From 73439e6f467d38a9c8a373fa2bb17672d57e82f5 Mon Sep 17 00:00:00 2001
From: Ben Walker <benjamin.walker@intel.com>
Date: Wed, 24 Jul 2019 10:15:08 -0700
Subject: [PATCH] build: Detect compiler toolchain in configure

We need to know this up front.

Change-Id: I3a9ceb90cf62eacbf3fdf518a9ccb4c4978b3a05
Signed-off-by: Ben Walker <benjamin.walker@intel.com>
Reviewed-on: https://review.gerrithub.io/c/spdk/spdk/+/463014
Reviewed-by: Tomasz Zawadzki <tomasz.zawadzki@intel.com>
Reviewed-by: Darek Stojaczyk <dariusz.stojaczyk@intel.com>
Reviewed-by: Paul Luse <paul.e.luse@intel.com>
Reviewed-by: Jim Harris <james.r.harris@intel.com>
Tested-by: SPDK CI Jenkins <sys_sgci@intel.com>
---
 Makefile             | 12 +++++-------
 configure            | 14 +++++++++++---
 mk/spdk.common.mk    |  4 ----
 scripts/detect_cc.sh | 15 +++++++++++++--
 4 files changed, 29 insertions(+), 16 deletions(-)

diff --git a/Makefile b/Makefile
index 565c20f52..d512d54da 100644
--- a/Makefile
+++ b/Makefile
@@ -43,7 +43,7 @@ DIRS-$(CONFIG_TESTS) += test
 DIRS-$(CONFIG_IPSEC_MB) += ipsecbuild
 DIRS-$(CONFIG_ISAL) += isalbuild
 
-.PHONY: all clean $(DIRS-y) include/spdk/config.h mk/config.mk mk/cc.mk \
+.PHONY: all clean $(DIRS-y) include/spdk/config.h mk/config.mk \
 	cc_version cxx_version .libs_only_other .ldflags ldflags install \
 	uninstall
 
@@ -72,9 +72,8 @@ LIB += isalbuild
 DPDK_DEPS += isalbuild
 endif
 
-all: $(DIRS-y)
+all: mk/cc.mk $(DIRS-y)
 clean: $(DIRS-y)
-	$(Q)rm -f mk/cc.mk
 	$(Q)rm -f include/spdk/config.h
 
 install: all
@@ -95,12 +94,11 @@ examples: $(LIB)
 pkgdep:
 	sh ./scripts/pkgdep.sh
 
-$(DIRS-y): mk/cc.mk include/spdk/config.h
+$(DIRS-y): include/spdk/config.h
 
 mk/cc.mk:
-	$(Q)scripts/detect_cc.sh --cc="$(CC)" --cxx="$(CXX)" --lto="$(CONFIG_LTO)" --ld="$(LD)" > $@.tmp; \
-	cmp -s $@.tmp $@ || mv $@.tmp $@ ; \
-	rm -f $@.tmp
+	$(Q)echo "Please run configure prior to make"
+	false
 
 include/spdk/config.h: mk/config.mk scripts/genconfig.py
 	$(Q)PYCMD=$$(cat PYTHON_COMMAND 2>/dev/null) ; \
diff --git a/configure b/configure
index 305d936c8..135074ef9 100755
--- a/configure
+++ b/configure
@@ -86,8 +86,11 @@ function usage()
 	echo ""
 	echo "Environment variables:"
 	echo ""
+	echo "CC                         C compiler"
 	echo "CFLAGS                     C compiler flags"
+	echo "CXX                        C++ compiler"
 	echo "CXXFLAGS                   C++ compiler flags"
+	echo "LD                         Linker"
 	echo "LDFLAGS                    Linker flags"
 	echo "DESTDIR                    Destination for 'make install'"
 	echo ""
@@ -100,8 +103,6 @@ declare -A CONFIG
 source CONFIG.sh
 rm CONFIG.sh
 
-BUILD_CMD="${CC:-cc} -o /dev/null -x c $CPPFLAGS $CFLAGS $LDFLAGS"
-
 function check_dir() {
 	arg="$1"
 	dir="${arg#*=}"
@@ -340,6 +341,14 @@ for i in "$@"; do
 	esac
 done
 
+# Detect the compiler toolchain
+scripts/detect_cc.sh --cc="$CC" --cxx="$CXX" --lto="${CONFIG[LTO]}" --ld="$LD" > mk/cc.mk
+
+CC=$(cat mk/cc.mk | grep "CC=" | cut -d "=" -f 2)
+CC_TYPE=$(cat mk/cc.mk | grep "CC_TYPE=" | cut -d "=" -f 2)
+
+BUILD_CMD="$CC -o /dev/null -x c $CPPFLAGS $CFLAGS $LDFLAGS"
+
 # Detect architecture and force no isal if non x86 archtecture
 arch=$(uname -m)
 if [[ $arch != x86_64* ]]; then
@@ -625,7 +634,6 @@ if [[ "${CONFIG[PGO_CAPTURE]}" = "y" && "${CONFIG[PGO_USE]}" = "y" ]]; then
 	echo "ERROR: --enable-pgo-capture and --enable-pgo-use are mutually exclusive."
 	exit 1
 elif [[ "${CONFIG[PGO_USE]}" = "y" ]]; then
-	CC_TYPE=$($rootdir/scripts/detect_cc.sh --cc="$CC" --cxx="$CXX" --lto="${CONFIG[LTO]}" --ld="$LD" | grep "CC_TYPE" | cut -d "=" -f 2)
 	if [[ "$CC_TYPE" = "clang" ]]; then
 		# For clang we need to run an extra step on gathered profiling data.
 		echo "Generating suitable profile data"
diff --git a/mk/spdk.common.mk b/mk/spdk.common.mk
index bf0be47fa..fb67677ac 100644
--- a/mk/spdk.common.mk
+++ b/mk/spdk.common.mk
@@ -138,10 +138,6 @@ endif
 ifeq ($(OS),FreeBSD)
 SYS_LIBS += -L/usr/local/lib
 COMMON_CFLAGS += -I/usr/local/include
-# Default to lld on FreeBSD
-ifeq ($(origin LD),default)
-LD = ld.lld
-endif
 endif
 
 # Attach only if PMDK lib specified with configure
diff --git a/scripts/detect_cc.sh b/scripts/detect_cc.sh
index e0f4bcc7f..1de93aa90 100755
--- a/scripts/detect_cc.sh
+++ b/scripts/detect_cc.sh
@@ -61,11 +61,22 @@ for i in "$@"; do
 	esac
 done
 
+OS=$(uname)
+
 : ${CC=cc}
 : ${CXX=c++}
-: ${LD=ld}
+: ${LD=}
 : ${LTO=n}
 
+if [ -z "$LD" ]; then
+	if [ "$OS" = "Linux" ]; then
+		LD=ld
+	fi
+	if [ "$OS" = "FreeBSD" ]; then
+		LD=ld.lld
+	fi
+fi
+
 CC_TYPE=$($CC -v 2>&1 | grep -o -E '\w+ version' | head -1 | awk '{ print $1 }')
 CXX_TYPE=$($CXX -v 2>&1 | grep -o -E '\w+ version' | head -1 | awk '{ print $1 }')
 if [ "$CC_TYPE" != "$CXX_TYPE" ]; then
@@ -104,7 +115,7 @@ fi
 
 function set_default() {
 	echo "ifeq (\$(origin $1),default)"
-	echo "$1 = $2"
+	echo "$1=$2"
 	echo "endif"
 	echo ""
 }