feat(Cabal): cpp-options apply only to .hs files

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

@@ -356,8 +356,8 @@ splitCandCxxOptions
   -> LocalBuildInfo
   -> BuildInfo
   -> ComponentLocalBuildInfo
-  -> SymbolicPathX 'AllowAbsolute Pkg (Dir Artifacts)
-  -> SymbolicPathX 'AllowAbsolute Pkg File
+  -> SymbolicPath Pkg (Dir Artifacts)
+  -> SymbolicPath Pkg File
   -> GhcOptions
 splitCandCxxOptions source verbosity lbi bi clbi odir filename = case source of
   CxxProgram ->
@@ -453,6 +453,9 @@ sourcesGhcOptions verbosity lbi bi clbi odir filename =
     , ghcOptInputFiles = toNubListR [filename]
     , ghcOptObjDir = toFlag odir
     , ghcOptPackages = toNubListR $ mkGhcOptPackages (promisedPkgs lbi) clbi
+    , -- cpp-options apply only to .hs files; GHC ignores -optP for non-Haskell
+      -- files (and since 9.10 this behavior is explicit/enforced)
+      ghcOptCppOptions = []
     }
 
 optimizationCFlags :: LocalBuildInfo -> [String]

cabal-testsuite/PackageTests/FFI/CppOptionsOnlyForHs/Main.hs

@@ -0,0 +1,5 @@
+module Main where
+
+main :: IO ()
+main = do
+  putStrLn "The secret is 11"

cabal-testsuite/PackageTests/FFI/CppOptionsOnlyForHs/cabal.out

@@ -0,0 +1,10 @@
+# cabal v2-build
+Resolving dependencies...
+Build profile: -w ghc-<GHCVER> -O1
+In order, the following will be built:
+ - cpp-options-only-for-hs-0.1 (exe:cpp-options-only-for-hs-exe) (first run)
+Configuring executable 'cpp-options-only-for-hs-exe' for cpp-options-only-for-hs-0.1...
+Preprocessing executable 'cpp-options-only-for-hs-exe' for cpp-options-only-for-hs-0.1...
+Building executable 'cpp-options-only-for-hs-exe' for cpp-options-only-for-hs-0.1...
+# cpp-options-only-for-hs cpp-options-only-for-hs-exe
+The secret is 11

cabal-testsuite/PackageTests/FFI/CppOptionsOnlyForHs/cabal.project

@@ -0,0 +1 @@
+packages: .

cabal-testsuite/PackageTests/FFI/CppOptionsOnlyForHs/cabal.test.hs

@@ -0,0 +1,4 @@
+import Test.Cabal.Prelude
+main = cabalTest $ do
+    cabal "v2-build" ["cpp-options-only-for-hs-exe"]
+    withPlan $ runPlanExe "cpp-options-only-for-hs" "cpp-options-only-for-hs-exe" []

cabal-testsuite/PackageTests/FFI/CppOptionsOnlyForHs/cbits/clib.c

@@ -0,0 +1,5 @@
+#ifdef SUPPORT_SSE
+#error "cpp-options should not be applied to C sources"
+#else
+#endif
+

cabal-testsuite/PackageTests/FFI/CppOptionsOnlyForHs/foreign-opts-c.cabal

@@ -0,0 +1,11 @@
+cabal-version:       2.2
+name:                cpp-options-only-for-hs
+version:             0.1
+build-type:          Simple
+
+executable cpp-options-only-for-hs-exe
+  main-is:             Main.hs
+  build-depends:       base
+  default-language:    Haskell2010
+  c-sources:           cbits/clib.c
+  cpp-options:         -DSUPPORT_SSE

changelog.d/11997.md

@@ -0,0 +1,9 @@
+---
+synopsis: cpp-options apply only to .hs files
+packages: [Cabal]
+prs: 11997
+issues: 11992
+---
+
+cpp-options apply only to .hs files; GHC ignores -optP for non-Haskell
+files (and since 9.10 this behavior is explicit/enforced)