User:Sabotage/QML Debugging

Environment variables

Try enabling (setting to non-zero value) in the environment before launching your QML app to get all kinds of interesting data about the runtime execution and data related to your QML app.

• QML_SHOW_FRAMERATE

  Dump stats during painting events, for example:

Debug: paintEvent: 13 time since last frame: 36

• QML_ENABLE_TEXT_IMAGE_CACHE

  TBD (please describe what this does if you know)

• QML_BINDINGS_DUMP

  Report details about various bindings between elements, for example:

...
Warning: Program.bindings: 1 
Warning: Program.dataLength: 28 
Warning: Program.subscriptions: 1 
Warning: Program.indentifiers: 0 
Warning: 	Skip			-1	0
Warning: 121:31:
Warning: 	LoadScope		0	0
Warning: 	FetchAndSubscribe	0	0	0
Warning: 	Store			0	16	0
Warning: 	Done
...

If you know how to use/interpret this data, please add that info here, or link to someplace that does.

• QML_COMPILER_DUMP

  Report runtime compiler operations and data per .qml parsed, for example:

...
Warning: -------------------------------------------------------------------------------
Warning: "file:///usr/lib/qt4/imports/MeeGo/Ux/Components/Indicators/StatusBar.qml"
Warning: Index  Line    Operation               Data1   Data2   Data3   Comments
Warning: -------------------------------------------------------------------------------
Warning: 0      0       INIT                    33      16      0       0
Warning: 1      43      CREATE                  0       -1              "Item"
Warning: 2      0       STORE_META              1
Warning: 3      0       SETID                   0                       "container"
Warning: 4      43      BEGIN                   16
Warning: 5      47      STORE_BINDING   4       3       0
Warning: 6      66      CREATE_SIMPLE           12
Warning: 7      0       DEFER                   8
Warning: 8      0       INIT                    33      16      -1      -1
Warning: 9      67      CREATE_SIMPLE           20
Warning: 10     67      BEGIN                   12
...

If you have good ideas on how to use this data, please add that info here, or link to someplace that does.

• QML_COMPILER_STATS

  Reports various statistics about components (objects, IDs, bindings) for each .qml parsed, for example:

Warning: QML Document: "file:///usr/lib/qt4/imports/MeeGo/Ux/Components/Indicators/StatusBar.qml"
Warning:     Component Line 100
Warning:         Total Objects:      5
Warning:         IDs Used:           3
Warning:         Optimized Bindings: 1
Warning:             (121:31)
Warning:         QScript Bindings:   6
Warning:             (112:20) (127:24) (114:20) (103:16) (113:21) (125:33)
Warning:     Component Line 242
Warning:         Total Objects:      1
Warning:         IDs Used:           0
Warning:         Optimized Bindings: 0
Warning:         QScript Bindings:   0
Warning:     Component Line 43
Warning:         Total Objects:      24
Warning:         IDs Used:           13
Warning:         Optimized Bindings: 25
Warning:             (200:24) (187:17) (75:23) (68:23) (163:23) (176:17) (261:23) (147:21) (151:21) (140:23)
            (142:18) (189:18) (155:27) (204:31) (175:24) (168:27) (256:17) (145:23) (185:24) (156:17)
            (255:24) (165:15) (169:18) (188:16) (160:18)
Warning:         QScript Bindings:   8
Warning:             (82:40) (45:40) (141:16) (46:38) (159:17) (203:38) (158:25) (47:40)

If you have good ideas on how to use this data, please add that info here, or link to someplace that does.

• QML_REWRITE_DUMP

  TBD (please describe what this does if you know)

• QML_EXPERIMENTAL

  TBD (please describe what this does if you know)

• QML_DISABLE_FAST_PROPERTIES

  TBD (please describe what this does if you know)

• QML_DISABLE_OPTIMIZER

  TBD (please describe what this does if you know)

• QML_XHR_DUMP

  TBD (please describe what this does if you know)

• QML_IMPORT_TRACE

  Dump details on the import actions being taken, including which Types are "resolved" by with imported qml files. Helps to trace unexpected results to possible namespace collision and/or search path order issues.

• QML_IMPORT_PATH

  Alter the paths search to resolve "import" directives

• QML_CHECK_TYPES