Optimize getfield lowering to avoid boxing in some cases

src/codegen.cpp

@@ -3325,7 +3325,7 @@ static jl_llvm_functions_t
         jl_value_t *jlrettype,
         jl_codegen_params_t &params);
 
-static void emit_hasnofield_error_ifnot(jl_codectx_t &ctx, Value *ok, jl_datatype_t *type, jl_cgval_t name);
+static void emit_hasnofield_error_ifnot(jl_codectx_t &ctx, Value *ok, jl_sym_t *type, jl_cgval_t name);
 
 static bool emit_builtin_call(jl_codectx_t &ctx, jl_cgval_t *ret, jl_value_t *f,
                               const jl_cgval_t *argv, size_t nargs, jl_value_t *rt,
@@ -3835,7 +3835,7 @@ static bool emit_builtin_call(jl_codectx_t &ctx, jl_cgval_t *ret, jl_value_t *f,
                     assert(jl_svec_len(fn) == 1);
                     Value *typ_sym = literal_pointer_val(ctx, jl_svecref(fn, 0));
                     Value *cond = ctx.builder.CreateICmpEQ(mark_callee_rooted(ctx, typ_sym), mark_callee_rooted(ctx, boxed(ctx, fld)));
-                    emit_hasnofield_error_ifnot(ctx, cond, utt, fld);
+                    emit_hasnofield_error_ifnot(ctx, cond, utt->name->name, fld);
                     *ret = emit_getfield_knownidx(ctx, obj, 0, utt, order);
                     return true;
                 }
@@ -4634,7 +4634,7 @@ static void undef_var_error_ifnot(jl_codectx_t &ctx, Value *ok, jl_sym_t *name)
     ctx.builder.SetInsertPoint(ifok);
 }
 
-static void emit_hasnofield_error_ifnot(jl_codectx_t &ctx, Value *ok, jl_datatype_t *type, jl_cgval_t name)
+static void emit_hasnofield_error_ifnot(jl_codectx_t &ctx, Value *ok, jl_sym_t *type, jl_cgval_t name)
 {
     ++EmittedUndefVarErrors;
     assert(name.typ == (jl_value_t*)jl_symbol_type);

src/datatype.c

@@ -1558,7 +1558,7 @@ JL_DLLEXPORT int jl_field_index(jl_datatype_t *t, jl_sym_t *fld, int err)
         }
     }
     if (err)
-        jl_has_no_field_error(t, fld);
+        jl_has_no_field_error(t->name->name, fld);
     return -1;
 }
 

src/julia.h

@@ -1790,7 +1790,7 @@ JL_DLLEXPORT void JL_NORETURN jl_type_error_rt(const char *fname,
                                                jl_value_t *ty JL_MAYBE_UNROOTED,
                                                jl_value_t *got JL_MAYBE_UNROOTED);
 JL_DLLEXPORT void JL_NORETURN jl_undefined_var_error(jl_sym_t *var);
-JL_DLLEXPORT void JL_NORETURN jl_has_no_field_error(jl_datatype_t *datatype, jl_sym_t *var);
+JL_DLLEXPORT void JL_NORETURN jl_has_no_field_error(jl_sym_t *type_name, jl_sym_t *var);
 JL_DLLEXPORT void JL_NORETURN jl_atomic_error(char *str);
 JL_DLLEXPORT void JL_NORETURN jl_bounds_error(jl_value_t *v JL_MAYBE_UNROOTED,
                                               jl_value_t *t JL_MAYBE_UNROOTED);

src/rtutils.c

@@ -134,9 +134,9 @@ JL_DLLEXPORT void JL_NORETURN jl_undefined_var_error(jl_sym_t *var)
     jl_throw(jl_new_struct(jl_undefvarerror_type, var));
 }
 
-JL_DLLEXPORT void JL_NORETURN jl_has_no_field_error(jl_datatype_t *datatype, jl_sym_t *var)
+JL_DLLEXPORT void JL_NORETURN jl_has_no_field_error(jl_sym_t *type_name, jl_sym_t *var)
 {
-    jl_errorf("type %s has no field %s", jl_symbol_name(datatype->name->name), jl_symbol_name(var));
+    jl_errorf("type %s has no field %s", jl_symbol_name(type_name), jl_symbol_name(var));
 }
 
 JL_DLLEXPORT void JL_NORETURN jl_atomic_error(char *str) // == jl_exceptionf(jl_atomicerror_type, "%s", str)

test/compiler/codegen.jl

@@ -820,3 +820,12 @@ end
 # issue 48917, hoisting load to above the parent
 f48917(x, w) = (y = (a=1, b=x); z = (; a=(a=(1, w), b=(3, y))))
 @test f48917(1,2) == (a = (a = (1, 2), b = (3, (a = 1, b = 1))),)
+
+# https://github.com/JuliaLang/julia/issues/50317 getproperty allocation on struct with 1 field
+@testset "getproperty noalloc"
+    struct Wrapper50317
+        lock::ReentrantLock
+    end
+    const MONITOR50317 = Wrapper50317(ReentrantLock())
+    @test (@allocated getproperty(MONITOR50317,:lock)) == 0
+end