[multiple changes]

2013-10-10  Robert Dewar  <dewar@adacore.com>

	* lib-xref-spark_specific.adb, par-ch13.adb, sem_prag.adb, sem_prag.ads,
	sem_ch12.adb, sem_attr.adb, sem_ch6.adb, sem_ch13.adb, a-sequio.adb,
	s-atocou-builtin.adb: Minor reformatting.

2013-10-10  Thomas Quinot  <quinot@adacore.com>

	* s-oscons-tmplt.c (NEED_PTHREAD_CONDATTR_SETCLOCK): This
	constant needs to be output to s-oscons.h, as it is tested
	by init.c.

2013-10-10  Robert Dewar  <dewar@adacore.com>

	* exp_ch3.adb (Expand_N_Variant_Part): Don't expand choices, too early
	* exp_ch5.adb (Expand_N_Case_Statement): Use new Has_SP_Choice
	flag to avoid expanding choices when not necessary.
	* exp_util.adb: Minor reformatting
	* freeze.adb (Freeze_Record_Type): Redo expansion of variants
	* sem_aggr.adb: Minor reformatting
	* sem_case.ads, sem_case.adb: Major rewrite, separating Analysis and
	Checking of choices.
	* sem_ch3.adb (Analyze_Variant_Part): Rewrite to call new
	Analyze_Choices.
	* sem_ch4.adb (Analyze_Case_Expression): Call Analyze_Choices
	and Check_Choices
	* sem_ch5.adb (Analyze_Case_Statement): Call Analyze_Choices
	and Check_Choices
	* sem_util.adb: Minor reformatting
	* sinfo.ads, sinfo.adb (Has_SP_Choice): New flag.

2013-10-10  Vincent Celier  <celier@adacore.com>

	* mlib-prj.adb (Build_Library): Do not issue link dynamic
	libraries with an Rpath, if switch -R was used.

2013-10-10  Tristan Gingold  <gingold@adacore.com>

	* s-stalib.ads (Image_Index_Table_8, Image_Index_Table_16,
	Image_Index_Table_32): Remove as not used.
	* s-imgint.adb (Image_Integer): Call Set_Image_Integer and
	remove duplicated code.

From-SVN: r203358

1 files changed, 95 insertions, 23 deletions

diff --git a/gcc/ada/sem_case.ads b/gcc/ada/sem_case.ads
index d788afe..c6917f0 100644
--- a/gcc/ada/sem_case.ads
+++ b/gcc/ada/sem_case.ads
@@ -30,52 +30,124 @@
 --  aggregate case, since issues with nested aggregates make that case
 --  substantially different.
 
+--  The following processing is required for such cases:
+
+--    1. Analysis of names of subtypes, constants, expressions appearing within
+--    the choices. This must be done when the construct is encountered to get
+--    proper visibility of names.
+
+--    2. Checking for semantic correctness of the choices. A lot of this could
+--    be done at the time when the construct is encountered, but not all, since
+--    in the case of variants, statically predicated subtypes won't be frozen
+--    (and the choice sets known) till the enclosing record type is frozen. So
+--    at least the check for no overlaps and covering the range must be delayed
+--    till the freeze point in this case.
+
+--    3. Set the Others_Discrete_Choices list for an others choice. This is
+--    used in various ways, e.g. to construct the disriminant checking function
+--    for the case of a variant with an others choice.
+
+--    4. In the case of static predicates, we need to expand out choices that
+--    correspond to the predicate for the back end. This expansion destroys
+--    the list of choices, so it should be delayed to expansion time. We do
+--    not want to mess up the -gnatct ASIS tree, which needs to be able to
+
+--  Step 1 is performed by the generic procedure Analyze_Choices, which is
+--  called when the variant record or case statement/expression is first
+--  encountered.
+
+--  Step 2 is performed by the generic procedure Check_Choices. We decide to
+--  do all semantic checking in that step, since as noted above some of this
+--  has to be deferred to the freeze point in any case for variants. For case
+--  statements and expressions, this procedure can be called at the time the
+--  case construct is encountered (after calling Analyze_Choices).
+
+--  Step 3 is also performed by Check_Choices, since we need the static ranges
+--  for predicated subtypes to accurately construct this.
+
+--  Step 4 is performed by the procedure Expand_Static_Predicates_In_Choices.
+--  For case statements, this call only happens during expansion, so the tree
+--  generated for ASIS does not have this expansion. For the Variant case, the
+--  expansion is done in the ASIS -gnatct case, but with a proper Rewrite call
+--  on the N_Variant node, so ASIS can retrieve the original. The reason we do
+--  the expansion unconditionally for variants is that other processing, for
+--  example for aggregates, relies on having a complete list of choices.
+
+--  Historical note: We used to perform all four of these functions at once in
+--  a single procedure called Analyze_Choices. This routine was called at the
+--  time the construct was first encountered. That seemed to work OK up to Ada
+--  2005, but the introduction of statically predicated subtypes with delayed
+--  evaluation of the static ranges made this completely wrong, both because
+--  the ASIS tree got destroyed by step 4, and steps 2 and 3 were too early
+--  in the variant record case.
+
 with Types; use Types;
 
 package Sem_Case is
 
    procedure No_OP (C : Node_Id);
    --  The no-operation routine. Does absolutely nothing. Can be used
-   --  in the following generic for the parameter Process_Empty_Choice.
+   --  in the following generics for the parameters Process_Empty_Choice,
+   --  or Process_Associated_Node.
 
    generic
-      with function Get_Alternatives (N : Node_Id) return List_Id;
-      --  Function used to get the list of case statement alternatives or
-      --  record variants, from which we can then access the actual lists of
-      --  discrete choices. N is the node for the original construct (case
-      --  statement or a record variant).
+      with procedure Process_Associated_Node (A : Node_Id);
+      --  Associated with each case alternative or record variant A there is
+      --  a node or list of nodes that need additional processing. This routine
+      --  implements that processing.
+
+   package Generic_Analyze_Choices is
+
+      procedure Analyze_Choices
+        (Alternatives : List_Id;
+         Subtyp       : Entity_Id);
+      --  From a case expression, case statement, or record variant, this
+      --  routine analyzes the corresponding list of discrete choices which
+      --  appear in each element of the list Alternatives (for the variant
+      --  part case, this is the variants, for a case expression or statement,
+      --  this is the Alternatives).
+      --
+      --  Subtyp is the subtype of the discrete choices. The type against which
+      --  the discrete choices must be resolved is its base type.
 
+   end Generic_Analyze_Choices;
+
+   generic
       with procedure Process_Empty_Choice (Choice : Node_Id);
       --  Processing to carry out for an empty Choice. Set to No_Op (declared
       --  above) if no such processing is required.
 
       with procedure Process_Non_Static_Choice (Choice : Node_Id);
-      --  Processing to carry out for a non static Choice
+      --  Processing to carry out for a non static Choice (gives an error msg)
 
       with procedure Process_Associated_Node (A : Node_Id);
       --  Associated with each case alternative or record variant A there is
       --  a node or list of nodes that need semantic processing. This routine
       --  implements that processing.
 
-   package Generic_Choices_Processing is
+   package Generic_Check_Choices is
 
-      procedure Analyze_Choices
-        (N              : Node_Id;
-         Subtyp         : Entity_Id;
-         Raises_CE      : out Boolean;
-         Others_Present : out Boolean);
+      procedure Check_Choices
+        (N                        : Node_Id;
+         Alternatives             : List_Id;
+         Subtyp                   : Entity_Id;
+         Others_Present           : out Boolean);
       --  From a case expression, case statement, or record variant N, this
-      --  routine analyzes the corresponding list of discrete choices. Subtyp
-      --  is the subtype of the discrete choices. The type against which the
-      --  discrete choices must be resolved is its base type.
+      --  routine analyzes the corresponding list of discrete choices which
+      --  appear in each element of the list Alternatives (for the variant
+      --  part case, this is the variants, for a case expression or statement,
+      --  this is the Alternatives).
       --
-      --  If one of the bounds of a discrete choice raises a constraint
-      --  error the flag Raise_CE is set.
+      --  Subtyp is the subtype of the discrete choices. The type against which
+      --  the discrete choices must be resolved is its base type.
       --
-      --  Finally Others_Present is set to True if an Others choice is present
-      --  in the list of choices, and in this case the call also sets
-      --  Others_Discrete_Choices in the N_Others_Choice node.
-
-   end Generic_Choices_Processing;
+      --  Others_Present is set to True if an Others choice is present in the
+      --  list of choices, and in this case Others_Discrete_Choices is set in
+      --  the N_Others_Choice node.
+      --
+      --  If a Discrete_Choice list contains at least one instance of a subtype
+      --  with a static predicate, then the Has_SP_Choice flag is set true in
+      --  the parent node (N_Variant, N_Case_Expression/Statement_Alternative).
 
+   end Generic_Check_Choices;
 end Sem_Case;