gnat_ugn.texi: Update -gnatN documentation.

2008-07-31  Robert Dewar  <dewar@adacore.com>

	* gnat_ugn.texi: Update -gnatN documentation.

	* gnat_rm.texi: Add note about pre/postcondition
	pragmas not checked in conjunction with front-end inlining.

From-SVN: r138366

gcc/ada/gnat_rm.texi

@@ -3792,6 +3792,13 @@ package Sort is
 end Sort;
 @end smallexample
 
+@noindent
+Note: postcondition pragmas associated with subprograms that are
+marked as Inline_Always, or those marked as Inline with front-end
+inlining (-gnatN option set) are accepted and legality-checked
+by the compiler, but are ignored at run-time even if postcondition
+checking is enabled.
+
 @node Pragma Precondition
 @unnumberedsec Pragma Precondition
 @cindex Preconditions
@@ -3826,13 +3833,22 @@ package Math_Functions is
 end Math_Functions;
 @end smallexample
 
-@code{Postcondition} pragmas may appear either immediate following the
+@noindent
+@code{Precondition} pragmas may appear either immediate following the
 (separate) declaration of a subprogram, or at the start of the
 declarations of a subprogram body. Only other pragmas may intervene
 (that is appear between the subprogram declaration and its
 postconditions, or appear before the postcondition in the
 declaration sequence in a subprogram body).
 
+Note: postcondition pragmas associated with subprograms that are
+marked as Inline_Always, or those marked as Inline with front-end
+inlining (-gnatN option set) are accepted and legality-checked
+by the compiler, but are ignored at run-time even if postcondition
+checking is enabled.
+
+
+
 @node Pragma Profile (Ravenscar)
 @unnumberedsec Pragma Profile (Ravenscar)
 @findex Ravenscar

gcc/ada/gnat_ugn.texi

@@ -2368,7 +2368,7 @@ that for inlining to actually occur as a result of the use of this switch,
 it is necessary to compile in optimizing mode.
 
 @cindex @option{-gnatN} switch
-The use of @option{-gnatN} activates a more extensive inlining optimization
+The use of @option{-gnatN} activates  inlining optimization
 that is performed by the front end of the compiler. This inlining does
 not require that the code generation be optimized. Like @option{-gnatn},
 the use of this switch generates additional dependencies.
@@ -2376,6 +2376,12 @@ Note that
 @option{-gnatN} automatically implies @option{-gnatn} so it is not necessary
 to specify both options.
 
+When using a gcc-based back end (in practice this means using any version
+of GNAT other than the JGNAT, .NET or GNAAMP versions), then the use of
+@option{-gnatN} is deprecated, and the use of @option{-gnatn} is preferred.
+Historically front end inlining was more extensive than the gcc back end
+inlining, but that is no longer the case.
+
 @item
 If an object file @file{O} depends on the proper body of a subunit through
 inlining or instantiation, it depends on the parent unit of the subunit.