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, 4 insertions, 3 deletions

diff --git a/src/con_.h b/src/con_.h
index eb03642..5de5608 100644
--- a/src/con_.h
+++ b/src/con_.h
@@ -19,6 +19,7 @@
 #define INC_CON_H
 
 #include "intdefs.h"
+#include "mem.h"
 
 #if defined(__GNUC__) || defined(__clang__)
 #define _CON_PRINTF(x, y) __attribute((format(printf, (x), (y))))
@@ -417,10 +418,10 @@ extern struct _con_vtab_iconvar_wrap {
 			   and back to avoid confusing side effects for the caller. */ \
 			/* XXX: not bothering with the null term here; should we be? */ \
 			const char *_orig_argv[80]; \
-			memcpy(_orig_argv, _con_argv, _orig_argc * sizeof(*argv)); \
-			memcpy(_con_argv, argv, argc * sizeof(*argv)); \
+			mem_copy(_orig_argv, _con_argv, _orig_argc * sizeof(*argv)); \
+			mem_copy(_con_argv, argv, argc * sizeof(*argv)); \
 			_orig_##name##_cb.v1(); \
-			memcpy(_con_argv, _orig_argv, _orig_argc * sizeof(*argv)); \
+			mem_copy(_con_argv, _orig_argv, _orig_argc * sizeof(*argv)); \
 		} \
 		else { \
 			_orig_##name##_cb.v1(); \