Usage: $$ [command-line-options-and-input-files] To compile and link a complete Haskell program, run the compiler like so: $$ --make Main where the module Main is in a file named Main.hs (or Main.lhs) in the current directory. The other modules in the program will be located and compiled automatically, and the linked program will be placed in the file `a.out' (or `Main.exe' on Windows). Alternatively, $$ can be used to compile files individually. Each input file is guided through (some of the) possible phases of a compilation: - unlit: extract code from a "literate program" - hscpp: run code through the C pre-processor (if -cpp flag given) - hsc: run the Haskell compiler proper - gcc: run the C compiler (if compiling via C) - as: run the assembler - ld: run the linker For each input file, the phase to START with is determined by the file's suffix: - .lhs literate Haskell unlit - .hs plain Haskell ghc - .hc C from the Haskell compiler gcc - .c C not from the Haskell compiler gcc - .s assembly language as - other passed directly to the linker ld The phase at which to STOP processing is determined by a command-line option: -E stop after generating preprocessed, de-litted Haskell (used in conjunction with -cpp) -C stop after generating C (.hc output) -S stop after generating assembler (.s output) -c stop after generating object files (.o output) Other commonly-used options are: -v[n] Control verbosity (n is 0--5, normal verbosity level is 1, -v alone is equivalent to -v3) -fglasgow-exts Allow Glasgow extensions (unboxed types, etc.) -O An `optimising' package of compiler flags, for faster code -prof Compile for cost-centre profiling (add -auto-all for automagic cost-centres on all top-level functions) -H14m Increase compiler's heap size (might make compilation faster, especially on large source files). -M Output Makefile rules recording the dependencies of a list of Haskell files. Given the above, here are some TYPICAL invocations of $$: # compile a Haskell module to a .o file, optimising: % $$ -c -O Foo.hs # link three .o files into an executable called "test": % $$ -o test Foo.o Bar.o Baz.o # compile a Haskell module to C (a .hc file), using a bigger heap: % $$ -C -H16m Foo.hs # compile Haskell-produced C (.hc) to assembly language: % $$ -S Foo.hc The User's Guide has more information about GHC's *many* options. An online copy can be found here: http://haskell.org/haskellwiki/GHC ------------------------------------------------------------------------