10131 2016-08-12 09:39:11 +0000 Suggested rewriting of '2.3.5. Dependency Graphs' 2016-08-12 21:52:20 +0000 1 1 9 Documentation Reference handbook 2.2 x86 Multiple RESOLVED FIXED 12 July 2016: RESOLVED Undecided normal 2.2 M4 1 ulfalizer srifenbark bluelightning poky.doc.watcher poky.watcher richard.purdie srifenbark --- --- Done (doc changes complete) oldest_to_newest 65119 0 ulfalizer 2016-08-12 09:39:11 +0000 Hello, Nothing currently hints at that the .dot files are easy to read directly in a text editor. The resulting graphs are completely unreadable without pruning and processing, so knowing this can be extremely useful. I suggest the following changes: * Move '2.3.5. Dependency Graphs' to 2.3.3. and rename it to "2.3.3. Viewing Dependencies". This makes the name consistent with the sections above it. * Rewrite it as follows: Sometimes it can be hard to see why BitBake wants to build other recipes before the one you have specified. To generate dependency information for a recipe, run the following command: $ bitbake -g recipename This command writes the following files in the current directory: * pn-buildlist: A list of recipes/targets involved in building `recipename`. "Involved" here means that at least one task from the recipe would need to run when building `recipename` from scratch. Targets that are in [ASSUME_PROVIDED] are not listed. * pn-depends.dot: A graph showing dependencies between build-time targets (recipes). * package-depends.dot: A graph showing (known) dependencies between runtime targets. * task-depends.dot: A graph showing dependencies between tasks. The graphs are in [DOT](https://en.wikipedia.org/wiki/DOT_%28graph_description_language%29) format and can be converted to images using e.g. the 'dot' tool from [Graphviz](http://www.graphviz.org/). Note { DOT files use a plain text format. The graphs generated by 'bitbake -g' are often so large as to be impossible to read without special pruning (e.g. with bitbake's -I option) and processing, but the corresponding .dot files are often still easy to read and can provide useful information. As an example, task-depends.dot contains lines like the following: "libxslt.do_configure" -> "libxml2.do_populate_sysroot" The above line tells us that libxslt's do_configure task depends on libxml2's do_populate_sysroot task (a normal [DEPENDS] dependency between the recipes). } A different way to view dependency information is with the following command: $ bitbake -g -u depexp recipename This will pop up a GUI window where build- and runtime dependencies can be viewed for the recipes involved in building recipename. I originally wanted to document exactly what information pn-depends.dot and package-depends.dot contain as well, but to be honest it escapes me (and I got frustrated trying to reverse-engineer it). It's not clear at all what stuff like "virtual:native:" and filled vs. dashed vs. dotted edges means. A much more concrete and detailed description is needed, but that's for another ticket in that case. Cheers, Ulf 65121 1 ulfalizer 2016-08-12 10:03:11 +0000 Nit - could get rid of the "often" below. Two "oftens" looks bad. ...but the corresponding .dot files are often still easy to read and can provide useful information. Cheers, Ulf 65147 2 srifenbark 2016-08-12 20:23:02 +0000 Ulf, See http://www.yoctoproject.org/docs/2.2/ref-manual/ref-manual.html#usingpoky-viewing-dependencies for the renamed and moved section. thanks, Scott 65150 3 ulfalizer 2016-08-12 20:34:42 +0000 Thanks! Some nits below: * The problem is usually to figure out why a recipe is built at all, so "dependency information can help you understand recipe build order" might be better as "dependency information can help you understand why a recipe is built". * There's a missing closing parenthesis here: The graphs are in DOT format and can be converted to images (e.g. using the "dot" tool from Graphviz. In addition, "dot" could use code highlighting instead of quotes. * "Despite the form and size of the files, ..." should be "Despite the form and size of the graphs, ..." Looks fine other than that. Cheers, Ulf 65156 4 ulfalizer 2016-08-12 21:07:56 +0000 Thought of one more thing. The Note box could be turned into a Notes box and one more note added: * For an example of how .dot files can be processed, see the scripts/contrib/graph-tool Python script, which finds and displays paths between graph nodes. That script is pretty useful in itself too, so providing an example is a good excuse to mention it. :) Cheers, Ulf 65165 5 srifenbark 2016-08-12 21:47:03 +0000 Ulf, I think I got everything - http://www.yoctoproject.org/docs/2.2/ref-manual/ref-manual.html#usingpoky-viewing-dependencies Scott 65166 6 ulfalizer 2016-08-12 21:49:22 +0000 Yup - looks like it. I'm fine with it now. Thanks, Ulf 65170 7 srifenbark 2016-08-12 21:52:20 +0000 Setting to RESOLVED and turning doc flag to "done". scott