LocalBuildInfo: track program coverage status

The status of Haskell program coverage is recorded in
LocalBuildInfo. Program coverage is disabled during configure if the
compiler does not support it.

Cabal/Distribution/Simple/Compiler.hs

@@ -57,6 +57,7 @@ module Distribution.Simple.Compiler (
         unifiedIPIDRequired,
         packageKeySupported,
         unitIdSupported,
+        coverageSupported,
 
         -- * Support for profiling detail levels
         ProfDetailLevel(..),
@@ -316,6 +317,14 @@ packageKeySupported = ghcSupported "Uses package keys"
 unitIdSupported :: Compiler -> Bool
 unitIdSupported = ghcSupported "Uses unit IDs"
 
+-- | Does this compiler support Haskell program coverage?
+coverageSupported :: Compiler -> Bool
+coverageSupported comp =
+  case compilerFlavor comp of
+    GHC -> True
+    GHCJS -> True
+    _ -> False
+
 -- | Utility function for GHC only features
 ghcSupported :: String -> Compiler -> Bool
 ghcSupported key comp =

Cabal/Distribution/Simple/Configure.hs

@@ -664,10 +664,7 @@ configure (pkg_descr0', pbi) cfg = do
         ++ "profiling is disabled. Linking will fail if any executables "
         ++ "depend on the library."
 
-    let configCoverage_ =
-          mappend (configCoverage cfg) (configLibCoverage cfg)
-
-        cfg' = cfg { configCoverage = configCoverage_ }
+    configCoverage <- configureCoverage verbosity cfg comp
 
     reloc <-
        if not (fromFlag $ configRelocatable cfg)
@@ -678,8 +675,9 @@ configure (pkg_descr0', pbi) cfg = do
             foldl' (\m clbi -> Map.insertWith (++) (componentLocalName clbi) [clbi] m)
                    Map.empty buildComponents
 
-    let lbi = LocalBuildInfo {
-                configFlags         = cfg',
+    let lbi = configCoverage
+              LocalBuildInfo {
+                configFlags         = cfg,
                 flagAssignment      = flags,
                 componentEnabledSpec = enabled,
                 extraConfigArgs     = [],  -- Currently configure does not
@@ -709,6 +707,8 @@ configure (pkg_descr0', pbi) cfg = do
                 splitObjs           = split_objs,
                 stripExes           = fromFlag $ configStripExes cfg,
                 stripLibs           = fromFlag $ configStripLibs cfg,
+                exeCoverage         = False,
+                libCoverage         = False,
                 withPackageDB       = packageDbs,
                 progPrefix          = fromFlag $ configProgPrefix cfg,
                 progSuffix          = fromFlag $ configProgSuffix cfg,
@@ -1016,6 +1016,29 @@ configureDependencies verbosity
 
     return (internalPkgDeps, externalPkgDeps)
 
+-- | Select and apply coverage settings for the build based on the
+-- 'ConfigFlags' and 'Compiler'.
+configureCoverage :: Verbosity -> ConfigFlags -> Compiler
+                  -> IO (LocalBuildInfo -> LocalBuildInfo)
+configureCoverage verbosity cfg comp = do
+    let tryExeCoverage = fromFlagOrDefault False (configCoverage cfg)
+        tryLibCoverage = fromFlagOrDefault tryExeCoverage
+                         (mappend (configCoverage cfg) (configLibCoverage cfg))
+    if coverageSupported comp
+      then do
+        let apply lbi = lbi { libCoverage = tryLibCoverage
+                            , exeCoverage = tryExeCoverage
+                            }
+        return apply
+      else do
+        let apply lbi = lbi { libCoverage = False
+                            , exeCoverage = False
+                            }
+        when (tryExeCoverage || tryLibCoverage) $ warn verbosity
+          ("The compiler " ++ showCompilerId comp ++ " does not support "
+           ++ "program coverage. Program coverage has been disabled.")
+        return apply
+
 -- -----------------------------------------------------------------------------
 -- Configuring package dependencies
 

Cabal/Distribution/Simple/GHC.hs

@@ -513,7 +513,7 @@ buildOrReplLib forRepl verbosity numJobs pkg_descr lbi lib clbi = do
 
   -- Determine if program coverage should be enabled and if so, what
   -- '-hpcdir' should be.
-  let isCoverageEnabled = fromFlag $ configCoverage $ configFlags lbi
+  let isCoverageEnabled = libCoverage lbi
       -- TODO: Historically HPC files have been put into a directory which
       -- has the package name.  I'm going to avoid changing this for
       -- now, but it would probably be better for this to be the
@@ -808,7 +808,7 @@ buildOrReplExe forRepl verbosity numJobs _pkg_descr lbi
 
   -- Determine if program coverage should be enabled and if so, what
   -- '-hpcdir' should be.
-  let isCoverageEnabled = fromFlag $ configCoverage $ configFlags lbi
+  let isCoverageEnabled = exeCoverage lbi
       distPref = fromFlag $ configDistPref $ configFlags lbi
       hpcdir way
         | forRepl = mempty  -- HPC is not supported in ghci

Cabal/Distribution/Simple/GHCJS.hs

@@ -293,7 +293,7 @@ buildOrReplLib forRepl verbosity numJobs pkg_descr lbi lib clbi = do
 
   -- Determine if program coverage should be enabled and if so, what
   -- '-hpcdir' should be.
-  let isCoverageEnabled = fromFlag $ configCoverage $ configFlags lbi
+  let isCoverageEnabled = libCoverage lbi
       pkg_name = display $ PD.package pkg_descr
       distPref = fromFlag $ configDistPref $ configFlags lbi
       hpcdir way
@@ -534,7 +534,7 @@ buildOrReplExe forRepl verbosity numJobs _pkg_descr lbi
 
   -- Determine if program coverage should be enabled and if so, what
   -- '-hpcdir' should be.
-  let isCoverageEnabled = fromFlag $ configCoverage $ configFlags lbi
+  let isCoverageEnabled = exeCoverage lbi
       distPref = fromFlag $ configDistPref $ configFlags lbi
       hpcdir way
         | isCoverageEnabled = toFlag $ Hpc.mixDir distPref way exeName'

Cabal/Distribution/Simple/Test.hs

@@ -20,6 +20,7 @@ import Distribution.Simple.Compiler
 import Distribution.Simple.Hpc
 import Distribution.Simple.InstallDirs
 import qualified Distribution.Simple.LocalBuildInfo as LBI
+import qualified Distribution.Types.LocalBuildInfo as LBI
 import Distribution.Simple.Setup
 import Distribution.Simple.UserHooks
 import qualified Distribution.Simple.Test.ExeV10 as ExeV10
@@ -110,8 +111,7 @@ test args pkg_descr lbi flags = do
     allOk <- summarizePackage verbosity packageLog
     writeFile packageLogFile $ show packageLog
 
-    let isCoverageEnabled = fromFlag $ configCoverage $ LBI.configFlags lbi
-    when isCoverageEnabled $
+    when (LBI.testCoverage lbi) $
         markupPackage verbosity lbi distPref (display $ PD.package pkg_descr) $
             map (fst . fst) testsToRun
 

Cabal/Distribution/Simple/Test/ExeV10.hs

@@ -11,6 +11,7 @@ import Distribution.Simple.Compiler
 import Distribution.Simple.Hpc
 import Distribution.Simple.InstallDirs
 import qualified Distribution.Simple.LocalBuildInfo as LBI
+import qualified Distribution.Types.LocalBuildInfo as LBI
 import Distribution.Simple.Setup
 import Distribution.Simple.Test.Log
 import Distribution.Simple.Utils
@@ -35,7 +36,7 @@ runTest :: PD.PackageDescription
         -> PD.TestSuite
         -> IO TestSuiteLog
 runTest pkg_descr lbi clbi flags suite = do
-    let isCoverageEnabled = fromFlag $ configCoverage $ LBI.configFlags lbi
+    let isCoverageEnabled = LBI.testCoverage lbi
         way = guessWay lbi
         tixDir_ = tixDir distPref way $ PD.testName suite
 

Cabal/Distribution/Simple/Test/LibV09.hs

@@ -17,6 +17,7 @@ import Distribution.Simple.Compiler
 import Distribution.Simple.Hpc
 import Distribution.Simple.InstallDirs
 import qualified Distribution.Simple.LocalBuildInfo as LBI
+import qualified Distribution.Types.LocalBuildInfo as LBI
 import Distribution.Simple.Setup
 import Distribution.Simple.Test.Log
 import Distribution.Simple.Utils
@@ -44,7 +45,7 @@ runTest :: PD.PackageDescription
         -> PD.TestSuite
         -> IO TestSuiteLog
 runTest pkg_descr lbi clbi flags suite = do
-    let isCoverageEnabled = fromFlag $ configCoverage $ LBI.configFlags lbi
+    let isCoverageEnabled = LBI.testCoverage lbi
         way = guessWay lbi
 
     pwd <- getCurrentDirectory

Cabal/Distribution/Types/LocalBuildInfo.hs

@@ -33,6 +33,7 @@ module Distribution.Types.LocalBuildInfo (
     withAllTargetsInBuildOrder',
     neededTargetsInBuildOrder',
     withNeededTargetsInBuildOrder',
+    testCoverage,
 
     -- * Functions you SHOULD NOT USE (yet), but are defined here to
     -- prevent someone from accidentally defining them
@@ -141,6 +142,8 @@ data LocalBuildInfo = LocalBuildInfo {
         splitObjs     :: Bool,  -- ^Use -split-objs with GHC, if available
         stripExes     :: Bool,  -- ^Whether to strip executables during install
         stripLibs     :: Bool,  -- ^Whether to strip libraries during install
+        exeCoverage :: Bool,  -- ^Whether to enable executable program coverage
+        libCoverage :: Bool,  -- ^Whether to enable library program coverage
         progPrefix    :: PathTemplate, -- ^Prefix to be prepended to installed executables
         progSuffix    :: PathTemplate, -- ^Suffix to be appended to installed executables
         relocatable   :: Bool --  ^Whether to build a relocatable package
@@ -253,6 +256,11 @@ withNeededTargetsInBuildOrder' :: PackageDescription -> LocalBuildInfo -> [UnitI
 withNeededTargetsInBuildOrder' pkg_descr lbi uids f
     = sequence_ [ f target | target <- neededTargetsInBuildOrder' pkg_descr lbi uids ]
 
+-- | Is coverage enabled for test suites? In practice, this requires library
+-- and executable profiling to be enabled.
+testCoverage :: LocalBuildInfo -> Bool
+testCoverage lbi = exeCoverage lbi && libCoverage lbi
+
 -------------------------------------------------------------------------------
 -- Stub functions to prevent someone from accidentally defining them