Update to OS/2 port; the build now uses OS_ARCH=OS2, in place of WINNT.

Checkin for sobotka@axess.com. Bugzilla 23544.

47 files changed, 535 insertions, 220 deletions

diff --git a/config/Makefile b/config/Makefile
index 4625ce73..e4ffc4d2 100644
--- a/config/Makefile
+++ b/config/Makefile
@@ -24,11 +24,16 @@ INTERNAL_TOOLS	= 1
 
 include $(MOD_DEPTH)/config/config.mk
 
-CSRCS	= nsinstall.c now.c
+CSRCS	= now.c
 
+# This version hasn't been ported for us; the one in mozilla/config has
+ifneq ($(OS_ARCH),OS2)
+CSRCS  += nsinstall.c
+ 
 PLSRCS	= nfspwd.pl
+endif
 
-ifeq ($(OS_ARCH), WINNT)
+ifeq (,$(filter-out WINNT OS2,$(OS_ARCH)))
 PROG_SUFFIX = .exe
 else
 PROG_SUFFIX =
@@ -64,7 +69,14 @@ ifeq ($(OS_ARCH), HP-UX)
     endif
 endif
 
-ifdef XP_OS2_EMX
+ifeq ($(MOZ_OS2_TOOLS),EMX)
+XCFLAGS = $(OS_EXE_CFLAGS)
+ifeq ($(MOZ_OS2_EMX_OBJECTFORMAT),OMF)
+XLDOPTS = -Zlinker /PM:VIO
+endif
+endif
+
+ifeq ($(MOZ_OS2_TOOLS),PGCC)
 XCFLAGS = $(OS_EXE_CFLAGS)
 XLDOPTS = -Zlinker /PM:VIO
 endif
@@ -77,7 +89,7 @@ include $(MOD_DEPTH)/config/rules.mk
 
 PROGS	= $(OBJDIR)/now$(PROG_SUFFIX)
 
-ifeq ($(OS_ARCH),WINNT)
+ifeq (,$(filter-out OS2 WINNT,$(OS_ARCH)))
 TARGETS = $(PROGS)
 else
 PROGS	+= $(OBJDIR)/nsinstall$(PROG_SUFFIX)
diff --git a/config/OS2.mk b/config/OS2.mk
index cf2d53dd..3f008cb9 100644
--- a/config/OS2.mk
+++ b/config/OS2.mk
@@ -38,6 +38,10 @@ XP_OS2_EMX   = 1
 endif
 endif
 
+ifeq ($(XP_OS2_EMX),1)
+MOZ_EMXTAG = $(subst .,,$(MOZ_OS2_EMX_OBJECTFORMAT))
+endif
+
 #
 # On OS/2 we proudly support gbash...
 #
@@ -46,7 +50,7 @@ SHELL = GBASH.EXE
 CC			= icc -q -DXP_OS2 -N10
 CCC			= icc -q -DXP_OS2 -DOS2=4 -N10
 LINK			= ilink
-AR			= ilib /noignorecase /nologo $(subst /,\\,$@)
+AR			= ilib /noignorecase /nologo /Out:$(subst /,\\,$@)
 RANLIB 			= @echo RANLIB
 BSDECHO 		= @echo BSDECHO
 NSINSTALL 		= nsinstall
@@ -65,7 +69,7 @@ OBJ_SUFFIX		= obj
 
 OS_CFLAGS     		= -W3 -Wcnd- -gm -gd+ -sd- -su4 -ge-
 OS_EXE_CFLAGS 		= -W3 -Wcnd- -gm -gd+ -sd- -su4 
-AR_EXTRA_ARGS 		= ,,
+AR_EXTRA_ARGS 		= 
 
 ifdef BUILD_OPT
 OPTIMIZER		= -O+ -Oi 
@@ -88,9 +92,9 @@ DEFINES += -D_PR_GLOBAL_THREADS_ONLY -DBSD_SELECT
 
 # Name of the binary code directories
 ifdef MOZ_LITE
-OBJDIR_NAME 		= $(subst OS2,NAV,$(OS_CONFIG))_$(MOZ_OS2_TOOLS)$(OBJDIR_TAG).OBJ
+OBJDIR_NAME 		= $(subst OS2,NAV,$(OS_CONFIG))_$(MOZ_OS2_TOOLS)$(MOZ_EMXTAG)$(OBJDIR_TAG).OBJ
 else
-OBJDIR_NAME 		= $(OS_CONFIG)_$(MOZ_OS2_TOOLS)$(OBJDIR_TAG).OBJ
+OBJDIR_NAME 		= $(OS_CONFIG)_$(MOZ_OS2_TOOLS)$(MOZ_EMXTAG)$(OBJDIR_TAG).OBJ
 endif
 
 OS_DLLFLAGS 		= -nologo -DLL -FREE -NOE
@@ -99,7 +103,7 @@ ifdef XP_OS2_VACPP
 
 OS_LIBS 		= so32dll.lib tcp32dll.lib
 
-DEFINES += -DXP_OS2_VACPP
+DEFINES += -DXP_OS2_VACPP -DTCPV40HDRS
 
 else
 CC			= gcc
@@ -122,20 +126,26 @@ endif
 
 OS_LIBS     		= -lsocket -lemxio
 
-DEFINES += -DXP_OS2 -DXP_OS2_EMX -DHAVE_SIGNED_CHAR
+DEFINES += -DXP_OS2 -DXP_OS2_EMX -DOS2EMX_PLAIN_CHAR
 
 OS_CFLAGS     		= $(OMF_FLAG) -Wall -Wno-unused -Zmtd
 OS_EXE_CFLAGS 		= $(OMF_FLAG) -Wall -Wno-unused -Zmtd
 OS_DLLFLAGS 		= $(OMF_FLAG) -Zmt -Zdll -Zcrtdll -o $@
+ifeq ($(MOZ_OS2_EMX_OBJECTFORMAT),OMF)
+EXEFLAGS                += -Zlinker /DE
+endif
 
 ifdef BUILD_OPT
 OPTIMIZER		= -O3
 DLLFLAGS		= 
 EXEFLAGS    		= -Zmtd -o $@
 else
-OPTIMIZER		= -g
-DLLFLAGS		= -g
-EXEFLAGS		= -g $(OMF_FLAG) -Zmtd -L$(DIST)/lib -o $@
+OPTIMIZER		= -g #-s
+DLLFLAGS		= -g #-s
+EXEFLAGS		= -g $(OMF_FLAG) -Zmtd -L$(DIST)/lib -o $@   # -s
+ifeq ($(MOZ_OS2_EMX_OBJECTFORMAT),OMF)
+EXEFLAGS                += -Zlinker /DE
+endif
 endif
 
 AR_EXTRA_ARGS 		=
diff --git a/config/arch.mk b/config/arch.mk
index 10dfc6a9..67734e44 100644
--- a/config/arch.mk
+++ b/config/arch.mk
@@ -164,7 +164,7 @@ ifeq ($(OS_ARCH),CYGWIN_95-4.0)
 	OS_TARGET := WIN95
 endif
 ifeq ($(OS_ARCH),OS2)
-	OS_ARCH   := WINNT
+	OS_ARCH   := OS2
 	OS_TARGET := OS2
 endif
 
diff --git a/config/rules.mk b/config/rules.mk
index 31bd759b..ed2a5f9f 100644
--- a/config/rules.mk
+++ b/config/rules.mk
@@ -81,7 +81,7 @@ endif
 #
 
 ifdef LIBRARY_NAME
-ifeq ($(OS_ARCH), WINNT)
+ifeq (,$(filter-out WINNT OS2,$(OS_ARCH)))
 
 #
 # Win95, Win16, and OS/2 require library names conforming to the 8.3 rule.
@@ -112,7 +112,7 @@ endif
 endif
 
 ifndef TARGETS
-ifeq ($(OS_ARCH), WINNT)
+ifeq (,$(filter-out WINNT OS2,$(OS_ARCH)))
 TARGETS		= $(LIBRARY) $(SHARED_LIBRARY) $(IMPORT_LIBRARY)
 else
 TARGETS		= $(LIBRARY) $(SHARED_LIBRARY)
@@ -146,11 +146,9 @@ endif
 
 ifeq ($(OS_ARCH), WINNT)
 ifneq ($(OS_TARGET), WIN16)
-ifneq ($(OS_TARGET), OS2)
 OBJS += $(RES)
 endif
 endif
-endif
 
 ALL_TRASH		= $(TARGETS) $(OBJS) $(filter-out . .., $(OBJDIR)) LOGS TAGS $(GARBAGE) \
 			  $(NOSUCHFILE) \
@@ -184,7 +182,7 @@ install::
 	+$(LOOP_OVER_DIRS)
 
 clean::
-	rm -rf $(OBJS) so_locations $(NOSUCHFILE)
+	rm -rf $(OBJS) so_locations $(NOSUCHFILE) $(GARBAGE)
 	+$(LOOP_OVER_DIRS)
 
 clobber::
@@ -259,13 +257,17 @@ $(PROGRAM): $(OBJS)
 ifeq ($(OS_ARCH),WINNT)
 	$(CC) $(OBJS) -Fe$@ -link $(LDFLAGS) $(OS_LIBS) $(EXTRA_LIBS)
 else
+ifeq ($(MOZ_OS2_TOOLS),VACPP)
+	$(CC) $(OBJS) -Fe$@ $(LDFLAGS) $(OS_LIBS) $(EXTRA_LIBS)
+else
 	$(CC) -o $@ $(CFLAGS) $(OBJS) $(LDFLAGS)
 endif
+endif
 
 $(LIBRARY): $(OBJS)
 	@$(MAKE_OBJDIR)
 	rm -f $@
-ifdef XP_OS2_VACPP
+ifneq ($(MOZ_OS2_TOOLS),VACPP)
 	$(AR) $(subst /,\\,$(OBJS)) $(AR_EXTRA_ARGS)
 else
 ifdef USE_AUTOCONF
@@ -319,20 +321,19 @@ ifeq ($(OS_TARGET), WIN16)
 	$(LINK) @w16link.
 	rm w16link
 else	# WIN16
-ifeq ($(OS_TARGET), OS2)
+	$(LINK_DLL) -MAP $(DLLBASE) $(OS_LIBS) $(EXTRA_LIBS) $(OBJS)
+endif # WINNT
+else
+ifeq ($(OS_ARCH),OS2)
 # append ( >> ) doesn't seem to be working under OS/2 gmake. Run through OS/2 shell instead.	
 	@cmd /C "echo LIBRARY $(notdir $(basename $(SHARED_LIBRARY))) INITINSTANCE TERMINSTANCE >$@.def"
 	@cmd /C "echo PROTMODE >>$@.def"
 	@cmd /C "echo CODE    LOADONCALL MOVEABLE DISCARDABLE >>$@.def"
 	@cmd /C "echo DATA    PRELOAD MOVEABLE MULTIPLE NONSHARED >>$@.def"	
 	@cmd /C "echo EXPORTS >>$@.def"
-	@cmd /C "$(FILTER) $(LIBRARY) >> $@.def"
+	@cmd /C "$(FILTER) $(LIBRARY) | grep -v _DLL_InitTerm >>$@.def"
 	$(LINK_DLL) $(DLLBASE) $(OBJS) $(OS_LIBS) $(EXTRA_LIBS) $@.def
-else
-	$(LINK_DLL) -MAP $(DLLBASE) $(OS_LIBS) $(EXTRA_LIBS) $(OBJS)
-endif	# OS2
-endif	# WIN16
-else	# WINNT
+else	# OS2
 ifeq ($(OS_TARGET), OpenVMS)
 	@if test ! -f $(OBJDIR)/VMSuni.opt; then \
 	    echo "Creating universal symbol option file $(OBJDIR)/VMSuni.opt";\
@@ -344,11 +345,13 @@ ifeq ($(OS_TARGET), OpenVMS)
 else	# OpenVMS
 	$(MKSHLIB) -o $@ $(OBJS) $(EXTRA_LIBS) $(OS_LIBS)
 endif	# OpenVMS
+endif   # OS2
 endif	# WINNT
 endif	# AIX 4.1
 endif   # USE_AUTOCONF
 
-ifeq ($(OS_ARCH), WINNT)
+
+ifeq (,$(filter-out WINNT OS2,$(OS_ARCH)))
 $(RES): $(RESNAME)
 	@$(MAKE_OBJDIR)
 ifeq ($(OS_TARGET),OS2)
@@ -363,14 +366,14 @@ endif
 $(OBJDIR)/%.$(OBJ_SUFFIX): %.cpp
 	@$(MAKE_OBJDIR)
 ifeq ($(OS_ARCH), WINNT)
-ifndef XP_OS2_EMX
 	$(CCC) -Fo$@ -c $(CCCFLAGS) $<
 else
-	$(CCC) -o $@ -c $(CCCFLAGS) $< 
-endif
+ifeq ($(MOZ_OS2_TOOLS),VACPP)
+	$(CCC) -Fo$@ -c $(CCCFLAGS) $<
 else
 	$(CCC) -o $@ -c $(CCCFLAGS) $<
 endif
+endif
 
 WCCFLAGS1 = $(subst /,\\,$(CFLAGS))
 WCCFLAGS2 = $(subst -I,-i=,$(WCCFLAGS1))
@@ -384,15 +387,16 @@ ifeq ($(OS_TARGET), WIN16)
 	$(CC) -zq -fo$(OBJDIR)\\$*.$(OBJ_SUFFIX)  @w16wccf $*.c
 	rm w16wccf
 else
-ifndef XP_OS2_EMX
 	$(CC) -Fo$@ -c $(CFLAGS) $<
-else
-	$(CC) -o $@ -c $(CFLAGS) $<
-endif
 endif
 else
+ifeq ($(MOZ_OS2_TOOLS),VACPP)
+	$(CC) -Fo$@ -c $(CFLAGS) $<
+else
 	$(CC) -o $@ -c $(CFLAGS) $<
 endif
+endif
+
 
 $(OBJDIR)/%.$(OBJ_SUFFIX): %.s
 	@$(MAKE_OBJDIR)
diff --git a/lib/ds/Makefile b/lib/ds/Makefile
index f01741ec..b3076f3c 100644
--- a/lib/ds/Makefile
+++ b/lib/ds/Makefile
@@ -45,13 +45,9 @@ HEADERS = \
 	$(NULL)
 
 ifeq ($(OS_ARCH), WINNT)
-ifeq (,$(filter-out WIN16 OS2,$(OS_TARGET)))
+ifeq ($(OS_TARGET), WIN16)
 # OS_CFLAGS = $(OS_EXE_CFLAGS)
-ifdef XP_OS2_EMX
-EXTRA_LIBS = -L$(DIST)/lib -lnspr$(MOD_VERSION)
-else
 EXTRA_LIBS = $(DIST)/lib/nspr$(MOD_VERSION).$(LIB_SUFFIX)
-endif
 else
 DLLBASE=/BASE:0x30000000
 RES=$(OBJDIR)/plds.res
@@ -68,8 +64,12 @@ ifdef GLOWCODE
 EXTRA_LIBS += $(GLOWDIR)/glowcode.lib
 endif
 endif
-
 endif
+
+else
+ifeq ($(MOZ_OS2_TOOLS),VACPP)
+EXTRA_LIBS = $(DIST)/lib/nspr$(MOD_VERSION).$(LIB_SUFFIX)
+
 else
 ifeq ($(OS_ARCH), AIX)
 ifeq ($(CLASSIC_NSPR),1)
@@ -84,6 +84,7 @@ else
 EXTRA_LIBS = -L$(DIST)/lib -lnspr$(MOD_VERSION)
 endif
 endif
+endif
 
 # On NCR and SCOOS, we can't link with extra libraries when
 # we build a shared library.  If we do so, the linker doesn't
@@ -116,11 +117,7 @@ SH_DATE = $(shell date)
 SH_NOW = $(shell $(NOW))
 
 ifeq ($(OS_ARCH), WINNT)
-ifeq ($(OS_TARGET),OS2)
-	SUF =
-else
 	SUF = i64
-endif
 else
 	SUF = LL
 endif
@@ -138,14 +135,14 @@ $(TINC):
 
 $(OBJDIR)/plvrsion.$(OBJ_SUFFIX): plvrsion.c $(TINC)
 ifeq ($(OS_ARCH), WINNT)
-ifdef XP_OS2_EMX
-	$(CC) -o $@ -c $(CFLAGS) -I$(OBJDIR) plvrsion.c
+	$(CC) -Fo$@ -c $(CFLAGS) -I$(OBJDIR) plvrsion.c
 else
+ifeq ($(MOZ_OS2_TOOLS), VACPP)
 	$(CC) -Fo$@ -c $(CFLAGS) -I$(OBJDIR) plvrsion.c
-endif
 else
 	$(CC) -o $@ -c $(CFLAGS) -I$(OBJDIR) plvrsion.c
 endif
+endif
 #
 # Version information generation (end)
 #
diff --git a/lib/ds/plevent.c b/lib/ds/plevent.c
index 362b5461..ba7deedf 100644
--- a/lib/ds/plevent.c
+++ b/lib/ds/plevent.c
@@ -980,10 +980,6 @@ static PRStatus InitEventLib( void )
 
 #endif /* Win16, Win32, OS2 */
 
-#if defined(_WIN32) || defined(WIN16) || defined(XP_OS2)
-
-#endif
-
 #if defined(_WIN32) || defined(WIN16)
 /*
 ** _md_CreateEventQueue() -- ModelDependent initializer
diff --git a/lib/ds/plevent.h b/lib/ds/plevent.h
index 82f5d0fa..38871055 100644
--- a/lib/ds/plevent.h
+++ b/lib/ds/plevent.h
@@ -176,6 +176,7 @@ and to ensure that no more events will be delivered for that owner.
 #elif defined(WIN16) || defined(__MINGW32__)
 #include <windows.h>
 #elif defined(XP_OS2)
+#define INCL_DOSPROCESS
 #include <os2.h>
 #endif
 
diff --git a/lib/libc/src/Makefile b/lib/libc/src/Makefile
index 265a74be..9fb0a22a 100644
--- a/lib/libc/src/Makefile
+++ b/lib/libc/src/Makefile
@@ -53,12 +53,8 @@ LIBRARY_VERSION	= $(MOD_VERSION)
 RELEASE_LIBS = $(TARGETS)
 
 ifeq ($(OS_ARCH),WINNT)
-ifeq (,$(filter-out WIN16 OS2,$(OS_TARGET)))
-ifdef XP_OS2_EMX
-EXTRA_LIBS = -L$(DIST)/lib -lnspr$(MOD_VERSION)
-else
+ifeq ($(OS_TARGET), WIN16)
 EXTRA_LIBS = $(DIST)/lib/nspr$(MOD_VERSION).lib
-endif
 else
 DLLBASE=/BASE:0x30000000
 RES=$(OBJDIR)/plc.res
@@ -74,8 +70,12 @@ ifdef GLOWCODE
 EXTRA_LIBS += $(GLOWDIR)/glowcode.lib
 endif
 endif
-
 endif
+
+else
+ifeq ($(MOZ_OS2_TOOLS),VACPP)
+EXTRA_LIBS = $(DIST)/lib/nspr$(MOD_VERSION).$(LIB_SUFFIX)
+
 else
 ifeq ($(OS_ARCH), AIX)
 ifeq ($(CLASSIC_NSPR),1)
@@ -90,6 +90,7 @@ else
 EXTRA_LIBS = -L$(DIST)/lib -lnspr$(MOD_VERSION)
 endif
 endif
+endif
 
 # On NCR and SCOOS, we can't link with extra libraries when
 # we build a shared library.  If we do so, the linker doesn't
@@ -115,15 +116,13 @@ SH_DATE = $(shell date)
 SH_NOW = $(shell $(NOW))
 
 ifeq ($(OS_ARCH), WINNT)
-ifeq ($(OS_TARGET),OS2)
-	SUF =
-else
 	SUF = i64
-endif
 else
 	SUF = LL
 endif
 
+GARBAGE += $(TINC)
+
 $(TINC):
 	@$(MAKE_OBJDIR)
 	@$(ECHO) '#define _BUILD_STRING "$(SH_DATE)"' > $(TINC)
@@ -137,14 +136,14 @@ $(TINC):
 
 $(OBJDIR)/plvrsion.$(OBJ_SUFFIX): plvrsion.c $(TINC)
 ifeq ($(OS_ARCH), WINNT)
-ifdef XP_OS2_EMX
-	$(CC) -o $@ -c $(CFLAGS) -I$(OBJDIR) plvrsion.c
+	$(CC) -Fo$@ -c $(CFLAGS) -I$(OBJDIR) plvrsion.c
 else
+ifeq ($(MOZ_OS2_TOOLS), VACPP)
 	$(CC) -Fo$@ -c $(CFLAGS) -I$(OBJDIR) plvrsion.c
-endif
 else
 	$(CC) -o $@ -c $(CFLAGS) -I$(OBJDIR) plvrsion.c
 endif
+endif
 #
 # Version information generation (end)
 #
diff --git a/lib/msgc/src/Makefile b/lib/msgc/src/Makefile
index c4073f5b..bf1b2d93 100644
--- a/lib/msgc/src/Makefile
+++ b/lib/msgc/src/Makefile
@@ -36,20 +36,20 @@ ifeq ($(OS_ARCH),WINNT)
 ifeq ($(OS_TARGET),WIN16)
 CSRCS += win16gc.c
 else
-ifeq ($(OS_TARGET),OS2)
-CSRCS += os2gc.c
-else
 CSRCS += win32gc.c
 endif
-endif
+else
+ifeq ($(OS_ARCH),OS2)
+CSRCS += os2gc.c
 else
 CSRCS += unixgc.c
 endif
+endif
 
 NSPR_VERSION = $(MOD_VERSION)
 
 ifeq ($(OS_ARCH), WINNT)
-ifeq (,$(filter-out WIN16 OS2,$(OS_TARGET)))
+ifeq ($(OS_TARGET), WIN16)
 EXTRA_LIBS = $(DIST)/lib/nspr$(NSPR_VERSION).lib
 else
 DLLBASE=/BASE:0x30000000
@@ -63,8 +63,12 @@ ifdef GLOWCODE
 EXTRA_LIBS += $(GLOWDIR)/glowcode.lib
 endif
 endif
-
 endif
+
+else
+ifeq ($(MOZ_OS2_TOOLS),VACPP)
+EXTRA_LIBS = $(DIST)/lib/nspr$(NSPR_VERSION).$(LIB_SUFFIX)
+
 else
 ifeq ($(OS_ARCH), AIX)
 ifeq ($(CLASSIC_NSPR),1)
@@ -79,6 +83,7 @@ else
 EXTRA_LIBS = -L$(DIST)/lib -lnspr$(NSPR_VERSION)
 endif
 endif
+endif
 
 # On NCR and SCOOS, we can't link with extra libraries when
 # we build a shared library.  If we do so, the linker doesn't
diff --git a/lib/msgc/tests/Makefile b/lib/msgc/tests/Makefile
index b07f4851..6716ead8 100644
--- a/lib/msgc/tests/Makefile
+++ b/lib/msgc/tests/Makefile
@@ -32,7 +32,7 @@ endif
 
 CSRCS = gc1.c thrashgc.c
 
-ifeq ($(OS_ARCH), WINNT)
+ifeq (,$(filter-out WINNT OS2,$(OS_ARCH)))
 PROG_SUFFIX = .exe
 else
 PROG_SUFFIX =
@@ -59,18 +59,22 @@ ifeq ($(OS_TARGET), WIN16)
   LIBPLC = $(DIST)/lib/plc$(NSPR_VERSION).lib
   LIBGC= $(DIST)/lib/msgc$(GC_VERSION).lib
 else
-ifeq ($(OS_TARGET),OS2)
-  LDOPTS = -NOE -DEBUG -nologo -PMTYPE:VIO
-  LIBPR = $(DIST)/lib/nspr$(NSPR_VERSION).lib
-  LIBPLC = $(DIST)/lib/plc$(NSPR_VERSION).lib
-  LIBGC= $(DIST)/lib/msgc$(GC_VERSION).lib
-else
   LDOPTS = -NOLOGO -DEBUG -DEBUGTYPE:CV -INCREMENTAL:NO
   LIBPR = $(DIST)/lib/libnspr$(NSPR_VERSION).$(LIB_SUFFIX)
   LIBPLC = $(DIST)/lib/libplc$(NSPR_VERSION).$(LIB_SUFFIX)
   LIBGC= $(DIST)/lib/libmsgc$(GC_VERSION).$(LIB_SUFFIX)
 endif
 endif
+
+ifeq ($(OS_ARCH),OS2)
+ifeq ($(MOZ_OS2_TOOLS),VACPP)
+  LDOPTS = -NOE -DEBUG -nologo -PMTYPE:VIO
+  LIBPR = $(DIST)/lib/nspr$(NSPR_VERSION).lib
+  LIBPLC = $(DIST)/lib/plc$(NSPR_VERSION).lib
+  LIBGC= $(DIST)/lib/msgc$(GC_VERSION).lib
+else
+  LDOPTS += -Zomf -Zlinker /PM:VIO
+endif
 endif
 
 ifneq ($(OS_ARCH), WINNT)
@@ -270,16 +274,14 @@ ifeq ($(OS_TARGET),WIN16)
 	echo winsock.lib     >>w16link
 	wlink @w16link.
 else
-ifeq ($(OS_TARGET),OS2)
-	$(LINK) $(LDOPTS) $< $(LIBGC) $(LIBPLC) $(LIBPR) so32dll.lib tcp32dll.lib -MAP:$(@:.exe=.map) -out:$@
-else
 	link $(LDOPTS) $< $(LIBGC) $(LIBPLC) $(LIBPR) wsock32.lib -out:$@
-endif
-endif
+else
+ifeq ($(OS_ARCH),OS2)
+	$(LINK) $(LDOPTS) $< $(LIBGC) $(LIBPLC) $(LIBPR) $(OS_LIBS) $(EXTRA_LIBS) -o $@
 else
 	$(CC) $(XCFLAGS) $< $(LDOPTS) $(LIBGC) $(LIBPLC) $(LIBPR) $(EXTRA_LIBS) -o $@
 endif
-
+endif
 endif
 
 export:: $(TARGETS)
diff --git a/lib/prstreams/Makefile b/lib/prstreams/Makefile
index 1c60d8d6..a4718ed1 100644
--- a/lib/prstreams/Makefile
+++ b/lib/prstreams/Makefile
@@ -50,7 +50,7 @@ endif
 
 INCLUDES = -I$(DIST)/include
 
-HEADERS = *.h
+HEADERS = $(wildcard *.h)
 
 CSRCS = \
 	plvrsion.c \
@@ -63,7 +63,7 @@ CXXSRCS = \
 OBJS = $(addprefix $(OBJDIR)/,$(CSRCS:.c=.$(OBJ_SUFFIX)) $(CXXSRCS:.cpp=.$(OBJ_SUFFIX)))
 
 ifeq ($(OS_ARCH), WINNT)
-    ifeq (,$(filter-out WIN16 OS2,$(OS_TARGET)))
+    ifeq ($(OS_TARGET), WIN16)
         EXTRA_LIBS = $(DIST)/lib/nspr$(MOD_VERSION).lib
     else
         DLLBASE=/BASE:0x30000000
@@ -77,6 +77,13 @@ ifeq ($(OS_ARCH), WINNT)
         endif
     endif
 else
+    ifeq ($(OS_ARCH),OS2)
+      ifeq ($(MOZ_OS2_TOOLS),VACPP)
+         EXTRA_LIBS = $(DIST)/lib/nspr$(MOD_VERSION).$(LIB_SUFFIX)
+      else
+         EXTRA_LIBS = -L$(DIST)/lib -lnspr$(MOD_VERSION) -lstdcpp
+      endif
+    else
     ifeq ($(OS_ARCH), AIX)
       ifeq ($(OS_RELEASE), 4.1)
         ifeq ($(CLASSIC_NSPR),1)
@@ -101,6 +108,7 @@ else
         EXTRA_LIBS = -L$(DIST)/lib -lnspr$(MOD_VERSION)
     endif
 endif
+endif
 
 # On NCR and SCOOS, we can't link with extra libraries when
 # we build a shared library.  If we do so, the linker doesn't
@@ -140,11 +148,7 @@ SH_DATE = $(shell date)
 SH_NOW = $(shell $(NOW))
 
 ifeq ($(OS_ARCH), WINNT)
-ifeq ($(OS_TARGET),OS2)
-	SUF =
-else
 	SUF = i64
-endif
 else
 	SUF = LL
 endif
@@ -162,14 +166,14 @@ $(TINC):
 
 $(OBJDIR)/plvrsion.$(OBJ_SUFFIX): plvrsion.c $(TINC)
 ifeq ($(OS_ARCH), WINNT)
-ifdef XP_OS2_EMX
-	$(CC) -o $@ -c $(CFLAGS) -I$(OBJDIR) plvrsion.c
+	$(CC) -Fo$@ -c $(CFLAGS) -I$(OBJDIR) plvrsion.c
 else
+ifeq ($(MOZ_OS2_TOOLS), VACPP)
 	$(CC) -Fo$@ -c $(CFLAGS) -I$(OBJDIR) plvrsion.c
-endif
 else
 	$(CC) -o $@ -c $(CFLAGS) -I$(OBJDIR) plvrsion.c
 endif
+endif
 #
 # Version information generation (end)
 #
@@ -177,6 +181,9 @@ endif
 export:: $(TARGETS) $(HEADERS)
 	$(INSTALL) -m 444 $(HEADERS) $(DIST)/include
 	$(INSTALL) -m 444 $(TARGETS) $(DIST)/lib
+ifeq ($(OS_ARCH),OS2)
+	$(INSTALL) -m 444 $(TARGETS) $(DIST)/bin
+endif
 ifeq ($(OS_ARCH),HP-UX)
 ifdef SHARED_LIBRARY
 	$(INSTALL) -m 755 $(SHARED_LIBRARY) $(DIST)/lib
diff --git a/lib/prstreams/tests/testprstrm/Makefile b/lib/prstreams/tests/testprstrm/Makefile
index 98c37ba8..a14e1878 100644
--- a/lib/prstreams/tests/testprstrm/Makefile
+++ b/lib/prstreams/tests/testprstrm/Makefile
@@ -31,7 +31,7 @@ CXXSRCS =           \
 
 OBJS = $(addprefix $(OBJDIR)/,$(CXXSRCS:.cpp=.$(OBJ_SUFFIX)))
 
-ifeq ($(OS_ARCH), WINNT)
+ifeq (,$(filter-out WINNT OS2,$(OS_ARCH)))
 PROG_SUFFIX = .exe
 else
 PROG_SUFFIX =
@@ -65,6 +65,16 @@ else
 endif
 endif
 
+ifeq ($(OS_ARCH),OS2)
+  ifeq ($(MOZ_OS2_TOOLS),VACPP)
+    LDOPTS = -NOE -DEBUG -nologo -PMTYPE:VIO /S:32768
+    LIBPR = $(DIST)/lib/nspr$(MOD_VERSION).lib
+    LIBPRSTRMS = $(DIST)/lib/prstrms$(MOD_VERSION).$(LIB_SUFFIX)
+  else
+    LDOPTS += -Zomf -Zlinker /PM:VIO -lstdcpp
+  endif
+endif
+
 ifneq ($(OS_ARCH), WINNT)
 PWD = $(shell pwd)
 endif
@@ -203,12 +213,18 @@ else
 	link $(LDOPTS) $< $(LIBPR) $(LIBPRSTRMS) wsock32.lib -out:$@
 endif
 else
+ifeq ($(OS_ARCH),OS2)
+	$(LINK) $(EXEFLAGS) $(LDOPTS) $< $(LIBPR) $(LIBPRSTRMS) $(OS_LIBS) $(EXTRA_LIBS)
+else
 	$(CCC) $(XCFLAGS) $< $(LDOPTS) $(LIBPR) $(LIBPRSTRMS) $(EXTRA_LIBS) -o $@
 endif
-
+endif
 endif
 
 export:: $(TARGETS)
 install:: export
 clean::
 	rm -f $(TARGETS)
+
+testlinker:
+	echo $(LINK)
diff --git a/lib/prstreams/tests/testprstrm/testprstrm.cpp b/lib/prstreams/tests/testprstrm/testprstrm.cpp
index b6047a9b..2f2c8574 100644
--- a/lib/prstreams/tests/testprstrm/testprstrm.cpp
+++ b/lib/prstreams/tests/testprstrm/testprstrm.cpp
@@ -21,7 +21,7 @@
 #include "prio.h"
 #include <string.h>
 #include <stdio.h>
-#ifdef XP_UNIX
+#if defined(XP_UNIX) || defined(XP_OS2_EMX)
 #include <sys/types.h>
 #include <sys/stat.h>
 #endif
@@ -36,6 +36,9 @@ typedef struct threadarg {
 } threadarg;
 
 void 
+#ifdef XP_OS2_VACPP
+_Optlink
+#endif
 threadmain(void *mytag)
 {
     threadarg arg;
diff --git a/lib/tests/Makefile b/lib/tests/Makefile
index e1c9e8b9..5cafffa3 100644
--- a/lib/tests/Makefile
+++ b/lib/tests/Makefile
@@ -34,7 +34,11 @@ CSRCS = \
 	event.c \
 	base64t.c
 
-ifeq ($(OS_ARCH), WINNT)
+ifeq (,$(filter-out WINNT OS2,$(OS_ARCH)))
+CSRCS += arena.c
+endif
+
+ifeq (,$(filter-out WINNT OS2,$(OS_ARCH)))
 PROG_SUFFIX = .exe
 else
 PROG_SUFFIX =
@@ -72,6 +76,17 @@ else
 endif
 endif
 
+ifeq ($(OS_ARCH),OS2)
+  ifeq ($(MOZ_OS2_TOOLS),VACPP)
+    LDOPTS = -NOE -DEBUG -nologo -PMTYPE:VIO /S:32768
+    LIBPR = $(DIST)/lib/nspr$(MOD_VERSION).lib
+    LIBPLC = $(DIST)/lib/plc$(MOD_VERSION).lib
+    LIBPLDS= $(DIST)/lib/plds$(MOD_VERSION).$(LIB_SUFFIX)	
+  else
+    LDOPTS += -Zomf -Zlinker /PM:VIO
+  endif
+endif
+
 ifneq ($(OS_ARCH), WINNT)
 PWD = $(shell pwd)
 endif
@@ -203,9 +218,12 @@ else
 	link $(LDOPTS) $< $(LIBPLC) $(LIBPLDS) $(LIBPR) wsock32.lib -out:$@
 endif
 else
+ifeq ($(OS_ARCH),OS2)
+	$(LINK) $(EXEFLAGS) $(LDOPTS) $< $(LIBPLC)  $(LIBPLDS) $(LIBPR) $(OS_LIBS) $(EXTRA_LIBS)
+else
 	$(CC) $(XCFLAGS) $< $(LDOPTS) $(LIBPLC) $(LIBPLDS) $(LIBPR) $(EXTRA_LIBS) -o $@
 endif
-
+endif
 endif
 
 export:: $(TARGETS)
diff --git a/pr/include/md/Makefile b/pr/include/md/Makefile
index 8aae21f7..08b0efc7 100644
--- a/pr/include/md/Makefile
+++ b/pr/include/md/Makefile
@@ -38,13 +38,13 @@ else
 ifeq ($(OS_TARGET), WIN16)
 MDCPUCFG_H = _win16.cfg
 else
-ifeq ($(OS_TARGET),OS2)
-MDCPUCFG_H = _os2.cfg
-else
 MDCPUCFG_H = _winnt.cfg
 endif
 endif
 endif
+
+ifeq ($(OS_ARCH),OS2)
+MDCPUCFG_H = _os2.cfg
 endif
 
 ifeq ($(OS_ARCH),AIX)
diff --git a/pr/include/md/_os2.cfg b/pr/include/md/_os2.cfg
index 517b8355..f72eab69 100644
--- a/pr/include/md/_os2.cfg
+++ b/pr/include/md/_os2.cfg
@@ -33,7 +33,11 @@
 
 #define IS_LITTLE_ENDIAN 1
 #undef  IS_BIG_ENDIAN
+#ifdef NO_LONG_LONG
 #undef HAVE_LONG_LONG
+#else
+#define HAVE_LONG_LONG 1
+#endif
 
 #define PR_BYTES_PER_BYTE   1
 #define PR_BYTES_PER_SHORT  2
@@ -42,7 +46,6 @@
 #define PR_BYTES_PER_LONG   4
 #define PR_BYTES_PER_FLOAT  4
 #define PR_BYTES_PER_DOUBLE 8
-#define PR_BYTES_PER_WORD_LOG2  2
 #define PR_BYTES_PER_WORD       4
 #define PR_BYTES_PER_DWORD	8
 
diff --git a/pr/include/md/_os2.h b/pr/include/md/_os2.h
index 3ab0d399..9fb935c2 100644
--- a/pr/include/md/_os2.h
+++ b/pr/include/md/_os2.h
@@ -251,6 +251,7 @@ extern PRInt32 _MD_CloseSocket(PRInt32 osfd);
 #define _MD_SETSOCKOPT                (_PR_MD_SETSOCKOPT)
 #define _MD_SELECT                    select
 #define _MD_FSYNC                     _PR_MD_FSYNC
+#define _MD_SET_FD_INHERITABLE        (_PR_MD_SET_FD_INHERITABLE)
 
 #define _MD_INIT_ATOMIC               _PR_MD_INIT_ATOMIC
 #define _MD_ATOMIC_INCREMENT(x)       _PR_MD_ATOMIC_INCREMENT(x)
@@ -265,6 +266,7 @@ extern PRInt32 _MD_CloseSocket(PRInt32 osfd);
 #define _MD_SOCKET                    (_PR_MD_SOCKET)
 extern PRInt32 _MD_SocketAvailable(PRFileDesc *fd);
 #define _MD_SOCKETAVAILABLE           _MD_SocketAvailable
+#define _MD_PIPEAVAILABLE             _MD_SocketAvailable
 #define _MD_CONNECT                   (_PR_MD_CONNECT)
 extern PRInt32 _MD_Accept(PRFileDesc *fd, PRNetAddr *raddr, PRUint32 *rlen,
         PRIntervalTime timeout);
@@ -492,6 +494,7 @@ typedef struct _CONTEXTRECORD {
 #endif
 
 extern APIRET (* APIENTRY QueryThreadContext)(TID, ULONG, PCONTEXTRECORD);
+unsigned long _System _DLL_InitTerm( unsigned long mod_handle, unsigned long flag);
 
 /*
 #define _pr_tid            (((PTIB2)_getTIBvalue(offsetof(TIB, tib_ptib2)))->tib2_ultid)
@@ -502,7 +505,7 @@ extern APIRET (* APIENTRY QueryThreadContext)(TID, ULONG, PCONTEXTRECORD);
  * little bit easier.  Only add one here if it is a DIRECT mapping.  We are
  * not emulating anything.  Just mapping.
  */
-#define FreeLibrary(x) DosFreeModule(x)
+#define FreeLibrary(x) DosFreeModule((HMODULE)x)
 #define OutputDebugString(x)
                                
 #endif /* nspr_os2_defs_h___ */
diff --git a/pr/include/prlong.h b/pr/include/prlong.h
index 8310a77e..1f2ad727 100644
--- a/pr/include/prlong.h
+++ b/pr/include/prlong.h
@@ -97,7 +97,7 @@ NSPR_API(PRInt64) LL_Zero(void);
 **  LL_OR             Logical or
 **  LL_XOR            Logical exclusion
 **  LL_OR2            A disgusting deviation
-**  LL_NOT            Negation (one's compliment)
+**  LL_NOT            Negation (one's complement)
 ***********************************************************************/
 #define LL_AND(r, a, b)        ((r) = (a) & (b))
 #define LL_OR(r, a, b)        ((r) = (a) | (b))
@@ -108,9 +108,9 @@ NSPR_API(PRInt64) LL_Zero(void);
 /***********************************************************************
 ** MACROS:      LL_<mathematical operators>
 **
-**  LL_NEG            Negation (two's compliment)
-**  LL_ADD            Summation (two's compliment)
-**  LL_SUB            Difference (two's compliment)
+**  LL_NEG            Negation (two's complement)
+**  LL_ADD            Summation (two's complement)
+**  LL_SUB            Difference (two's complement)
 ***********************************************************************/
 #define LL_NEG(r, a)        ((r) = -(a))
 #define LL_ADD(r, a, b)     ((r) = (a) + (b))
@@ -119,9 +119,9 @@ NSPR_API(PRInt64) LL_Zero(void);
 /***********************************************************************
 ** MACROS:      LL_<mathematical operators>
 **
-**  LL_MUL            Product (two's compliment)
-**  LL_DIV            Quotient (two's compliment)
-**  LL_MOD            Modulus (two's compliment)
+**  LL_MUL            Product (two's complement)
+**  LL_DIV            Quotient (two's complement)
+**  LL_MOD            Modulus (two's complement)
 ***********************************************************************/
 #define LL_MUL(r, a, b)        ((r) = (a) * (b))
 #define LL_DIV(r, a, b)        ((r) = (a) / (b))
diff --git a/pr/include/prtime.h b/pr/include/prtime.h
index 11f7be15..9f1f6ae0 100644
--- a/pr/include/prtime.h
+++ b/pr/include/prtime.h
@@ -253,7 +253,7 @@ NSPR_API(PRStatus) PR_ParseTimeString (
 /*
  * FIXME: should we also have a formatting function, such as asctime, ctime,
  * and strftime in standard C library?  But this would involve
- * internationalization issues.  Might want to provide a US Engligh version.
+ * internationalization issues.  Might want to provide a US English version.
  */
 
 /**********************************************************************/
diff --git a/pr/include/prtypes.h b/pr/include/prtypes.h
index 81cb9b30..02ea6412 100644
--- a/pr/include/prtypes.h
+++ b/pr/include/prtypes.h
@@ -147,7 +147,7 @@
 #define PR_CALLBACK_DECL
 #define PR_STATIC_CALLBACK(__x) static __x
 
-#elif defined(XP_OS2) 
+#elif defined(XP_OS2_VACPP) 
 
 #define PR_EXPORT(__type) extern __type
 #define PR_EXPORT_DATA(__type) extern __type
diff --git a/pr/src/Makefile b/pr/src/Makefile
index c064e7ad..f93aba82 100644
--- a/pr/src/Makefile
+++ b/pr/src/Makefile
@@ -23,6 +23,11 @@ include $(MOD_DEPTH)/config/config.mk
 
 DIRS = io linking malloc md memory misc threads
 
+# For VAC++ 4 geticcdata rule in config/OS2.mk
+ifeq ($(MOZ_OS2_TOOLS),VACPP)
+CSRCS = prvrsion.c
+endif
+
 ifeq ($(USE_PTHREADS), 1)
 	DIRS += pthreads
 endif
@@ -135,14 +140,10 @@ OS_LIBS		= -lsocket -lnsl -lgen -lresolv
 endif
 
 ifeq ($(OS_ARCH),WINNT)
-ifeq ($(OS_TARGET),OS2)
-# We define this in os2.mk.
-else
 ifneq ($(OS_TARGET),WIN16)
 OS_LIBS		= wsock32.lib winmm.lib
 endif
 endif
-endif
 
 #
 # Define platform-dependent OBJS
@@ -165,7 +166,6 @@ OBJS = \
 	threads/$(OBJDIR)/prrwlock.$(OBJ_SUFFIX) \
 	threads/$(OBJDIR)/prtpd.$(OBJ_SUFFIX) \
     linking/$(OBJDIR)/prlink.$(OBJ_SUFFIX) \
-    malloc/$(OBJDIR)/prmalloc.$(OBJ_SUFFIX) \
     malloc/$(OBJDIR)/prmem.$(OBJ_SUFFIX) \
     md/$(OBJDIR)/prosdep.$(OBJ_SUFFIX) \
     memory/$(OBJDIR)/prshm.$(OBJ_SUFFIX) \
@@ -192,6 +192,11 @@ OBJS = \
     misc/$(OBJDIR)/prtrace.$(OBJ_SUFFIX) \
     misc/$(OBJDIR)/prtime.$(OBJ_SUFFIX)
 
+# ilib now rejects empty objects
+ifneq ($(MOZ_OS2_TOOLS),VACPP)
+OBJS += malloc/$(OBJDIR)/prmalloc.$(OBJ_SUFFIX)
+endif
+
 ifdef USE_PTHREADS
 OBJS += \
     pthreads/$(OBJDIR)/ptsynch.$(OBJ_SUFFIX) \
@@ -240,7 +245,7 @@ OBJS += \
 endif
 
 ifeq ($(OS_ARCH), WINNT)
-ifneq (,$(filter-out WIN16 OS2,$(OS_TARGET)))
+ifneq ($(OS_TARGET),WIN16)
 DLLBASE=/BASE:0x30000000
 RES=$(OBJDIR)/nspr.res
 RESNAME=nspr.rc
@@ -291,18 +296,6 @@ OBJS +=	md/windows/$(OBJDIR)/w95io.$(OBJ_SUFFIX) \
 	md/windows/$(OBJDIR)/w32shm.$(OBJ_SUFFIX)	\
 	md/windows/$(OBJDIR)/w95dllmain.$(OBJ_SUFFIX)
 else
-ifeq ($(OS_TARGET),OS2)
-OBJS +=	md/os2/$(OBJDIR)/os2io.$(OBJ_SUFFIX) \
-	md/os2/$(OBJDIR)/os2sock.$(OBJ_SUFFIX) \
-	md/os2/$(OBJDIR)/os2thred.$(OBJ_SUFFIX) \
-	md/os2/$(OBJDIR)/os2cv.$(OBJ_SUFFIX) \
-	md/os2/$(OBJDIR)/os2gc.$(OBJ_SUFFIX) \
-	md/os2/$(OBJDIR)/os2misc.$(OBJ_SUFFIX) \
-	md/os2/$(OBJDIR)/os2inrval.$(OBJ_SUFFIX) \
-	md/os2/$(OBJDIR)/os2sem.$(OBJ_SUFFIX)	\
-	md/os2/$(OBJDIR)/os2_errors.$(OBJ_SUFFIX) \
-	md/os2/$(OBJDIR)/os2poll.$(OBJ_SUFFIX)
-else
 OBJS +=	md/windows/$(OBJDIR)/ntdllmn.$(OBJ_SUFFIX) \
 	md/windows/$(OBJDIR)/ntio.$(OBJ_SUFFIX) \
 	md/windows/$(OBJDIR)/ntgc.$(OBJ_SUFFIX) \
@@ -317,10 +310,23 @@ OBJS +=	md/windows/$(OBJDIR)/ntdllmn.$(OBJ_SUFFIX) \
 	md/windows/$(OBJDIR)/w32poll.$(OBJ_SUFFIX)
 endif
 endif
-endif
 
 else
 
+ifeq ($(OS_ARCH),OS2)
+OBJS +=	md/os2/$(OBJDIR)/os2io.$(OBJ_SUFFIX) \
+	md/os2/$(OBJDIR)/os2sock.$(OBJ_SUFFIX) \
+	md/os2/$(OBJDIR)/os2thred.$(OBJ_SUFFIX) \
+	md/os2/$(OBJDIR)/os2cv.$(OBJ_SUFFIX) \
+	md/os2/$(OBJDIR)/os2gc.$(OBJ_SUFFIX) \
+	md/os2/$(OBJDIR)/os2misc.$(OBJ_SUFFIX) \
+	md/os2/$(OBJDIR)/os2inrval.$(OBJ_SUFFIX) \
+	md/os2/$(OBJDIR)/os2sem.$(OBJ_SUFFIX)	\
+	md/os2/$(OBJDIR)/os2_errors.$(OBJ_SUFFIX) \
+	md/os2/$(OBJDIR)/os2poll.$(OBJ_SUFFIX) \
+	md/os2/$(OBJDIR)/os2rng.$(OBJ_SUFFIX)
+else
+
 ifeq ($(OS_ARCH), BeOS)
 	include md/beos/objs.mk
 	include bthreads/objs.mk
@@ -328,7 +334,7 @@ else
 	# Unix
 	include md/unix/objs.mk
 endif
-
+endif
 endif
 
 LIBRARY_NAME = nspr
@@ -349,17 +355,19 @@ endif
 ECHO = echo
 INCLUDES = -I$(DIST)/include
 TINC = $(OBJDIR)/_pr_bld.h
+
+ifeq ($(OS_TARGET),OS2)
+PROD = nspr$(MOD_VERSION).$(DLL_SUFFIX)
+else
 PROD = $(notdir $(SHARED_LIBRARY))
+endif
+
 NOW = $(MOD_DEPTH)/config/$(OBJDIR)/now
 SH_DATE = $(shell date)
 SH_NOW = $(shell $(NOW))
 
 ifeq ($(OS_ARCH), WINNT)
-ifeq ($(OS_TARGET),OS2)
-	SUF =
-else
 	SUF = i64
-endif
 else
 	SUF = LL
 endif
@@ -379,14 +387,14 @@ $(TINC):
 
 $(OBJDIR)/prvrsion.$(OBJ_SUFFIX): prvrsion.c $(TINC)
 ifeq ($(OS_ARCH), WINNT)
-ifdef XP_OS2_EMX
-	$(CC) -o $@ -c $(CFLAGS) -I$(OBJDIR) prvrsion.c
+	$(CC) -Fo$@ -c $(CFLAGS) -I$(OBJDIR) prvrsion.c
 else
+ifeq ($(MOZ_OS2_TOOLS), VACPP)
 	$(CC) -Fo$@ -c $(CFLAGS) -I$(OBJDIR) prvrsion.c
-endif
 else
 	$(CC) -o $@ -c $(CFLAGS) -I$(OBJDIR) prvrsion.c
 endif
+endif
 #
 # Version information generation (end)
 #
diff --git a/pr/src/cplus/Makefile b/pr/src/cplus/Makefile
index 35c9df7b..fc75f115 100644
--- a/pr/src/cplus/Makefile
+++ b/pr/src/cplus/Makefile
@@ -44,7 +44,7 @@ DEFINES     += -D_NSPR_BUILD_
 
 include $(MOD_DEPTH)/config/rules.mk
 
-HEADERS = *.h
+HEADERS = $(wildcard *.h)
 
 export:: $(TARGETS)
 
diff --git a/pr/src/cplus/tests/Makefile b/pr/src/cplus/tests/Makefile
index 7ba24d22..b7e658d7 100644
--- a/pr/src/cplus/tests/Makefile
+++ b/pr/src/cplus/tests/Makefile
@@ -37,7 +37,7 @@ CXXSRCS =           \
 
 OBJS = $(addprefix $(OBJDIR)/,$(CXXSRCS:.cpp=.$(OBJ_SUFFIX)))
 
-ifeq ($(OS_ARCH), WINNT)
+ifeq (,$(filter-out WINNT OS2,$(OS_ARCH)))
 PROG_SUFFIX = .exe
 else
 PROG_SUFFIX =
@@ -112,6 +112,16 @@ else
 endif
 endif
 
+ifeq ($(OS_ARCH),OS2)
+  ifeq ($(MOZ_OS2_TOOLS),VACPP)
+    LDOPTS = -NOE -DEBUG -nologo -PMTYPE:VIO
+    LIBPR = $(DIST)/lib/nspr$(MOD_VERSION).lib
+    LIBPLC = $(DIST)/lib/plc$(MOD_VERSION).lib
+  else
+    LDOPTS += -Zomf -Zlinker /PM:VIO -lstdcpp
+  endif
+endif
+
 ifneq ($(OS_ARCH), WINNT)
 PWD = $(shell pwd)
 endif
@@ -238,9 +248,12 @@ else
 	link $(LDOPTS) $< $(LIBPR) $(LIBPL) wsock32.lib -out:$@
 endif
 else
+ifeq ($(OS_ARCH),OS2)
+	$(LINK) $(LDOPTS) $< $(LIBGC) $(LIBPLC) $(LIBPR) $(OS_LIBS) $(EXTRA_LIBS) -o $@
+else
 	$(CCC) $(XCFLAGS) $< $(LDOPTS) $(LIBPR) $(LIBPL) $(EXTRA_LIBS) -o $@
 endif
-
+endif
 endif
 
 export:: $(TARGETS)
diff --git a/pr/src/io/prfile.c b/pr/src/io/prfile.c
index ab16e27a..70baeebf 100644
--- a/pr/src/io/prfile.c
+++ b/pr/src/io/prfile.c
@@ -638,12 +638,20 @@ PR_IMPLEMENT(PRStatus) PR_CreatePipe(
     (*readPipe)->secret->inheritable = PR_TRUE;
     (*writePipe)->secret->inheritable = PR_TRUE;
     return PR_SUCCESS;
-#elif defined(XP_UNIX)
+#elif defined(XP_UNIX) || defined(XP_OS2)
+#ifdef XP_OS2
+    HFILE pipefd[2];
+#else
     int pipefd[2];
+#endif
 
     if (!_pr_initialized) _PR_ImplicitInitialization();
 
+#ifdef XP_OS2
+    if (DosCreatePipe(&pipefd[0], &pipefd[1], 4096) != 0) {
+#else
     if (pipe(pipefd) == -1) {
+#endif
         /* XXX map pipe error */
         PR_SetError(PR_UNKNOWN_ERROR, errno);
         return PR_FAILURE;
diff --git a/pr/src/io/prio.c b/pr/src/io/prio.c
index 6e940096..84da9988 100644
--- a/pr/src/io/prio.c
+++ b/pr/src/io/prio.c
@@ -122,7 +122,7 @@ PR_IMPLEMENT(PRStatus) PR_SetFDInheritable(
     PRFileDesc *fd,
     PRBool inheritable)
 {
-#if defined(XP_UNIX) || defined(WIN32)
+#if defined(XP_UNIX) || defined(WIN32) || defined(XP_OS2)
     /*
      * Only a non-layered, NSPR file descriptor can be inherited
      * by a child process.
diff --git a/pr/src/io/prsocket.c b/pr/src/io/prsocket.c
index 5b0a4ab4..69c61bb2 100644
--- a/pr/src/io/prsocket.c
+++ b/pr/src/io/prsocket.c
@@ -190,7 +190,7 @@ PRFileDesc *fd;
 }
 
 
-static const PRIOMethods* PR_GetSocketPollFdMethods();
+static const PRIOMethods* PR_GetSocketPollFdMethods(void);
 
 PR_IMPLEMENT(PRFileDesc*) PR_CreateSocketPollFd(PRInt32 osfd)
 {
diff --git a/pr/src/linking/prlink.c b/pr/src/linking/prlink.c
index d9c59b6e..998e6378 100644
--- a/pr/src/linking/prlink.c
+++ b/pr/src/linking/prlink.c
@@ -82,8 +82,13 @@ struct PRLibrary {
     const PRStaticLinkTable*    staticTable;
 
 #ifdef XP_PC
+#ifdef XP_OS2
+    HMODULE                     dlh;
+#else
     HINSTANCE                   dlh;
 #endif
+#endif
+
 #ifdef XP_MAC
     CFragConnectionID           dlh;
 #endif
diff --git a/pr/src/md/Makefile b/pr/src/md/Makefile
index 765d0f62..cb047e20 100644
--- a/pr/src/md/Makefile
+++ b/pr/src/md/Makefile
@@ -22,16 +22,16 @@ MOD_DEPTH = ../../..
 include $(MOD_DEPTH)/config/config.mk
 
 ifeq ($(OS_ARCH),WINNT)
-  ifeq ($(OS_TARGET),OS2)
-    DIRS = os2
-  else
     DIRS = windows
-  endif
 else
+  ifeq ($(OS_ARCH),OS2)
+    DIRS = os2
+  else
   ifeq ($(OS_ARCH),BeOS)
     DIRS = beos
   else
     DIRS = unix
+    endif
   endif
 endif
 
diff --git a/pr/src/md/os2/Makefile b/pr/src/md/os2/Makefile
index 6e9390dc..03e4c863 100644
--- a/pr/src/md/os2/Makefile
+++ b/pr/src/md/os2/Makefile
@@ -33,6 +33,7 @@ CSRCS = \
     os2sock.c \
     os2_errors.c \
     os2poll.c \
+    os2rng.c \
     $(NULL)
 endif
 
diff --git a/pr/src/md/os2/os2io.c b/pr/src/md/os2/os2io.c
index 8b200aab..e6977ff7 100644
--- a/pr/src/md/os2/os2io.c
+++ b/pr/src/md/os2/os2io.c
@@ -28,6 +28,7 @@
 #ifdef XP_OS2_VACPP
 #include <direct.h>
 #else
+#include <limits.h>
 #include <dirent.h>
 #include <fcntl.h>
 #include <io.h>
@@ -153,7 +154,7 @@ _PR_MD_OPEN(const char *name, PRIntn osflags, int mode)
 PRInt32
 _PR_MD_READ(PRFileDesc *fd, void *buf, PRInt32 len)
 {
-    PRUword bytes;
+    ULONG bytes;
     int rv;
 
     rv = DosRead((HFILE)fd->secret->md.osfd,
@@ -172,13 +173,13 @@ _PR_MD_READ(PRFileDesc *fd, void *buf, PRInt32 len)
         return -1;
     }
     }
-    return bytes;
+    return (PRInt32)bytes;
 }
 
 PRInt32
 _PR_MD_WRITE(PRFileDesc *fd, const void *buf, PRInt32 len)
 {
-    PRUword bytes;
+    PRInt32 bytes;
     int rv; 
 
     /* No longer using DosWrite since it doesn't convert \n to \n\r like C runtime does */
@@ -195,7 +196,7 @@ _PR_MD_WRITE(PRFileDesc *fd, const void *buf, PRInt32 len)
     }
 #else
     bytes = write(fd->secret->md.osfd, buf, len);
-    if (rv == -1) 
+    if (bytes == -1) 
        _PR_MD_MAP_WRITE_ERROR(errno);
 #endif
 
@@ -220,6 +221,7 @@ _PR_MD_LSEEK(PRFileDesc *fd, PRInt32 offset, PRSeekWhence whence)
 PRInt64
 _PR_MD_LSEEK64(PRFileDesc *fd, PRInt64 offset, PRSeekWhence whence)
 {
+#ifdef NO_LONG_LONG
     PRInt64 result;
     PRInt32 rv, low = offset.lo, hi = offset.hi;
     PRUword newLocation;
@@ -235,6 +237,45 @@ _PR_MD_LSEEK64(PRFileDesc *fd, PRInt64 offset, PRSeekWhence whence)
     result.lo = newLocation;
     result.hi = hi;
 	return result;
+
+#else
+    PRInt32 where, rc, lo = (PRInt32)offset, hi = (PRInt32)(offset >> 32);
+    PRUint64 rv;
+    PRUint32 newLocation, uhi;
+
+    switch (whence)
+      {
+      case PR_SEEK_SET:
+        where = FILE_BEGIN;
+        break;
+      case PR_SEEK_CUR:
+        where = FILE_CURRENT;
+        break;
+      case PR_SEEK_END:
+        where = FILE_END;
+        break;
+      default:
+        PR_SetError(PR_INVALID_ARGUMENT_ERROR, 0);
+        return -1;
+}
+
+    rc = DosSetFilePtr((HFILE)fd->secret->md.osfd, lo, where, (PULONG)&newLocation);
+     
+    if (rc != NO_ERROR) {
+      _PR_MD_MAP_LSEEK_ERROR(rc);
+      return -1;
+    }
+    
+    uhi = (PRUint32)hi;
+    PR_ASSERT((PRInt32)uhi >= 0);
+    rv = uhi;
+    PR_ASSERT((PRInt64)rv >= 0);
+    rv = (rv << 32);
+    PR_ASSERT((PRInt64)rv >= 0);
+    rv += newLocation;
+    PR_ASSERT((PRInt64)rv >= 0);
+    return (PRInt64)rv;
+#endif
 }
 
 PRInt32
@@ -443,6 +484,7 @@ _PR_MD_GETFILEINFO(const char *fn, PRFileInfo *info)
 {
     struct stat sb;
     PRInt32 rv;
+    PRInt64 s, s2us;
  
     if ( (rv = _PR_MD_STAT(fn, &sb)) == 0 ) {
         if (info) {
@@ -453,8 +495,13 @@ _PR_MD_GETFILEINFO(const char *fn, PRFileInfo *info)
             else
                 info->type = PR_FILE_OTHER;
             info->size = sb.st_size;
-            info->modifyTime.lo = sb.st_mtime;
-            info->creationTime.lo = sb.st_ctime;
+            LL_I2L(s2us, PR_USEC_PER_SEC);
+            LL_I2L(s, sb.st_mtime);
+            LL_MUL(s, s, s2us);
+            info->modifyTime = s;
+            LL_I2L(s, sb.st_ctime);
+            LL_MUL(s, s, s2us);
+            info->creationTime = s;
         }
     }
     return rv;
@@ -468,7 +515,7 @@ _PR_MD_GETFILEINFO64(const char *fn, PRFileInfo64 *info)
     if (0 == rv)
     {
         info->type = info32.type;
-        info->size.lo = info32.size;
+        LL_UI2L(info->size,info32.size);
         info->modifyTime = info32.modifyTime;
         info->creationTime = info32.creationTime;
     }
@@ -493,6 +540,7 @@ _PR_MD_GETOPENFILEINFO(const PRFileDesc *fd, PRFileInfo *info)
     * point is now moot.
     */
    struct stat hinfo;
+    PRInt64 s, s2us;
 
     _setmode(fd->secret->md.osfd, O_BINARY);
     if(fstat((int)fd->secret->md.osfd, &hinfo) != NO_ERROR) {
@@ -506,8 +554,13 @@ _PR_MD_GETOPENFILEINFO(const PRFileDesc *fd, PRFileInfo *info)
         info->type = PR_FILE_FILE;
 
     info->size = hinfo.st_size;
-    info->modifyTime.lo = hinfo.st_mtime;
-    info->creationTime.lo = hinfo.st_ctime;
+    LL_I2L(s2us, PR_USEC_PER_SEC);
+    LL_I2L(s, hinfo.st_mtime);
+    LL_MUL(s, s, s2us);
+    info->modifyTime = s;
+    LL_I2L(s, hinfo.st_ctime);
+    LL_MUL(s, s, s2us);
+    info->creationTime = s;
 
     return 0;
 }
@@ -520,7 +573,8 @@ _PR_MD_GETOPENFILEINFO64(const PRFileDesc *fd, PRFileInfo64 *info)
    if (0 == rv)
    {
        info->type = info32.type;
-       info->size.lo = info32.size;
+       LL_UI2L(info->size,info32.size);
+
        info->modifyTime = info32.modifyTime;
        info->creationTime = info32.creationTime;
    }
@@ -651,3 +705,28 @@ _PR_MD_UNLOCKFILE(PRInt32 f)
     }
 } /* end _PR_MD_UNLOCKFILE() */
 
+PRStatus
+_PR_MD_SET_FD_INHERITABLE(PRFileDesc *fd, PRBool inheritable)
+{
+    int rv = 0;
+    ULONG flags;
+
+    rv = DosQueryFHState((HFILE)fd->secret->md.osfd, &flags);
+    if (rv != 0) {
+        PR_SetError(PR_UNKNOWN_ERROR, _MD_ERRNO());
+        return PR_FAILURE;
+    }
+
+    if (inheritable)
+      flags &= OPEN_FLAGS_NOINHERIT;
+    else
+      flags |= OPEN_FLAGS_NOINHERIT;
+
+    rv = DosSetFHState((HFILE)fd->secret->md.osfd, flags);
+    if (rv != 0) {
+        PR_SetError(PR_UNKNOWN_ERROR, _MD_ERRNO());
+        return PR_FAILURE;
+    }
+    return PR_SUCCESS;
+}
+
diff --git a/pr/src/md/os2/os2misc.c b/pr/src/md/os2/os2misc.c
index de675e43..27277e68 100644
--- a/pr/src/md/os2/os2misc.c
+++ b/pr/src/md/os2/os2misc.c
@@ -23,6 +23,11 @@
 #include <string.h>
 #include "primpl.h"
 
+extern int   _CRT_init(void);
+extern void  _CRT_term(void);
+extern void __ctordtorInit(int flag);
+extern void __ctordtorTerm(int flag);
+
 char *
 _PR_MD_GET_ENV(const char *name)
 {
@@ -303,7 +308,9 @@ PRProcess * _PR_CreateOS2Process(
    HFILE hStdIn  = 0,
            hStdOut = 0, 
            hStdErr = 0;
-
+   HFILE hStdInSave  = -1,
+         hStdOutSave = -1, 
+         hStdErrSave = -1;
 
    proc = PR_NEW(PRProcess);
    if (!proc) {
@@ -343,16 +350,19 @@ PRProcess * _PR_CreateOS2Process(
        * and gross I know. If you know a better way, please use it.
        */
        if (attr->stdinFd) {
-            hStdIn = (HFILE) attr->stdinFd->secret->md.osfd;
-            DosDupHandle(0, &hStdIn);
+            hStdIn = 0;
+            DosDupHandle(hStdIn, &hStdInSave);
+            DosDupHandle((HFILE) attr->stdinFd->secret->md.osfd, &hStdIn);
         }
         if (attr->stdoutFd) {
-            hStdOut = (HFILE) attr->stdoutFd->secret->md.osfd;
-            DosDupHandle(1, &hStdOut);
+            hStdOut = 1;
+            DosDupHandle(hStdOut, &hStdOutSave);
+            DosDupHandle((HFILE) attr->stdoutFd->secret->md.osfd, &hStdOut);
         }
         if (attr->stderrFd) {
-            hStdErr = (HFILE) attr->stderrFd->secret->md.osfd;
-            DosDupHandle(2, &hStdErr);
+            hStdErr = 2;
+            DosDupHandle(hStdErr, &hStdErrSave);
+            DosDupHandle((HFILE) attr->stderrFd->secret->md.osfd, &hStdErr);
         }
    }
 
@@ -365,17 +375,17 @@ PRProcess * _PR_CreateOS2Process(
                        argv[0]);
 
    /* Restore our old values.  Hope this works */
-   if(hStdIn){
-      hStdIn = 0;
-      DosDupHandle(0, &hStdIn);      
+   if(hStdInSave != -1){
+      DosDupHandle(hStdInSave, &hStdIn);
+      DosClose(hStdInSave);
    }
-   if(hStdOut){
-      hStdOut = 1;
-      DosDupHandle(1, &hStdOut);      
+   if(hStdOutSave != -1){
+      DosDupHandle(hStdOutSave, &hStdOut);
+      DosClose(hStdOutSave);
    }
-   if(hStdErr){
-      hStdErr = 1;
-      DosDupHandle(0, &hStdErr);      
+   if(hStdErrSave != -1){
+      DosDupHandle(hStdErrSave, &hStdErr);
+      DosClose(hStdErrSave);
    }
 
    if (retVal != NO_ERROR) {
@@ -509,3 +519,37 @@ PRStatus _MD_CloseFileMap(PRFileMap *fmap)
     return PR_FAILURE;
 }
 
+/*
+ *  Automatically set apptype switch for interactive and other
+ *  tests that create an invisible plevent window.
+ */
+unsigned long _System _DLL_InitTerm( unsigned long mod_handle, unsigned long flag)
+{
+   unsigned long rc = 0; /* failure */
+
+   if( !flag)
+   {
+      /* init */
+      if( _CRT_init() == 0)
+      {
+         PPIB pPib;
+         PTIB pTib;
+
+         /* probably superfluous, but can't hurt */
+         __ctordtorInit(0);
+
+         DosGetInfoBlocks( &pTib, &pPib);
+         pPib->pib_ultype = 3; /* PM */
+
+         rc = 1;
+      }
+   }
+   else
+   {
+      __ctordtorTerm(0);
+      _CRT_term();
+      rc = 1;
+   }
+
+   return rc;
+}
diff --git a/pr/src/md/os2/os2rng.c b/pr/src/md/os2/os2rng.c
index 18a4c729..c98fe3ad 100644
--- a/pr/src/md/os2/os2rng.c
+++ b/pr/src/md/os2/os2rng.c
@@ -20,9 +20,9 @@
 #define INCL_DOS
 #define INCL_DOSERRORS
 #include <os2.h>
-#include <secrng.h>
 #include <stdlib.h>
-#include <primpl.h>
+#include <time.h>
+#include "primpl.h"
 
 static BOOL clockTickTime(unsigned long *phigh, unsigned long *plow)
 {
@@ -39,7 +39,7 @@ static BOOL clockTickTime(unsigned long *phigh, unsigned long *plow)
     return TRUE;
 }
 
-extern PRSize _PR_MD_GetRandomNoise( buf, size )
+extern PRSize _PR_MD_GetRandomNoise(void *buf, PRSize size )
 {
     unsigned long high = 0;
     unsigned long low  = 0;
diff --git a/pr/src/md/os2/os2thred.c b/pr/src/md/os2/os2thred.c
index 6d4c3ddc..b6c1615b 100644
--- a/pr/src/md/os2/os2thred.c
+++ b/pr/src/md/os2/os2thred.c
@@ -23,6 +23,10 @@
 #include <time.h>     /* for _tzset() */
 #endif
 
+#ifdef XP_OS2_EMX
+#include <signal.h>
+#endif
+
 /* --- Declare these to avoid "implicit" warnings --- */
 PR_EXTERN(void) _PR_MD_NEW_SEM(_MDSemaphore *md, PRUintn value);
 PR_EXTERN(void) _PR_MD_DESTROY_SEM(_MDSemaphore *md);
@@ -51,7 +55,7 @@ _PR_MD_EARLY_INIT()
 {
    HMODULE hmod;
 
-   if (DosLoadModule(NULL, 0, "DOSCALL1.DLL", &hmod) == 0)
+   if (DosLoadModule(NULL, 0, "DOSCALL1", &hmod) == 0)
        DosQueryProcAddr(hmod, 877, "DOSQUERYTHREADCONTEXT",
                         (PFN *)&QueryThreadContext);
 
@@ -76,6 +80,15 @@ _pr_SetThreadMDHandle(PRThread *thread)
 PR_IMPLEMENT(PRStatus)
 _PR_MD_INIT_THREAD(PRThread *thread)
 {
+#ifdef XP_OS2_EMX
+   /* disable SIGPIPE */
+   struct sigaction sa;
+   sa.sa_handler = SIG_IGN;
+   sa.sa_flags = 0;
+   sigemptyset( &sa.sa_mask);
+   sigaction( SIGPIPE, &sa, NULL);
+#endif
+
    if (thread->flags & (_PR_PRIMORDIAL | _PR_ATTACHED)) {
       _pr_SetThreadMDHandle(thread);
    }
diff --git a/pr/src/misc/pratom.c b/pr/src/misc/pratom.c
index 103eb213..5c26670a 100644
--- a/pr/src/misc/pratom.c
+++ b/pr/src/misc/pratom.c
@@ -34,7 +34,7 @@
  * compiled in.
  */
 
-#ifndef _PR_HAVE_ATOMIC_OPS
+#if !defined(_PR_HAVE_ATOMIC_OPS)
 
 #if defined(_PR_PTHREADS) && !defined(_PR_DCETHREADS)
 /*
@@ -207,7 +207,7 @@ _PR_MD_ATOMIC_SET(PRInt32 *val, PRInt32 newval)
  * The lock contention should be acceptable.
  */
 static PRLock *atomic_lock = NULL;
-void _PR_MD_INIT_ATOMIC()
+void _PR_MD_INIT_ATOMIC(void)
 {
     if (atomic_lock == NULL) {
         atomic_lock = PR_NewLock();
diff --git a/pr/src/misc/prsystem.c b/pr/src/misc/prsystem.c
index 574791d3..4c74b3b4 100644
--- a/pr/src/misc/prsystem.c
+++ b/pr/src/misc/prsystem.c
@@ -87,14 +87,17 @@ PR_IMPLEMENT(PRStatus) PR_GetSystemInfo(PRSysInfo cmd, char *buf, PRUint32 bufle
             ULONG os2ver[2] = {0};
             DosQuerySysInfo(QSV_VERSION_MINOR, QSV_VERSION_REVISION,
                             &os2ver, sizeof(os2ver));
-            /* Formatting for normal usage (2.11, 3.0, 4.0); officially,
-               Warp 4 is version 2.40.00 */
+            /* Formatting for normal usage (2.11, 3.0, 4.0, 4.5); officially,
+               Warp 4 is version 2.40.00, WSeB 2.45.00 */
             if (os2ver[0] < 30)
               (void)PR_snprintf(buf, buflen, "%s%lu",
                                 "2.", os2ver[0]);
-            else
+            else if (os2ver[0] < 45)
               (void)PR_snprintf(buf, buflen, "%lu%s%lu",
                                 os2ver[0]/10, ".", os2ver[1]);
+            else
+              (void)PR_snprintf(buf, buflen, "%.1f",
+                                os2ver[0]/10.0);
         }
 #endif /* OS2 */
         break;
diff --git a/pr/tests/Makefile b/pr/tests/Makefile
index b3138a06..2fd2c0cd 100644
--- a/pr/tests/Makefile
+++ b/pr/tests/Makefile
@@ -175,7 +175,7 @@ CSRCS +=            \
 	$(NULL)
 endif
 
-ifeq ($(OS_ARCH), WINNT)
+ifeq (,$(filter-out WINNT OS2,$(OS_ARCH)))
 PROG_SUFFIX = .exe
 else
 PROG_SUFFIX =
@@ -198,15 +198,6 @@ ifeq ($(OS_TARGET), WIN16)
   LIBPR = $(DIST)/lib/nspr$(MOD_VERSION).lib
   LIBPLC= $(DIST)/lib/plc$(MOD_VERSION).lib
 else
-ifeq ($(OS_TARGET), OS2)
-ifdef XP_OS2_VACPP
-  LDOPTS =
-  LIBPR = $(DIST)/lib/nspr$(MOD_VERSION).lib
-  LIBPLC= $(DIST)/lib/plc$(MOD_VERSION).lib
-else
-  LDOPTS = -Zlinker /PM:VIO
-endif
-else
   LDOPTS = -NOLOGO -DEBUG -DEBUGTYPE:CV -INCREMENTAL:NO
   ifeq ($(OS_TARGET), WIN95)
     LIBPR = $(DIST)/lib/nspr$(MOD_VERSION).$(LIB_SUFFIX)
@@ -220,6 +211,17 @@ else
   endif # profile
 endif
 endif
+
+ifeq ($(OS_ARCH),OS2)
+ifeq ($(MOZ_OS2_TOOLS),VACPP)
+  LDOPTS = -NOE -DEBUG -nologo -PMTYPE:VIO
+  LIBPR  = $(DIST)/lib/nspr$(MOD_VERSION).lib
+  LIBPLC = $(DIST)/lib/plc$(MOD_VERSION).lib
+else
+ifeq ($(MOZ_OS2_EMX_OBJECTFORMAT),OMF)
+  LDOPTS = -Zlinker /PM:VIO
+endif
+endif
 endif
 
 ifneq ($(OS_ARCH), WINNT)
@@ -479,16 +481,15 @@ ifeq ($(OS_TARGET),WIN16)
 	echo winsock.lib     >>w16link
 	wlink @w16link.
 else
-ifeq ($(OS_TARGET),OS2)
-	$(LINK) $(EXEFLAGS) $(LDOPTS) $< $(LIBPLC) $(LIBPR) $(OS_LIBS) $(EXTRA_LIBS)
-else
 	link $(LDOPTS) $(EXTRA_LDOPTS) $< $(LIBPLC) $(LIBPR) $(EXTRA_LIBS) wsock32.lib -out:$@
 endif
-endif
+else
+ifeq ($(OS_ARCH),OS2)
+	$(LINK) $(EXEFLAGS) $(LDOPTS) $< $(LIBPLC) $(LIBPR) $(OS_LIBS) $(EXTRA_LIBS)
 else
 	$(PURE) $(CC) $(XCFLAGS) $< $(LDOPTS) $(LIBPLC) $(LIBPR) $(EXTRA_LIBS) -o $@
 endif
-
+endif
 endif
 
 export:: $(TARGETS)
@@ -529,7 +530,7 @@ PROGRAMS = $(notdir $(PROGS))
 ifdef NSPR_TEST_LOGFILE
 LOGFILE = $(NSPR_TEST_LOGFILE)
 else
-ifeq ($(OS_ARCH), WINNT)
+ifeq (,$(filter-out WINNT OS2,$(OS_ARCH)))
 LOGFILE = nul
 else
 LOGFILE = /dev/null
diff --git a/pr/tests/bigfile.c b/pr/tests/bigfile.c
index 0ac78c64..b3173dc4 100644
--- a/pr/tests/bigfile.c
+++ b/pr/tests/bigfile.c
@@ -190,24 +190,24 @@ PRIntn main(PRIntn argc, char **argv)
     if (!LL_IS_ZERO(big_answer)) return Error("empty available64()", filename);
 
 	LL_SUB(big_size, filesize64, one_meg);
-    VERBOSE(v_whisper, "Creating sparce big file by seeking to end");
+    VERBOSE(v_whisper, "Creating sparse big file by seeking to end");
 	big_answer = file->methods->seek64(file, big_size, PR_SEEK_SET);
     if (!LL_EQ(big_answer, big_size)) return Error("seek", filename);
 
-    VERBOSE(v_whisper, "Writing block at end of sparce file");
+    VERBOSE(v_whisper, "Writing block at end of sparse file");
 	bytes = file->methods->write(file, buffer, BUFFER_SIZE);
     if (bytes != BUFFER_SIZE) return Error("write", filename);
 
-    VERBOSE(v_whisper, "Testing available space at end of sparce file");
+    VERBOSE(v_whisper, "Testing available space at end of sparse file");
     big_answer = file->methods->available64(file);
     if (!LL_IS_ZERO(big_answer)) return Error("eof available64()", filename);
 
-    VERBOSE(v_whisper, "Getting big info on sparce big file");
+    VERBOSE(v_whisper, "Getting big info on sparse big file");
     rv = file->methods->fileInfo64(file, &big_info);
     if (PR_FAILURE == rv) return Error("fileInfo64()", filename);
     if (v_shout <= verbose) PrintInfo(&big_info, filename);
 
-    VERBOSE(v_whisper, "Getting small info on sparce big file");
+    VERBOSE(v_whisper, "Getting small info on sparse big file");
     rv = file->methods->fileInfo(file, &small_info);
     if (LL_CMP(sevenFox, <, filesize64) && (PR_SUCCESS == rv))
     {
diff --git a/pr/tests/bigfile2.c b/pr/tests/bigfile2.c
index 5dfc091f..9b0a9cae 100644
--- a/pr/tests/bigfile2.c
+++ b/pr/tests/bigfile2.c
@@ -24,7 +24,7 @@
 #include <windows.h>
 #endif
 
-#define TEST_FILE_NAME "m:\\bigfile2.txt"
+#define TEST_FILE_NAME "bigfile2.txt"
 
 #define MESSAGE "Hello world!"
 #define MESSAGE_SIZE 13
diff --git a/pr/tests/bigfile3.c b/pr/tests/bigfile3.c
index 996d5434..3ff8b5d5 100644
--- a/pr/tests/bigfile3.c
+++ b/pr/tests/bigfile3.c
@@ -24,7 +24,7 @@
 #include <windows.h>
 #endif
 
-#define TEST_FILE_NAME "m:\\bigfile3.txt"
+#define TEST_FILE_NAME "bigfile3.txt"
 
 #define MESSAGE "Hello world!"
 #define MESSAGE_SIZE 13
diff --git a/pr/tests/dll/Makefile b/pr/tests/dll/Makefile
index 68360c50..66acab4a 100644
--- a/pr/tests/dll/Makefile
+++ b/pr/tests/dll/Makefile
@@ -28,6 +28,8 @@ OPTIMIZER =
 endif
 endif
 
+CSRCS = mygetval.c mysetval.c
+
 INCLUDES = -I$(DIST)/include
 
 OBJS = $(OBJDIR)/mygetval.$(OBJ_SUFFIX) \
@@ -38,7 +40,7 @@ W16OBJS = $(subst $(space),$(comma)$(space),$(OBJS))
 endif
 
 ifeq ($(OS_ARCH), WINNT)
-ifeq (,$(filter-out WIN16 OS2,$(OS_TARGET)))
+ifeq ($(OS_TARGET), WIN16)
 # do nothing
 else
 DLLBASE=/BASE:0x30000000
@@ -47,10 +49,10 @@ RESNAME=../../../pr/src/nspr.rc
 endif
 endif
 
-ifeq ($(OS_ARCH), WINNT)
-IMPORT_LIBRARY	= $(OBJDIR)/my.lib
+ifeq (,$(filter-out WINNT OS2,$(OS_ARCH)))
+IMPORT_LIBRARY	= $(OBJDIR)/my.$(LIB_SUFFIX)
 SHARED_LIBRARY	= $(OBJDIR)/my.dll
-ifeq ($(OS_TARGET), OS2)
+ifeq ($(OS_ARCH), OS2)
 LIBRARY		= $(OBJDIR)/my_s.lib
 # XXX $(LIBRARY) probably doesn't need to be added to TARGETS.
 TARGETS		= $(LIBRARY) $(SHARED_LIBRARY) $(IMPORT_LIBRARY)
diff --git a/pr/tests/ipv6.c b/pr/tests/ipv6.c
index 478d59ae..7e92f3e2 100644
--- a/pr/tests/ipv6.c
+++ b/pr/tests/ipv6.c
@@ -74,6 +74,7 @@ static PRStatus PrintAddress(const PRNetAddr* address)
     PRNetAddr translation;
     char buffer[ADDR_BUFFER];
     PRStatus rv = PR_NetAddrToString(address, buffer, sizeof(buffer));
+    memset(&translation, 0, sizeof(PRNetAddr));
     if (PR_FAILURE == rv) PL_FPrintError(err, "PR_NetAddrToString");
     else
     {
diff --git a/pr/tests/pipeping.c b/pr/tests/pipeping.c
index 7c51cf11..570c5929 100644
--- a/pr/tests/pipeping.c
+++ b/pr/tests/pipeping.c
@@ -39,7 +39,11 @@
 #include <stdlib.h>
 #include <string.h>
 
+#ifdef XP_OS2
+static char *child_argv[] = { "pipepong.exe", NULL };
+#else
 static char *child_argv[] = { "pipepong", NULL };
+#endif
 
 #define NUM_ITERATIONS 10
 
diff --git a/pr/tests/prpoll.c b/pr/tests/prpoll.c
index 88662181..4dc09092 100644
--- a/pr/tests/prpoll.c
+++ b/pr/tests/prpoll.c
@@ -20,6 +20,10 @@
 #include <windows.h>
 #endif
 
+#ifdef XP_OS2_VACPP
+#include <io.h>      /* for close() */
+#endif
+
 #include "prinit.h"
 #include "prio.h"
 #include "prlog.h"
diff --git a/pr/tests/sigpipe.c b/pr/tests/sigpipe.c
index b0d267ad..42c061f7 100644
--- a/pr/tests/sigpipe.c
+++ b/pr/tests/sigpipe.c
@@ -26,32 +26,51 @@
  *************************************************************************
  */
 
-#if !defined(XP_UNIX)
+#if !defined(XP_UNIX) && !defined(XP_OS2)
 
-int main()
+int main(void)
 {
-    /* This test applies to Unix only. */
+    /* This test applies to Unix and OS/2 (emx build). */
     return 0;
 }
 
-#else /* XP_UNIX */
+#else /* XP_UNIX && OS/2 */
 
 #include "nspr.h"
 
+#ifdef XP_OS2
+#define INCL_DOSQUEUES
+#define INCL_DOSERRORS
+#include <os2.h>
+#endif
+
 #include <stdio.h>
+#ifdef XP_OS2_VACPP
+#define EPIPE EBADF  /* IBM's write() doesn't return EPIPE */
+#include <io.h>
+#else
 #include <unistd.h>
+#endif
 #include <errno.h>
 
-int main()
+int main(void)
 {
+#ifdef XP_OS2
+    HFILE pipefd[2];
+#else
     int pipefd[2];
+#endif
     int rv;
     char c = '\0';
 
     /* This initializes NSPR. */
     PR_SetError(0, 0);
 
+#ifdef XP_OS2
+    if (DosCreatePipe(&pipefd[0], &pipefd[1], 4096) != 0) {
+#else
     if (pipe(pipefd) == -1) {
+#endif
         fprintf(stderr, "cannot create pipe: %d\n", errno);
         exit(1);
     }
diff --git a/pr/tests/testfile.c b/pr/tests/testfile.c
index b6b03882..794ea5ed 100644
--- a/pr/tests/testfile.c
+++ b/pr/tests/testfile.c
@@ -35,6 +35,7 @@
 #include <os2.h>
 #ifdef XP_OS2_EMX
 #include <getopt.h>
+#include <errno.h>
 #endif /* XP_OS2_EMX */
 #endif /* XP_OS2 */
 
@@ -48,7 +49,7 @@ static int _debug_on = 0;
 extern void SetupMacPrintfLog(char *logFile);
 #endif
 
-#ifdef XP_PC
+#ifdef XP_WIN
 #define mode_t int
 #endif
 
@@ -111,7 +112,9 @@ PRThread* create_new_thread(PRThreadType type,
 PRInt32 native_thread = 0;
 
 	PR_ASSERT(state == PR_UNJOINABLE_THREAD);
-#if (defined(_PR_PTHREADS) && !defined(_PR_DCETHREADS)) || defined(WIN32)
+
+#if (defined(_PR_PTHREADS) && !defined(_PR_DCETHREADS)) || defined(WIN32) || defined(XP_OS2)
+
 	switch(index %  4) {
 		case 0:
 			scope = (PR_LOCAL_THREAD);
@@ -136,6 +139,17 @@ PRInt32 native_thread = 0;
 			return((PRThread *) tid);
 		else
 			return (NULL);
+#elif defined(XP_OS2)
+        TID tid;
+
+        tid = (TID)_beginthread((void(* _Optlink)(void*))start,
+                                NULL, 32768, arg);
+        if (tid == -1) {
+          printf("_beginthread failed. errno %d\n", errno);
+          return (NULL);
+        }
+        else
+          return((PRThread *) tid);
 #else
 		HANDLE thandle;
 		unsigned tid;
diff --git a/pr/tests/yield.c b/pr/tests/yield.c
index 33ab416b..80e04bd9 100644
--- a/pr/tests/yield.c
+++ b/pr/tests/yield.c
@@ -19,6 +19,13 @@
 #include <stdio.h>
 #include "prthread.h"
 #include "prinit.h"
+#ifndef XP_OS2
+#include "private/pprmisc.h"
+#include <windows.h>
+#else
+#include "primpl.h"
+#include <os2.h>
+#endif
 
 #define THREADS 10
 
diff --git a/tools/Makefile b/tools/Makefile
index 527ca57f..6effac67 100644
--- a/tools/Makefile
+++ b/tools/Makefile
@@ -33,7 +33,7 @@ CSRCS =             \
 	tail.c		    \
 	$(NULL)
 
-ifeq ($(OS_ARCH), WINNT)
+ifeq (,$(filter-out WINNT OS2,$(OS_ARCH)))
 PROG_SUFFIX = .exe
 else
 PROG_SUFFIX =
@@ -64,6 +64,16 @@ LIBPLC= $(DIST)/lib/libplc$(NSPR_VERSION).$(LIB_SUFFIX)
 endif
 endif
 
+ifeq ($(OS_ARCH),OS2)
+  ifeq ($(MOZ_OS2_TOOLS),VACPP)
+    LDOPTS = -NOE -DEBUG -nologo -PMTYPE:VIO
+    LIBPR = $(DIST)/lib/nspr$(NSPR_VERSION).lib
+    LIBPLC= $(DIST)/lib/plc$(NSPR_VERSION).lib
+  else
+    LDOPTS += -Zomf -Zlinker /PM:VIO
+  endif
+endif
+
 ifneq ($(OS_ARCH), WINNT)
 PWD = $(shell pwd)
 endif
@@ -200,9 +210,12 @@ else
 	link $(LDOPTS) $< $(LIBPR) $(LIBPLC) wsock32.lib -out:$@
 endif
 else
+ifeq ($(OS_ARCH),OS2)
+	$(LINK) $(LDOPTS) $< $(LIBPR) $(LIBPLC) $(OS_LIBS) $(EXTRA_LIBS) -o $@
+else
 	$(CC) $(XCFLAGS) $< $(LDOPTS) $(LIBPR) $(LIBPLC) $(EXTRA_LIBS) -o $@
 endif
-
+endif
 endif
 
 export:: $(TARGETS)