+ Building GHC happens in two stages: First you have to prepare the tree
+ with make boot; and second, you build the compiler and
+ associated libraries with make all. The boot
+ stage builds some tools used during the main build process, generates
+ parsers and other pre-computed source, and finally computes dependency
+ information. There is considerable detail on the build process in GHC's
+ Building Guide.
+
+
+ If you are hacking the compiler or like to play with unstable
+ development versions, chances are that the compiler someday just crashes
+ on you. Then, it is a good idea to load the core into
+ gdb as usual, but unfortunately there is usually not too
+ much useful information.
+
+ The next step, then, is somewhat tedious. You should build a compiler
+ producing programs with a runtime system that has debugging turned on
+ and use that to build the crashing compiler. There are many sanity
+ checks in the RTS, which may detect inconsistency before they lead to a
+ crash and you may include more debugging information, which helps
+ gdb. For a RTS with debugging turned on, add the following
+ to build.mk (see also the comment in
+ config.mk.in that you find when searching for
+ GhcRtsHcOpts):
+
++GhcRtsHcOpts+=-optc-DDEBUG +GhcRtsCcOpts+=-g +EXTRA_LD_OPTS=-lbfd -liberty
+ Then go into fptools/ghc/rts and make clean boot &&
+ make all. With the resulting runtime system, you have to re-link
+ the compiler. Go into fptools/ghc/compiler, delete the
+ file hsc (up to version 4.08) or
+ ghc-<version>, and execute make all.
+
+ The EXTRA_LD_OPTS are necessary as some of the debugging
+ code uses the BFD library, which in turn requires liberty.
+ I would also recommend (in 4.11 and from 5.0 upwards) adding these linker
+ options to the files package.conf and
+ package.conf.inplace in the directory
+ fptools/ghc/driver/ to the extra_ld_opts entry
+ of the package RTS. Otherwise, you have to supply them
+ whenever you compile and link a program with a compiler that uses the
+ debugging RTS for the programs it produces.
+
+ To run GHC up to version 4.08 in gdb, first invoke the
+ compiler as usual, but pass it the option -v. This will
+ show you the exact invocation of the compiler proper hsc.
+ Run hsc with these options in gdb. The
+ development version 4.11 and stable releases from 5.0 on do no longer
+ use the Perl driver; so, you can run them directly with gdb.
+
+ Debugging a compiler during building from HC files.
+ If you are boot strapping the compiler on new platform from HC files and
+ it crashes somewhere during the build (e.g., when compiling the
+ libraries), do as explained above, but you may have to re-configure the
+ build system with --enable-hc-boot before re-making the
+ code in fptools/ghc/driver/.
+ If you do this with a compiler up to version 4.08, run the build process
+ with make EXTRA_HC_OPTS=-v to get the exact arguments with
+ which you have to invoke hsc in gdb.
+
+
+ +Last modified: Sun Apr 24 22:16:30 CEST 2005 + + + +