Debugger Setup. For Qt Environment

Item class

The Python Item class is a small wrapper around values ​​corresponding to one line of the form Variables . The Item class has the following members:

• __init __ (self, value, parentiname, iname, name = None) - Constructor. The internal name of the object is created by combining parentiname and iname. If None is passed as an argument to name, the serial number is used.
• value is an object of type gdb.Value representing the display value.
• iname is the internal name of the object, consisting of a list of identifiers separated by dots corresponding to the position of the object being represented as.
• name - Additional name. If it is set, it will be used in the View Name column. If not specified, a simple number in brackets will be used instead.

Dumper class

For each line in the Variables view, a line of the following content must be created and connected to the debug plug-in.

"{iname = 'some internal name',

addr = 'address of an object in memory',

name = 'Name column',

value = 'the contents of the column Value',

type = 'Type column contents',

numchild = 'number of descendants', // it is enough to specify zero / non zero

childtype = 'type of child by default', // not necessary

childnumchild = 'default number of grandchildren', // not necessary

children = [// required only if the item is expanded as

{iname = 'internal name of the first child',

...},

{iname = 'internal name of the second child',

...},

...

]} "

Although, in principle, you can assemble the entire line above manually, it is much easier to use the Python Dumper class for this purpose. The Python Dumper class contains a full framework for processing iname and addr fields, for processing descendants of simple types, references, pointers, enumerations, known and unknown structures, as well as some auxiliary methods for handling common situations.

The Dumper class has the following members:

• __init __ (self) - Initializes the output with an empty string and clears the stack of children.
• put (self, value) is a low-level method for directly adding to the output string.
• putCommaIfNeeded (self) - adds a comma if the current output ends with '}', '"' or ']'.
• putField (self, name, value) - adds, if necessary, a comma and the name = 'value' field.
• beginItem (self, name) - Begins the field with the entry name = '.
• endItem (self) - Ends field entry with '.
• endChildren (self) - Ends record of the list of descendants.
• childRange (self) - Returns the number of children specified in the current Children space.
• putItemCount (self, count) - Adds the value = '<% d items' field to the output.
• putEllipsis (self) - Adds the field '{name = "<incomplete>", value = "", type = "", numchild = "0"}'. This is automatically done by endChildren if the number of descendants for output is less than the current number of descendants.
• putName (self, name) - Adds a field name = '...'.
• putType (self, type) - Adds a field type = '...' if type does not match the type of the descendant of the parent by default.
• putNumChild (self, numchild) - Adds the numchild = '...' field if numchild does not match the value of the descendant of the parent numchild by default.
• putValue (self, value, encoding = None) - Adds a field value = '...' with an optional field valueencoding = '...'. The value value must be convertible to a string consisting entirely of numeric and alphabetic values. The encoding parameter can be used to specify the encoding method in case the present value should be encoded in some way to fulfill the requirement of containing only numeric and alphabetic values. The following encoding methods are currently supported:
  • 0: unencrypted 8-bit data interpreted as Latin1.
  • 1: Base64-encrypted 8-bit data used for QByteArray will add double quotes.
  • 2: Base64-encrypted 16-bit data used for a QString will be added with double quotes.
  • 3: 32-bit data encrypted with base64, double quotes will be added.
  • 4: base64-encrypted 16-bit data, without quotes (see 2).
  • 5: Base64-encrypted 8-bit data, without quotes (see 1).
  • 6: 8-bit data encrypted as% 02x (as with QByteArray :: toHex), double quotes will be added.
  • 7: 16-bit data encrypted as% 04x (as with QByteArray :: toHex), double quotes will be added.
• putStringValue (self, value) - Encodes a QString and calls putValue with the appropriate encoding method.
• putByteArrayValue (self, value) - Encodes QByteArray and calls putValue with the appropriate encoding method encoding.
• isExpanded (self, item) - Checks if an item with the internal name item.iname is expanded as.
• isExpandedIName (self, iname) - Checks whether the element with the internal name iname is expanded in the form.
• putIntItem (self, name, value) - Equivalent to:

self.beginHash ()

self.putName (name)

self.putValue (value)

self.putType ("int")

self.putNumChild (0)

self.endHash ()

• putBoolItem (self, name, value) - Equivalent to:

self.beginHash ()

self.putName (name)

self.putValue (value)

self.putType ("bool")

self.putNumChild (0)

self.endHash ()

• pushOutput (self) - Moves the output line to a safe place from where it will be sent to the plug-in debugger even if further operations cause an exception.
• putCallItem (self, name, item, func) - Uses gdb to call the func function for the value specified in item.value , and displays the result. This feature is not available when debugging core dumps and is not available for the Symbian platform due to limitations imposed by AppTRK.
• putItemHelper (self, item) is the "Main function", which immediately processes the basic types, references, pointers and enumerations, passes through all descendants and members of the classes of composite types, and calls the appropriate functions qdump __ *.
• putItem (self, item) - Equivalent to:

with SubItem (self):

self.putItemHelper (item)

The exceptions that appear in subsequent calls to functions are caught, and the entire output of putItemHelper is replaced with the output:

...

except RuntimeError:

d.put ('value = "<invalid>", type = "<unknown>", numchild = "0",')

Class of descendants and subitems

Attempting to create child elements may lead to errors if the data is not initialized or damaged. For successful recovery in such situations, use Children and SubItem to create nested items.

The Children __init __ constructor (self, dumper, numChild = 1, childType = None, childNumChild = None) takes one mandatory and three optional arguments. A required argument refers to the current Dumper object. Optional arguments can be used to specify the number of descendants of numChild with the type childType_ and the number of grandchildren childNumChild_ each. If numChild_ is a list of two integers, then the first one will indicate the current number of descendants, and the second - the maximum number of descendants for output.

Similarly, using the SubItem class helps protect individual items.

Example:

d.putNumChild (2)

if d.isExpanded (item):

with Children (d):

with SubItem (d):

d.putName ("key")

d.putItemHelper (Item (key, item.iname, "key"))

with SubItem (d):

d.putName ("value")

d.putItemHelper (Item (value, item.iname, "value"))