Include git sha in prompt if available

The sha will only be included if there is no tag
starting with OTP_R* associated with the sha. This
is because we do not want the sha to show on offical
releases.

erts/emulator/Makefile.in

@@ -20,6 +20,8 @@
 include $(ERL_TOP)/make/target.mk
 include ../vsn.mk
 include $(ERL_TOP)/make/$(TARGET)/otp.mk
+include $(TARGET)/gen_git_version.mk
+
 
 ENABLE_ALLOC_TYPE_VARS = @ENABLE_ALLOC_TYPE_VARS@
 HIPE_ENABLED=@HIPE_ENABLED@
@@ -196,7 +198,7 @@ else
 EMU_CC  = @EMU_CC@
 endif
 WFLAGS  = @WFLAGS@
-CFLAGS  = @STATIC_CFLAGS@ $(TYPE_FLAGS) $(FLAVOR_FLAGS) $(DEFS) $(WFLAGS) $(THR_DEFS) $(ARCHCFLAGS)
+CFLAGS  = @STATIC_CFLAGS@ $(TYPE_FLAGS) $(FLAVOR_FLAGS) $(DEFS) $(WFLAGS) $(THR_DEFS) $(ARCHCFLAGS) $(GIT_VSN)
 HCC     = @HCC@
 LD      = @LD@
 DEXPORT = @DEXPORT@
@@ -1006,6 +1008,12 @@ DEP_FLAGS=-MM $(MG_FLAG) $(CFLAGS) $(INCLUDES) -Idrivers/common -Idrivers/$(ERLA
 SYS_SRC=$(ALL_SYS_SRC)
 endif
 
+.PHONY: $(TARGET)/gen_git_version.mk
+$(TARGET)/gen_git_version.mk:
+# We touch beam/erl_bif.info.c if we regenerated the git version to force a
+# rebuild.
+	if $(gen_verbose)utils/gen_git_version $@; then touch beam/erl_bif_info.c; fi
+
 .PHONY: depend
 ifdef VOID_EMULATOR
 depend:

erts/emulator/beam/erl_bif_info.c

@@ -69,7 +69,11 @@ static char erts_system_version[] = ("Erlang " ERLANG_OTP_RELEASE
 				     " [no-c-stack-objects]"
 #endif
 #ifndef OTP_RELEASE
+#ifdef ERLANG_GIT_VERSION
+				     " [source-" ERLANG_GIT_VERSION "]"
+#else
 				     " [source]"
+#endif
 #endif	
 #ifdef ARCH_64
 #if HALFWORD_HEAP

erts/emulator/utils/gen_git_version

@@ -0,0 +1,40 @@
+#!/bin/sh
+
+OUTPUT_FILE=$1
+
+if command -v git 2>&1 >/dev/null &&
+    test -d $ERL_TOP/.git -o -f $ERL_TOP/.git
+then
+    VSN=`git describe --match "OTP_R[0-9][0-9][A-B]*" HEAD`
+    case "$VSN" in
+	OTP_R*-g*) 
+	    VSN=`echo $VSN | sed -e 's/.*-g\\(.*\\)/\\1/g'` ;;
+	*)  VSN="na" ;;
+    esac
+else
+    VSN="na"
+fi
+
+
+# Only update the file if there has been a change to
+# the version number.
+if test -r $OUTPUT_FILE
+then
+	VC=`sed -n -e 's/^.*"\\\\"\\(.*\\)\\\\"".*/\\1/p' < $OUTPUT_FILE`
+else
+	VC=unset
+fi
+echo "VSN = $VSN"
+echo "VC = $VC"
+if test "$VSN" != "$VC"
+then
+    echo "# Automatically generated by $0 - DO NOT EDIT." > $OUTPUT_FILE
+    if test "$VSN" = "na"
+    then
+	echo "# GIT_VSN=-DERLANG_GIT_VERSION=\"\\\"$VSN\\\"\"" >> $OUTPUT_FILE
+    else
+	echo "GIT_VSN=-DERLANG_GIT_VERSION=\"\\\"$VSN\\\"\"" >> $OUTPUT_FILE
+    fi
+    exit 0
+fi
+exit 1