Adopted unused variable and attribtue check

The unused variable check now uses two passes. One to collect the
used variables and one to report the unused variables.

Futhermore attribute checks are extended to composite declaration.
Also the check is now performed after elaboration.
Bug 19872

1 files changed, 53 insertions, 28 deletions

diff --git a/cparser/Checks.ml b/cparser/Checks.ml
index dc08e254..76bd095c 100644
--- a/cparser/Checks.ml
+++ b/cparser/Checks.ml
@@ -78,6 +78,7 @@ let unknown_attrs_program p =
           List.iter (unknown_attrs_decl env g.gloc) f.fd_locals;
           Env.add_ident env f.fd_name f.fd_storage (fundef_typ f)
         | Gcompositedecl(su, id, attr) ->
+          unknown_attrs g.gloc attr;
           Env.add_composite env id (composite_info_decl su attr)
         | Gcompositedef(su, id, attr, fl) ->
           unknown_attrs g.gloc attr;
@@ -121,53 +122,77 @@ and vars_used_init env = function
   | Init_struct (_,sl) -> List.fold_left (fun env (_,i) -> vars_used_init env i) env sl
   | Init_union (_,_,ui) -> vars_used_init env ui
 
-let rec vars_used_stmt ((dec_env,used_env) as acc) s =
+let rec vars_used_stmt env s =
   match s.sdesc with
   | Sbreak
   | Scontinue
   | Sgoto _
   | Sreturn None
-  | Sskip -> acc
+  | Sskip -> env
   | Sreturn (Some e)
-  | Sdo e -> dec_env,(vars_used_expr used_env e)
+  | Sdo e -> (vars_used_expr env e)
   | Sseq (s1,s2) ->
-    let acc = vars_used_stmt acc s1 in
-    vars_used_stmt acc s2
+    let env = vars_used_stmt env s1 in
+    vars_used_stmt env s2
   | Sif (e,s1,s2) ->
-    let used_env = vars_used_expr used_env e in
-    let acc = vars_used_stmt (dec_env,used_env) s1 in
-    vars_used_stmt acc s2
+    let env = vars_used_expr env e in
+    let env = vars_used_stmt env s1 in
+    vars_used_stmt env s2
   | Sfor (s1,e,s2,s3) ->
-    let used_env = vars_used_expr used_env e in
-    let acc = vars_used_stmt (dec_env,used_env) s1 in
-    let acc = vars_used_stmt acc s2 in
-    vars_used_stmt acc s3
+    let env = vars_used_expr env e in
+    let env = vars_used_stmt env s1 in
+    let env = vars_used_stmt env s2 in
+    vars_used_stmt env s3
   | Sswitch (e,s)
   | Swhile (e,s)
   | Sdowhile (s,e) ->
-    let used_env = vars_used_expr used_env e in
-    vars_used_stmt (dec_env,used_env) s
-  | Sblock sl -> List.fold_left vars_used_stmt acc sl
+    let env = vars_used_expr env e in
+    vars_used_stmt env s
+  | Sblock sl -> List.fold_left vars_used_stmt env sl
   | Sdecl (sto,id,ty,init) ->
-    let dec_env = IdentMap.add id s.sloc dec_env
-    and used_env = match init with
-      | Some init ->vars_used_init used_env init
-      | None -> used_env in
-    dec_env,used_env
-  | Slabeled (lbl,s) -> vars_used_stmt acc s
+    let env = match init with
+      | Some init ->vars_used_init env init
+      | None -> env in
+    env
+  | Slabeled (lbl,s) -> vars_used_stmt env s
   | Sasm (attr,str,op,op2,constr) ->
     let vars_asm_op env (_,_,e) =
       vars_used_expr env e in
-    let used_env = List.fold_left vars_asm_op used_env op in
-    let used_env = List.fold_left vars_asm_op used_env op2 in
-    dec_env,used_env
+    let env = List.fold_left vars_asm_op env op in
+    let env = List.fold_left vars_asm_op env op2 in
+    env
+
+let rec unused_variables_stmt env s =
+  match s.sdesc with
+  | Sbreak
+  | Scontinue
+  | Sgoto _
+  | Sreturn _
+  | Sskip
+  | Sasm _
+  | Sdo _ -> ()
+  | Sseq (s1,s2)
+  | Sif (_,s1,s2) ->
+    unused_variables_stmt env s1;
+    unused_variables_stmt env s2
+  | Sfor (s1,e,s2,s3) ->
+    unused_variables_stmt env s1;
+    unused_variables_stmt env s2;
+    unused_variables_stmt env s3
+  | Slabeled (_,s)
+  | Sswitch (_,s)
+  | Swhile (_,s)
+  | Sdowhile (s,_) ->
+    unused_variables_stmt env s
+  | Sblock sl -> List.iter (unused_variables_stmt env) sl
+  | Sdecl (sto,id,ty,init) -> if not (IdentSet.mem id env) then
+      warning s.sloc Unused_variable "unused variable '%s'" id.name
 
 let unused_variables p =
   List.iter (fun g -> match g.gdesc with
       | Gfundef fd ->
-        let dec_env,used_env = vars_used_stmt (IdentMap.empty,IdentSet.empty) fd.fd_body in
-        IdentMap.iter (fun id loc -> if not (IdentSet.mem id used_env) then
-                          warning loc Unused_variable "unused variable '%s'" id.name) dec_env;
-        List.iter (fun (id,_) -> if not (IdentSet.mem id used_env) then
+        let env = vars_used_stmt IdentSet.empty fd.fd_body in
+        unused_variables_stmt env fd.fd_body;
+        List.iter (fun (id,_) -> if not (IdentSet.mem id env) then
                       warning g.gloc Unused_parameter "unused parameter '%s'" id.name) fd.fd_params
       | _ -> ()) p