Further document ada-lang.c::value_assign_to_component & fix whitespaces.

This patch improves the documentation of ada-lang.c's
value_assign_to_component to publish the fact that it also works
with not_lval values.

And touching this area of the code showed that there were a number
of whitespace issues, as well as a formatting issue of the main comment
(no leading '*' on each line). This patch fixes those while at it.

No functional change, however.

gdb/ChangeLog:

        * ada-lang.c (value_assign_to_component): Reformat and improve
        documentation. Remove all trailing spaces.

2 files changed, 22 insertions, 11 deletions

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index f36a7626f64..98558f78c2e 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,5 +1,10 @@
 2015-05-05  Joel Brobecker  <brobecker@adacore.com>
 
+	* ada-lang.c (value_assign_to_component): Reformat and improve
+	documentation. Remove all trailing spaces.
+
+2015-05-05  Joel Brobecker  <brobecker@adacore.com>
+
 	* inline-frame.c (inline_frame_sniffer, skip_inline_frames):
 	Stop counting inlined frames as soon as an out-of-line function
 	is found.
diff --git a/gdb/ada-lang.c b/gdb/ada-lang.c
index c56e8bb9c43..7fe85c09217 100644
--- a/gdb/ada-lang.c
+++ b/gdb/ada-lang.c
@@ -2682,21 +2682,27 @@ ada_value_assign (struct value *toval, struct value *fromval)
 }
 
 
-/* Given that COMPONENT is a memory lvalue that is part of the lvalue 
- * CONTAINER, assign the contents of VAL to COMPONENTS's place in 
- * CONTAINER.  Modifies the VALUE_CONTENTS of CONTAINER only, not 
- * COMPONENT, and not the inferior's memory.  The current contents 
- * of COMPONENT are ignored.  */
+/* Given that COMPONENT is a memory lvalue that is part of the lvalue
+   CONTAINER, assign the contents of VAL to COMPONENTS's place in
+   CONTAINER.  Modifies the VALUE_CONTENTS of CONTAINER only, not
+   COMPONENT, and not the inferior's memory.  The current contents
+   of COMPONENT are ignored.
+
+   Although not part of the initial design, this function also works
+   when CONTAINER and COMPONENT are not_lval's: it works as if CONTAINER
+   had a null address, and COMPONENT had an address which is equal to
+   its offset inside CONTAINER.  */
+
 static void
 value_assign_to_component (struct value *container, struct value *component,
 			   struct value *val)
 {
   LONGEST offset_in_container =
     (LONGEST)  (value_address (component) - value_address (container));
-  int bit_offset_in_container = 
+  int bit_offset_in_container =
     value_bitpos (component) - value_bitpos (container);
   int bits;
-  
+
   val = value_cast (value_type (component), val);
 
   if (value_bitsize (component) == 0)
@@ -2705,17 +2711,17 @@ value_assign_to_component (struct value *container, struct value *component,
     bits = value_bitsize (component);
 
   if (gdbarch_bits_big_endian (get_type_arch (value_type (container))))
-    move_bits (value_contents_writeable (container) + offset_in_container, 
+    move_bits (value_contents_writeable (container) + offset_in_container,
 	       value_bitpos (container) + bit_offset_in_container,
 	       value_contents (val),
 	       TYPE_LENGTH (value_type (component)) * TARGET_CHAR_BIT - bits,
 	       bits, 1);
   else
-    move_bits (value_contents_writeable (container) + offset_in_container, 
+    move_bits (value_contents_writeable (container) + offset_in_container,
 	       value_bitpos (container) + bit_offset_in_container,
 	       value_contents (val), 0, bits, 0);
-}	       
-			
+}
+
 /* The value of the element of array ARR at the ARITY indices given in IND.
    ARR may be either a simple array, GNAT array descriptor, or pointer
    thereto.  */