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, 5 insertions, 3 deletions

diff --git a/src/sst.c b/src/sst.c
index 070ce12..f5f61bd 100644
--- a/src/sst.c
+++ b/src/sst.c
@@ -180,7 +180,7 @@ DEF_CCMD_HERE(sst_autoload_enable, "Register SST to load on game startup", 0) {
 			}
 		}
 	}
-c:	memcpy(r, p + slash + 1, rellen);
+c:	mem_copy(r, p + slash + 1, rellen);
 #endif
 	int len = os_strlen(gameinfo_gamedir);
 	if (len + ssizeof("/addons/" VDFBASENAME ".vdf") > countof(path)) {
@@ -200,9 +200,11 @@ c:	memcpy(r, p + slash + 1, rellen);
 	if_cold (f == -1) { errmsg_errorsys("couldn't open %" fS, path); return; }
 #ifdef _WIN32
 	char buf[19 + PATH_MAX];
-	memcpy(buf, "Plugin { file \"", 15);
+	// XXX: with actual calls to memcpy gone, we need this builtin to produce 4
+	// 4-byte movs from this string; can we expose this in a less hideous way?
+	__builtin_memcpy_inline(buf, "Plugin { file \"", 15);
 	for (int i = 0; i < rellen; ++i) buf[i + 15] = relpath[i];
-	memcpy(buf + 15 + rellen, "\" }\n", 4);
+	__builtin_memcpy_inline(buf + 15 + rellen, "\" }\n", 4);
 	if_cold (os_write(f, buf, rellen + 19) == -1) { // blegh
 #else
 	struct iovec iov[3] = {