From 8cce0bebc102531155bece6f56200cb7cf12d976 Mon Sep 17 00:00:00 2001
From: Bernhard Urban <lewurm@gmail.com>
Date: Tue, 17 Jul 2012 20:27:06 +0200
Subject: [PATCH] gdb: disable ghc's rts timer and disable signal handlers

debugging jitted code is nice again (as it was with 6.12.*)
---
 .gdbcmds           |  3 +++
 HACKING            |  8 ++++++++
 Makefile           |  5 ++++-
 Mate/MethodPool.hs | 11 ++++++-----
 4 files changed, 21 insertions(+), 6 deletions(-)
 create mode 100644 .gdbcmds

diff --git a/.gdbcmds b/.gdbcmds
new file mode 100644
index 0000000..f40cd9e
--- /dev/null
+++ b/.gdbcmds
@@ -0,0 +1,3 @@
+handle SIGILL nostop
+handle SIGSEGV nostop
+run
diff --git a/HACKING b/HACKING
index 2d12341..c70e194 100644
--- a/HACKING
+++ b/HACKING
@@ -1,11 +1,19 @@
 for testing with a release build, use
 $ make tests/Fib
 
+
 for testing a release build against OpenJDK output, use
 $ make tests/Fib.test
 
+
 for testing with a debug build, use
 $ DBGFLAGS='-DDBG_JIT -DDBG_BB' make tests/Fib.dbg
 
 `make clean' is needed if you change $DBGFLAGS.
 for all available flags, see `debug.h'.
+
+
+for debugging with gdb, modify Mate/MethodPool.hs and make a debug build with at
+least -DDBG_JIT enabled, then use
+$ make tests/Fib.gdb
+and follow the instructions in the source file.
diff --git a/Makefile b/Makefile
index c3fc8e8..cd0e887 100644
--- a/Makefile
+++ b/Makefile
@@ -15,7 +15,7 @@ O_STATIC_FILES = $(shell ls $(B_STATIC)/Mate/*.o) $(wildcard $(B_STATIC)/ffi/*.o
 PACKAGES_ := bytestring harpy hs-java plugins
 PACKAGES := $(addprefix -package ,$(PACKAGES_))
 
-GHC_OPT := -I. -Wall -O0 -fno-warn-unused-do-bind
+GHC_OPT := -I. -Wall -O0 -fno-warn-unused-do-bind -rtsopts
 GHC_LD := -optl-Xlinker -optl-x
 
 
@@ -58,6 +58,9 @@ mate.static: Mate.hs ffi/trap.c $(HS_FILES) $(HS_BOOT) ffi/native.o $(CLASS_FILE
 %.dbg: %.class mate.dbg
 	./mate.dbg $(basename $<)
 
+%.gdb: %.class mate.dbg
+	gdb -x .gdbcmds -q --args mate.dbg $(basename $<) +RTS -V0 --install-signal-handlers=no
+
 ifeq (${DBGFLAGS},)
 DEBUGFLAGS = -DDBG_JIT -DDBG_MP
 else
diff --git a/Mate/MethodPool.hs b/Mate/MethodPool.hs
index f7038f3..1403eae 100644
--- a/Mate/MethodPool.hs
+++ b/Mate/MethodPool.hs
@@ -146,11 +146,12 @@ compileBB hmap methodinfo = do
   mapM_ (printfJit "%s\n" . showAtt) (snd right)
   printfJit "\n\n"
   -- UNCOMMENT NEXT LINES FOR GDB FUN
-  --if (toString $ methName methodinfo) == "thejavamethodIwant2debug"
-  --  then getLine
-  --  else return "foo"
-  -- (1) start it with `gdb ./mate' and then `run <classfile>'
-  -- (2) on getLine, press ctrl+c
+  -- if (toString $ methName methodinfo) == "thejavamethodIwant2debug"
+  --   then putStrLn "press CTRL+C now for setting a breakpoint. then `c' and ENTER for continue" >> getLine
+  --   else return "foo"
+  -- (1) build a debug build (see HACKING) and execute `make tests/Fib.gdb'
+  --     for example, where the suffix is important
+  -- (2) on getLine, press CTRL+C
   -- (3) `br *0x<addr>'; obtain the address from the disasm above
   -- (4) `cont' and press enter
   return $ fromIntegral $ ptrToIntPtr entry
-- 
2.25.1