Fold gen-deps.sh into Makefile.

Makefile

@@ -66,9 +66,13 @@ endif
 # of the scheme we use that compiles the same source file multiple times with
 # different -D options, which can include different header files.
 ALLSRC=$(shell find . -name '*.c' -print | grep -v perf-tmp)
-deps: gen-deps.sh Makefile $(ALLSRC)
-	$(Q) CPPFLAGS="$(CPPFLAGS)" ./gen-deps.sh $(ALLSRC)
+deps: Makefile $(ALLSRC)
 	$(E) Regenerating dependencies for upb/...
+	@set -e
+	@rm -f deps
+	@for file in $(ALLSRC); do \
+	  gcc -MM $$file -MT $${file%.*}.o $(CPPFLAGS) -I. >> deps; \
+	done
 
 
 # Source files. ###############################################################

gen-deps.sh

@@ -1,18 +0,0 @@
-#!/bin/sh
-# This script wraps gcc -MM, which unhelpfully strips the directory
-# off of the input filename.  In other words, if you run:
-#
-# $ gcc -MM src/upb_parse.c
-#
-# ...the emitted dependency information looks like:
-#
-# upb_parse.o: src/upb_parse.h [...]
-#
-# Since upb_parse.o is actually in src, the dependency information is
-# not used.  To remedy this, we use the -MT flag (see gcc docs).
-
-set -e
-rm -f deps
-for file in $@; do
-  gcc -MM $file -MT ${file%.*}.o $CPPFLAGS -I. >> deps
-done