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(gdb.info)Value Annotations

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Values
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   When a value is printed in various contexts, GDB uses annotations to
delimit the value from the surrounding text.

   If a value is printed using `print' and added to the value history,
the annotation looks like

     ^Z^Zvalue-history-begin HISTORY-NUMBER VALUE-FLAGS
     HISTORY-STRING
     ^Z^Zvalue-history-value
     THE-VALUE
     ^Z^Zvalue-history-end

where HISTORY-NUMBER is the number it is getting in the value history,
HISTORY-STRING is a string, such as `$5 = ', which introduces the value
to the user, THE-VALUE is the output corresponding to the value itself,
and VALUE-FLAGS is `*' for a value which can be dereferenced and `-'
for a value which cannot.

   If the value is not added to the value history (it is an invalid
float or it is printed with the `output' command), the annotation is
similar:

     ^Z^Zvalue-begin VALUE-FLAGS
     THE-VALUE
     ^Z^Zvalue-end

   When GDB prints an argument to a function (for example, in the output
from the `backtrace' command), it annotates it as follows:

     ^Z^Zarg-begin
     ARGUMENT-NAME
     ^Z^Zarg-name-end
     SEPARATOR-STRING
     ^Z^Zarg-value VALUE-FLAGS
     THE-VALUE
     ^Z^Zarg-end

where ARGUMENT-NAME is the name of the argument, SEPARATOR-STRING is
text which separates the name from the value for the user's benefit
(such as `='), and VALUE-FLAGS and THE-VALUE have the same meanings as
in a `value-history-begin' annotation.

   When printing a structure, GDB annotates it as follows:

     ^Z^Zfield-begin VALUE-FLAGS
     FIELD-NAME
     ^Z^Zfield-name-end
     SEPARATOR-STRING
     ^Z^Zfield-value
     THE-VALUE
     ^Z^Zfield-end

where FIELD-NAME is the name of the field, SEPARATOR-STRING is text
which separates the name from the value for the user's benefit (such as
`='), and VALUE-FLAGS and THE-VALUE have the same meanings as in a
`value-history-begin' annotation.

   When printing an array, GDB annotates it as follows:

     ^Z^Zarray-section-begin ARRAY-INDEX VALUE-FLAGS

where ARRAY-INDEX is the index of the first element being annotated and
VALUE-FLAGS has the same meaning as in a `value-history-begin'
annotation.  This is followed by any number of elements, where is
element can be either a single element:

     `,' WHITESPACE         ; omitted for the first element
     THE-VALUE
     ^Z^Zelt

   or a repeated element

     `,' WHITESPACE         ; omitted for the first element
     THE-VALUE
     ^Z^Zelt-rep NUMBER-OF-REPITITIONS
     REPETITION-STRING
     ^Z^Zelt-rep-end

   In both cases, THE-VALUE is the output for the value of the element
and WHITESPACE can contain spaces, tabs, and newlines.  In the repeated
case, NUMBER-OF-REPITITONS is the number of consecutive array elements
which contain that value, and REPETITION-STRING is a string which is
designed to convey to the user that repitition is being depicted.

   Once all the array elements have been output, the array annotation is
ended with

     ^Z^Zarray-section-end