1 files changed, 80 insertions, 0 deletions
diff --git a/hadrian/src/Oracles/Flag.hs b/hadrian/src/Oracles/Flag.hs
new file mode 100644
index 0000000000..447f0bc076
--- /dev/null
+++ b/hadrian/src/Oracles/Flag.hs
@@ -0,0 +1,80 @@
+module Oracles.Flag (
+    Flag (..), flag, crossCompiling, platformSupportsSharedLibs,
+    ghcWithSMP, ghcWithNativeCodeGen, supportsSplitObjects
+    ) where
+
+import Hadrian.Oracles.TextFile
+
+import Base
+import Oracles.Setting
+
+data Flag = ArSupportsAtFile
+          | CrossCompiling
+          | GccIsClang
+          | GccLt34
+          | GccLt44
+          | GccLt46
+          | GhcUnregisterised
+          | LeadingUnderscore
+          | SolarisBrokenShld
+          | SplitObjectsBroken
+          | WithLibdw
+          | HaveLibMingwEx
+          | UseSystemFfi
+
+-- Note, if a flag is set to empty string we treat it as set to NO. This seems
+-- fragile, but some flags do behave like this, e.g. GccIsClang.
+flag :: Flag -> Action Bool
+flag f = do
+    let key = case f of
+            ArSupportsAtFile   -> "ar-supports-at-file"
+            CrossCompiling     -> "cross-compiling"
+            GccIsClang         -> "gcc-is-clang"
+            GccLt34            -> "gcc-lt-34"
+            GccLt44            -> "gcc-lt-44"
+            GccLt46            -> "gcc-lt-46"
+            GhcUnregisterised  -> "ghc-unregisterised"
+            LeadingUnderscore  -> "leading-underscore"
+            SolarisBrokenShld  -> "solaris-broken-shld"
+            SplitObjectsBroken -> "split-objects-broken"
+            WithLibdw          -> "with-libdw"
+            HaveLibMingwEx     -> "have-lib-mingw-ex"
+            UseSystemFfi       -> "use-system-ffi"
+    value <- lookupValueOrError configFile key
+    when (value `notElem` ["YES", "NO", ""]) . error $ "Configuration flag "
+        ++ quote (key ++ " = " ++ value) ++ " cannot be parsed."
+    return $ value == "YES"
+
+crossCompiling :: Action Bool
+crossCompiling = flag CrossCompiling
+
+platformSupportsSharedLibs :: Action Bool
+platformSupportsSharedLibs = do
+    badPlatform   <- anyTargetPlatform [ "powerpc-unknown-linux"
+                                       , "x86_64-unknown-mingw32"
+                                       , "i386-unknown-mingw32" ]
+    solaris       <- anyTargetPlatform [ "i386-unknown-solaris2" ]
+    solarisBroken <- flag SolarisBrokenShld
+    return $ not (badPlatform || solaris && solarisBroken)
+
+ghcWithSMP :: Action Bool
+ghcWithSMP = do
+    goodArch <- anyTargetArch ["i386", "x86_64", "sparc", "powerpc", "arm"]
+    ghcUnreg <- flag GhcUnregisterised
+    return $ goodArch && not ghcUnreg
+
+ghcWithNativeCodeGen :: Action Bool
+ghcWithNativeCodeGen = do
+    goodArch <- anyTargetArch ["i386", "x86_64", "sparc", "powerpc"]
+    badOs    <- anyTargetOs ["ios", "aix"]
+    ghcUnreg <- flag GhcUnregisterised
+    return $ goodArch && not badOs && not ghcUnreg
+
+supportsSplitObjects :: Action Bool
+supportsSplitObjects = do
+    broken   <- flag SplitObjectsBroken
+    ghcUnreg <- flag GhcUnregisterised
+    goodArch <- anyTargetArch [ "i386", "x86_64", "powerpc", "sparc" ]
+    goodOs   <- anyTargetOs [ "mingw32", "cygwin32", "linux", "darwin", "solaris2"
+                            , "freebsd", "dragonfly", "netbsd", "openbsd" ]
+    return $ not broken && not ghcUnreg && goodArch && goodOs