Report reverse dependencies for dangling rules.
To help find what pulls them in.
Test: m checkbuild on a tree that exhibited the problem in
https://android-build.googleplex.com/builds/pending/P13607612/aosp_crosshatch-userdebug/latest/view/logs/build_error.log
Change-Id: I59f3c98f21e5fb45dbd0aa814400f734d769a442
diff --git a/ui/build/test_build.go b/ui/build/test_build.go
index 5109465..4ff9483 100644
--- a/ui/build/test_build.go
+++ b/ui/build/test_build.go
@@ -50,10 +50,10 @@
// Get a list of leaf nodes in the dependency graph from ninja
executable := config.PrebuiltBuildTool("ninja")
- args := []string{}
- args = append(args, config.NinjaArgs()...)
- args = append(args, "-f", config.CombinedNinjaFile())
- args = append(args, "-t", "targets", "rule")
+ common_args := []string{}
+ common_args = append(common_args, config.NinjaArgs()...)
+ common_args = append(common_args, "-f", config.CombinedNinjaFile())
+ args := append(common_args, "-t", "targets", "rule")
cmd := Command(ctx, config, "ninja", executable, args...)
stdout, err := cmd.StdoutPipe()
@@ -96,9 +96,31 @@
sb := &strings.Builder{}
title := "Dependencies in out found with no rule to create them:"
fmt.Fprintln(sb, title)
- for _, dep := range danglingRulesList {
- fmt.Fprintln(sb, " ", dep)
+
+ report_lines := 1
+ for i, dep := range danglingRulesList {
+ if report_lines > 20 {
+ fmt.Fprintf(sb, " ... and %d more\n", len(danglingRulesList)-i)
+ break
+ }
+ // It's helpful to see the reverse dependencies. ninja -t query is the
+ // best tool we got for that. Its output starts with the dependency
+ // itself.
+ query_cmd := Command(ctx, config, "ninja", executable,
+ append(common_args, "-t", "query", dep)...)
+ query_stdout, err := query_cmd.StdoutPipe()
+ if err != nil {
+ ctx.Fatal(err)
+ }
+ query_cmd.StartOrFatal()
+ scanner := bufio.NewScanner(query_stdout)
+ for scanner.Scan() {
+ report_lines++
+ fmt.Fprintln(sb, " ", scanner.Text())
+ }
+ query_cmd.WaitOrFatal()
}
+
ts.FinishAction(status.ActionResult{
Action: action,
Error: fmt.Errorf(title),