configure: support out-of-source builds

.github/workflows/ci.yml

@@ -247,6 +247,49 @@ jobs:
           ${{matrix.build_args.cxx}} -x c++ -o a.out $TEST_FILE -luring $SANITIZE_FLAGS;
 
 
+  out-of-source-build:
+    needs: get_commit_list
+    runs-on: ubuntu-24.04
+    strategy:
+      matrix:
+        commit: ${{ fromJson(needs.get_commit_list.outputs.commit_list) }}
+
+    steps:
+      - name: Checkout source
+        uses: actions/checkout@v4
+        with:
+          fetch-depth: 0
+
+      - name: Checkout commit
+        run: |
+          git checkout ${{ matrix.commit }};
+
+      - name: Out-of-source build
+        run: |
+          mkdir build && cd build;
+          ../configure;
+          make -j$(nproc) V=1;
+
+      - name: Test install from out-of-source build
+        run: |
+          cd build;
+          sudo make install;
+
+      - name: Test build against the installed liburing
+        run: |
+          gcc -x c -o a.out .github/workflows/test_build.c -luring;
+          gcc -x c++ -o a.out .github/workflows/test_build.c -luring;
+
+      - name: Verify source tree is clean
+        run: |
+          dirty=$(git ls-files --others --exclude-standard --ignored -- ':!build');
+          if [ -n "$dirty" ]; then
+            echo "Out-of-source build leaked into source tree:";
+            echo "$dirty";
+            exit 1;
+          fi
+
+
   alpine-musl-build:
     needs: get_commit_list
     runs-on: ubuntu-24.04

Makefile

@@ -1,4 +1,7 @@
-include Makefile.common
+root ?= .
+include $(root)/Makefile.common
+
+VPATH = $(root)
 
 RPMBUILD=$(shell `which rpmbuild >&/dev/null` && echo "rpmbuild" || echo "rpm")
 
@@ -24,10 +27,10 @@ runtests-loop: all
 runtests-parallel: all
 	@$(MAKE) -C test runtests-parallel
 
-config-host.mak: configure
+config-host.mak: $(root)/configure
 	+@if [ ! -e "$@" ]; then				\
 	  echo "Running configure ...";				\
-	  ./configure;						\
+	  $(root)/configure;				\
 	else							\
 	  echo "$@ is out-of-date, running configure";		\
 	  sed -n "/.*Configured with/s/[^:]*: //p" "$@" | sh;	\
@@ -54,11 +57,11 @@ install: $(NAME).pc $(NAME)-ffi.pc
 	$(INSTALL) -D -m 644 $(NAME).pc $(DESTDIR)$(libdevdir)/pkgconfig/$(NAME).pc
 	$(INSTALL) -D -m 644 $(NAME)-ffi.pc $(DESTDIR)$(libdevdir)/pkgconfig/$(NAME)-ffi.pc
 	$(INSTALL) -m 755 -d $(DESTDIR)$(mandir)/man2
-	$(INSTALL) -m 644 man/*.2 $(DESTDIR)$(mandir)/man2
+	$(INSTALL) -m 644 $(root)/man/*.2 $(DESTDIR)$(mandir)/man2
 	$(INSTALL) -m 755 -d $(DESTDIR)$(mandir)/man3
-	$(INSTALL) -m 644 man/*.3 $(DESTDIR)$(mandir)/man3
+	$(INSTALL) -m 644 $(root)/man/*.3 $(DESTDIR)$(mandir)/man3
 	$(INSTALL) -m 755 -d $(DESTDIR)$(mandir)/man7
-	$(INSTALL) -m 644 man/*.7 $(DESTDIR)$(mandir)/man7
+	$(INSTALL) -m 644 $(root)/man/*.7 $(DESTDIR)$(mandir)/man7
 
 uninstall:
 	@$(MAKE) -C src uninstall prefix=$(DESTDIR)$(prefix) datadir=$(DESTDIR)$(datadir)

Makefile.common

@@ -1,4 +1,4 @@
-TOP := $(dir $(CURDIR)/$(word $(words $(MAKEFILE_LIST)),$(MAKEFILE_LIST)))
+TOP := $(dir $(abspath $(lastword $(MAKEFILE_LIST))))
 NAME=liburing
 SPECFILE=$(TOP)/$(NAME).spec
 VERSION=$(shell awk '/Version:/ { print $$2 }' $(SPECFILE))

README

@@ -75,6 +75,14 @@ Building liburing
 
 See './configure --help' for more information about build config options.
 
+Out-of-source builds are also supported, keeping the source tree clean, and
+allowing you to have different configurations side-by-side:
+
+    mkdir build && cd build
+    ../configure
+    make -j$(nproc)
+    sudo make install
+
 
 FFI support
 -----------

configure

@@ -5,6 +5,10 @@ set -e
 cc=${CC:-gcc}
 cxx=${CXX:-g++}
 
+# Determine source directory (where this configure script lives)
+root=$(cd "$(dirname "$0")" && pwd)
+builddir=$(pwd)
+
 for opt do
   optarg=$(expr "x$opt" : 'x[^=]*=\(.*\)' || true)
   case "$opt" in
@@ -85,6 +89,20 @@ EOF
 exit 0
 fi
 
+# Set up out-of-source build if needed
+if test "$root" != "$builddir"; then
+  mkdir -p src/include/liburing test examples
+
+  for dir in . src test examples; do
+    cat > "$dir/Makefile" << MEOF
+root := $root
+include \$(root)/$dir/Makefile
+MEOF
+  done
+else
+  mkdir -p src/include/liburing
+fi
+
 TMP_DIRECTORY="$(mktemp -d)"
 TMPC="$TMP_DIRECTORY/liburing-conf.c"
 TMPC2="$TMP_DIRECTORY/liburing-conf-2.c"
@@ -636,11 +654,12 @@ print_config "CC" "$cc"
 echo "CXX=$cxx" >> $config_host_mak
 echo "BUILD_CFLAGS=$BUILD_CFLAGS" >> $config_host_mak
 print_config "CXX" "$cxx"
+echo "root=$root" >> $config_host_mak
 
 # generate io_uring_version.h
 # Reset MAKEFLAGS
 MAKEFLAGS=
-MAKE_PRINT_VARS="include Makefile.common\nprint-%%: ; @echo \$(\$*)\n"
+MAKE_PRINT_VARS="include $root/Makefile.common\nprint-%%: ; @echo \$(\$*)\n"
 VERSION_MAJOR=$(printf "$MAKE_PRINT_VARS" | make -s --no-print-directory -f - print-VERSION_MAJOR)
 VERSION_MINOR=$(printf "$MAKE_PRINT_VARS" | make -s --no-print-directory -f - print-VERSION_MINOR)
 io_uring_version_h="src/include/liburing/io_uring_version.h"

examples/Makefile

@@ -1,15 +1,19 @@
+root ?= ..
+
 CPPFLAGS ?=
-override CPPFLAGS += -D_GNU_SOURCE -I../src/include/
+override CPPFLAGS += -D_GNU_SOURCE -I../src/include/ -I$(root)/src/include/
 CFLAGS ?= -g -O2 -Wall
 LDFLAGS ?=
 override LDFLAGS += -L../src/ -luring
 
-include ../Makefile.quiet
+include $(root)/Makefile.quiet
 
 ifneq ($(MAKECMDGOALS),clean)
 include ../config-host.mak
 endif
 
+VPATH = $(root)/examples
+
 LDFLAGS ?=
 override LDFLAGS += -L../src/ -luring -lpthread
 

src/Makefile

@@ -1,4 +1,5 @@
-include ../Makefile.common
+root ?= ..
+include $(root)/Makefile.common
 
 prefix ?= /usr
 includedir ?= $(prefix)/include
@@ -8,8 +9,11 @@ libdevdir ?= $(prefix)/lib
 LIBURING_CFLAGS ?=
 CPPFLAGS ?=
 override CPPFLAGS += -D_GNU_SOURCE \
-	-Iinclude/ -include ../config-host.h \
+	-Iinclude/ -I$(root)/src/include/ \
+	-include ../config-host.h \
 	-D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64
+
+VPATH = $(root)/src
 CFLAGS ?= -O3 -Wall -Wextra -fno-stack-protector
 override CFLAGS += -Wno-unused-parameter \
 	-DLIBURING_INTERNAL \
@@ -32,7 +36,7 @@ all_targets += $(libname)
 all_targets += $(ffi_libname)
 endif
 
-include ../Makefile.quiet
+include $(root)/Makefile.quiet
 
 ifneq ($(MAKECMDGOALS),clean)
 include ../config-host.mak
@@ -95,20 +99,20 @@ liburing-ffi.a: $(liburing_objs) $(liburing_ffi_objs)
 	$(QUIET_AR)$(AR) r liburing-ffi.a $^
 	$(QUIET_RANLIB)$(RANLIB) liburing-ffi.a
 
-$(libname): $(liburing_sobjs) liburing.map
-	$(QUIET_CC)$(CC) $(SO_CFLAGS) -shared -Wl,--version-script=liburing.map -Wl,-soname=$(soname) -o $@ $(liburing_sobjs) $(LINK_FLAGS)
+$(libname): $(liburing_sobjs) $(root)/src/liburing.map
+	$(QUIET_CC)$(CC) $(SO_CFLAGS) -shared -Wl,--version-script=$(root)/src/liburing.map -Wl,-soname=$(soname) -o $@ $(liburing_sobjs) $(LINK_FLAGS)
 
-$(ffi_libname): $(liburing_ffi_objs) $(liburing_ffi_sobjs) $(liburing_sobjs) liburing-ffi.map
-	$(QUIET_CC)$(CC) $(SO_CFLAGS) -shared -Wl,--version-script=liburing-ffi.map -Wl,-soname=$(ffi_soname) -o $@ $(liburing_sobjs) $(liburing_ffi_sobjs) $(LINK_FLAGS)
+$(ffi_libname): $(liburing_ffi_objs) $(liburing_ffi_sobjs) $(liburing_sobjs) $(root)/src/liburing-ffi.map
+	$(QUIET_CC)$(CC) $(SO_CFLAGS) -shared -Wl,--version-script=$(root)/src/liburing-ffi.map -Wl,-soname=$(ffi_soname) -o $@ $(liburing_sobjs) $(liburing_ffi_sobjs) $(LINK_FLAGS)
 
 install: $(all_targets)
-	install -D -m 644 include/liburing/io_uring.h $(includedir)/liburing/io_uring.h
-	install -D -m 644 include/liburing.h $(includedir)/liburing.h
+	install -D -m 644 $(root)/src/include/liburing/io_uring.h $(includedir)/liburing/io_uring.h
+	install -D -m 644 $(root)/src/include/liburing.h $(includedir)/liburing.h
 	install -D -m 644 include/liburing/compat.h $(includedir)/liburing/compat.h
-	install -D -m 644 include/liburing/barrier.h $(includedir)/liburing/barrier.h
+	install -D -m 644 $(root)/src/include/liburing/barrier.h $(includedir)/liburing/barrier.h
 	install -D -m 644 include/liburing/io_uring_version.h $(includedir)/liburing/io_uring_version.h
-	install -D -m 644 include/liburing/io_uring/query.h $(includedir)/liburing/io_uring/query.h
-	install -D -m 644 include/liburing/io_uring/bpf_filter.h $(includedir)/liburing/io_uring/bpf_filter.h
+	install -D -m 644 $(root)/src/include/liburing/io_uring/query.h $(includedir)/liburing/io_uring/query.h
+	install -D -m 644 $(root)/src/include/liburing/io_uring/bpf_filter.h $(includedir)/liburing/io_uring/bpf_filter.h
 	install -D -m 644 liburing.a $(libdevdir)/liburing.a
 	install -D -m 644 liburing-ffi.a $(libdevdir)/liburing-ffi.a
 ifeq ($(ENABLE_SHARED),1)

test/Makefile

@@ -1,11 +1,13 @@
+root ?= ..
+
 prefix ?= /usr
 datadir ?= $(prefix)/share
 
 CLANG ?= clang
 BPFTOOL ?= $(or $(shell command -v bpftool 2>/dev/null), \
 		$(shell command -v /usr/sbin/bpftool 2>/dev/null), \
 		bpfool)
-BPF_PROGS_DIR = bpf-progs
+BPF_PROGS_DIR = $(root)/test/bpf-progs
 BPF_OUTPUT = output/bpf
 
 INSTALL=install
@@ -20,9 +22,12 @@ override CPPFLAGS += \
 	-D_GNU_SOURCE \
 	-D__SANE_USERSPACE_TYPES__ \
 	-I../src/include/ \
+	-I$(root)/src/include/ \
 	-include ../config-host.h \
 	-D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64
 
+VPATH = $(root)/test
+
 CFLAGS ?= -g -O3 -Wall -Wextra
 XCFLAGS = -Wno-unused-parameter -Wno-sign-compare
 
@@ -303,7 +308,7 @@ asan_test_srcs := \
 	# EOL
 
 all_targets :=
-include ../Makefile.quiet
+include $(root)/Makefile.quiet
 
 ifeq ($(CONFIG_NOLIBC),y)
 	test_srcs += nolibc.c
@@ -385,11 +390,11 @@ $(BPF_OUTPUT)/%.bpf.o: $(BPF_PROGS_DIR)/%.bpf.c $(wildcard %.h)
 $(BPF_OUTPUT)/%.skel.h: $(BPF_OUTPUT)/%.bpf.o
 	$(BPFTOOL) gen skeleton $< > $@
 
-install: $(test_targets) runtests.sh runtests-loop.sh
+install: $(test_targets) $(root)/test/runtests.sh $(root)/test/runtests-loop.sh
 	$(INSTALL) -D -d -m 755 $(datadir)/liburing-test/
 	$(INSTALL) -D -m 755 $(test_targets) $(datadir)/liburing-test/
-	$(INSTALL) -D -m 755 runtests.sh  $(datadir)/liburing-test/
-	$(INSTALL) -D -m 755 runtests-loop.sh  $(datadir)/liburing-test/
+	$(INSTALL) -D -m 755 $(root)/test/runtests.sh  $(datadir)/liburing-test/
+	$(INSTALL) -D -m 755 $(root)/test/runtests-loop.sh  $(datadir)/liburing-test/
 
 uninstall:
 	@rm -rf $(datadir)/liburing-test/
@@ -399,13 +404,13 @@ clean:
 	@rm -rf output/
 
 runtests: all
-	@./runtests.sh $(test_targets) $(asan_test_targets)
+	@$(root)/test/runtests.sh $(test_targets) $(asan_test_targets)
 
 runtests-loop: all
-	@./runtests-loop.sh $(test_targets) $(asan_test_targets)
+	@$(root)/test/runtests-loop.sh $(test_targets) $(asan_test_targets)
 
 %.run_test: %.t
-	@./runtests-quiet.sh $<
+	@$(root)/test/runtests-quiet.sh $<
 
 runtests-parallel: $(run_test_targets)
 	@echo "All tests passed"