2014-07-17 Robert Dewar <dewar@adacore.com>

	* gnat_rm.texi: Improve documentation of Unrestricted_Access.
	* sinfo.ads: Document restriction on aggregates (must expand to
	assignments if one or more assignments needs expansion, e.g. for
	controlled types).
	* sem_ch13.adb: All warning messages regarding bit order should
	be info: messages.
	* gnat_ugn.texi: Minor correction of missing @ on @code

2014-07-17  Robert Dewar  <dewar@adacore.com>

	* restrict.ads (Implementation_Restriction): Add No_Long_Long_Integer.
	* s-rident.ads (Partition_Boolean_Restrictions): Add
	No_Long_Long_Integer.
	* sem_ch3.adb (Modular_Type_Declaration): Size must be <=
	Long_Integer'Size if restriction No_Long_Long_Integer is active.
	(Signed_Integer_Type_Declaration): Do not allow Long_Long_Integer
	as the implicit base type for a signed integer type declaration
	if restriction No_Long_Long_Integer is active.
	* sem_util.ads, sem_util.adb (Set_Entity_With_Checks): Include check for
	No_Long_Long_Integer.



git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@212727 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 22 insertions, 5 deletions

diff --git a/gcc/ada/sinfo.ads b/gcc/ada/sinfo.ads
index 4c282132abd..4bb9d4f34fe 100644
--- a/gcc/ada/sinfo.ads
+++ b/gcc/ada/sinfo.ads
@@ -3627,6 +3627,16 @@ package Sinfo is
       --  references a subprogram that is a renaming, then the front end must
       --  rewrite the attribute to refer directly to the renamed entity.
 
+      --  Note: syntactically the prefix of an attribute reference must be a
+      --  name, and this (somewhat artificial) requirement is enforced by the
+      --  parser. However, for many attributes, such as 'Valid, it is quite
+      --  reasonable to apply the attribute to any value, and hence to any
+      --  expression. Internally in the tree, the prefix is an expression which
+      --  does not have to be a name, and this is handled fine by the semantic
+      --  analysis and expansion, and back ends. This arises for the case of
+      --  attribute references built by the expander (e.g. 'Valid for the case
+      --  of an implicit validity check).
+
       --  Note: In generated code, the Address and Unrestricted_Access
       --  attributes can be applied to any expression, and the meaning is
       --  to create an object containing the value (the object is in the
@@ -3638,7 +3648,7 @@ package Sinfo is
 
       --  N_Attribute_Reference
       --  Sloc points to apostrophe
-      --  Prefix (Node3)
+      --  Prefix (Node3) (general expression, see note above)
       --  Attribute_Name (Name2) identifier name from attribute designator
       --  Expressions (List1) (set to No_List if no associated expressions)
       --  Entity (Node4-Sem) used if the attribute yields a type
@@ -3731,11 +3741,18 @@ package Sinfo is
       --  are not met, then the front end must translate the aggregate into
       --  an appropriate set of assignments into a temporary.
 
-      --  Note: for the record aggregate case, gigi/gcc can handle all cases of
-      --  record aggregates, including those for packed, and rep-claused
+      --  Note: for the record aggregate case, gigi/gcc can handle most cases
+      --  of record aggregates, including those for packed, and rep-claused
       --  records, and also variant records, providing that there are no
-      --  variable length fields whose size is not known at compile time, and
-      --  providing that the aggregate is presented in fully named form.
+      --  variable length fields whose size is not known at compile time,
+      --  and providing that the aggregate is presented in fully named form.
+
+      --  The other situation in which array aggregates and record aggregates
+      --  cannot be passed to the back end is if assignment to one or more
+      --  components itself needs expansion, e.g. in the case of an assignment
+      --  of an object of a controlled type. In such cases, the front end
+      --  must expand the aggregate to a series of assignments, and apply
+      --  the required expansion to the individual assignment statements.
 
       ----------------------------------------------
       -- 4.3.1  Record Component Association List --