This patch extends the functionality of routine Is_Variable to avoid
duplicating part of its code in routine Side_Effect_Free.
No functionality change.
Tested on x86_64-pc-linux-gnu, committed on trunk
2011-08-02 Javier Miranda <mira...@adacore.com>
* sem_util.ads, sem_util.adb (Is_Variable): Add a new formal to
determine if the analysis is performed using N or Original_Node (N).
* exp_util.adb (Side_Effect_Free): Code cleanup since the new
functionality of routine Is_Variable avoids code duplication.
* checks.adb (Determine_Range): Handle temporaries generated by
Remove_Side_Effects.
Index: exp_util.adb
===================================================================
--- exp_util.adb (revision 177129)
+++ exp_util.adb (working copy)
@@ -4692,32 +4692,12 @@
if Is_Entity_Name (N) then
- -- If the entity is a constant, it is definitely side effect free.
- -- Note that the test of Is_Variable (N) below might be expected
- -- to catch this case, but it does not, because this test goes to
- -- the original tree, and we may have already rewritten a variable
- -- node with a constant as a result of an earlier Force_Evaluation
- -- call.
-
- if Ekind_In (Entity (N), E_Constant, E_In_Parameter) then
- return True;
-
- -- Functions are not side effect free
-
- elsif Ekind (Entity (N)) = E_Function then
- return False;
-
-- Variables are considered to be a side effect if Variable_Ref
-- is set or if we have a volatile reference and Name_Req is off.
-- If Name_Req is True then we can't help returning a name which
-- effectively allows multiple references in any case.
- -- Need comment for Is_True_Constant test below ???
-
- elsif Is_Variable (N)
- or else (Ekind (Entity (N)) = E_Variable
- and then not Is_True_Constant (Entity (N)))
- then
+ if Is_Variable (N, Use_Original_Node => False) then
return not Variable_Ref
and then (not Is_Volatile_Reference (N) or else Name_Req);
Index: checks.adb
===================================================================
--- checks.adb (revision 177053)
+++ checks.adb (working copy)
@@ -3087,6 +3087,20 @@
-- Start of processing for Determine_Range
begin
+ -- For temporary constants internally generated to remove side effects
+ -- we must use the corresponding expression to determine the range of
+ -- the expression.
+
+ if Is_Entity_Name (N)
+ and then Nkind (Parent (Entity (N))) = N_Object_Declaration
+ and then Ekind (Entity (N)) = E_Constant
+ and then Is_Internal_Name (Chars (Entity (N)))
+ then
+ Determine_Range
+ (Expression (Parent (Entity (N))), OK, Lo, Hi, Assume_Valid);
+ return;
+ end if;
+
-- Prevent junk warnings by initializing range variables
Lo := No_Uint;
Index: sem_util.adb
===================================================================
--- sem_util.adb (revision 177127)
+++ sem_util.adb (working copy)
@@ -7508,15 +7508,12 @@
-- Is_Variable --
-----------------
- function Is_Variable (N : Node_Id) return Boolean is
+ function Is_Variable
+ (N : Node_Id;
+ Use_Original_Node : Boolean := True) return Boolean
+ is
+ Orig_Node : Node_Id;
- Orig_Node : constant Node_Id := Original_Node (N);
- -- We do the test on the original node, since this is basically a test
- -- of syntactic categories, so it must not be disturbed by whatever
- -- rewriting might have occurred. For example, an aggregate, which is
- -- certainly NOT a variable, could be turned into a variable by
- -- expansion.
-
function In_Protected_Function (E : Entity_Id) return Boolean;
-- Within a protected function, the private components of the enclosing
-- protected type are constants. A function nested within a (protected)
@@ -7580,6 +7577,18 @@
-- Start of processing for Is_Variable
begin
+ -- Check if we perform the test on the original node since this may be a
+ -- test of syntactic categories which must not be disturbed by whatever
+ -- rewriting might have occurred. For example, an aggregate, which is
+ -- certainly NOT a variable, could be turned into a variable by
+ -- expansion.
+
+ if Use_Original_Node then
+ Orig_Node := Original_Node (N);
+ else
+ Orig_Node := N;
+ end if;
+
-- Definitely OK if Assignment_OK is set. Since this is something that
-- only gets set for expanded nodes, the test is on N, not Orig_Node.
Index: sem_util.ads
===================================================================
--- sem_util.ads (revision 177127)
+++ sem_util.ads (working copy)
@@ -866,13 +866,18 @@
-- object used to represent access-to-subprogram types. This is only
-- relevant to CIL, will always return false for other targets.
- function Is_Variable (N : Node_Id) return Boolean;
+ function Is_Variable
+ (N : Node_Id;
+ Use_Original_Node : Boolean := True) return Boolean;
-- Determines if the tree referenced by N represents a variable, i.e. can
-- appear on the left side of an assignment. There is one situation (formal
-- parameters) in which non-tagged type conversions are also considered
-- variables, but Is_Variable returns False for such cases, since it has
-- no knowledge of the context. Note that this is the point at which
-- Assignment_OK is checked, and True is returned for any tree thus marked.
+ -- Use_Original_Node is used to perform the test on Original_Node (N). By
+ -- default is True since this routine is commonly invoked as part of the
+ -- semantic analysis and it must not be disturbed by the rewriten nodes.
function Is_Visibly_Controlled (T : Entity_Id) return Boolean;
-- Check whether T is derived from a visibly controlled type. This is true
