freebsd/dragonflybsd introduces backtrace api for debugging

libc-test/build.rs

@@ -1715,6 +1715,7 @@ fn test_freebsd(target: &str) {
                 "dlfcn.h",
                 "elf.h",
                 "errno.h",
+                "execinfo.h",
                 "fcntl.h",
                 "glob.h",
                 "grp.h",

libc-test/semver/dragonfly.txt

@@ -1154,6 +1154,9 @@ arc4random_buf
 arc4random_uniform
 arphdr
 atof
+backtrace
+backtrace_symbols
+backtrace_symbols_fd
 bpf_dltlist
 bpf_hdr
 bpf_insn

libc-test/semver/freebsd.txt

@@ -1340,6 +1340,9 @@ arc4random_buf
 arc4random_uniform
 arphdr
 atof
+backtrace
+backtrace_symbols
+backtrace_symbols_fd
 bpf_dltlist
 bpf_hdr
 bpf_insn

src/unix/bsd/freebsdlike/mod.rs

@@ -1682,6 +1682,17 @@ extern "C" {
     pub fn login_tty(fd: ::c_int) -> ::c_int;
 }
 
+#[link(name = "execinfo")]
+extern "C" {
+    pub fn backtrace(addrlist: *mut *mut ::c_void, len: ::size_t) -> ::size_t;
+    pub fn backtrace_symbols(addrlist: *const *mut ::c_void, len: ::size_t) -> *mut *mut ::c_char;
+    pub fn backtrace_symbols_fd(
+        addrlist: *const *mut ::c_void,
+        len: ::size_t,
+        fd: ::c_int,
+    ) -> ::c_int;
+}
+
 cfg_if! {
     if #[cfg(target_os = "freebsd")] {
         mod freebsd;