#21 Add debug flag

.github/workflows/haskell-ci.yml

@@ -273,6 +273,14 @@ jobs:
       - name: prepare for constraint sets
         run: |
           rm -f cabal.project.local
+      - name: constraint set no-tasty-debug
+        run: |
+          $CABAL v2-build $ARG_COMPILER --disable-tests --disable-benchmarks --constraint='tasty-bench -tasty +debug' --dependencies-only -j2 all
+          $CABAL v2-build $ARG_COMPILER --disable-tests --disable-benchmarks --constraint='tasty-bench -tasty +debug' all
+      - name: constraint set debug
+        run: |
+          $CABAL v2-build $ARG_COMPILER --disable-tests --disable-benchmarks --constraint='tasty-bench +debug' --dependencies-only -j2 all
+          $CABAL v2-build $ARG_COMPILER --disable-tests --disable-benchmarks --constraint='tasty-bench +debug' all
       - name: constraint set no-tasty
         run: |
           $CABAL v2-build $ARG_COMPILER --disable-tests --disable-benchmarks --constraint='tasty-bench -tasty' --dependencies-only -j2 all

Test/Tasty/Bench.hs

@@ -651,6 +651,10 @@ import System.IO.Unsafe
 import System.Mem
 import Text.Printf
 
+#ifdef DEBUG
+import Debug.Trace
+#endif
+
 #ifdef MIN_VERSION_tasty
 #if MIN_VERSION_containers(0,5,0)
 import qualified Data.IntMap.Strict as IM
@@ -914,12 +918,17 @@ measure n (Benchmarkable act) = do
   act n
   endTime <- fromInteger <$> getCPUTime
   (endAllocs, endCopied, endMaxMemInUse) <- getAllocsAndCopied
-  pure $ Measurement
-    { measTime   = endTime - startTime
-    , measAllocs = endAllocs - startAllocs
-    , measCopied = endCopied - startCopied
-    , measMaxMem = max endMaxMemInUse startMaxMemInUse
-    }
+  let meas = Measurement
+        { measTime   = endTime - startTime
+        , measAllocs = endAllocs - startAllocs
+        , measCopied = endCopied - startCopied
+        , measMaxMem = max endMaxMemInUse startMaxMemInUse
+        }
+#ifdef DEBUG
+  pure $ trace (show n ++ (if n == 1 then " iteration gives " else " iterations give ") ++ show meas) meas
+#else
+  pure meas
+#endif
 
 measureUntil :: Bool -> Timeout -> RelStDev -> Benchmarkable -> IO Estimate
 measureUntil _ _ (RelStDev targetRelStDev) b

cabal.haskell-ci

@@ -1,2 +1,8 @@
 constraint-set no-tasty
   constraints: tasty-bench -tasty
+
+constraint-set debug
+  constraints: tasty-bench +debug
+
+constraint-set no-tasty-debug
+  constraints: tasty-bench -tasty +debug

tasty-bench.cabal

@@ -37,6 +37,12 @@ flag tasty
     When disabled, reduces API to functions independent of @tasty@: combinators
     to construct @Benchmarkable@ and @measureCpuTime@.
 
+flag debug
+  default: False
+  manual: True
+  description:
+    Emit ongoing diagnostic information for benchmarks.
+
 library
   exposed-modules:  Test.Tasty.Bench
   hs-source-dirs:   .
@@ -57,3 +63,6 @@ library
   if impl(ghc < 7.8)
     build-depends:
       tagged >= 0.2
+
+  if flag(debug)
+    cpp-options: -DDEBUG