build(macOS): set the LC_ID_DYLIB for mac binaries to set correct name for linking (#1646)

# What does this PR do?

for macOS builds we were not setting `LC_ID_DYLIB`, so the absolute path at build time was being used, which causes problems when you link against the dylib on another machine. 

This PR should correctly set `LC_ID_DYLIB` for macOS. Something similar was done for linux in #1258 

The post-build fix logic has been removed since it doesn't seem to be used anywhere else anymore.   
# Motivation

What inspired you to submit this pull request?

# Additional Notes

Anything else we should know when reviewing?

# How to test the change?

`cargo run --bin release --release -- --out /tmp/libdatadog-output`

Prior to this change the output would have looked like:
```
cmd LC_ID_DYLIB
cmdsize 184
name /Users/ec2-user/builds/.../libdatadog_profiling_ffi.dylib (offset 24)
```

With this change it now looks like:
```
cmd LC_ID_DYLIB
cmdsize 64
name @rpath/libdatadog_profiling.dylib (offset 24)
```


Co-authored-by: hoolioh <107922352+hoolioh@users.noreply.github.com>
Co-authored-by: julio.gonzalez <julio.gonzalez@datadoghq.com>

Author: ekump

builder/src/arch/apple.rs

@@ -2,7 +2,6 @@
 // SPDX-License-Identifier: Apache-2.0
 
 use std::ffi::OsStr;
-use std::os::unix::process::ExitStatusExt;
 use std::process::Command;
 
 use crate::utils::wait_for_success;
@@ -13,34 +12,13 @@ pub const PROF_DYNAMIC_LIB: &str = "libdatadog_profiling.dylib";
 pub const PROF_STATIC_LIB: &str = "libdatadog_profiling.a";
 pub const PROF_DYNAMIC_LIB_FFI: &str = "libdatadog_profiling_ffi.dylib";
 pub const PROF_STATIC_LIB_FFI: &str = "libdatadog_profiling_ffi.a";
-pub const REMOVE_RPATH: bool = true;
 pub const BUILD_CRASHTRACKER: bool = true;
-pub const RUSTFLAGS: [&str; 2] = ["-C", "relocation-model=pic"];
-
-pub fn fix_rpath(lib_path: &str) {
-    if REMOVE_RPATH {
-        let lib_name = lib_path.split('/').next_back().unwrap();
-
-        let exit_status = Command::new("install_name_tool")
-            .arg("-id")
-            .arg("@rpath/".to_string() + lib_name)
-            .arg(lib_path)
-            .status()
-            .expect("Failed to fix rpath using install_name_tool");
-        match exit_status.code() {
-            Some(0) => {}
-            Some(rc) => panic!("Failed to fix rpath using install_name_tool: return code {rc}"),
-            None => match exit_status.signal() {
-                Some(sig) => {
-                    panic!("Failed to fix rpath using install_name_tool: killed by signal {sig}")
-                }
-                None => panic!(
-                    "Failed to fix rpath using install_name_tool: exit status {exit_status:?}"
-                ),
-            },
-        }
-    }
-}
+pub const RUSTFLAGS: [&str; 4] = [
+    "-C",
+    "relocation-model=pic",
+    "-C",
+    "link-arg=-Wl,-install_name,@rpath/libdatadog_profiling.dylib",
+];
 
 pub fn strip_libraries(lib_path: &str) {
     // objcopy is not available in macos image. Investigate llvm-objcopy

builder/src/arch/linux.rs

@@ -11,7 +11,6 @@ pub const PROF_DYNAMIC_LIB: &str = "libdatadog_profiling.so";
 pub const PROF_STATIC_LIB: &str = "libdatadog_profiling.a";
 pub const PROF_DYNAMIC_LIB_FFI: &str = "libdatadog_profiling_ffi.so";
 pub const PROF_STATIC_LIB_FFI: &str = "libdatadog_profiling_ffi.a";
-pub const REMOVE_RPATH: bool = false;
 pub const BUILD_CRASHTRACKER: bool = true;
 pub const RUSTFLAGS: [&str; 4] = [
     "-C",
@@ -20,18 +19,6 @@ pub const RUSTFLAGS: [&str; 4] = [
     "link-arg=-Wl,-soname,libdatadog_profiling.so",
 ];
 
-pub fn fix_rpath(lib_path: &str) {
-    if REMOVE_RPATH {
-        let patchelf = Command::new("patchelf")
-            .arg("--remove-rpath")
-            .arg(lib_path)
-            .spawn()
-            .expect("failed to spawn patchelf");
-
-        wait_for_success(patchelf, "patchelf");
-    }
-}
-
 pub fn strip_libraries(lib_path: &str) {
     let rm_section = Command::new("objcopy")
         .arg("--remove-section")

builder/src/arch/musl.rs

@@ -11,7 +11,6 @@ pub const PROF_DYNAMIC_LIB: &str = "libdatadog_profiling.so";
 pub const PROF_STATIC_LIB: &str = "libdatadog_profiling.a";
 pub const PROF_DYNAMIC_LIB_FFI: &str = "libdatadog_profiling_ffi.so";
 pub const PROF_STATIC_LIB_FFI: &str = "libdatadog_profiling_ffi.a";
-pub const REMOVE_RPATH: bool = false;
 pub const BUILD_CRASHTRACKER: bool = true;
 pub const RUSTFLAGS: [&str; 4] = [
     "-C",
@@ -20,16 +19,6 @@ pub const RUSTFLAGS: [&str; 4] = [
     "link-arg=-Wl,-soname,libdatadog_profiling.so",
 ];
 
-pub fn fix_rpath(lib_path: &str) {
-    if REMOVE_RPATH {
-        Command::new("patchelf")
-            .arg("--remove-rpath")
-            .arg(lib_path)
-            .spawn()
-            .expect("failed to remove rpath");
-    }
-}
-
 pub fn strip_libraries(lib_path: &str) {
     let rm_section = Command::new("objcopy")
         .arg("--remove-section")

builder/src/arch/windows.rs

@@ -12,7 +12,6 @@ pub const PROF_PDB: &str = "datadog_profiling.pdb";
 pub const PROF_DYNAMIC_LIB_FFI: &str = "datadog_profiling_ffi.dll";
 pub const PROF_STATIC_LIB_FFI: &str = "datadog_profiling_ffi.lib";
 pub const PROF_PDB_FFI: &str = "datadog_profiling_ffi.pdb";
-pub const REMOVE_RPATH: bool = false;
 pub const BUILD_CRASHTRACKER: bool = false;
 pub const RUSTFLAGS: [&str; 4] = [
     "-C",
@@ -21,7 +20,6 @@ pub const RUSTFLAGS: [&str; 4] = [
     "target-feature=+crt-static",
 ];
 
-pub fn fix_rpath(_lib_path: &str) {}
 pub fn strip_libraries(_lib_path: &str) {}
 
 pub fn add_additional_files(lib_path: &str, target_path: &OsStr) {

builder/src/bin/release.rs

@@ -124,7 +124,6 @@ pub fn main() {
     let res = builder.build();
     match res {
         Ok(_) => {
-            builder.sanitize_libraries();
             // Note: tar creation is handled by CI, not by this binary
         }
         Err(err) => panic!("{}", format!("Building failed: {err}")),

builder/src/builder.rs

@@ -123,19 +123,6 @@ impl Builder {
             .expect("Failed to create include directory");
     }
 
-    // TODO: maybe do this in module's build.rs
-    pub fn sanitize_libraries(&self) {
-        let datadog_lib_dir = Path::new(self.source_lib.as_ref());
-
-        let libs = fs::read_dir(datadog_lib_dir).unwrap();
-        for lib in libs.flatten() {
-            let name = lib.file_name().into_string().unwrap();
-            if name.ends_with(".so") {
-                arch::fix_rpath(lib.path().to_str().unwrap());
-            }
-        }
-    }
-
     pub fn add_cmake(&self) {
         let libs = arch::NATIVE_LIBS.to_owned();
         let cmake_dir: PathBuf = [&self.target_dir, "cmake"].iter().collect();