Fix various _FOR_BUILD and related variables

When doing a FOR_BUILD thing, you have to override CFLAGS with
CFLAGS_FOR_BUILD. And if you use C++, you also have to override
CXXFLAGS with CXXFLAGS_FOR_BUILD.
Without this, when building for mingw, you end up trying to use
the mingw headers for a host build.

The same goes for other variables as well, such as CPPFLAGS,
CPP, and GMPINC.

Upstream-Status: Pending

Signed-off-by: Peter Seebach <peter.seebach@windriver.com>
Signed-off-by: Mark Hatle <mark.hatle@windriver.com>

diff --git a/Makefile.in b/Makefile.in
index 9370174..011c29a 100644
--- a/Makefile.in
+++ b/Makefile.in
@@ -152,6 +152,7 @@ BUILD_EXPORTS = \
 	CPP="$(CC_FOR_BUILD) -E"; export CPP; \
 	CFLAGS="$(CFLAGS_FOR_BUILD)"; export CFLAGS; \
 	CONFIG_SHELL="$(SHELL)"; export CONFIG_SHELL; \
+	CPPFLAGS="$(CPPFLAGS_FOR_BUILD)"; export CPPFLAGS; \
 	CXX="$(CXX_FOR_BUILD)"; export CXX; \
 	CXXFLAGS="$(CXXFLAGS_FOR_BUILD)"; export CXXFLAGS; \
 	GCJ="$(GCJ_FOR_BUILD)"; export GCJ; \
@@ -170,6 +171,9 @@ BUILD_EXPORTS = \
 # built for the build system to override those in BASE_FLAGS_TO_PASS.
 EXTRA_BUILD_FLAGS = \
 	CFLAGS="$(CFLAGS_FOR_BUILD)" \
+	CXXFLAGS="$(CXXFLAGS_FOR_BUILD)" \
+	CPP="$(CC_FOR_BUILD) -E" \
+	CPPFLAGS="$(CPPFLAGS_FOR_BUILD)" \
 	LDFLAGS="$(LDFLAGS_FOR_BUILD)"
 
 # This is the list of directories to built for the host system.
@@ -187,6 +191,7 @@ HOST_SUBDIR = @host_subdir@
 HOST_EXPORTS = \
 	$(BASE_EXPORTS) \
 	CC="$(CC)"; export CC; \
+	CPP="$(CC) -E"; export CPP; \
 	ADA_CFLAGS="$(ADA_CFLAGS)"; export ADA_CFLAGS; \
 	CFLAGS="$(CFLAGS)"; export CFLAGS; \
 	CONFIG_SHELL="$(SHELL)"; export CONFIG_SHELL; \
@@ -711,6 +715,7 @@ BASE_FLAGS_TO_PASS = \
 	"CC_FOR_BUILD=$(CC_FOR_BUILD)" \
 	"CFLAGS_FOR_BUILD=$(CFLAGS_FOR_BUILD)" \
 	"CXX_FOR_BUILD=$(CXX_FOR_BUILD)" \
+	"CXXFLAGS_FOR_BUILD=$(CXXFLAGS_FOR_BUILD)" \
 	"EXPECT=$(EXPECT)" \
 	"FLEX=$(FLEX)" \
 	"INSTALL=$(INSTALL)" \
diff --git a/Makefile.tpl b/Makefile.tpl
index 1ea1954..78a59c3 100644
--- a/Makefile.tpl
+++ b/Makefile.tpl
@@ -154,6 +154,7 @@ BUILD_EXPORTS = \
 	CC="$(CC_FOR_BUILD)"; export CC; \
 	CFLAGS="$(CFLAGS_FOR_BUILD)"; export CFLAGS; \
 	CONFIG_SHELL="$(SHELL)"; export CONFIG_SHELL; \
+	CPPFLAGS="$(CPPFLAGS_FOR_BUILD)"; export CPPFLAGS; \
 	CXX="$(CXX_FOR_BUILD)"; export CXX; \
 	CXXFLAGS="$(CXXFLAGS_FOR_BUILD)"; export CXXFLAGS; \
 	GCJ="$(GCJ_FOR_BUILD)"; export GCJ; \
@@ -172,6 +173,9 @@ BUILD_EXPORTS = \
 # built for the build system to override those in BASE_FLAGS_TO_PASS.
 EXTRA_BUILD_FLAGS = \
 	CFLAGS="$(CFLAGS_FOR_BUILD)" \
+	CXXFLAGS="$(CXXFLAGS_FOR_BUILD)" \
+	CPP="$(CC_FOR_BUILD) -E" \
+	CPPFLAGS="$(CPPFLAGS_FOR_BUILD)" \
 	LDFLAGS="$(LDFLAGS_FOR_BUILD)"
 
 # This is the list of directories to built for the host system.
@@ -189,6 +193,7 @@ HOST_SUBDIR = @host_subdir@
 HOST_EXPORTS = \
 	$(BASE_EXPORTS) \
 	CC="$(CC)"; export CC; \
+	CPP="$(CC) -E"; export CPP; \
 	ADA_CFLAGS="$(ADA_CFLAGS)"; export ADA_CFLAGS; \
 	CFLAGS="$(CFLAGS)"; export CFLAGS; \
 	CONFIG_SHELL="$(SHELL)"; export CONFIG_SHELL; \
diff --git a/gcc/Makefile.in b/gcc/Makefile.in
index cd5bc4a..98ae4f4 100644
--- a/gcc/Makefile.in
+++ b/gcc/Makefile.in
@@ -762,7 +762,7 @@ BUILD_LINKERFLAGS = $(BUILD_CXXFLAGS)
 # Native linker and preprocessor flags.  For x-fragment overrides.
 BUILD_LDFLAGS=@BUILD_LDFLAGS@
 BUILD_CPPFLAGS= -I. -I$(@D) -I$(srcdir) -I$(srcdir)/$(@D) \
-		-I$(srcdir)/../include @INCINTL@ $(CPPINC) $(CPPFLAGS)
+		-I$(srcdir)/../include @INCINTL@ $(CPPINC) $(CPPFLAGS_FOR_BUILD)
 
 # Actual name to use when installing a native compiler.
 GCC_INSTALL_NAME := $(shell echo gcc|sed '$(program_transform_name)')
diff --git a/gcc/configure b/gcc/configure
index c7ac14b..5ac63e4 100755
--- a/gcc/configure
+++ b/gcc/configure
@@ -11521,7 +11521,7 @@ else
 	CC="${CC_FOR_BUILD}" CFLAGS="${CFLAGS_FOR_BUILD}" \
 	CXX="${CXX_FOR_BUILD}" CXXFLAGS="${CXXFLAGS_FOR_BUILD}" \
 	LD="${LD_FOR_BUILD}" LDFLAGS="${LDFLAGS_FOR_BUILD}" \
-	GMPINC="" CPPFLAGS="${CPPFLAGS} -DGENERATOR_FILE" \
+	GMPINC="" CPPFLAGS="${CPPFLAGS_FOR_BUILD} -DGENERATOR_FILE" \
 	${realsrcdir}/configure \
 		--enable-languages=${enable_languages-all} \
 		--target=$target_alias --host=$build_alias --build=$build_alias
diff --git a/gcc/configure.ac b/gcc/configure.ac
index 50856e6..17a4dfd 100644
--- a/gcc/configure.ac
+++ b/gcc/configure.ac
@@ -1633,7 +1633,7 @@ else
 	CC="${CC_FOR_BUILD}" CFLAGS="${CFLAGS_FOR_BUILD}" \
 	CXX="${CXX_FOR_BUILD}" CXXFLAGS="${CXXFLAGS_FOR_BUILD}" \
 	LD="${LD_FOR_BUILD}" LDFLAGS="${LDFLAGS_FOR_BUILD}" \
-	GMPINC="" CPPFLAGS="${CPPFLAGS} -DGENERATOR_FILE" \
+	GMPINC="" CPPFLAGS="${CPPFLAGS_FOR_BUILD} -DGENERATOR_FILE" \
 	${realsrcdir}/configure \
 		--enable-languages=${enable_languages-all} \
 		--target=$target_alias --host=$build_alias --build=$build_alias