Tweak the Makefile to run "rpython" using python rather than pypy, if

there is no pypy installed.  Gives a proper warning in this case.

1 files changed, 25 insertions, 3 deletions

diff --git a/Makefile b/Makefile
index 53e0d060db..d598115249 100644
--- a/Makefile
+++ b/Makefile
@@ -1,7 +1,29 @@
 
 all: pypy-c
 
+PYPY_EXECUTABLE := $(shell which pypy)
+URAM := $(shell python -c "import sys; print 4.5 if sys.maxint>1<<32 else 2.5")
+
+ifeq ($(PYPY_EXECUTABLE),)
+RUNINTERP = python
+else
+RUNINTERP = $(PYPY_EXECUTABLE)
+endif
+
 pypy-c:
-	@echo "Building PyPy with JIT, it'll take about 40 minutes and 4G of RAM"
-	@sleep 3
-	rpython/bin/rpython -Ojit pypy/goal/targetpypystandalone.py
+	@echo
+	@echo "============================================================="
+ifeq ($(PYPY_EXECUTABLE),)
+	@echo "Building a regular (jitting) version of PyPy, using CPython."
+	@echo "This takes around 2 hours and $(URAM) GB of RAM."
+	@echo "Note that pre-installing a PyPy binary would reduce this time"
+	@echo "and produce basically the same result."
+else
+	@echo "Building a regular (jitting) version of PyPy, using"
+	@echo "$(PYPY_EXECUTABLE) to run the translation itself."
+	@echo "This takes around 45 minutes and $(URAM) GB of RAM."
+endif
+	@echo "============================================================="
+	@echo
+	@sleep 5
+	$(RUNINTERP) rpython/bin/rpython -Ojit pypy/goal/targetpypystandalone.py