Let --enable-lock-counter build an additional emulator

"./configure --enable-lock-counter" would modify the behavior
of the default emulator (usually SMP).

To make lock counting more accessible, change --enable-lock-counter
to build an additional emulator in the same way as:

  (cd erts/emulator && make lcnt)

(The next commit will make it easier to start the built lock-counter
emulator.)

5 files changed, 21 insertions, 8 deletions

diff --git a/erts/Makefile b/erts/Makefile
index e9928b6b47..12d2ec57a8 100644
--- a/erts/Makefile
+++ b/erts/Makefile
@@ -40,8 +40,8 @@ all: $(FLAVORS)
 docs:
 	$(V_at)( cd doc/src && $(MAKE) $@ )
 
-.PHONY: debug opt clean
-debug opt clean:
+.PHONY: debug opt lcnt clean
+debug opt lcnt clean:
 	$(V_at)for d in emulator $(ERTSDIRS); do \
 		if test -d $$d; then \
 			( cd $$d && $(MAKE) $@ FLAVOR=$(FLAVOR) ) || exit $$? ; \
@@ -56,7 +56,9 @@ debug opt clean:
 
 .PHONY: $(FLAVORS)
 $(FLAVORS):
-	$(V_at)( $(MAKE) opt FLAVOR=$@ )
+	$(V_at)for type in $(TYPES); do \
+		( $(MAKE) $$type FLAVOR=$@ ); \
+	done
 
 # Make erl script and erlc in $(ERL_TOP)/bin which runs the compiled version
 # Note that erlc is not a script and requires extra handling on cygwin.
@@ -128,7 +130,9 @@ makefiles:
 .PHONY: release
 release:
 	$(V_at)for f in $(FLAVORS); do \
-		( cd emulator && $(MAKE) release FLAVOR=$$f ) \
+		for t in $(TYPES); do \
+		  ( cd emulator && $(MAKE) release FLAVOR=$$f TYPE=$$t ) \
+		done \
 	done
 	$(V_at)for d in $(ERTSDIRS) $(XINSTDIRS); do \
 		if test -d $$d; then \
diff --git a/erts/configure.in b/erts/configure.in
index c82ebaa74c..830e3d7776 100644
--- a/erts/configure.in
+++ b/erts/configure.in
@@ -1002,6 +1002,7 @@ else
 fi
 
 FLAVORS=
+TYPES=opt
 ERTS_BUILD_SMP_EMU=$enable_smp_support
 AC_MSG_CHECKING(whether an emulator with smp support should be built)
 case $ERTS_BUILD_SMP_EMU in
@@ -1210,6 +1211,7 @@ esac
 
 AC_SUBST(ERTS_BUILD_PLAIN_EMU)
 AC_SUBST(FLAVORS)
+AC_SUBST(TYPES)
 
 case "$ERTS_BUILD_PLAIN_EMU-$ERTS_BUILD_SMP_EMU" in
      no-no)
@@ -1365,7 +1367,7 @@ else
 	AC_MSG_CHECKING(whether lock counters should be enabled)
 	AC_MSG_RESULT($enable_lock_count)
 	if test "x$enable_lock_count" != "xno"; then
-	    EMU_THR_DEFS="$EMU_THR_DEFS -DERTS_ENABLE_LOCK_COUNT"
+	    TYPES="$TYPES lcnt"
 	fi
 
 	case $host_os in
diff --git a/erts/doc/src/erl.xml b/erts/doc/src/erl.xml
index 6046e94599..e1aa5ce76e 100644
--- a/erts/doc/src/erl.xml
+++ b/erts/doc/src/erl.xml
@@ -239,6 +239,13 @@
       <item>
         <p>Useful for debugging. Prints the arguments sent to the emulator.</p>
       </item>
+      <tag><c><![CDATA[-emu_type Type]]></c></tag>
+      <item>
+        <p>Start an emulator of a different type. For example, to start
+	the lock-counter emualator, use <c>-emu_type lcnt</c>. (The emulator
+	must already be built. Use the <c>configure</c> option
+	<c>--enable-lock-counter</c> to build the lock-counter emulator.)</p>
+      </item>
       <tag><c><![CDATA[-env Variable Value]]></c></tag>
       <item>
         <p>Sets the host OS environment variable <c><![CDATA[Variable]]></c> to
diff --git a/erts/etc/unix/Makefile b/erts/etc/unix/Makefile
index 2fa9cd047b..17de4d8878 100644
--- a/erts/etc/unix/Makefile
+++ b/erts/etc/unix/Makefile
@@ -24,7 +24,7 @@ include $(ERL_TOP)/make/target.mk
 include $(ERL_TOP)/make/$(TARGET)/otp.mk
 include ../../vsn.mk
 
-opt debug: etc
+opt debug lcnt: etc
 
 .PHONY: etc
 etc: etp-commands
@@ -44,4 +44,4 @@ clean:
 include $(ERL_TOP)/make/otp_release_targets.mk
 
 .PHONY: release_spec
-release_spec: etc
\ No newline at end of file
+release_spec: etc
diff --git a/erts/start_scripts/Makefile b/erts/start_scripts/Makefile
index ae2521474e..047e42170a 100644
--- a/erts/start_scripts/Makefile
+++ b/erts/start_scripts/Makefile
@@ -68,7 +68,7 @@ include $(LIBPATH)/stdlib/vsn.mk
 
 ##############################################################################
 
-debug opt script: rel $(INSTALL_SCRIPTS) $(RELEASES_SRC)
+debug opt lcnt script: rel $(INSTALL_SCRIPTS) $(RELEASES_SRC)
 
 rel:	$(REL_SCRIPTS)