Perforce: How to find changes made in a branch

1
votes

Here's the scenario -

  1. Development branch was created from mainline, with many thousands of files in it
  2. A couple of thousand files were modified.
  3. Changes from mainline were "p4 integrated" into the branch. Hopefully integrations always included the complete mainline as of a known-good label, but I'm not sure of this
  4. Steps 2 and 3 were repeated an unknown number of times - let's guess a dozen integrates, and probably another 1000 or more changes, usually to files already modified

I am now in the painful position of trying to code review this.

Are there any commands that can help me get the diffs for each modified file between the version last integrated to it, and the version in the branch?

Or do I need to write:

  1. A script which will identify all locally changed files.
  2. A script which will find the integration point for each file in the above list
  3. Another script which will use (2) to purge the list in (1) of files with no net change
  4. A wrapper on (2) that will issue an appropriate p4 diff2 command

FWIW, I basically know how to do this manually, file by file. It's the scale that's daunting. Also, there are changes still going into the branch, in response to code review feedback, so I'll probably be recreating my lists repeatedly.

1
perforce
If somebody asked me to code review a couple thousand changes to a couple thousand files, I'd just stare at them, silently, until they went away. That is, you don't have a tools problem, you have a management problem. Best of luck! But from a tools point of view, you might find P4V's "folder diff" useful, too. - Bryan Pendleton
@Bryan I agree that we also have non-technical issues, and I've been working them as well. But in this case, the change is supposed to be just a rearrangement of header files, only a few lines per file, with no net effect. Unfortunately, I've found mistakes even in that, and we're now on the third pass of the review. - Arlie Stephens

1 Answers

2
votes

If you know what the known-good label in the mainline was that was used to do the last integrate, this should just be:

p4 diff2 main/...@good-label dev-branch/...

since for each file "the version last integrated" will be @good-label. Files that weren't locally modified won't have any diffs, so there's no special need to filter them out.

FWIW if I were in your position I'd be making use of "p4 ichanges dev-branch/... main/..." and going through by changelist, since diffs make more sense when each is in the context of its changelist, rather than looking at one monster diff per file that each contains a dozen unrelated changes.