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Link libc++/libc++abi on macOS for static LLVM builds #17

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Link libc++/libc++abi on macOS for static LLVM builds #17

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8 changes: 8 additions & 0 deletions openvaf/openvaf-driver/build.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -22,6 +22,14 @@ fn main() {
// Add rpath for LLVM on macOS
#[cfg(target_os = "macos")]
{
// Official LLVM release tarballs ship only static component libs (no
// libLLVM.dylib), so llvm-sys's `prefer-dynamic` falls back to static
// linking. Those archives are C++ and need libc++ for their runtime
// symbols (operator new, __cxa_guard_*, __cxa_pure_virtual). Homebrew's
// LLVM has libLLVM.dylib so it never hits this, but link libc++ here so
// building against a static LLVM works too.
println!("cargo:rustc-link-lib=dylib=c++");
println!("cargo:rustc-link-lib=dylib=c++abi");
Comment on lines +31 to +32

@gemini-code-assist gemini-code-assist Bot Jul 2, 2026

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medium

On macOS, libc++ (linked via c++) transitively links to libc++abi [16.1.1]. Therefore, explicitly linking c++abi is redundant and unnecessary, as the dynamic linker (dyld) will automatically load it and resolve all C++ runtime symbols (such as __cxa_guard_acquire and __cxa_pure_virtual). We can safely remove the explicit link to c++abi.

Suggested change
println!("cargo:rustc-link-lib=dylib=c++");
println!("cargo:rustc-link-lib=dylib=c++abi");
println!("cargo:rustc-link-lib=dylib=c++");

if let Ok(output) = std::process::Command::new("llvm-config").arg("--libdir").output() {
if output.status.success() {
let libdir = String::from_utf8_lossy(&output.stdout).trim().to_string();
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