pgbench: Add a real expression syntax to \set

Previously, you could do \set variable operand1 operator operand2, but
nothing more complicated.  Now, you can \set variable expression, which
makes it much simpler to do multi-step calculations here.  This also
adds support for the modulo operator (%), with the same semantics as in
C.

Robert Haas and Fabien Coelho, reviewed by Álvaro Herrera and
Stephen Frost

1 files changed, 16 insertions, 1 deletions

diff --git a/contrib/pgbench/Makefile b/contrib/pgbench/Makefile
index b8e2fc841ec..6d132228dd7 100644
--- a/contrib/pgbench/Makefile
+++ b/contrib/pgbench/Makefile
@@ -4,7 +4,9 @@ PGFILEDESC = "pgbench - a simple program for running benchmark tests"
 PGAPPICON = win32
 
 PROGRAM = pgbench
-OBJS	= pgbench.o $(WIN32RES)
+OBJS	= pgbench.o exprparse.o $(WIN32RES)
+
+EXTRA_CLEAN	= exprparse.c exprscan.c
 
 PG_CPPFLAGS = -I$(libpq_srcdir)
 PG_LIBS = $(libpq_pgport) $(PTHREAD_LIBS)
@@ -18,8 +20,21 @@ subdir = contrib/pgbench
 top_builddir = ../..
 include $(top_builddir)/src/Makefile.global
 include $(top_srcdir)/contrib/contrib-global.mk
+
+distprep: exprparse.c exprscan.c
 endif
 
 ifneq ($(PORTNAME), win32)
 override CFLAGS += $(PTHREAD_CFLAGS)
 endif
+
+# There is no correct way to write a rule that generates two files.
+# Rules with two targets don't have that meaning, they are merely
+# shorthand for two otherwise separate rules.  To be safe for parallel
+# make, we must chain the dependencies like this.  The semicolon is
+# important; otherwise, make will choose the built-in rule.
+
+exprparse.h: exprparse.c ;
+
+# exprscan is compiled as part of exprparse
+exprparse.o: exprscan.c