build: allow picking the env values for compiler variables

Don't force the usage of the hardcoded compiler values if those are
already set on the environment. This allows the Xen build system to
correctly pick CC/CXX values present on the environment, and fixes the
usage of those by the Gitlab CI test system.

Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
---
Cc: Andrew Cooper <andrew.cooper3@citrix.com>
Cc: George Dunlap <George.Dunlap@eu.citrix.com>
Cc: Ian Jackson <ian.jackson@eu.citrix.com>
Cc: Jan Beulich <jbeulich@suse.com>
Cc: Julien Grall <julien.grall@arm.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Stefano Stabellini <sstabellini@kernel.org>
Cc: Tim Deegan <tim@xen.org>
Cc: Wei Liu <wl@xen.org>

diff --git a/config/StdGNU.mk b/config/StdGNU.mk
index 7a6159021bca4b6fadeeff9dc6374e8d66615b7e..b3072f5b13f5c2a4bd944d627fabe4acd2046487 100644 (file)
--- a/config/StdGNU.mk
+++ b/config/StdGNU.mk
@@ -1,28 +1,31 @@
 # Use Clang/LLVM instead of GCC?
 clang     ?= n
 
-# If we are not cross-compiling, default HOSTC{C/XX} to C{C/XX}
-ifeq ($(XEN_TARGET_ARCH), $(XEN_COMPILE_ARCH))
-HOSTCC    ?= $(CC)
-HOSTCXX   ?= $(CXX)
-endif
-
 AS         = $(CROSS_COMPILE)as
 LD         = $(CROSS_COMPILE)ld
 ifeq ($(clang),y)
 gcc       := n
-CC         = $(CROSS_COMPILE)clang
-CXX        = $(CROSS_COMPILE)clang++
-LD_LTO     = $(CROSS_COMPILE)llvm-ld
-HOSTCC    ?= clang
-HOSTCXX   ?= clang++
+DEF_CC     = clang
+DEF_CXX    = clang++
+LD_LTO    ?= $(CROSS_COMPILE)llvm-ld
 else
 gcc       := y
-CC         = $(CROSS_COMPILE)gcc
-CXX        = $(CROSS_COMPILE)g++
-LD_LTO     = $(CROSS_COMPILE)ld
-HOSTCC    ?= gcc
-HOSTCXX   ?= g++
+DEF_CC     = gcc
+DEF_CXX    = g++
+LD_LTO    ?= $(CROSS_COMPILE)ld
+endif
+
+CC        ?= $(CROSS_COMPILE)$(DEF_CC)
+CXX       ?= $(CROSS_COMPILE)$(DEF_CXX)
+
+# If we are not cross-compiling, default HOSTC{C/XX} to C{C/XX}
+# else use the default values if unset
+ifeq ($(XEN_TARGET_ARCH), $(XEN_COMPILE_ARCH))
+HOSTCC    ?= $(CC)
+HOSTCXX   ?= $(CXX)
+else
+HOSTCC    ?= $(DEF_CC)
+HOSTCXX   ?= $(DEF_CXX)
 endif
 
 CPP        = $(CC) -E

diff --git a/scripts/travis-build b/scripts/travis-build
index 0cb15a89e4ee970ec269b9f9276e3388ce4bb34c..a264e286b2a25b855b27f260074e5d8cc85cb657 100755 (executable)
--- a/scripts/travis-build
+++ b/scripts/travis-build
@@ -1,6 +1,14 @@
 #!/bin/bash -ex
 
+# Set HOST{CC/CXX} in case we are cross building
+export HOSTCC=${CC}
+export HOSTCXX=${CXX}
+# Prefix environment CC/CXX with CROSS_COMPILE if present
+export CC=${CROSS_COMPILE}${CC}
+export CXX=${CROSS_COMPILE}${CXX}
+
 $CC --version
+[[ "${CC}" != "${HOSTCC}" ]] && $HOSTCC --version
 
 # random config or default config
 if [[ "${RANDCONFIG}" == "y" ]]; then