enable backtrace for some BSD OSs

Cargo.toml

@@ -22,7 +22,6 @@ exclude = ['crates/without_debuginfo', 'crates/macos_frames_test', 'crates/line-
 cfg-if = "1.0"
 rustc-demangle = "0.1.4"
 backtrace-sys = { path = "crates/backtrace-sys", version = "0.1.35", optional = true, default_features = false }
-libc = { version = "0.2.45", default-features = false }
 
 # Optionally enable the ability to serialize a `Backtrace`, controlled through
 # the `serialize-*` features below.
@@ -43,6 +42,12 @@ optional = true
 default-features = false
 features = ['read_core', 'elf', 'macho', 'pe', 'unaligned']
 
+[dependencies.libc]
+version = "0.2"
+default-features = false
+git = "https://github.com/lzutao/rust-libc"
+branch = "i78184"
+
 [target.'cfg(windows)'.dependencies]
 winapi = { version = "0.3.3", optional = true }
 

src/symbolize/gimli.rs

@@ -358,6 +358,10 @@ cfg_if::cfg_if! {
     } else if #[cfg(any(
         target_os = "linux",
         target_os = "fuchsia",
+        target_os = "freebsd",
+        target_os = "netbsd",
+        target_os = "openbsd",
+        target_os = "dragonfly",
     ))] {
         // Other Unix (e.g. Linux) platforms use ELF as an object file format
         // and typically implement an API called `dl_iterate_phdr` to load
@@ -372,28 +376,31 @@ cfg_if::cfg_if! {
         fn native_libraries() -> Vec<Library> {
             let mut ret = Vec::new();
             unsafe {
-                libc::dl_iterate_phdr(Some(callback), &mut ret as *mut _ as *mut _);
+                libc::dl_iterate_phdr(Some(callback), ret.as_mut_ptr() as *mut _);
             }
             return ret;
         }
 
+        // SAFETY: `info` and `vec` should be valid pointers
         unsafe extern "C" fn callback(
             info: *mut libc::dl_phdr_info,
             _size: libc::size_t,
             vec: *mut libc::c_void,
         ) -> libc::c_int {
+            let info = &*info;
             let libs = &mut *(vec as *mut Vec<Library>);
-            let name = if (*info).dlpi_name.is_null() || *(*info).dlpi_name == 0{
+            let is_main_prog = info.dlpi_name.is_null() || info.dlpi_name.read() == 0;
+            let name = if is_main_prog {
                 if libs.is_empty() {
                     mystd::env::current_exe().map(|e| e.into()).unwrap_or_default()
                 } else {
                     OsString::new()
                 }
             } else {
-                let bytes = CStr::from_ptr((*info).dlpi_name).to_bytes();
+                let bytes = CStr::from_ptr(info.dlpi_name).to_bytes();
                 OsStr::from_bytes(bytes).to_owned()
             };
-            let headers = core::slice::from_raw_parts((*info).dlpi_phdr, (*info).dlpi_phnum as usize);
+            let headers = core::slice::from_raw_parts(info.dlpi_phdr, info.dlpi_phnum as usize);
             libs.push(Library {
                 name,
                 segments: headers
@@ -403,7 +410,7 @@ cfg_if::cfg_if! {
                         stated_virtual_memory_address: (*header).p_vaddr as usize,
                     })
                     .collect(),
-                bias: (*info).dlpi_addr as usize,
+                bias: info.dlpi_addr as usize,
             });
             0
         }