#7478: setSessionDynFlags does not always work
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Reporter: edsko | Owner:
Type: bug | Status: new
Priority: normal | Component: Compiler
Version: 7.6.1 | Keywords:
Os: Unknown/Multiple | Architecture: Unknown/Multiple
Failure: None/Unknown | Blockedby:
Blocking: | Related:
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The attached test case runs GHC in a separate thread (with a single call
to `runGhc` when the thread is started), waiting for compile requests on
one channel and outputting "done" on another. Requests consist of a list
of filenames to compile. These file names are added as targets and then
`load LoadAddTargets` is called.
On every request we also call `setSessionDynFlags` with a different
`log_action`. On the first request the `log_action` is set to `dispatcher
0` (defined in `forkGhc`), on the second request the `log_action` is set
to `dispatcher 1`, and so on. This dispatcher just outputs the messages it
receives from GHC, along with this integer; hence, all messages from the
first request should include the integer 0, all messages from the second
request should include the integer 1, and so on. However, when the program
is run (in a directory containing all the specified source files), the
output is
{{{
----- 0 ------
(0,"[1 of 2] Compiling B ( B.hs, B.o )")
(0,"[2 of 2] Compiling Main ( A.hs, A.o )")
----- 1 ------
(0,"[2 of 2] Compiling Main ( A.hs, A.o )")
----- 2 ------
(2,"[1 of 1] Compiling Main ( C.hs, C.o )")
(2,"Linking A ...")
}}}
On the first request we ask Ghc to compile A.hs and B.hs; A.hs here
depends on B.hs, which is compiled first, but A.hs contains an error and
cannot be compiled. Then on the second request we ask GHC to compile A.hs
and B.hs again; since B.hs is already compiled it only tries to compile
A.hs, but this still fails. On the third request we ask Ghc to compile
C.hs, an independent source file.
Note that the integer listed for the second request is ''0'', not ''1''.
For some reason the `setSessionDynFlags` does not seem to affect the
recompilation of A.hs, even though when we compile C.hs in the third
request, the output is ''2'', as expected.
(This bug also occurs in GHC 7.4, but the API is slightly different so
some minor modifications to to the code need to be made.)
--
Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/7478>
GHC <http://www.haskell.org/ghc/>
The Glasgow Haskell Compiler
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