Subj : Compiling from source
To   : tenser
From : Oli
Date : Mon Jan 18 2021 16:49:55

tenser wrote (2021-01-19):

 Ol>> I still get warnings like:

 Ol>> $ ./makespoon
 Ol>> spoon.cpp:60:7: warning: built-in function ‘logf’ declared as
 Ol>> non-function [-Wbuiltin-declaration-mismatch]
 Ol>>  FILE *logf = NULL;
 Ol>>        ^~~~

 t> Ah, this is due to an unfortunate name.  `logf` is the
 t> name of a function from the standard math library
 t> (single-precision floating point natural logarithm),

that worked.

 Ol>> spoon.cpp: In function ‘void checkdir(char*)’:
 Ol>> spoon.cpp:143:69: warning: ISO C++ forbids converting a string
 Ol>> constant to ‘char*’ [-Wwrite-strings]
 Ol>>        logprintf("FATAL ERROR: subdirectory %s does not exist\n",
 Ol>> dir);

 Ol>> but it compiles and run.

 t> This is a single type error.  `logprintf` is probably
 t> defined to take `char *` as its first argument; this
 t> warning is saying that one is passing a string constant
 t> as that argument, but that the function is defined so
 t> that it could mutate the thing it points to.  The fix
 t> here is to add a `const` qualifier to the argument.

void logprintf(const char *s, ...);

compiles, but so does

void logprintf(char const *s, ...);

is it the same?

---
 * Origin: this message must NOT be gated to Telegram (21:3/102)

.