in all the .c files where it is being used ? If that is the case then the executable code will grow considerably which is not a good thing. Consider this code:
[niko@dev1 snippets]$ cat str.c
#include <stdio.h>
#define CADENA "stringy string\n"
void printit(char *s) {
printf("%s",s);
}
void main(void) {
printit(CADENA);
printit(CADENA);
}
[niko@dev1 snippets]$ gcc -o str str.c
[niko@dev1 snippets]$ ./str
stringy string
stringy string
[niko@dev1 snippets]$
Will the compiler create 2 constant strings in this case or just one ? If it is just a single one then how do you control if the content of the #define directive is copied or a unique reference is made ? Does GCC has any switch or command line option for this?
I checked out what the preprocessor generates, and indeed, the string is duplicated:
[niko@dev1 snippets]$ gcc -E str.c | tail
# 5 "str.c"
void printit(char *s) {
printf("%s",s);
}
void main(void) {
printit("stringy string\n");
printit("stringy string\n");
}
[niko@dev1 snippets]$
In a real use case:
if (some condition) {
fatal_error(__FILE__,__LINE__,"Can't write to socket");
}
I am using the constant __FILE__ for debugging purposes, should I better store it in a variable to reduce the code size?
