Merge branch 'master' into newparser

Changelog

@@ -1,3 +1,38 @@
+Release 3.5, 2019-02-27
+=======================
+
+Bug fixing:
+- Modeling error in PowerPC ISA: how register 0 is interpreted when
+  used as base register for indexed load/stores.  The code generated
+  by CompCert was correct, but was proved correct against the wrong
+  specification.
+- Modeling error in x86 ISA: how flag ZF is set by floating-point
+  comparisons.  Here as well, the code generated by CompCert was
+  correct, but was proved correct against the wrong specification.
+- Revised handling of attributes so that they behave more like in
+  GCC and Clang.  CompCert now distinguishes between attributes that
+  attach to names (variables, fields, typedefs, structs and unions)
+  and attributes that attach to objects (variables).  In particular,
+  the `aligned(N)` attribute now attaches to names, while the `_Alignas(N)`
+   modifier still attaches to objects.  This fixes issue 256.
+- Issue with NULL as argument to a variadic function on 64-bit platforms
+  (issue 265)
+- Macro __bool_true_false_are_defined was missing from <stdbool.h> (issue 266)
+
+Coq development:
+- Can now be entirely rechecked using coqchk
+  (contributed by Vincent Laporte)
+- Support Coq version 8.9.0
+- Avoid using "refine mode" when defining Instance
+  (contributed by Maxime Dénès)
+- Do not support Menhir versions more recent than 20181026, because
+  they will introduce an incompatibility with this CompCert release.
+
+New feature:
+- PowerPC port: add __builtin_isel (conditional move) at types int64, uint64,
+  and _Bool.
+
+
 Release 3.4, 2018-09-17
 =======================
 

cfrontend/C2C.ml

@@ -315,8 +315,9 @@ let attributes = [
   ("noinline",Cutil.Attr_function);
   (* name-related *)
   ("aligned", Cutil.Attr_name);
-  ("section", Cutil.Attr_name);
-  ("unused", Cutil.Attr_name)
+  (* object-related *)
+  ("section", Cutil.Attr_object);
+  ("unused", Cutil.Attr_object)
 ]
 
 

cparser/Checks.ml

@@ -18,19 +18,12 @@ open Diagnostics
 open Cutil
 open Env
 
-let attribute_string = function
-  | AConst -> "const"
-  | AVolatile -> "volatile"
-  | ARestrict -> "restrict"
-  | AAlignas n -> "_Alignas"
-  | Attr(name, _) ->  name
-
 let unknown_attrs loc attrs =
   let unknown attr =
     let attr_class = class_of_attribute attr in
     if attr_class = Attr_unknown then
       warning loc Unknown_attribute
-        "unknown attribute '%s' ignored" (attribute_string attr) in
+        "unknown attribute '%s' ignored" (name_of_attribute attr) in
   List.iter unknown attrs
 
 let unknown_attrs_typ env loc ty =

cparser/Cutil.ml

@@ -95,7 +95,10 @@ let rec remove_custom_attributes (names: string list)  (al: attributes) =
 (* Classification of attributes *)
 
 type attribute_class =
-  | Attr_name           (* Attribute applies to the names being declared  *)
+  | Attr_object         (* Attribute applies to the object being declared
+                           (function, global variable, local variable)  *)
+  | Attr_name           (* Attribute applies to the name being declared
+                          (object, struct/union member, struct/union/enum tag *)
   | Attr_type           (* Attribute applies to types *)
   | Attr_struct         (* Attribute applies to struct, union and enum *)
   | Attr_function       (* Attribute applies to function types and decls *)
@@ -111,11 +114,20 @@ let declare_attributes l =
 
 let class_of_attribute = function
   | AConst | AVolatile | ARestrict -> Attr_type
-  | AAlignas _ -> Attr_name
+  | AAlignas _ -> Attr_object
   | Attr(name, args) ->
       try Hashtbl.find attr_class (normalize_attrname name)
       with Not_found -> Attr_unknown
 
+(* Name for printing an attribute *)
+
+let name_of_attribute = function
+  | AConst -> "const"
+  | AVolatile -> "volatile"
+  | ARestrict -> "restrict"
+  | AAlignas n -> "_Alignas"
+  | Attr(name, _) ->  name
+
 (* Is an attribute a ISO C standard attribute? *)
 
 let attr_is_standard = function
@@ -163,7 +175,10 @@ let rec unroll env t =
       unroll env (add_attributes_type attr ty)
   | _ -> t
 
-(* Extracting the attributes of a type *)
+(* Extracting the attributes of a type, including the attributes
+   attached to typedefs, structs and unions.  In other words,
+   typedefs are unrolled and composite definitions expanded
+   before extracting the attributes.  *)
 
 let rec attributes_of_type env t =
   match t with
@@ -190,6 +205,23 @@ let rec attributes_of_type env t =
       | exception Env.Error(Env.Unbound_tag _) -> a
       end
 
+(* Extracting the attributes of a type, excluding the attributes
+   attached to typedefs, structs and unions.  In other words,
+   typedefs are not unrolled and composite definitions are not expanded. *)
+
+let rec attributes_of_type_no_expand t =
+  match t with
+  | TVoid a -> a
+  | TInt(ik, a) -> a
+  | TFloat(fk, a) -> a
+  | TPtr(ty, a) -> a
+  | TArray(ty, sz, a) -> add_attributes a (attributes_of_type_no_expand ty)
+  | TFun(ty, params, vararg, a) -> a
+  | TNamed(s, a) -> a
+  | TStruct(s, a) -> a
+  | TUnion(s, a) -> a
+  | TEnum(s, a) -> a
+
 (* Changing the attributes of a type (at top-level) *)
 (* Same hack as above for array types. *)
 

cparser/Cutil.mli

@@ -50,6 +50,8 @@ val remove_custom_attributes : string list -> attributes -> attributes
      in the given list of names. *)
 val attributes_of_type : Env.t -> typ -> attributes
   (* Return the attributes of the given type, expanding typedefs if needed. *)
+val attributes_of_type_no_expand : typ -> attributes
+  (* Return the attributes of the given type, without expanding typedefs. *)
 val add_attributes_type : attributes -> typ -> typ
   (* Add the given set of attributes to those of the given type. *)
 val remove_attributes_type : Env.t -> attributes -> typ -> typ
@@ -62,7 +64,10 @@ val has_std_alignas :  Env.t -> typ -> bool
   (* Do the attributes of the type contain the C11 _Alignas attribute *)
 
 type attribute_class =
-  | Attr_name           (* Attribute applies to the names being declared  *)
+  | Attr_object         (* Attribute applies to the object being declared
+                          (function, global variable, local variable)  *)
+  | Attr_name           (* Attribute applies to the name being declared
+                          (object, struct/union member, struct/union/enum tag *)
   | Attr_type           (* Attribute applies to types *)
   | Attr_struct         (* Attribute applies to struct, union and enum *)
   | Attr_function       (* Attribute applies to function types and decls *)
@@ -76,6 +81,8 @@ val class_of_attribute: attribute -> attribute_class
      have class [Attr_type].  Custom attributes have the class that
      was given to them using [declare_attribute], or [Attr_unknown]
      if not declared. *)
+val name_of_attribute: attribute -> string
+  (* Name for printing an attribute *)
 val attr_inherited_by_members: attribute -> bool
   (* Is an attribute of a composite inherited by members of the composite? *)
 

cparser/Elab.ml

@@ -598,7 +598,7 @@ let get_nontype_attrs env ty =
     | Attr_type -> false
     | Attr_function -> not (is_function_type env ty)
     | _ -> true in
-  let nta = List.filter to_be_removed (attributes_of_type env ty) in
+  let nta = List.filter to_be_removed (attributes_of_type_no_expand ty) in
   (remove_attributes_type env nta ty, nta)
 
 (* Elaboration of a type specifier.  Returns 6-tuple:
@@ -656,15 +656,31 @@ let rec elab_specifier ?(only = false) loc env specifier =
     restrict_check ty;
     (!sto, !inline, !noreturn ,!typedef, add_attributes_type !attr ty, env) in
 
-  (* As done in CIL, partition !attr into struct-related attributes,
+  (* Partition !attr into name- and struct-related attributes,
      which are returned, and other attributes, which are left in !attr.
-     The returned struct-related attributes are applied to the
+     The returned name-or-struct-related attributes are applied to the
      struct/union/enum being defined.
-     The leftover non-struct-related attributes will be applied
-     to the variable being defined. *)
-  let get_struct_attrs () =
+     The leftover attributes (e.g. object attributes) will be applied
+     to the variable being defined.
+     If [optmembers] is [None], name-related attributes are not returned
+     but left in !attr.  This corresponds to two use cases:
+     - A use of an already-defined struct/union/enum.  In this case
+       the name-related attributes should go to the name being declared.
+       Sending them to the struct/union/enum would cause them to be ignored,
+       with a warning.  The struct-related attributes go to the 
+       struct/union/enum, are ignored, and cause a warning.
+     - An incomplete declaration of a struct/union.  In this case
+       the name- and struct-related attributes are just ignored,
+       like GCC does.
+  *)
+  let get_definition_attrs optmembers =
     let (ta, nta) =
-      List.partition (fun a -> class_of_attribute a = Attr_struct) !attr in
+      List.partition
+        (fun a -> match class_of_attribute a with
+                  | Attr_struct -> true
+                  | Attr_name -> optmembers <> None
+                  | _ -> false)
+        !attr in
     attr := nta;
     ta in
 
@@ -723,7 +739,8 @@ let rec elab_specifier ?(only = false) loc env specifier =
 
     | [Cabs.Tstruct_union(STRUCT, id, optmembers, a)] ->
         let a' =
-          add_attributes (get_struct_attrs()) (elab_attributes env a) in
+          add_attributes (get_definition_attrs optmembers)
+                         (elab_attributes env a) in
         let (id', env') =
           elab_struct_or_union only Struct loc id optmembers a' env in
         let ty =  TStruct(id', !attr) in
@@ -732,7 +749,8 @@ let rec elab_specifier ?(only = false) loc env specifier =
 
     | [Cabs.Tstruct_union(UNION, id, optmembers, a)] ->
         let a' =
-          add_attributes (get_struct_attrs()) (elab_attributes env a) in
+          add_attributes (get_definition_attrs optmembers)
+                         (elab_attributes env a) in
         let (id', env') =
           elab_struct_or_union only Union loc id optmembers a' env in
         let ty =  TUnion(id', !attr) in
@@ -741,7 +759,8 @@ let rec elab_specifier ?(only = false) loc env specifier =
 
     | [Cabs.Tenum(id, optmembers, a)] ->
         let a' =
-          add_attributes (get_struct_attrs()) (elab_attributes env a) in
+          add_attributes (get_definition_attrs optmembers)
+                         (elab_attributes env a) in
         let (id', env') =
           elab_enum only loc id optmembers a' env in
         let ty = TEnum (id', !attr) in
@@ -2362,6 +2381,13 @@ let enter_typedefs loc env sto dl =
       error loc "initializer in typedef";
     if has_std_alignas env ty then
       error loc "alignment specified for typedef '%s'" s;
+    List.iter
+      (fun a -> match class_of_attribute a with
+                | Attr_object | Attr_struct ->
+                    error loc "attribute '%s' not allowed in 'typedef'"
+                              (name_of_attribute a)
+                | _ -> ())
+      (attributes_of_type_no_expand ty);
     match previous_def Env.lookup_typedef env s with
     | Some (s',ty') when Env.in_current_scope env s' ->
         if equal_types env ty ty' then begin

test/regression/Makefile

@@ -23,7 +23,7 @@ TESTS=int32 int64 floats floats-basics \
 TESTS_COMP=attribs1 bitfields1 bitfields2 bitfields3 bitfields4 \
   bitfields5 bitfields6 bitfields7 bitfields8 \
   builtins-$(ARCH) packedstruct1 packedstruct2 alignas \
-  varargs1 varargs2 varargs3 sections alias
+  varargs1 varargs2 varargs3 sections alias aligned
 
 # Can run, both in compiled mode and in interpreter mode,
 # but produce processor-dependent results, so no reference output in Results

test/regression/Results/aligned

@@ -0,0 +1,12 @@
+a: size 1, offset mod 16 = 0
+b: size 3, offset mod 16 = 0
+c: size is that of a pointer, offset mod 16 is good
+d: size 1, offset mod 16 = 0
+f: size is that of a pointer, offset mod 16 is good
+g: size 32, offset mod 16 = 0
+h: size 16, offset mod 16 = 0
+i: size 16, offset mod 16 = 0
+j: size 16, offset mod 16 = 0
+T2: size 112, alignment 16
+T4: size is that of a pointer, alignment is that of a pointer
+t2: size 9, alignment 1