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Diffstat (limited to 'gdb/doc')
| -rw-r--r-- | gdb/doc/ChangeLog | 5 | ||||
| -rw-r--r-- | gdb/doc/gdb.texinfo | 42 |
2 files changed, 47 insertions, 0 deletions
diff --git a/gdb/doc/ChangeLog b/gdb/doc/ChangeLog index da49549..176fcb1 100644 --- a/gdb/doc/ChangeLog +++ b/gdb/doc/ChangeLog @@ -1,3 +1,8 @@ +2016-02-01 Andrew Burgess <andrew.burgess@embecosm.com> + + * gdb.texinfo (Value Sizes): New section. + (Data): Add the 'Value Sizes' node to the menu. + 2016-01-26 John Baldwin <jhb@FreeBSD.org> * gdb.texinfo (Debugging Output): Fix subject verb disagreements. diff --git a/gdb/doc/gdb.texinfo b/gdb/doc/gdb.texinfo index de3fe57..c1529a5 100644 --- a/gdb/doc/gdb.texinfo +++ b/gdb/doc/gdb.texinfo @@ -8636,6 +8636,7 @@ being passed the type of @var{arg} as the argument. character set than GDB does * Caching Target Data:: Data caching for targets * Searching Memory:: Searching memory for a sequence of bytes +* Value Sizes:: Managing memory allocated for values @end menu @node Expressions @@ -11711,6 +11712,47 @@ $1 = 1 $2 = (void *) 0x8049560 @end smallexample +@node Value Sizes +@section Value Sizes + +Whenever @value{GDBN} prints a value memory will be allocated within +@value{GDBN} to hold the contents of the value. It is possible in +some languages with dynamic typing systems, that an invalid program +may indicate a value that is incorrectly large, this in turn may cause +@value{GDBN} to try and allocate an overly large ammount of memory. + +@table @code +@kindex set max-value-size +@itemx set max-value-size @var{bytes} +@itemx set max-value-size unlimited +Set the maximum size of memory that @value{GDBN} will allocate for the +contents of a value to @var{bytes}, trying to display a value that +requires more memory than that will result in an error. + +Setting this variable does not effect values that have already been +allocated within @value{GDBN}, only future allocations. + +There's a minimum size that @code{max-value-size} can be set to in +order that @value{GDBN} can still operate correctly, this minimum is +currently 16 bytes. + +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 +@var{x.y} is dynamic and exceeds @var{bytes}. On the other hand, +@value{GDBN} is sometimes clever; the expression @code{A[i]}, where +@var{A} is an array variable with non-constant size, will generally +succeed regardless of the bounds on @var{A}, as long as the component +size is less than @var{bytes}. + +The default value of @code{max-value-size} is currently 64k. + +@kindex show max-value-size +@item show max-value-size +Show the maximum size of memory, in bytes, that @value{GDBN} will +allocate for the contents of a value. +@end table + @node Optimized Code @chapter Debugging Optimized Code @cindex optimized code, debugging |