Some more debugging

Author: antoyo

src/back/lto.rs

@@ -280,7 +280,8 @@ fn fat_lto(
             context.set_optimization_level(to_gcc_opt_level(config.opt_level));
             context.add_command_line_option("-flto=auto");
             context.add_command_line_option("-flto-partition=one");
-            //context.add_command_line_option("-fno-use-linker-plugin");
+            context.add_command_line_option("-fno-use-linker-plugin");
+            context.add_driver_option("-fno-use-linker-plugin");
             context.compile_to_file(OutputKind::ObjectFile, path);
             let buffer = ModuleBuffer::new(PathBuf::from(path));
             let llmod_id = CString::new(&module.name[..]).unwrap();
@@ -652,6 +653,8 @@ pub unsafe fn optimize_thin_module(
         Some(thin_buffer) => Arc::clone(&thin_buffer.context),
         None => {
             let context = Context::default();
+            context.add_command_line_option("-fno-use-linker-plugin");
+            context.add_driver_option("-fno-use-linker-plugin");
             let len = thin_module.shared.thin_buffers.len();
             let module = &thin_module.shared.serialized_modules[thin_module.idx - len];
             match *module {

src/back/write.rs

@@ -67,7 +67,11 @@ pub(crate) unsafe fn codegen(
                     );
                     context.add_command_line_option("-flto=auto");
                     context.add_command_line_option("-flto-partition=one");
-                    //context.add_command_line_option("-fno-use-linker-plugin");
+                    // FIXME FIXME FIXME: it seems that uncommenting "ADD_ARG ("-fno-use-linker-plugin")" in libgccjit
+                    // make the test fail (undefined symbol main).
+                    // TODO: Perhaps we're not sending this flag somewhere?
+                    context.add_command_line_option("-fno-use-linker-plugin");
+                    context.add_driver_option("-fno-use-linker-plugin");
                     // TODO(antoyo): remove since we don't want fat objects when it is for Bitcode only.
                     context.add_command_line_option("-ffat-lto-objects");
                     context.compile_to_file(
@@ -86,7 +90,8 @@ pub(crate) unsafe fn codegen(
 
                     context.add_command_line_option("-flto=auto");
                     context.add_command_line_option("-flto-partition=one");
-                    //context.add_command_line_option("-fno-use-linker-plugin");
+                    context.add_command_line_option("-fno-use-linker-plugin");
+                    context.add_driver_option("-fno-use-linker-plugin");
                     context.add_command_line_option("-ffat-lto-objects");
                     // TODO(antoyo): Send -plugin/usr/lib/gcc/x86_64-pc-linux-gnu/11.1.0/liblto_plugin.so to linker (this should be done when specifying the appropriate rustc cli argument).
                     context.compile_to_file(
@@ -175,7 +180,8 @@ pub(crate) unsafe fn codegen(
                         context.add_command_line_option("-flto=auto");
                         context.add_command_line_option("-flto-partition=one");
                         //context.add_command_line_option("-ffat-lto-objects");
-                        //context.add_command_line_option("-fno-use-linker-plugin");
+                        context.add_command_line_option("-fno-use-linker-plugin");
+                        context.add_driver_option("-fno-use-linker-plugin");
 
                         // FIXME FIXME FIXME:
                         // /usr/bin/ld: warning: incremental linking of LTO and non-LTO objects; using -flinker-output=nolto-rel which will bypass whole program optimization
@@ -215,6 +221,8 @@ pub(crate) unsafe fn codegen(
                         println!("****************************************************************************************************");
 
                         let context = Context::default();
+                        context.add_command_line_option("-fno-use-linker-plugin");
+                        context.add_driver_option("-fno-use-linker-plugin");
                         if cgcx.target_arch == "x86" || cgcx.target_arch == "x86_64" {
                             // NOTE: it seems we need to use add_driver_option instead of
                             // add_command_line_option here because we use the LTO frontend via gcc.

src/gcc_util.rs

@@ -207,6 +207,8 @@ fn handle_native(name: &str) -> &str {
     {
         // Get the native arch.
         let context = Context::default();
+        context.add_command_line_option("-fno-use-linker-plugin");
+        context.add_driver_option("-fno-use-linker-plugin");
         context.get_target_info().arch().unwrap().to_str().unwrap()
     }
     #[cfg(not(feature = "master"))]

src/lib.rs

@@ -195,6 +195,8 @@ impl CodegenBackend for GccCodegenBackend {
 
             // Get the second TargetInfo with the correct CPU features by setting the arch.
             let context = Context::default();
+            context.add_command_line_option("-fno-use-linker-plugin");
+            context.add_driver_option("-fno-use-linker-plugin");
             if target_cpu != "generic" {
                 context.add_command_line_option(format!("-march={}", target_cpu));
             }
@@ -210,6 +212,8 @@ impl CodegenBackend for GccCodegenBackend {
             let temp_dir = TempDir::new().expect("cannot create temporary directory");
             let temp_file = temp_dir.into_path().join("result.asm");
             let check_context = Context::default();
+            context.add_command_line_option("-fno-use-linker-plugin");
+            context.add_driver_option("-fno-use-linker-plugin");
             check_context.set_print_errors_to_stderr(false);
             let _int128_ty = check_context.new_c_type(CType::UInt128t);
             // NOTE: we cannot just call compile() as this would require other files than libgccjit.so.
@@ -267,6 +271,8 @@ impl CodegenBackend for GccCodegenBackend {
 
 fn new_context<'gcc, 'tcx>(tcx: TyCtxt<'tcx>) -> Context<'gcc> {
     let context = Context::default();
+    context.add_command_line_option("-fno-use-linker-plugin");
+    context.add_driver_option("-fno-use-linker-plugin");
     if tcx.sess.target.arch == "x86" || tcx.sess.target.arch == "x86_64" {
         context.add_command_line_option("-masm=intel");
     }
@@ -461,6 +467,8 @@ pub fn __rustc_codegen_backend() -> Box<dyn CodegenBackend> {
         // Check whether the target supports 128-bit integers, and sized floating point types (like
         // Float16).
         let context = Context::default();
+        context.add_command_line_option("-fno-use-linker-plugin");
+        context.add_driver_option("-fno-use-linker-plugin");
         Arc::new(Mutex::new(IntoDynSyncSend(context.get_target_info())))
     };
     #[cfg(not(feature = "master"))]