cparser/*: refactoring of the expansion of read-modify-write operators

cparser/PackedStructs: treat r-m-w operations over byte-swapped fields
cparser/PackedStructs: allow static initialization of packed structs
test/regression: more packedstruct tests


git-svn-id: https://yquem.inria.fr/compcert/svn/compcert/trunk@1738 fca1b0fc-160b-0410-b1d3-a4f43f01ea2e

1 files changed, 25 insertions, 2 deletions

diff --git a/cparser/Transform.mli b/cparser/Transform.mli
index 8215997..5736abc 100644
--- a/cparser/Transform.mli
+++ b/cparser/Transform.mli
@@ -15,18 +15,41 @@
 
 (** Creation of fresh temporary variables. *)
 val reset_temps : unit -> unit
+val get_temps : unit -> C.decl list
 val new_temp_var : ?name:string -> C.typ -> C.ident
 val new_temp : ?name:string -> C.typ -> C.exp
-val get_temps : unit -> C.decl list
+val mk_temp : Env.t -> ?name:string -> C.typ -> C.exp
 
 (** Avoiding repeated evaluation of a l-value *)
 
 val bind_lvalue: Env.t -> C.exp -> (C.exp -> C.exp) -> C.exp
 
-(** Generic transformation of a statement *)
+(* Most transformations over expressions can be optimized if the
+   value of the expression is not needed and it is evaluated only
+   for its side-effects.  The type [context] records whether
+   we are in a side-effects-only position ([Effects]) or not ([Val]). *)
 
 type context = Val | Effects
 
+(** Expansion of assignment expressions *)
+val op_for_assignop : C.binary_operator -> C.binary_operator
+val op_for_incr_decr : C.unary_operator -> C.binary_operator
+val assignop_for_incr_decr : C.unary_operator -> C.binary_operator
+val expand_assign :
+  write:(C.exp -> C.exp -> C.exp) ->
+  Env.t -> context -> C.exp -> C.exp -> C.exp
+val expand_assignop :
+  read:(C.exp -> C.exp) -> write:(C.exp -> C.exp -> C.exp) ->
+  Env.t -> context -> C.binary_operator -> C.exp -> C.exp -> C.typ -> C.exp
+val expand_preincrdecr :
+  read:(C.exp -> C.exp) -> write:(C.exp -> C.exp -> C.exp) ->
+  Env.t -> context -> C.unary_operator -> C.exp -> C.exp
+val expand_postincrdecr :
+  read:(C.exp -> C.exp) -> write:(C.exp -> C.exp -> C.exp) ->
+  Env.t -> context -> C.unary_operator -> C.exp -> C.exp
+
+(** Generic transformation of a statement *)
+
 val stmt : (C.location -> Env.t -> context -> C.exp -> C.exp) ->
            Env.t -> C.stmt -> C.stmt