build: fix VPATH builds

* configure (fn_dirname): New.
Use it to ensure the creation of proper symlinks to Makefiles.
(config.mak): Define top_builddir and top_srcdir.
(CPPFLAGS): Be sure to find the headers.
* Makefile, lib/Makefile, tests/Makefile, tests2/Makefile: Adjust
to set VPATH properly.
Fix confusion between top_builddir and top_srcdir.

Makefile

@@ -4,6 +4,7 @@
 
 TOP ?= .
 include $(TOP)/config.mak
+VPATH = $(top_srcdir)
 
 CPPFLAGS_P=$(CPPFLAGS) -DCONFIG_TCC_STATIC
 CFLAGS_P=$(CFLAGS) -pg -static
@@ -356,11 +357,11 @@ tcc-doc.html: tcc-doc.texi
 	-texi2html -monolithic -number $<
 
 tcc.1: tcc-doc.texi
-	-./texi2pod.pl $< tcc.pod
+	-$(top_srcdir)/texi2pod.pl $< tcc.pod
 	-pod2man --section=1 --center=" " --release=" " tcc.pod > $@
 
 tcc-doc.info: tcc-doc.texi
-	-makeinfo tcc-doc.texi
+	-makeinfo $<
 
 .PHONY: all clean tar distclean install uninstall FORCE
 

README

@@ -35,6 +35,16 @@ Documentation:
    make test
    make install
 
+Alternatively, VPATH builds are supported: you may use different
+directories to old build objects, kept separate from your source tree:
+
+   mkdir _build
+   cd _build
+   ../configure
+   make
+   make test
+   make install
+
 By default, tcc is installed in /usr/local/bin.
 ./configure --help  shows configuration options.
 

configure

@@ -2,6 +2,14 @@
 #
 # tcc configure script (c) 2003 Fabrice Bellard
 
+fn_dirname()
+{
+  case $1 in
+    */*) echo "$1" | sed -e 's,/[^/]*,,';;
+      *) echo '.'
+  esac
+}
+
 # set temporary file name
 if test ! -z "$TMPDIR" ; then
     TMPDIR1="${TMPDIR}"
@@ -411,10 +419,13 @@ echo "#define GCC_MAJOR $gcc_major" >> $TMPH
 echo "HOST_CC=$host_cc" >> config.mak
 echo "AR=$ar" >> config.mak
 echo "STRIP=$strip -s -R .comment -R .note" >> config.mak
-echo "CFLAGS=$CFLAGS" >> config.mak
+cat >> config.mak <<EOF
-echo "LDFLAGS=$LDFLAGS" >> config.mak
+CPPFLAGS = -I. -I\$(top_srcdir)
-echo "LIBSUF=$LIBSUF" >> config.mak
+CFLAGS=$CFLAGS
-echo "EXESUF=$EXESUF" >> config.mak
+LDFLAGS=$LDFLAGS
+LIBSUF=$LIBSUF
+EXESUF=$EXESUF
+EOF
 
 if test "$cpu" = "x86" ; then
   echo "ARCH=i386" >> config.mak
@@ -491,16 +502,23 @@ echo "@set VERSION $version" > config.texi
 
 # build tree in object directory if source path is different from current one
 if test "$source_path_used" = "yes" ; then
-    DIRS="tests"
+    FILES="Makefile lib/Makefile tests/Makefile tests2/Makefile"
-    FILES="Makefile tests/Makefile"
-    for dir in $DIRS ; do
-        mkdir -p $dir
-    done
     for f in $FILES ; do
-        ln -sf $source_path/$f $f
+        dir=`fn_dirname "$f"`
+        test -d "$dir" || mkdir -p "$dir"
+        back=`echo "$source_path/$dir/" | sed 's,/\./,/,g;s,[^/]*/,../,g'`
+        back=$back$f
+        ln -sf $back $f
     done
 fi
-echo "SRC_PATH=$source_path" >> config.mak
+cat >>config.mak <<EOF
+SRC_PATH = $source_path
+top_builddir = \$(TOP)
+EOF
+case $source_path in
+  /*) echo 'top_srcdir = $(SRC_PATH)';;
+   *) echo 'top_srcdir = $(TOP)/$(SRC_PATH)';;
+esac >>config.mak
 
 diff $TMPH config.h >/dev/null 2>&1
 if test $? -ne 0 ; then

lib/Makefile

@@ -4,6 +4,7 @@
 
 TOP = ..
 include $(TOP)/config.mak
+VPATH = $(top_srcdir)/lib $(top_srcdir)/win32/lib
 
 ifndef TARGET
  ifdef CONFIG_WIN64
@@ -42,8 +43,6 @@ X86_64_O = libtcc1.o alloca86_64.o
 WIN32_O = $(I386_O) crt1.o wincrt1.o dllcrt1.o dllmain.o chkstk.o bcheck.o
 WIN64_O = $(X86_64_O) crt1.o wincrt1.o dllcrt1.o dllmain.o chkstk.o
 
-VPATH = $(TOP)/lib $(TOP)/win32/lib
-
 ifeq "$(TARGET)" "i386-win32"
  OBJ = $(addprefix $(DIR)/,$(WIN32_O))
  TGT = -DTCC_TARGET_I386 -DTCC_TARGET_PE

tests/Makefile

@@ -4,6 +4,7 @@
 
 TOP = ..
 include $(TOP)/Makefile
+VPATH = $(top_srcdir)/tests
 
 # what tests to run
 TESTS = libtest \
@@ -56,7 +57,7 @@ endif
 # run local version of tcc with local libraries and includes
 TCC = ../tcc -B.. $(NATIVE_DEFINES)
 ifdef CONFIG_WIN32
-	TCC := $(TCC) -I $(TOP)/win32/include -L$(TOP)
+	TCC := $(TCC) -I $(top_srcdir)/win32/include -L$(top_build)
 endif
 RUN_TCC = $(NATIVE_DEFINES) -run -DONE_SOURCE ../tcc.c -B..
 DISAS=objdump -d
@@ -77,8 +78,8 @@ libtest: libtcc_test$(EXESUF) $(LIBTCC1)
 	@echo ------------ $@ ------------
 	./libtcc_test$(EXESUF) lib_path=..
 
-libtcc_test$(EXESUF): libtcc_test.c ../$(LIBTCC)
+libtcc_test$(EXESUF): libtcc_test.c $(top_builddir)/$(LIBTCC)
-	$(CC) -o $@ $^ -I.. $(CPPFLAGS) $(CFLAGS) $(NATIVE_DEFINES) $(LIBS) $(LINK_LIBTCC) $(LDFLAGS)
+	$(CC) -o $@ $^ $(CPPFLAGS) $(CFLAGS) $(NATIVE_DEFINES) $(LIBS) $(LINK_LIBTCC) $(LDFLAGS)
 
 # test.ref - generate using gcc
 # copy only tcclib.h so GCC's stddef and stdarg will be used
@@ -169,9 +170,9 @@ btest: boundtest.c ../bcheck.o
 speedtest: ex2 ex3
 	@echo ------------ $@ ------------
 	time ./ex2 1238 2 3 4 10 13 4
-	time $(TCC) -run ../examples/ex2.c 1238 2 3 4 10 13 4
+	time $(TCC) -run $(top_srcdir)/examples/ex2.c 1238 2 3 4 10 13 4
 	time ./ex3 35
-	time $(TCC) -run ../examples/ex3.c 35
+	time $(TCC) -run $(top_srcdir)/examples/ex3.c 35
 
 weaktest: test.ref
 	$(TCC) -c tcctest.c -o weaktest.tcc.o $(CPPFLAGS) $(CFLAGS)
@@ -180,7 +181,7 @@ weaktest: test.ref
 	objdump -t weaktest.gcc.o | grep ' w ' | sed -e 's/.* \([a-zA-Z0-9_]*\)$$/\1/' | LC_ALL=C sort > weaktest.gcc.o.txt
 	diff weaktest.gcc.o.txt weaktest.tcc.o.txt && echo "Weak Auto Test OK"
 
-ex%: ../examples/ex%.c
+ex%: $(top_srcdir)/examples/ex%.c
 	$(CC) -o $@ $< $(CPPFLAGS) $(CFLAGS) $(LDFLAGS)
 
 # tiny assembler testing

tests2/Makefile

@@ -1,5 +1,6 @@
 TOP = ..
 include $(TOP)/Makefile
+VPATH = $(top_srcdir)/tests2
 
 ifeq ($(TARGETOS),Darwin)
     CFLAGS+=-Wl,-flat_namespace,-undefined,warning
@@ -77,15 +78,15 @@ ifdef CONFIG_WIN32
     TESTS := $(filter-out 28_strings.test,$(TESTS))
 endif
 
-%.test: %.expect %.c
+%.test: %.c %.expect
 	@echo Test: $*...
 	@if [ "x`echo $* | grep args`" != "x" ]; \
 	then \
-		../tcc -B.. $(TCCFLAGS) -run $*.c - arg1 arg2 arg3 arg4 2>&1 >$*.output; \
+		../tcc -B.. $(TCCFLAGS) -run $< - arg1 arg2 arg3 arg4 2>&1 >$*.output; \
 	else \
-		../tcc -B.. $(TCCFLAGS) -run $*.c 2>&1 >$*.output; \
+		../tcc -B.. $(TCCFLAGS) -run $< 2>&1 >$*.output; \
 	fi
-	@if diff -bu $*.expect $*.output ; \
+	@if diff -bu $(<:.c=.expect) $*.output ; \
 	then \
         rm -f $*.output \
 	else \