On 29/11/2013 10:28, Joachim Breitner wrote:

Hi,

Am Freitag, den 29.11.2013, 10:08 +0000 schrieb Simon Marlow:

...

Actually this isn't quite right. compiler_debugged() is true when GhcDebugged=YES in the build system, and GhcDebugged controls whether GHC is compiled with -debug or not.

That is, compiler_debugged() tells us whether the compiler was compiled with -debug, not -DDEBUG. The -debug flag links in the debug RTS and doesn't change allocation or heap residency, whereas -DDEBUG enables assertions in the compiler and *does* change allocation and heap residency.

It looks like we need another predicate to tell us whether GHC was compiled with -DDEBUG or not.

Would you mind backing out these changes in the meantime?

are you sure? compiler_debugged() is certainly true when I build ghc with GhcStage2HcOpts = -O0 -DDEBUG which yields ./inplace/bin/ghc-stage2 --info|grep 'Debug on' ,("Debug on","True") but ./inplace/bin/ghc-stage2 +RTS --info|grep -i debug is empty.

The test runner sets the value testsuite/mk/ghc-config.hs: info <- readProcess ghc ["--info"] "" let fields = read info :: [(String,String)] getGhcFieldOrFail fields "GhcDebugged" "Debug on" which writes to testsuite/mk/ghcconfig_* which is then read by testsuite/mk/boilerplate.mk which is included everywhere including mk/test.mk which sets "-e ghc_debugged=$(GhcDebugged)"

Oh, we use the same variable name GhcDebugged to mean two different things: in the GHC build system it means that GHC was compiled with -debug, but in the testsuite build system it means that GHC was compiled with -DDEBUG. How confusing! Anyway you're right - there doesn't seem to be a bug, but we should rename things to avoid confusion. I'll do that.

So it seems that it is simply the wiki documentation that is wrong here.

I didn't check the wiki, just got confused by the source. Please go ahead and fix the wiki if there's something wrong there. Cheers, Simon