diff --git a/gcc/ada/a-tags.adb b/gcc/ada/a-tags.adb
index 5a0cf71494a2236db3d4c0d8db1dc1bc5189c3c5..0b735be7a443ca4f2d3993fdf4743383daa10bb6 100644
--- a/gcc/ada/a-tags.adb
+++ b/gcc/ada/a-tags.adb
@@ -351,8 +351,8 @@ package body Ada.Tags is
                   Obj_Base := Obj_Base +
                     Iface_Table.Ifaces_Table (Id).Offset_To_Top_Value;
 
-               --  Otherwise we call the function generated by the expander
-               --  to provide us with this value
+               --  Otherwise call the function generated by the expander to
+               --  provide the value.
 
                else
                   Obj_Base := Obj_Base +
@@ -637,11 +637,10 @@ package body Ada.Tags is
       --  Handle library-level tagged types
 
       else
-         --  Make a copy of the string representing the external tag with
-         --  a null at the end.
+         --  Make NUL-terminated copy of external tag string
 
          Ext_Copy (External'Range) := External;
-         Ext_Copy (Ext_Copy'Last) := ASCII.NUL;
+         Ext_Copy (Ext_Copy'Last)  := ASCII.NUL;
          Res := External_Tag_HTable.Get (Ext_Copy'Address);
       end if;
 
diff --git a/gcc/ada/gnat_ugn.texi b/gcc/ada/gnat_ugn.texi
index ec77d30a6d5bad1f3fd7204bb25eae34798f26a8..b35707e9f812dc9ee6e8ee86413f0f0aff604f4f 100644
--- a/gcc/ada/gnat_ugn.texi
+++ b/gcc/ada/gnat_ugn.texi
@@ -6855,13 +6855,21 @@ and communicates it to the compiler using this switch.
 @subsection Integrated Preprocessing
 
 @noindent
-GNAT sources may be preprocessed immediately before compilation; the actual
+GNAT sources may be preprocessed immediately before compilation.
+In this case, the actual
 text of the source is not the text of the source file, but is derived from it
 through a process called preprocessing. Integrated preprocessing is specified
 through switches @option{-gnatep} and/or @option{-gnateD}. @option{-gnatep}
 indicates, through a text file, the preprocessing data to be used.
 @option{-gnateD} specifies or modifies the values of preprocessing symbol.
 
+@noindent
+Note that when integrated preprocessing is used, the output from the
+preprocessor is not written to any external file. Instead it is passed
+internally to the compiler. If you need to preserve the result of
+preprocessing in a file, then you should use @command{gnatprep}
+to perform the desired preprocessing in stand-alone mode.
+
 @noindent
 It is recommended that @command{gnatmake} switch ^-s^/SWITCH_CHECK^ should be
 used when Integrated Preprocessing is used. The reason is that preprocessing
diff --git a/gcc/ada/sem_ch4.adb b/gcc/ada/sem_ch4.adb
index 9a70be8219970f44152743e5feb53a9d0b8dc370..6530cb4a1ac0651b84c702d05796cf56a32a19f4 100644
--- a/gcc/ada/sem_ch4.adb
+++ b/gcc/ada/sem_ch4.adb
@@ -1005,10 +1005,10 @@ package body Sem_Ch4 is
       Analyze_Expression (L);
       Analyze_Expression (R);
 
-      --  If the entity is present, the  node appears in an instance,
-      --  and denotes a predefined concatenation operation. The resulting
-      --  type is obtained from the arguments when possible. If the arguments
-      --  are aggregates, the array type and the concatenation type must be
+      --  If the entity is present, the node appears in an instance, and
+      --  denotes a predefined concatenation operation. The resulting type is
+      --  obtained from the arguments when possible. If the arguments are
+      --  aggregates, the array type and the concatenation type must be
       --  visible.
 
       if Present (Op_Id) then
diff --git a/gcc/ada/sem_type.ads b/gcc/ada/sem_type.ads
index 0cc5e5d43f34c3de964a3f0c58d41ffea8b96851..d40f441e38bae16114c1812233cfbf1e84d2bc3f 100644
--- a/gcc/ada/sem_type.ads
+++ b/gcc/ada/sem_type.ads
@@ -53,7 +53,7 @@ package Sem_Type is
    --  Both these structures are initialized at the beginning of every complete
    --  context.
 
-   --  Corresponding to the set of interpretation for a given overloadable
+   --  Corresponding to the set of interpretations for a given overloadable
    --  identifier, there is a set of possible types corresponding to the types
    --  that the overloaded call may return. We keep a 1-to-1 correspondence
    --  between interpretations and types: for user-defined subprograms the