Strip libraries at install/copy time. Never strip libraries in build directory.

Two changes:

  * strip static libraries (.a files) at install/copy time, instead of
    at build time. Note that Cabal strips shared libraries (.so files)
    and executables at install/copy time also.

    This is needed for GHC, because it uses Cabal (via ghc-cabal copy)
    to install the boot libraries, and relies on Cabal to take of
    library stripping. Currently .so files indeed get properly stripped,
    but .a files do not.

    (Stripping static libraries at build time was introduced in
    60409cb, with the explanation:
    "Call 'stripLib' from createLibArchive so that it's done only
    once.")

    This bug (if you want to call it that) partially explains the
    difference in size of a GHC installation before and after manual
    stripping, reported in
    #1622 (comment)
    (The other parts are that the GHC build system currently doesn't
    strip executables on installation:
    https://ghc.haskell.org/trac/ghc/ticket/9087, and neither are the
    RTS library stripped, since they don't go through Cabal).

  * never strip the copy of a library in the build directory. Only
    strip the copy that is installed. Note that Cabal never strips
    executables in the build directory either.

    This might speed up compilation of a package under development,
    since stripping won't be performed for every 'cabal build'. It is
    also consistent with the GNU coding standards for 'install-strip':

      "install-strip should not strip the executables in the build
      directory which are being copied for installation. It should only
      strip the copies that are installed."

    Source:
    http://www.gnu.org/prep/standards/html_node/Standard-Targets.html

Author: thomie

Cabal/Distribution/Simple/GHC.hs

@@ -1074,12 +1074,14 @@ installLib verbosity lbi targetDir dynlibTargetDir builtDir _pkg lib clbi = do
       let src = srcDir </> name
           dst = dstDir </> name
       createDirectoryIfMissingVerbose verbosity True dstDir
+
       if isShared
-        then do when (stripLibs lbi) $ Strip.stripLib verbosity
-                                       (hostPlatform lbi) (withPrograms lbi) src
-                installExecutableFile verbosity src dst
+        then installExecutableFile verbosity src dst
         else installOrdinaryFile   verbosity src dst
 
+      when (stripLibs lbi) $ Strip.stripLib verbosity
+                             (hostPlatform lbi) (withPrograms lbi) dst
+
     installOrdinary = install False
     installShared   = install True
 

Cabal/Distribution/Simple/GHCJS.hs

@@ -740,12 +740,14 @@ installLib verbosity lbi targetDir dynlibTargetDir builtDir _pkg lib clbi = do
       let src = srcDir </> name
           dst = dstDir </> name
       createDirectoryIfMissingVerbose verbosity True dstDir
+
       if isShared
-        then do when (stripLibs lbi) $ Strip.stripLib verbosity
-                                       (hostPlatform lbi) (withPrograms lbi) src
-                installExecutableFile verbosity src dst
+        then installExecutableFile verbosity src dst
         else installOrdinaryFile   verbosity src dst
 
+      when (stripLibs lbi) $ Strip.stripLib verbosity
+                             (hostPlatform lbi) (withPrograms lbi) dst
+
     installOrdinary = install False
     installShared   = install True
 

Cabal/Distribution/Simple/Program/Ar.hs

@@ -15,7 +15,7 @@ module Distribution.Simple.Program.Ar (
     multiStageProgramInvocation
   ) where
 
-import Control.Monad (when, unless)
+import Control.Monad (unless)
 import qualified Data.ByteString as BS
 import qualified Data.ByteString.Char8 as BS8
 import Data.Char (isSpace)
@@ -26,8 +26,6 @@ import Distribution.Simple.Program
 import Distribution.Simple.Program.Run
          ( programInvocation, multiStageProgramInvocation
          , runProgramInvocation )
-import qualified Distribution.Simple.Program.Strip as Strip
-         ( stripLib )
 import Distribution.Simple.Utils
          ( dieWithLocation, withTempDirectory )
 import Distribution.System
@@ -86,16 +84,14 @@ createArLibArchive verbosity lbi targetPath files = do
         | inv <- multiStageProgramInvocation
                    simple (initial, middle, final) files ]
 
-  when stripLib $ Strip.stripLib verbosity platform progConf tmpPath
   unless (hostArch == Arm) $ -- See #1537
     wipeMetadata tmpPath
   equal <- filesEqual tmpPath targetPath
   unless equal $ renameFile tmpPath targetPath
 
   where
     progConf = withPrograms lbi
-    stripLib = stripLibs    lbi
-    platform@(Platform hostArch hostOS) = hostPlatform lbi
+    Platform hostArch hostOS = hostPlatform lbi
     verbosityOpts v | v >= deafening = ["-v"]
                     | v >= verbose   = []
                     | otherwise      = ["-c"]