Pretty-print symbols in HIR

Author: tekknolagi

zjit.c

@@ -739,5 +739,11 @@ rb_zjit_print_exception(void)
     rb_warn("Ruby error: %"PRIsVALUE"", rb_funcall(exception, rb_intern("full_message"), 0));
 }
 
+VALUE
+rb_zjit_sym2str(VALUE v)
+{
+    return rb_sym2str(v);
+}
+
 // Preprocessed zjit.rb generated during build
 #include "zjit.rbinc"

zjit/bindgen/src/main.rs

@@ -343,6 +343,7 @@ fn main() {
         .allowlist_function("rb_iseq_reset_jit_func")
         .allowlist_function("rb_RSTRING_PTR")
         .allowlist_function("rb_RSTRING_LEN")
+        .allowlist_function("rb_zjit_sym2str")
         .allowlist_function("rb_ENCODING_GET")
         .allowlist_function("rb_optimized_call")
         .allowlist_function("rb_zjit_icache_invalidate")

zjit/src/cruby.rs

@@ -743,6 +743,14 @@ fn ruby_str_to_rust(v: VALUE) -> String {
     }
 }
 
+// Convert a Ruby symbol to a Rust string by going through a Ruby string first.
+pub fn ruby_sym_to_rust_str(v: VALUE) -> String {
+    assert!(v.symbol_p());
+    let ruby_str = unsafe { rb_zjit_sym2str(v) };
+    assert!(ruby_str != VALUE(0), "Could not convert symbol to string");
+    ruby_str_to_rust(ruby_str)
+}
+
 /// A location in Rust code for integrating with debugging facilities defined in C.
 /// Use the [src_loc!] macro to crate an instance.
 pub struct SourceLocation {

zjit/src/cruby_bindings.inc.rs

@@ -69,6 +69,7 @@ impl<'a> std::fmt::Display for VALUEPrinter<'a> {
             Qnil => write!(f, "nil"),
             Qtrue => write!(f, "true"),
             Qfalse => write!(f, "false"),
+            val if val.symbol_p() => write!(f, ":{}", ruby_sym_to_rust_str(val)),
             val => write!(f, "VALUE({:p})", self.ptr_map.map_ptr(val.as_ptr::<VALUE>())),
         }
     }