Cabal: Take into account compilerBuildWay when computing final library ways

Cabal/src/Distribution/Simple/GHC/Build.hs

@@ -12,7 +12,7 @@ import Distribution.Simple.Flag (Flag)
 import Distribution.Simple.GHC.Build.ExtraSources
 import Distribution.Simple.GHC.Build.Link
 import Distribution.Simple.GHC.Build.Modules
-import Distribution.Simple.GHC.Build.Utils (isHaskell)
+import Distribution.Simple.GHC.Build.Utils (compilerBuildWay, isHaskell)
 import Distribution.Simple.LocalBuildInfo
 import Distribution.Simple.Program.Builtin (ghcProgram)
 import Distribution.Simple.Program.Db (requireProgram)
@@ -73,6 +73,7 @@ build numJobs pkg_descr pbci = do
     verbosity = buildVerbosity pbci
     isLib = buildIsLib pbci
     lbi = localBuildInfo pbci
+    bi = buildBI pbci
     clbi = buildCLBI pbci
     isIndef = componentIsIndefinite clbi
     mbWorkDir = mbWorkDirLBI lbi
@@ -111,9 +112,22 @@ build numJobs pkg_descr pbci = do
 
   (ghcProg, _) <- liftIO $ requireProgram verbosity ghcProgram (withPrograms lbi)
 
+  -- Ways which are wanted from configuration flags
   let wantedWays@(wantedLibWays, _, wantedExeWay) = buildWays lbi
 
-  liftIO $ info verbosity ("Wanted build ways(" ++ show isLib ++ "): " ++ show (if isLib then wantedLibWays isIndef else [wantedExeWay]))
+  -- Ways which are needed due to the compiler configuration
+  let doingTH = usesTemplateHaskellOrQQ bi
+      defaultGhcWay = compilerBuildWay (buildCompiler pbci)
+      wantedLibBuildWays =
+        if isLib
+          then wantedLibWays isIndef
+          else [wantedExeWay]
+      finalLibBuildWays =
+        wantedLibBuildWays
+          ++ [defaultGhcWay | doingTH && defaultGhcWay `notElem` wantedLibBuildWays]
+
+  liftIO $ info verbosity ("Wanted build ways(" ++ show isLib ++ "): " ++ show wantedLibBuildWays)
+  liftIO $ info verbosity ("Final lib build ways(" ++ show isLib ++ "): " ++ show finalLibBuildWays)
   -- We need a separate build and link phase, and C sources must be compiled
   -- after Haskell modules, because C sources may depend on stub headers
   -- generated from compiling Haskell modules (#842, #3294).
@@ -127,7 +141,7 @@ build numJobs pkg_descr pbci = do
             | otherwise ->
                 (Nothing, Just mainFile)
           Nothing -> (Nothing, Nothing)
-  buildOpts <- buildHaskellModules numJobs ghcProg hsMainFile inputModules buildTargetDir (wantedLibWays isIndef) pbci
+  buildOpts <- buildHaskellModules numJobs ghcProg hsMainFile inputModules buildTargetDir finalLibBuildWays pbci
   extraSources <- buildAllExtraSources nonHsMainFile ghcProg buildTargetDir wantedWays pbci
   linkOrLoadComponent
     ghcProg

cabal-testsuite/PackageTests/BuildWays/p/CHANGELOG.md

@@ -0,0 +1,5 @@
+# Revision history for p
+
+## 0.1.0.0 -- YYYY-mm-dd
+
+* First version. Released on an unsuspecting world.

cabal-testsuite/PackageTests/BuildWays/p/p.cabal

@@ -0,0 +1,18 @@
+cabal-version:   3.12
+name:            p
+version:         0.1.0.0
+license:         NONE
+author:          Matthew Pickering
+maintainer:      [email protected]
+build-type:      Simple
+extra-doc-files: CHANGELOG.md
+
+common warnings
+    ghc-options: -Wall
+
+library
+    import:           warnings
+    exposed-modules:  MyLib
+    build-depends:    base
+    hs-source-dirs:   src
+    default-language: Haskell2010

cabal-testsuite/PackageTests/BuildWays/p/src/MyLib.hs

@@ -0,0 +1,4 @@
+module MyLib (someFunc) where
+
+someFunc :: IO ()
+someFunc = putStrLn "someFunc"

cabal-testsuite/PackageTests/BuildWays/q/CHANGELOG.md

@@ -0,0 +1,5 @@
+# Revision history for q
+
+## 0.1.0.0 -- YYYY-mm-dd
+
+* First version. Released on an unsuspecting world.

cabal-testsuite/PackageTests/BuildWays/q/app/Main.hs

@@ -0,0 +1,7 @@
+{-# LANGUAGE TemplateHaskell #-}
+module Main where
+
+import MyLib
+
+main :: IO ()
+main = someFunc

cabal-testsuite/PackageTests/BuildWays/q/q.cabal

@@ -0,0 +1,19 @@
+cabal-version:   3.12
+name:            q
+version:         0.1.0.0
+license:         NONE
+author:          Matthew Pickering
+maintainer:      [email protected]
+build-type:      Simple
+extra-doc-files: CHANGELOG.md
+
+common warnings
+    ghc-options: -Wall
+
+executable q
+    import:           warnings
+    main-is:          Main.hs
+    build-depends:    p, base
+    hs-source-dirs:   app
+    ghc-options: -dynamic-too
+    default-language: Haskell2010

cabal-testsuite/PackageTests/BuildWays/setup.test.hs

@@ -0,0 +1,10 @@
+import Test.Cabal.Prelude
+
+opts = ["--enable-shared", "--enable-library-vanilla", "--enable-library-profiling"]
+
+-- See #10418
+main = setupTest $ recordMode DoNotRecord $ withPackageDb $ do
+    skipIfNoSharedLibraries
+    skipIfNoProfiledLibraries
+    withDirectory "p" $ setup_install opts
+    withDirectory "q" $ setup_install opts

changelog.d/i10418

@@ -0,0 +1,13 @@
+synopsis: Fix build ways for modules in executables
+packages: Cabal
+prs: #10419
+issues: #10418
+significance: significant
+
+description: {
+
+- Modules belonging to executables were being built in too many ways. For instance, if you
+had configured to build profiled library files then your executable modules would also
+be built profiled. Which was a regression in behaviour since `Cabal-3.12`.
+
+}