On 04 December 2005 00:51, John Meacham wrote:
I was thinking it would be nice if ghc --make could touch the output file with the timestamp of the most recently modified source file.
As it is, if you edit a file in between when ghc --make starts and it finishes (a substantial amount of time in some cases) then 'make' will not realize the dependencies have changed.
Hmm, I'm not sure about this. I see the problem: you have a Makefile rule that looks like this: myprog : Main.hs Foo.hs Bar.hs ... $(GHC) -o $@ --make Main.hs and while building myprog, you edit Foo.hs after it has been compiled, with the result that myprog has a later modification date than Foo.hs so won't be recompiled. However, touching myprog to match the date of Foo.hs when it was compiled doesn't seem right - the date on the executable would be earlier than the object files, which might not cause problems with the Makefile rule above, but would likely lead to problems with different Makefile setups. Perhaps the date on an object file should be set to the same as the source file? And the date on the .hi file? The easiest thing to do is not to try to use make dependencies with --make, just run ghc --make every time. It doesn't link if linking isn't required any more. Cheers, Simon
Shouldn't it work to pass "-M --make"? Or, hmm, maybe -M isn't generating enough dependencies - like, it seems that it should generate a dependency for the final output file specified with "-o" but it isn't... Frederik On Wed, Dec 07, 2005 at 11:34:55AM -0000, Simon Marlow wrote:
On 04 December 2005 00:51, John Meacham wrote:
I was thinking it would be nice if ghc --make could touch the output file with the timestamp of the most recently modified source file.
As it is, if you edit a file in between when ghc --make starts and it finishes (a substantial amount of time in some cases) then 'make' will not realize the dependencies have changed.
Hmm, I'm not sure about this. I see the problem: you have a Makefile rule that looks like this:
myprog : Main.hs Foo.hs Bar.hs ... $(GHC) -o $@ --make Main.hs
and while building myprog, you edit Foo.hs after it has been compiled, with the result that myprog has a later modification date than Foo.hs so won't be recompiled.
However, touching myprog to match the date of Foo.hs when it was compiled doesn't seem right - the date on the executable would be earlier than the object files, which might not cause problems with the Makefile rule above, but would likely lead to problems with different Makefile setups. Perhaps the date on an object file should be set to the same as the source file? And the date on the .hi file?
The easiest thing to do is not to try to use make dependencies with --make, just run ghc --make every time. It doesn't link if linking isn't required any more.
Cheers, Simon
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participants (2)
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Frederik Eaton -
Simon Marlow