[dpdk-dev] [RFC 1/4] mk: Add support for C++ compilation

[Declan Doherty]

From: Anatoly Burakov <anatoly.burakov at intel.com>

Adding support for compiling C++ files as part of the build system

Signed-off-by: Declan Doherty <declan.doherty at intel.com>
---
 mk/internal/rte.compile-pre.mk | 52 ++++++++++++++++++++++++++++++++++++++----
 mk/target/generic/rte.vars.mk  |  3 +++
 mk/toolchain/clang/rte.vars.mk | 14 +++++++++---
 mk/toolchain/gcc/rte.vars.mk   | 14 +++++++++---
 mk/toolchain/icc/rte.vars.mk   | 10 +++++---
 5 files changed, 80 insertions(+), 13 deletions(-)

diff --git a/mk/internal/rte.compile-pre.mk b/mk/internal/rte.compile-pre.mk
index f740179..2342942 100644
--- a/mk/internal/rte.compile-pre.mk
+++ b/mk/internal/rte.compile-pre.mk
@@ -32,12 +32,12 @@
 #
 # Common to rte.lib.mk, rte.app.mk, rte.obj.mk
 #
-
 SRCS-all := $(SRCS-y) $(SRCS-n) $(SRCS-)
 
 # convert source to obj file
 src2obj = $(strip $(patsubst %.c,%.o,\
-	$(patsubst %.S,%_s.o,$(1))))
+	$(patsubst %.S,%_s.o,\
+	$(patsubst %.cpp,%_cpp.o,$(1)))))
 
 # add a dot in front of the file name
 dotfile = $(strip $(foreach f,$(1),\
@@ -46,12 +46,14 @@ dotfile = $(strip $(foreach f,$(1),\
 # convert source/obj files into dot-dep filename (does not
 # include .S files)
 src2dep = $(strip $(call dotfile,$(patsubst %.c,%.o.d, \
-		$(patsubst %.S,,$(1)))))
+		$(patsubst %.cpp,%_cpp.o.d, \
+		$(patsubst %.S,,$(1))))))
 obj2dep = $(strip $(call dotfile,$(patsubst %.o,%.o.d,$(1))))
 
 # convert source/obj files into dot-cmd filename
 src2cmd = $(strip $(call dotfile,$(patsubst %.c,%.o.cmd, \
-		$(patsubst %.S,%_s.o.cmd,$(1)))))
+		$(patsubst %.cpp,%_cpp.o.cmd, \
+		$(patsubst %.S,%_s.o.cmd,$(1))))))
 obj2cmd = $(strip $(call dotfile,$(patsubst %.o,%.o.cmd,$(1))))
 
 OBJS-y := $(call src2obj,$(SRCS-y))
@@ -186,3 +188,45 @@ S_TO_O_DO = @set -e; \
 		$(depfile_missing),\
 		$(depfile_newer)),\
 		$(S_TO_O_DO))
+
+
+# command to compile a .cpp file to generate an object
+ifeq ($(USE_HOST),1)
+CXX_TO_O = $(HOSTCXX) -Wp,-MD,$(call obj2dep,$(@)).tmp $(HOST_CXXFLAGS) \
+	$(CXXFLAGS_$(@)) $(HOST_EXTRA_CXXFLAGS) -o $@ -c $<
+CXX_TO_O_STR = $(subst ','\'',$(CXX_TO_O)) #'# fix syntax highlight
+CXX_TO_O_DISP = $(if $(V),"$(CXX_TO_O_STR)","  HOSTCXX $(@)")
+else
+CXX_TO_O = $(CXX) -Wp,-MD,$(call obj2dep,$(@)).tmp $(CXXFLAGS) \
+	$(CXXFLAGS_$(@)) $(EXTRA_CXXFLAGS) -o $@ -c $<
+CXX_TO_O_STR = $(subst ','\'',$(CXX_TO_O)) #'# fix syntax highlight
+CXX_TO_O_DISP = $(if $(V),"$(CXX_TO_O_STR)","  CXX $(@)")
+endif
+CXX_TO_O_CMD = 'cmd_$@ = $(CXX_TO_O_STR)'
+CXX_TO_O_DO = @set -e; \
+	echo $(CXX_TO_O_DISP); \
+	$(CXX_TO_O) && \
+	echo $(CXX_TO_O_CMD) > $(call obj2cmd,$(@)) && \
+	sed 's,'$@':,dep_'$@' =,' $(call obj2dep,$(@)).tmp > $(call obj2dep,$(@)) && \
+	rm -f $(call obj2dep,$(@)).tmp
+
+#
+# Compile .cpp file if needed
+# Note: dep_$$@ is from the .d file and DEP_$$@ can be specified by
+# user (by default it is empty)
+#
+.SECONDEXPANSION:
+%_cpp.o: %.cpp $$(wildcard $$(dep_$$@)) $$(DEP_$$(@)) FORCE
+	@[ -d $(dir $@) ] || mkdir -p $(dir $@)
+	$(if $(D),\
+		@echo -n "$< -> $@ " ; \
+		echo -n "file_missing=$(call boolean,$(file_missing)) " ; \
+		echo -n "cmdline_changed=$(call boolean,$(call cmdline_changed,$(CXX_TO_O))) " ; \
+		echo -n "depfile_missing=$(call boolean,$(depfile_missing)) " ; \
+		echo "depfile_newer=$(call boolean,$(depfile_newer))")
+	$(if $(or \
+		$(file_missing),\
+		$(call cmdline_changed,$(CXX_TO_O)),\
+		$(depfile_missing),\
+		$(depfile_newer)),\
+		$(CXX_TO_O_DO))
\ No newline at end of file
diff --git a/mk/target/generic/rte.vars.mk b/mk/target/generic/rte.vars.mk
index 75a616a..128d4e2 100644
--- a/mk/target/generic/rte.vars.mk
+++ b/mk/target/generic/rte.vars.mk
@@ -138,7 +138,10 @@ endif
 LDFLAGS += -L$(RTE_SDK_BIN)/lib
 endif
 
+CXXFLAGS := $(CFLAGS)
+
 export CFLAGS
+export CXXFLAGS
 export LDFLAGS
 
 endif
diff --git a/mk/toolchain/clang/rte.vars.mk b/mk/toolchain/clang/rte.vars.mk
index 7749b99..2a7105e 100644
--- a/mk/toolchain/clang/rte.vars.mk
+++ b/mk/toolchain/clang/rte.vars.mk
@@ -32,8 +32,9 @@
 #
 # toolchain:
 #
-#   - define CC, LD, AR, AS, ... (overriden by cmdline value)
+#   - define CC, CXX, LD, AR, AS, ... (overriden by cmdline value)
 #   - define TOOLCHAIN_CFLAGS variable (overriden by cmdline value)
+#   - define TOOLCHAIN_CXXFLAGS variable (overriden by cmdline value)
 #   - define TOOLCHAIN_LDFLAGS variable (overriden by cmdline value)
 #   - define TOOLCHAIN_ASFLAGS variable (overriden by cmdline value)
 #
@@ -41,6 +42,7 @@
 CC        = $(CROSS)clang
 KERNELCC  = $(CROSS)gcc
 CPP       = $(CROSS)cpp
+CXX       = $(CROSS)clang++
 # for now, we don't use as but nasm.
 # AS      = $(CROSS)as
 AS        = nasm
@@ -57,10 +59,16 @@ HOSTCC    = $(CC)
 else
 HOSTCC    = clang
 endif
+ifeq ("$(origin CXX)", "command line")
+HOSTCXX    = $(CXX)
+else
+HOSTCXX    = clang++
+endif
 HOSTAS    = as
 
 TOOLCHAIN_ASFLAGS =
 TOOLCHAIN_CFLAGS =
+TOOLCHAIN_CXXFLAGS =
 TOOLCHAIN_LDFLAGS =
 
 WERROR_FLAGS := -W -Wall -Wstrict-prototypes -Wmissing-prototypes
@@ -79,5 +87,5 @@ include $(RTE_SDK)/mk/toolchain/$(RTE_TOOLCHAIN)/rte.toolchain-compat.mk
 # workaround clang bug with warning "missing field initializer" for "= {0}"
 WERROR_FLAGS += -Wno-missing-field-initializers
 
-export CC AS AR LD OBJCOPY OBJDUMP STRIP READELF
-export TOOLCHAIN_CFLAGS TOOLCHAIN_LDFLAGS TOOLCHAIN_ASFLAGS
+export CC CXX AS AR LD OBJCOPY OBJDUMP STRIP READELF
+export TOOLCHAIN_CFLAGS TOOLCHAIN_CXXFLAGS TOOLCHAIN_LDFLAGS TOOLCHAIN_ASFLAGS
diff --git a/mk/toolchain/gcc/rte.vars.mk b/mk/toolchain/gcc/rte.vars.mk
index ff70f3d..1961f6c 100644
--- a/mk/toolchain/gcc/rte.vars.mk
+++ b/mk/toolchain/gcc/rte.vars.mk
@@ -32,8 +32,9 @@
 #
 # toolchain:
 #
-#   - define CC, LD, AR, AS, ... (overriden by cmdline value)
+#   - define CC, CXX, LD, AR, AS, ... (overriden by cmdline value)
 #   - define TOOLCHAIN_CFLAGS variable (overriden by cmdline value)
+#   - define TOOLCHAIN_CXXFLAGS variable (overriden by cmdline value)
 #   - define TOOLCHAIN_LDFLAGS variable (overriden by cmdline value)
 #   - define TOOLCHAIN_ASFLAGS variable (overriden by cmdline value)
 #
@@ -41,6 +42,7 @@
 CC        = $(CROSS)gcc
 KERNELCC  = $(CROSS)gcc
 CPP       = $(CROSS)cpp
+CXX       = $(CROSS)g++
 # for now, we don't use as but nasm.
 # AS      = $(CROSS)as
 AS        = nasm
@@ -57,10 +59,16 @@ HOSTCC    = $(CC)
 else
 HOSTCC    = gcc
 endif
+ifeq ("$(origin CXX)", "command line")
+HOSTCXX    = $(CXX)
+else
+HOSTCXX    = g++
+endif
 HOSTAS    = as
 
 TOOLCHAIN_ASFLAGS =
 TOOLCHAIN_CFLAGS =
+TOOLCHAIN_CXXFLAGS =
 TOOLCHAIN_LDFLAGS =
 
 ifeq ($(CONFIG_RTE_LIBRTE_GCOV),y)
@@ -99,5 +107,5 @@ ifeq ($(shell test $(GCC_VERSION) -lt 47 && echo 1), 1)
 WERROR_FLAGS += -Wno-uninitialized
 endif
 
-export CC AS AR LD OBJCOPY OBJDUMP STRIP READELF
-export TOOLCHAIN_CFLAGS TOOLCHAIN_LDFLAGS TOOLCHAIN_ASFLAGS
+export CC CXX AS AR LD OBJCOPY OBJDUMP STRIP READELF
+export TOOLCHAIN_CFLAGS TOOLCHAIN_CXXFLAGS TOOLCHAIN_LDFLAGS TOOLCHAIN_ASFLAGS
diff --git a/mk/toolchain/icc/rte.vars.mk b/mk/toolchain/icc/rte.vars.mk
index ba69f1f..e9d6721 100644
--- a/mk/toolchain/icc/rte.vars.mk
+++ b/mk/toolchain/icc/rte.vars.mk
@@ -32,8 +32,9 @@
 #
 # toolchain:
 #
-#   - define CC, LD, AR, AS, ... (overriden by cmdline value)
+#   - define CC, CXX, LD, AR, AS, ... (overriden by cmdline value)
 #   - define TOOLCHAIN_CFLAGS variable (overriden by cmdline value)
+#   - define TOOLCHAIN_CXXFLAGS variable (overriden by cmdline value)
 #   - define TOOLCHAIN_LDFLAGS variable (overriden by cmdline value)
 #   - define TOOLCHAIN_ASFLAGS variable (overriden by cmdline value)
 #
@@ -42,6 +43,7 @@
 # x86->x86 compiler
 
 CC        = icc
+CXX       = icc
 KERNELCC  = gcc
 CPP       = cpp
 AS        = nasm
@@ -57,9 +59,11 @@ HOSTCC    = icc
 else
 HOSTCC    = gcc
 endif
+HOSTCXX   = icc
 HOSTAS    = as
 
 TOOLCHAIN_CFLAGS =
+TOOLCHAIN_CXXFLAGS =
 TOOLCHAIN_LDFLAGS =
 TOOLCHAIN_ASFLAGS =
 
@@ -83,5 +87,5 @@ ifeq ($(shell test $(ICC_MAJOR_VERSION) -ge 14 && echo 1), 1)
 	TOOLCHAIN_CFLAGS += -no-inline-max-size -no-inline-max-total-size
 endif
 
-export CC AS AR LD OBJCOPY OBJDUMP STRIP READELF
-export TOOLCHAIN_CFLAGS TOOLCHAIN_LDFLAGS TOOLCHAIN_ASFLAGS
+export CC CXX AS AR LD OBJCOPY OBJDUMP STRIP READELF
+export TOOLCHAIN_CFLAGS TOOLCHAIN_CXXFLAGS TOOLCHAIN_LDFLAGS TOOLCHAIN_ASFLAGS
-- 
2.5.5