Do away with memcpy/memset/memcmp

Now everything is either explicitly a rep thing, or explicitly some
other small run of reasonably efficient instructions. No library calls
or function call overhead of any kind. Code size remains nice and small.

Ban a few other bad libc functions while we're at it. More can be added
later if we decide that's a useful idea.

This will require some discipline and workarounds to cope with Clang's
tendency to shove mem* calls in places you don't want them even when you
tell it not to. Well, c'est la vie.

I'm a little nervous that the __builtin_memmove() usage in shuntvars()
could still one day emit actual library calls. It appears we're not
importing memmove() from anywhere at the moment, though. So I guess it's
good enough for now.

Also I had to get rid of alloca() in con_.c but that was kind of bad
anyway, so that's fine.

1 files changed, 1 insertions, 4 deletions

diff --git a/src/os.h b/src/os.h
index 83b5d32..6466e45 100644
--- a/src/os.h
+++ b/src/os.h
@@ -120,10 +120,7 @@ typedef char os_char;
 #endif
 
 /* Copies n characters from src to dest, using the OS-specific char type. */
-static inline void os_spancopy(os_char *restrict dest,
-		const os_char *restrict src, int n) {
-	memcpy(dest, src, n * sizeof(os_char));
-}
+void os_spancopy(os_char *restrict dest, const os_char *restrict src, int n);
 
 /*
  * Returns the last error code from an OS function - equivalent to calling