diff options
| author | Moritz Angermann <moritz.angermann@gmail.com> | 2017-11-17 19:29:25 +0800 |
|---|---|---|
| committer | Moritz Angermann <moritz.angermann@gmail.com> | 2017-11-18 11:00:11 +0800 |
| commit | 12a7444463184e9eddbe7b7251a0ee1e976f4d75 (patch) | |
| tree | a7c9e04baae103166f7d12d77676294ad50cb6c8 /docs | |
| parent | c7297342a4797ea36df8767d9c208cfb45de2d09 (diff) | |
| download | haskell-12a7444463184e9eddbe7b7251a0ee1e976f4d75.tar.gz | |
Adds -ghc-version flag to ghc.
Summary:
When building the rts with ghc (e.g. using ghc as a c compiler), ghc's
"Value Add"[1] is, it includes adding `-include /path/to/ghcversion.h`. For
this it looksup the rts package in the package database, which--if
empty--fails. Thus to allow compiling C files with GHC, we add the
`-ghc-version` flag, which takes the path to the `ghcversion.h` file.
A `-no-ghc-version` flag was omitted, as at that point it becomes
questionable why one would use ghc to compile c if one doesn't
any of the added value.
--
[1] from `compiler/main/DriverPipeline.hs`
> -- add package include paths even if we're just compiling .c
> -- files; this is the Value Add(TM) that using ghc instead of
> -- gcc gives you :)
Reviewers: bgamari, geekosaur, austin
Reviewed By: bgamari
Subscribers: rwbarton, thomie
Differential Revision: https://phabricator.haskell.org/D4135
Diffstat (limited to 'docs')
| -rw-r--r-- | docs/users_guide/using.rst | 23 |
1 files changed, 23 insertions, 0 deletions
diff --git a/docs/users_guide/using.rst b/docs/users_guide/using.rst index a963ead8f1..e3fa74127e 100644 --- a/docs/users_guide/using.rst +++ b/docs/users_guide/using.rst @@ -1064,3 +1064,26 @@ Some flags only make sense for particular target platforms. and later). The :ref:`LLVM backend <llvm-code-gen>` will also use SSE4.2 if your processor supports it but detects this automatically so no flag is required. + +Miscellaneous flags +------------------- + +.. index:: + single: miscellaneous flags + +Some flags only make sense for a particular use case. + +.. ghc-flag:: -ghc-version ⟨path to ghcversion.h⟩ + :shortdesc: (GHC as a C compiler only) Use this ``ghcversion.h`` file + :type: dynamic + :category: misc + + When GHC is used to compile C files, GHC adds package include paths and + includes ``ghcversion.h`` directly. The compiler will lookup the path for + the ``ghcversion.h`` file from the ``rts`` package in the package database. + In some cases, the compiler's package database does not contain the ``rts`` + package, or one wants to specify a specific ``ghcversions.h`` to be + included. This option can be used to specify the path to the + ``ghcversions.h`` file to be included. This is primarily intended to be + used by GHC's build system. + |