feat(rivetc): support export annotation

rivetc/src/codegen/__init__.py

@@ -408,11 +408,20 @@ def gen_decl(self, decl):
                         )
                         self.generated_array_returns.append(name)
                     ret_typ = ir.Type(name)
+            if decl.is_extern and not decl.has_body:
+                name = decl.sym.name
+            elif (not decl.is_method) and decl.annotations.has("export"):
+                export_annotation = decl.annotations.find("export")
+                if isinstance(export_annotation.args[0].expr, ast.StringLiteral):
+                    name = export_annotation.args[0].expr.lit
+                else:
+                    assert False
+            else:
+                name = mangle_symbol(decl.sym)
             fn_decl = ir.FuncDecl(
                 False, decl.annotations, decl.is_extern and not decl.has_body,
-                decl.sym.name if decl.is_extern and not decl.has_body else
-                mangle_symbol(decl.sym), args, decl.is_variadic
-                and decl.is_extern, ret_typ, decl.ret_typ == self.comp.never_t
+                name, args, decl.is_variadic and decl.is_extern, ret_typ,
+                decl.ret_typ == self.comp.never_t
             )
             self.cur_fn = fn_decl
             self.cur_fn.arr_ret_struct = arr_ret_struct
@@ -1264,6 +1273,12 @@ def gen_expr(self, expr, custom_tmp = None):
             if not is_vtable_call:
                 if expr.is_closure:
                     name = self.gen_expr_with_cast(expr.left.typ, expr.left)
+                elif (not expr.sym.is_method) and expr.sym.annotations.has("export"):
+                    export_annotation = expr.sym.annotations.find("export")
+                    if isinstance(export_annotation.args[0].expr, ast.StringLiteral):
+                        name = export_annotation.args[0].expr.lit
+                    else:
+                        assert False
                 elif expr.sym.is_extern and expr.sym.abi != sym.ABI.Rivet and not expr.sym.has_body:
                     name = ir.Name(expr.sym.name)
                 else:

rivetc/src/register.py

@@ -218,7 +218,7 @@ def walk_decls(self, decls):
                             decl.is_unsafe, decl.is_method, decl.is_variadic,
                             decl.name, decl.args, decl.ret_typ,
                             decl.has_named_args, decl.has_body, decl.name_pos,
-                            decl.self_is_mut, decl.self_is_ptr
+                            decl.self_is_mut, decl.self_is_ptr, annotations=decl.annotations
                         )
                     )
                     decl.sym.is_main = decl.is_main

rivetc/src/sym.py

@@ -625,7 +625,7 @@ class Fn(Sym):
     def __init__(
         self, abi, is_public, is_extern, is_unsafe, is_method, is_variadic,
         name, args, ret_typ, has_named_args, has_body, name_pos, self_is_mut,
-        self_is_ptr, self_typ = None
+        self_is_ptr, self_typ = None, annotations = None
     ):
         Sym.__init__(self, is_public, name)
         self.is_main = False
@@ -642,6 +642,7 @@ def __init__(
         self.has_named_args = has_named_args
         self.has_body = has_body
         self.name_pos = name_pos
+        self.annotations = annotations
 
     def get_arg(self, idx):
         arg = self.args[idx]