Enable eventlog support in all ways by default

Here we deprecate the eventlogging RTS ways and instead enable eventlog
support in the remaining ways. This simplifies packaging and reduces GHC
compilation times (as we can eliminate two whole compilations of the RTS)
while simplifying the end-user story. The trade-off is a small increase
in binary sizes in the case that the user does not want eventlogging
support, but we think that this is a fine trade-off.

This also revealed a latent RTS bug: some files which included `Cmm.h`
also assumed that it defined various macros which were in fact defined
by `Config.h`, which `Cmm.h` did not include. Fixing this in turn
revealed that `StgMiscClosures.cmm` failed to import various spinlock
statistics counters, as evidenced by the failed unregisterised build.

Closes #18948.

2 files changed, 0 insertions, 14 deletions

diff --git a/ghc/ghc-bin.cabal.in b/ghc/ghc-bin.cabal.in
index 8a9178a183..946086b305 100644
--- a/ghc/ghc-bin.cabal.in
+++ b/ghc/ghc-bin.cabal.in
@@ -27,11 +27,6 @@ Flag threaded
     Default: True
     Manual: True
 
-Flag eventlog
-    Description: Link the ghc executable against the event-logging RTS
-    Default: True
-    Manual: True
-
 Executable ghc
     Default-Language: Haskell2010
 
@@ -94,10 +89,6 @@ Executable ghc
     if flag(threaded)
       ghc-options: -threaded
 
-    -- Same for GhcEventLoggingRts
-    if flag(eventlog)
-      ghc-options: -eventlog
-
     Other-Extensions:
         CPP
         NondecreasingIndentation
diff --git a/ghc/ghc.mk b/ghc/ghc.mk
index 627f4bc13c..fcfb61f65a 100644
--- a/ghc/ghc.mk
+++ b/ghc/ghc.mk
@@ -67,11 +67,6 @@ else
 ghc_stage1_CONFIGURE_OPTS += -f-threaded
 endif
 
-# Same for an event-logging RTS.
-ifeq "$(GhcEventLoggingRts)" "NO"
-ghc_stage1_CONFIGURE_OPTS += -f-eventlog
-endif
-
 ifeq "$(GhcProfiled)" "YES"
 ghc_stage2_PROGRAM_WAY = p
 endif