set varsize-limit: New GDB setting for maximum dynamic object size

[external/binutils.git] / gdb / doc / gdb.texinfo

diff --git a/gdb/doc/gdb.texinfo b/gdb/doc/gdb.texinfo
index d37b107..bd20b39 100644 (file)
--- a/gdb/doc/gdb.texinfo
+++ b/gdb/doc/gdb.texinfo
@@ -16272,6 +16272,7 @@ to be difficult.
 * Ada Tasks and Core Files::    Tasking Support when Debugging Core Files
 * Ravenscar Profile::           Tasking Support when using the Ravenscar
                                    Profile
+* Ada Settings::                New settable GDB parameters for Ada.
 * Ada Glitches::                Known peculiarities of Ada mode.
 @end menu
 
@@ -16927,6 +16928,37 @@ using the Ravenscar Profile.
 
 @end table
 
+@node Ada Settings
+@subsubsection Ada Settings
+@cindex Ada settings
+
+@table @code
+@kindex set varsize-limit
+@item set varsize-limit @var{size}
+Prevent @value{GDBN} from attempting to evaluate objects whose size
+is above the given limit (@var{size}) when those sizes are computed
+from run-time quantities.  This is typically the case when the object
+has a variable size, such as an array whose bounds are not known at
+compile time for example.  Setting @var{size} to @code{unlimited}
+removes the size limitation.  By default, the limit is about 65KB.
+
+The purpose of having such a limit is to prevent @value{GDBN} from
+trying to grab enormous chunks of virtual memory when asked to evaluate
+a quantity whose bounds have been corrupted or have not yet been fully
+initialized.  The limit applies to the results of some subexpressions
+as well as to complete expressions.  For example, an expression denoting
+a simple integer component, such as @code{x.y.z}, may fail if the size of
+@code{x.y} is variable and exceeds @code{size}.  On the other hand,
+@value{GDBN} is sometimes clever; the expression @code{A(i)}, where
+@code{A} is an array variable with non-constant size, will generally
+succeed regardless of the bounds on @code{A}, as long as the component
+size is less than @var{size}.
+
+@kindex show varsize-limit
+@item show varsize-limit
+Show the limit on types whose size is determined by run-time quantities.
+@end table
+
 @node Ada Glitches
 @subsubsection Known Peculiarities of Ada Mode
 @cindex Ada, problems