From be0b1872bf2ad36df9b0c7a0ffa63b9e77fa769b Mon Sep 17 00:00:00 2001 From: Xavier Leroy Date: Tue, 18 Feb 2020 16:57:17 +0100 Subject: Refine the type of function results in AST.signature Before it was "option typ". Now it is a proper inductive type that can also express small integer types (8/16-bit unsigned/signed integers). One benefit is that external functions get more precise types that control better their return values. As a consequence, the CompCert C type preservation property now holds unconditionally, without extra typing hypotheses on external functions. --- cfrontend/Cshmgen.v | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'cfrontend/Cshmgen.v') diff --git a/cfrontend/Cshmgen.v b/cfrontend/Cshmgen.v index 792a73f9..ee135dcd 100644 --- a/cfrontend/Cshmgen.v +++ b/cfrontend/Cshmgen.v @@ -602,7 +602,7 @@ Fixpoint transl_statement (ce: composite_env) (tyret: type) (nbrk ncnt: nat) do tb <- transl_expr ce b; do tcl <- transl_arglist ce cl args; OK(Scall x {| sig_args := typlist_of_arglist cl args; - sig_res := opttyp_of_type res; + sig_res := rettype_of_type res; sig_cc := cconv |} tb tcl) | _ => Error(msg "Cshmgen.transl_stmt(call)") @@ -667,7 +667,7 @@ Definition transl_var (ce: composite_env) (v: ident * type) := Definition signature_of_function (f: Clight.function) := {| sig_args := map typ_of_type (map snd (Clight.fn_params f)); - sig_res := opttyp_of_type (Clight.fn_return f); + sig_res := rettype_of_type (Clight.fn_return f); sig_cc := Clight.fn_callconv f |}. Definition transl_function (ce: composite_env) (f: Clight.function) : res function := -- cgit