DNM (needs cleanup): explicitly list functions to be used through c2rust

At this point, the examples build with it.

Author: chrysn

build.rs

@@ -630,6 +630,15 @@ fn main() {
 
     rustcode = rustcode_functionsreplaced;
 
+    // actually we don't even need that function any more, but in particular a) the pub is one too
+    // many, and b) we don't even want it pub.
+    rustcode = rustcode.replace(
+        "pub pub unsafe fn use_everything()",
+        "unsafe fn use_everything()",
+    );
+    // not sure why that pops up everywhere, probably b/c we made them manually pub just before
+    rustcode = rustcode.replace("pub pub unsafe fn ", "pub unsafe fn ");
+
     let output_replaced = out_path.join("riot_c2rust_replaced.rs");
     std::fs::File::create(output_replaced)
         .expect("Failed to create riot_c2rust_replaced.rs")

riot-c2rust.h

@@ -148,3 +148,56 @@ static inline void __masked_builtin_arm_set_fpscr(int fpscr){
 #define IS_C2RUST
 
 #include "riot-headers.h"
+
+void use_everything(void) {
+	/* While most of them are from modules somewhere, we only need to make them
+	 * conditional if their corresponding includes in riot-headers.h are
+	 * conditional. */
+
+	ztimer_acquire(NULL);
+	thread_get(0);
+	thread_getpid();
+	pid_is_valid(0);
+	gpio_is_valid(0);
+	irq_is_in();
+	irq_is_enabled();
+	irq_disable();
+	irq_restore(0);
+	mutex_lock(0);
+	mutex_trylock(0);
+	ztimer_now(NULL);
+	ztimer_spin(NULL, 0);
+
+	gnrc_netapi_dispatch_send(0, 0, NULL);
+	gnrc_netif_hdr_sizeof(NULL);
+	gnrc_pktbuf_release(NULL);
+	gnrc_pkt_len(NULL);
+	gnrc_pkt_count(NULL);
+
+	thread_measure_stack_free(NULL);
+
+	gnrc_ipv6_nib_nc_get_ar_state(NULL);
+	gnrc_netif_ipv6_addrs_get(NULL, NULL, 0);
+	ipv6_addr_is_unspecified(NULL);
+	ipv6_addr_is_loopback(NULL);
+	ipv6_addr_is_multicast(NULL);
+	ipv6_addr_is_link_local(NULL);
+	gnrc_ipv6_nib_nc_get_iface(NULL);
+	gnrc_netif_ipv6_addrs_get(NULL, NULL, 0);
+	gnrc_ipv6_nib_nc_get_nud_state(NULL);
+	gnrc_ipv6_nib_nc_is_router(NULL);
+
+#ifdef MODULE_NANOCOAP
+	coap_pkt_set_code(NULL, 0);
+	coap_get_code_raw(NULL);
+#endif
+
+#ifdef MODULE_SOCK_UDP
+	sock_udp_send(NULL, NULL, 0, NULL);
+	sock_udp_recv(NULL, NULL, 0, 0, NULL);
+#endif
+
+#ifdef MODULE_SOCK
+	gnrc_netreg_entry_init_cb(NULL, 0, NULL);
+#endif
+}