Parse the ghc --info values using a Haskell program, and cache the results

Should improve startup time of make in the testsuite, and it is
simpler.

1 files changed, 29 insertions, 0 deletions

diff --git a/testsuite/mk/ghc-config.hs b/testsuite/mk/ghc-config.hs
new file mode 100644
index 0000000000..d2e9e7fef0
--- /dev/null
+++ b/testsuite/mk/ghc-config.hs
@@ -0,0 +1,29 @@
+import System.Environment
+import System.Process
+
+main = do
+  [ghc] <- getArgs
+
+  info <- readProcess ghc ["+RTS", "--info"] ""
+  let fields = read info :: [(String,String)]
+  getGhcField fields "HostOS" "Host OS"
+  getGhcField fields "WORDSIZE" "Word size"
+  getGhcField fields "TARGETPLATFORM" "Target platform"
+  getGhcField fields "TargetOS_CPP" "Target OS"
+  getGhcField fields "TargetARCH_CPP" "Target architecture"
+
+  info <- readProcess ghc ["--info"] ""
+  let fields = read info :: [(String,String)]
+  getGhcField fields "GhcStage" "Stage"
+  getGhcField fields "GhcWithNativeCodeGen" "Have native code generator"
+  getGhcField fields "GhcWithInterpreter" "Have interpreter"
+  getGhcField fields "GhcUnregisterised" "Unregisterised"
+  getGhcField fields "GhcWithSMP" "Support SMP"
+  getGhcField fields "GhcRTSWays" "RTS ways"
+  getGhcField fields "AR" "ar command"
+
+getGhcField :: [(String,String)] -> String -> String -> IO ()
+getGhcField fields mkvar key = do
+   case lookup key fields of
+      Nothing  -> fail ("No field: " ++ key)
+      Just val -> putStrLn (mkvar ++ '=':val)