X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=docs%2Fusers_guide%2Fusing.xml;h=3ab73a1b3b1be1edd4108451078b6e5dd0caa3b6;hb=2eb04ca0f8d0ec72b417cddc60672c696b4a3daa;hp=82d7afe581ac3f9d3371e33b74a0fb11bdb58426;hpb=bb7d80b3b8d1396d481d3b24302bee24a3d92f71;p=ghc-hetmet.git diff --git a/docs/users_guide/using.xml b/docs/users_guide/using.xml index 82d7afe..3ab73a1 100644 --- a/docs/users_guide/using.xml +++ b/docs/users_guide/using.xml @@ -839,7 +839,17 @@ ghc -c Foo.hs : - Turns on all warning options. + Turns on all warning options that indicate potentially + suspicious code. The warnings that are + not enabled by + are: + + + + + + + @@ -905,6 +915,31 @@ ghc -c Foo.hs + : + + + implicit prelude, warning + Have the compiler warn if the Prelude is implicitly + imported. This happens unless either the Prelude module is + explicitly imported with an import ... Prelude ... + line, or this implicit import is disabled (either by + or a + LANGUAGE NoImplicitPrelude pragma). + + Note that no warning is given for syntax that implicitly + refers to the Prelude, even if + would change whether it refers to the Prelude. + For example, no warning is given when + 368 means + Prelude.fromInteger (368::Prelude.Integer) + (where Prelude refers to the actual Prelude module, + regardless of the imports of the module being compiled). + + This warning is off by default. + + + + : @@ -1025,7 +1060,7 @@ f foo = foo { x = 6 } in the inadvertent cyclic definition let x = ... x ... in. - Consequently, this option does + Consequently, this option will complain about cyclic recursive definitions. @@ -1136,6 +1171,20 @@ f "2" = 2 + : + + + monomorphism restriction, warning + Have the compiler warn/inform you where in your source + the Haskell Monomorphism Restriction is applied. If applied silently + the MR can give rise to unexpected behaviour, so it can be helpful + to have an explicit warning that it is being applied. + + This warning is off by default. + + + + : @@ -1227,7 +1276,7 @@ f "2" = 2 Note that higher optimisation levels cause more cross-module optimisation to be performed, which can have an impact on how much of your program needs to be recompiled when - you change something. This is one reaosn to stick to + you change something. This is one reason to stick to no-optimisation when developing code. @@ -1436,6 +1485,50 @@ f "2" = 2 + + + + + Turn off the "state hack" whereby any lambda with a + State# token as argument is considered to be + single-entry, hence it is considered OK to inline things inside + it. This can improve performance of IO and ST monad code, but it + runs the risk of reducing sharing. + + + + + + + + + + Tells GHC to omit all inessential information from the interface file + generated for the module being compiled (say M). This means that a module + importing M will see only the types of the functions that M exports, but not + their unfoldings, strictness info, etc. Hence, for example, + no function exported by M will be inlined + into an importing module. The benefit is that modules that import M will + need to be recompiled less often (only when M's exports change their type, + not when they change their implementation). + + + + + + + + + + + Tells GHC to ignore all inessential information when reading interface files. + That is, even if M.hi contains unfolding or strictness information + for a function, GHC will ignore that information. + + + + + : strict constructor fields @@ -1458,7 +1551,7 @@ f "2" = 2 - + @@ -1476,7 +1569,7 @@ f "2" = 2 - : + : inlining, controlling unfolding, controlling @@ -1502,7 +1595,7 @@ f "2" = 2 - : + inlining, controlling