sentinel pointers and c strings

examples/interop/header/app/main.bro

@@ -9,6 +9,7 @@ main :: func() void {
 	_ = native.imported_scalar(3, 4)
 	_ = native.child_value(7)
 	_ = native.imported_read(native.imported_handle()?)
+	_ = native.imported_string("hello")
 	_ = native.configured_value(9)
 	signed i8 :: -2
 	unsigned u16 :: 3

examples/interop/header/include/native.h

@@ -21,6 +21,7 @@ int imported_add(imported_int_alias left, int right);
 unsigned long imported_scalar(unsigned char value, unsigned long extra);
 Imported_Handle *imported_handle(void);
 int imported_read(const Imported_Handle *handle);
+int imported_string(const char *value);
 Imported_Value imported_by_value(Imported_Value value);
 int imported_volatile(volatile int *value);
 _Bool imported_bool(_Bool value);

examples/interop/header/native.c

@@ -1,6 +1,7 @@
 #include "include/native.h"
 #include <stdarg.h>
 #include <stdlib.h>
+#include <string.h>
 
 struct Imported_Handle {
 	int value;
@@ -28,6 +29,13 @@ int imported_read(const Imported_Handle *value) {
 	return value->value;
 }
 
+int imported_string(const char *value) {
+	if (strcmp(value, "hello") != 0) {
+		abort();
+	}
+	return 0;
+}
+
 int imported_variadic(int marker, ...) {
 	va_list args;
 	va_start(args, marker);

examples/interop/printf/main.bro

@@ -0,0 +1,5 @@
+printf :: c_func(format *c_char, ...) c_int
+
+main :: func() void {
+	_ = printf("answer: %d\n", 42)
+}