Auto merge of #2527 - devnexen:obsd_execinfo, r=JohnTitor

openbsd backtrace api addition

Author: bors

libc-test/build.rs

@@ -393,6 +393,7 @@ fn test_openbsd(target: &str) {
     headers! { cfg:
         "elf.h",
         "errno.h",
+        "execinfo.h",
         "fcntl.h",
         "limits.h",
         "link.h",

libc-test/semver/openbsd.txt

@@ -913,6 +913,10 @@ arc4random_buf
 arc4random_uniform
 arphdr
 atof
+backtrace
+backtrace_symbols
+backtrace_symbols_fd
+backtrace_symbols_fmt
 bsearch
 caddr_t
 calloc_conceal

src/unix/bsd/netbsdlike/openbsd/mod.rs

@@ -1606,6 +1606,22 @@ extern "C" {
     pub fn calloc_conceal(nmemb: ::size_t, size: ::size_t) -> *mut ::c_void;
 }
 
+#[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;
+    pub fn backtrace_symbols_fmt(
+        addrlist: *const *mut ::c_void,
+        len: ::size_t,
+        fmt: *const ::c_char,
+    ) -> *mut *mut ::c_char;
+}
+
 cfg_if! {
     if #[cfg(libc_union)] {
         extern {