Recompilation check should include flags
|Reported by:||simonpj||Owned by:||nobody|
|Type of failure:||Test Case:|
|Related Tickets:||Differential Revisions:|
GHC skips recompilation of a module if the module code hasn't changed, even if the flags in use *have* changed. A benign version is that switching on -O won't recompile modules that were compiled without -O. But here's a nastier version: changing the -main-is flag can lead to an obscure link error. Details below supplied by Niels [[email protected]] Simon Actually, i reproduced it now and the reason is a bit different. I have an application Test and Test2. They both have a main function. Test imports Test2 for some other function. So this is how those files look like: ~/pancake > cat Test.hs module Test where import Test2 hiding (main) main = doit ~/pancake > cat Test2.hs module Test2 where doit = print "Test2.doit" main = print "Test2.main" I then first compile the first app: ~/pancake > ghc --make -main-is Test.main Test.hs Chasing modules from: Test.hs Compiling Test2 ( ./Test2.hs, ./Test2.o ) Compiling Test ( Test.hs, Test.o ) Linking ... then i compile the second app: ~/pancake > ghc --make -main-is Test2.main Test2.hs Chasing modules from: Test2.hs Skipping Test2 ( Test2.hs, Test2.o ) Linking ... /usr/lib/ghc-6.4/libHSrts.a(Main.o)(.text+0xe): In function `main': : undefined reference to `__stginit_ZCMain' /usr/lib/ghc-6.4/libHSrts.a(Main.o)(.text+0x28): In function `main': : undefined reference to `ZCMain_main_closure' collect2: ld returned 1 exit status So I guess generating Test2.o the first time and using - main-is renamed the main in Test2.o . Since it is not recompiled when I want to compile the second app, it fails because it cant find the main...I thought providing a -main-is flag again when compiling the second app would somehow force recompilation of Test2.o or at least fixing the 'renaming' that the first compilation of Test2.o had caused. greetings, Niels.
Change History (1)
Note: See TracTickets for help on using tickets.