Disable the inline asm support using a feature flag

Author: bjorn3

Cargo.toml

@@ -36,8 +36,9 @@ libloading = { version = "0.6.0", optional = true }
 #gimli = { path = "../" }
 
 [features]
-default = ["jit"]
+default = ["jit", "inline_asm"]
 jit = ["cranelift-simplejit", "libloading"]
+inline_asm = []
 
 [profile.dev]
 # By compiling dependencies with optimizations, performing tests gets much faster.

src/driver/aot.rs

@@ -298,13 +298,20 @@ fn codegen_global_asm(tcx: TyCtxt<'_>, cgu_name: &str, global_asm: &str) {
         return;
     }
 
-    if tcx.sess.target.target.options.is_like_osx || tcx.sess.target.target.options.is_like_windows {
+    if cfg!(not(feature = "inline_asm"))
+        || tcx.sess.target.target.options.is_like_osx
+        || tcx.sess.target.target.options.is_like_windows
+    {
         if global_asm.contains("__rust_probestack") {
             return;
         }
 
         // FIXME fix linker error on macOS
-        tcx.sess.fatal("asm! and global_asm! are not yet supported on macOS and Windows");
+        if cfg!(not(feature = "inline_asm")) {
+            tcx.sess.fatal("asm! and global_asm! support is disabled while compiling rustc_codegen_cranelift");
+        } else {
+            tcx.sess.fatal("asm! and global_asm! are not yet supported on macOS and Windows");
+        }
     }
 
     let assembler = crate::toolchain::get_toolchain_binary(tcx.sess, "as");