Pass -optcxx for GHC >= 8.10

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

@@ -686,7 +686,11 @@ renderGhcOptions comp _platform@(Platform _arch os) opts
   , concat [ [ "-optP-include", "-optP" ++ inc]
            | inc <- flags ghcOptCppIncludes ]
   , [ "-optc" ++ opt | opt <- ghcOptCcOptions opts]
-  , [ "-optc" ++ opt | opt <- ghcOptCxxOptions opts]
+  , -- C++ compiler options: GHC >= 8.10 requires -optcxx, older requires -optc
+    let cxxflag = case compilerCompatVersion GHC comp of
+                Just v | v >= mkVersion [8, 10] -> "-optcxx"
+                _ -> "-optc"
+    in [ cxxflag ++ opt | opt <- ghcOptCxxOptions opts]
   , [ "-opta" ++ opt | opt <- ghcOptAsmOptions opts]
 
   -----------------

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

@@ -0,0 +1,16 @@
+{-# LANGUAGE ForeignFunctionInterface #-}
+
+module Main where
+
+import Foreign.C (CInt (..))
+
+foreign import ccall "clib.h meaning_of_life_c"
+  meaning_of_life_c :: IO CInt
+
+main :: IO ()
+main = do
+    secret <- meaning_of_life_c
+    -- The value 11 comes from __TESTOPT_C__ - see the cabal file.
+    if (secret == 11)
+        then putStrLn ("The secret is " ++ show secret)
+        else error ("Expected value 11, got " ++ show secret)

cabal-testsuite/PackageTests/FFI/ForeignOptsC/README.md

@@ -0,0 +1,5 @@
+# ForeignOptsC
+
+This test case asserts that cabal passes `cc-options` to the C compiler (and NOT `cxx-options`).
+
+See the additional case `ForeignOptsCxx`.

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

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

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

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

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

@@ -0,0 +1,4 @@
+import Test.Cabal.Prelude
+main = cabalTest $ do
+    cabal "v2-build" ["foreign-opts-c-exe"]
+    withPlan $ runPlanExe "foreign-opts-c" "foreign-opts-c-exe" []

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

@@ -0,0 +1,13 @@
+#include "clib.h"
+
+#ifndef __TESTOPT_C__
+#error "Did not get required __TESTOPT_C__ from cc-options"
+#endif
+
+#ifdef __TESTOPT_CXX__
+#error "Got unexpected __TESTOPT_CXX__ from cxx-options"
+#endif
+
+int meaning_of_life_c() {
+    return __TESTOPT_C__;
+}

cabal-testsuite/PackageTests/FFI/ForeignOptsC/cbits/clib.h

@@ -0,0 +1,6 @@
+#ifndef CLIB_H
+#define CLIB_H
+
+int meaning_of_life_c();
+
+#endif

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

@@ -0,0 +1,14 @@
+cabal-version:       2.2
+name:                foreign-opts-c
+version:             0.1
+build-type:          Simple
+
+executable foreign-opts-c-exe
+  main-is:             Main.hs
+  build-depends:       base
+  default-language:    Haskell2010
+  include-dirs:        cbits
+  c-sources:           cbits/clib.c
+  -- The following options are shared in all ForeignOpts cases:
+  cc-options:          -D__TESTOPT_C__=11
+  cxx-options:         -D__TESTOPT_CXX__=22

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

@@ -0,0 +1,16 @@
+{-# LANGUAGE ForeignFunctionInterface #-}
+
+module Main where
+
+import Foreign.C (CInt (..))
+
+foreign import ccall "cxxlib.h meaning_of_life_cxx"
+  meaning_of_life_cxx :: IO CInt
+
+main :: IO ()
+main = do
+    secret <- meaning_of_life_cxx
+    -- The value 22 comes from __TESTOPT_CXX__ - see the cabal file.
+    if (secret == 22)
+        then putStrLn ("The secret is " ++ show secret)
+        else error ("Expected value 22, got " ++ show secret)

cabal-testsuite/PackageTests/FFI/ForeignOptsCxx/README.md

@@ -0,0 +1,7 @@
+# ForeignOptsCxx
+
+This asserts that cabal passes `cxx-options` to the C++ compiler (and NOT `cc-options`).
+
+Since GHC 8.10, they are passed through GHC with `-optcxx`. Before that, they were passed with `-optc`.
+
+See the additional case `ForeignOptsC`.

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

@@ -0,0 +1,10 @@
+# cabal v2-build
+Resolving dependencies...
+Build profile: -w ghc-<GHCVER> -O1
+In order, the following will be built:
+ - foreign-opts-cxx-0.1 (exe:foreign-opts-cxx-exe) (first run)
+Configuring executable 'foreign-opts-cxx-exe' for foreign-opts-cxx-0.1..
+Preprocessing executable 'foreign-opts-cxx-exe' for foreign-opts-cxx-0.1..
+Building executable 'foreign-opts-cxx-exe' for foreign-opts-cxx-0.1..
+# foreign-opts-cxx foreign-opts-cxx-exe
+The secret is 22

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

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

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

@@ -0,0 +1,4 @@
+import Test.Cabal.Prelude
+main = cabalTest $ do
+    cabal "v2-build" ["foreign-opts-cxx-exe"]
+    withPlan $ runPlanExe "foreign-opts-cxx" "foreign-opts-cxx-exe" []

cabal-testsuite/PackageTests/FFI/ForeignOptsCxx/cxxbits/cxxlib.cpp

@@ -0,0 +1,13 @@
+#include "cxxlib.h"
+
+#ifdef __TESTOPT_C__
+#error "Got unexpected __TESTOPT_C__ from cc-options"
+#endif
+
+#ifndef __TESTOPT_CXX__
+#error "Did not get required __TESTOPT_CXX__ from cxx-options"
+#endif
+
+int meaning_of_life_cxx() {
+    return __TESTOPT_CXX__;
+}

cabal-testsuite/PackageTests/FFI/ForeignOptsCxx/cxxbits/cxxlib.h

@@ -0,0 +1,12 @@
+#ifndef CXXLIB_H
+#define CXXLIB_H
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+int meaning_of_life_cxx();
+
+#ifdef __cplusplus
+}
+#endif
+#endif

cabal-testsuite/PackageTests/FFI/ForeignOptsCxx/foreign-opts-cxx.cabal

@@ -0,0 +1,15 @@
+cabal-version:       2.2
+name:                foreign-opts-cxx
+version:             0.1
+build-type:          Simple
+
+executable foreign-opts-cxx-exe
+  main-is:             Main.hs
+  build-depends:       base
+  default-language:    Haskell2010
+  include-dirs:        cxxbits
+  extra-libraries:     stdc++
+  cxx-sources:         cxxbits/cxxlib.cpp
+  -- The following options are shared in all ForeignOpts cases:
+  cc-options:          -D__TESTOPT_C__=11
+  cxx-options:         -D__TESTOPT_CXX__=22