diff options
Diffstat (limited to 'ghc/docs/users_guide/using.vsgml')
| -rw-r--r-- | ghc/docs/users_guide/using.vsgml | 37 |
1 files changed, 37 insertions, 0 deletions
diff --git a/ghc/docs/users_guide/using.vsgml b/ghc/docs/users_guide/using.vsgml index 5de6c1a561..4507712034 100644 --- a/ghc/docs/users_guide/using.vsgml +++ b/ghc/docs/users_guide/using.vsgml @@ -891,6 +891,43 @@ construction of interface files, is (allegedly) in the works. %************************************************************************ %* * +<sect1>Command line options in source files +<label id="source-file-options"> +<p> +<nidx>source-file options</nidx> +%* * +%************************************************************************ + +GHC expects its flags on the command line, but it is also possible +to embed them in the Haskell module itself, using the @OPTIONS@ +pragma <nidx>OPTIONS pragma</nidx>: +<tscreen><verb> + {-# OPTIONS -fglasgow-exts -fno-cpr-analyse #-} + module X where + + ... +</verb></tscreen> +@OPTIONS@ pragmas are only looked for at the top of your source +files, upto the first (non-literate,non-empty) line not containing +@OPTIONS@. Multiple @OPTIONS@ pragmas are recognised. Note +that your command shell does not get to the source file options, they +are just included literally in the array of command-line arguments +the compiler driver maintains internally, so you'll be desperately +disappointed if you try to @glob@ etc. inside @OPTIONS@. + +The contents of @OPTIONS@ are prepended to the command-line +options, so you *do* have the ability to override @OPTIONS@ settings +via the command line. + +It is not recommended to move all the contents of your Makefiles into +your source files, but in some circumstances, the @OPTIONS@ pragma +is the Right Thing. (If you use @-keep-hc-file-too@ and have @OPTIONS@ +flags in your module, the @OPTIONS@ will get put into the generated .hc +file). + + +%************************************************************************ +%* * <sect1>Optimisation (code improvement) <label id="options-optimise"> <p> |