#13616: Old file used when later calls to GHC omit -dynamic-too -------------------------------------+------------------------------------- Reporter: nomeata | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.0.1 Keywords: | Operating System: Unknown/Multiple Architecture: | Type of failure: None/Unknown Unknown/Multiple | Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- This may possibly only hurt few people who develop Plugins, but it is still quite annoying: If `ghc`, in `--make` mode, recompiles a plugin that it is going to use, but without `-dynamic-too`, it will create new `.dyn` and `.o` files, but it will happily use the old `.dyn_hs` or `.dyn_o` files that are still lying around. I guess the desired behavior is: If it determines that it needs the dynamically compiled version of some module, and it is recompiling the module, then it should complain instead of later either ungracefully falling over the missing `.dyn_o` file or – worse – using an old one. This script reproduces the issue: {{{ #!/bin/bash rm -f *.o *.hi *.dyn_o *.dyn_hi cat > Plugin.hs <<__END__ module Plugin where import GhcPlugins plugin :: Plugin plugin = defaultPlugin { installCoreToDos = install } install :: [CommandLineOption] -> [CoreToDo] -> CoreM [CoreToDo] install _ _ = error "First version" __END__ cat > Code.hs <<__END__ {-# OPTIONS_GHC -O -fplugin Plugin #-} module Code where __END__ echo "No dynamic file found (fine, but the error message could be more helpful)" ghc -package ghc Code.hs -fforce-recomp echo "Compiling with -dynamic-too" ghc -dynamic-too -package ghc Code.hs -fforce-recomp cat > Plugin.hs <<__END__ module Plugin where import GhcPlugins plugin :: Plugin plugin = defaultPlugin { installCoreToDos = install } install :: [CommandLineOption] -> [CoreToDo] -> CoreM [CoreToDo] install _ _ = error "Second version" __END__ echo "Recompiling without -dynamic-too, it still uses the old file" ghc -package ghc Code.hs -fforce-recomp echo "Recompiling with -dynamic-too, now it works" ghc -dynamic-too -package ghc Code.hs -fforce-recomp }}} And here is the slightly redacted output: {{{ $ ./repro.sh No dynamic file found (fine, but the error message could be more helpful) [1 of 2] Compiling Plugin ( Plugin.hs, Plugin.o ) [2 of 2] Compiling Code ( Code.hs, Code.o ) <no location info>: fatal: cannot find object file ‘./Plugin.dyn_o’ while linking an interpreted expression Compiling with -dynamic-too [1 of 2] Compiling Plugin ( Plugin.hs, Plugin.o ) [2 of 2] Compiling Code ( Code.hs, Code.o ) ghc: panic! (the 'impossible' happened) First version Recompiling without -dynamic-too, it still uses the old file [1 of 2] Compiling Plugin ( Plugin.hs, Plugin.o ) [2 of 2] Compiling Code ( Code.hs, Code.o ) ghc: panic! (the 'impossible' happened) First version Recompiling with -dynamic-too, now it works [1 of 2] Compiling Plugin ( Plugin.hs, Plugin.o ) [2 of 2] Compiling Code ( Code.hs, Code.o ) ghc: panic! (the 'impossible' happened) Second version }}} -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/13616 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler