[dev.ssa] cmd/compile: detect unbalanced rules

Rules may span multiple lines,
but if we're still unbalanced at the
end of the file, something is wrong.

I write unbalanced rules depressingly often.

Change-Id: Ibd04aa06539e2a0ffef73bb665febf3542fd11f1
Reviewed-on: https://go-review.googlesource.com/12710
Reviewed-by: Keith Randall <khr@golang.org>

diff --git a/src/cmd/compile/internal/ssa/gen/rulegen.go b/src/cmd/compile/internal/ssa/gen/rulegen.go
index 46e0e507c4e72d7d7db84bd88478d3c8e8ad7f24..8dca0bca1f4e86975ab12b2f01f9bfb59ad14b98 100644 (file)
--- a/src/cmd/compile/internal/ssa/gen/rulegen.go
+++ b/src/cmd/compile/internal/ssa/gen/rulegen.go
@@ -88,6 +88,9 @@ func genRules(arch arch) {
                }
                rule = ""
        }
+       if unbalanced(rule) {
+               log.Fatalf("unbalanced rule: %v\n", rule)
+       }
        if err := scanner.Err(); err != nil {
                log.Fatalf("scanner failed: %v\n", err)
        }