[Qemu-devel] [RFC PATCH v2 01/11] configure: Support configuring c++ compiler

[Tomoki Sekiyama <tsekiyam@redhat.com>]

Add configuration for c++ compiler (${corss_prefix}g++ as default) in
configure and Makefiles.

Currently, usage of c++ language is only for access to Windows VSS
using COM+ services in qemu-guest-agent for Windows.

Signed-off-by: Tomoki Sekiyama <tomoki.sekiyama@hds.com>
---
 configure |    6 ++++++
 rules.mak |    9 ++++++++-
 2 files changed, 14 insertions(+), 1 deletion(-)

diff --git a/configure b/configure
index 1ed939a..b74572f 100755
--- a/configure
+++ b/configure
@@ -278,6 +278,7 @@ else
   cc="${CC-${cross_prefix}gcc}"
 fi
 
+cxx="${CXX-${cross_prefix}g++}"
 ar="${AR-${cross_prefix}ar}"
 as="${AS-${cross_prefix}as}"
 cpp="${CPP-$cc -E}"
@@ -615,6 +616,8 @@ for opt do
   ;;
   --host-cc=*) host_cc="$optarg"
   ;;
+  --cxx=*) cxx="$optarg"
+  ;;
   --objcc=*) objcc="$optarg"
   ;;
   --make=*) make="$optarg"
@@ -1053,6 +1056,7 @@ echo "  --cross-prefix=PREFIX    use PREFIX for compile tools [$cross_prefix]"
 echo "  --cc=CC                  use C compiler CC [$cc]"
 echo "  --host-cc=CC             use C compiler CC [$host_cc] for code run at"
 echo "                           build time"
+echo "  --cxx=CXX                use C++ compiler CXX [$cxx]"
 echo "  --objcc=OBJCC            use Objective-C compiler OBJCC [$objcc]"
 echo "  --extra-cflags=CFLAGS    append extra C compiler flags QEMU_CFLAGS"
 echo "  --extra-ldflags=LDFLAGS  append extra linker flags LDFLAGS"
@@ -3349,6 +3353,7 @@ fi
 echo "Source path       $source_path"
 echo "C compiler        $cc"
 echo "Host C compiler   $host_cc"
+echo "C++ compiler      $cxx"
 echo "Objective-C compiler $objcc"
 echo "CFLAGS            $CFLAGS"
 echo "QEMU_CFLAGS       $QEMU_CFLAGS"
@@ -3860,6 +3865,7 @@ echo "PYTHON=$python" >> $config_host_mak
 echo "CC=$cc" >> $config_host_mak
 echo "CC_I386=$cc_i386" >> $config_host_mak
 echo "HOST_CC=$host_cc" >> $config_host_mak
+echo "CXX=$cxx" >> $config_host_mak
 echo "OBJCC=$objcc" >> $config_host_mak
 echo "AR=$ar" >> $config_host_mak
 echo "AS=$as" >> $config_host_mak
diff --git a/rules.mak b/rules.mak
index edc2552..9dfd23a 100644
--- a/rules.mak
+++ b/rules.mak
@@ -8,9 +8,13 @@ MAKEFLAGS += -rR
 %.d:
 %.h:
 %.c:
+%.cpp:
 %.m:
 %.mak:
 
+# Flags for C++ compilation
+QEMU_CXXFLAGS = -D__STDC_LIMIT_MACROS $(filter-out -Wstrict-prototypes -Wmissing-prototypes -Wnested-externs -Wold-style-declaration -Wold-style-definition -Wredundant-decls, $(QEMU_CFLAGS))
+
 # Flags for dependency generation
 QEMU_DGFLAGS += -MMD -MP -MT $@ -MF $(*D)/$(*F).d
 
@@ -45,6 +49,9 @@ endif
 %.o: %.asm
 	$(call quiet-command,$(AS) $(ASFLAGS) -o $@ $<,"  AS    $(TARGET_DIR)$@")
 
+%.o: %.cpp
+	$(call quiet-command,$(CXX) $(QEMU_INCLUDES) $(QEMU_CXXFLAGS) $(QEMU_DGFLAGS) $(CFLAGS) -c -o $@ $<,"  CXX   $(TARGET_DIR)$@")
+
 %.o: %.m
 	$(call quiet-command,$(OBJCC) $(QEMU_INCLUDES) $(QEMU_CFLAGS) $(QEMU_DGFLAGS) $(CFLAGS) -c -o $@ $<,"  OBJC  $(TARGET_DIR)$@")
 
@@ -65,7 +72,7 @@ quiet-command = $(if $(V),$1,$(if $(2),@echo $2 && $1, @$1))
 cc-option = $(if $(shell $(CC) $1 $2 -S -o /dev/null -xc /dev/null \
               >/dev/null 2>&1 && echo OK), $2, $3)
 
-VPATH_SUFFIXES = %.c %.h %.S %.m %.mak %.texi %.sh
+VPATH_SUFFIXES = %.c %.h %.S %.cpp %.m %.mak %.texi %.sh
 set-vpath = $(if $1,$(foreach PATTERN,$(VPATH_SUFFIXES),$(eval vpath $(PATTERN) $1)))
 
 # find-in-path