[NaCl SDK] Make is easier to override linux host compiler

Switch from HOST_CC/HOST_CC/etc to the more standard
CC/CXX/etc for the names of the varaibles in the
SDK example build system.

This allow things like "CXX=clang++ make TOOLCHAIN=linux".

Also, fix kernel_wrap.h so that it compiles with
clang++ on desktop linux.

R=binji@chromium.org

Review URL: https://codereview.chromium.org/85813004

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@237472 0039d316-1c4b-4281-b951-d872f2087c98

3 files changed, 22 insertions, 23 deletions

diff --git a/native_client_sdk/src/libraries/nacl_io/kernel_wrap.h b/native_client_sdk/src/libraries/nacl_io/kernel_wrap.h
index 39eb863..e8e4e99 100644
--- a/native_client_sdk/src/libraries/nacl_io/kernel_wrap.h
+++ b/native_client_sdk/src/libraries/nacl_io/kernel_wrap.h
@@ -56,9 +56,9 @@ int _fstat32(int fd, struct _stat32* buf);
 int _fstat64(int fd, struct _stat64* buf);
 int _fstat32i64(int fd, struct _stat32i64* buf);
 int _fstat64i32(int fd, struct _stat64i32* buf);
-#else
+#elif !defined(__linux__)
 struct stat;
-int fstat(int fd, struct stat* buf) NOTHROW;
+extern int fstat(int fd, struct stat* buf) NOTHROW;
 #endif
 int fsync(int fd);
 int ftruncate(int fd, off_t length) NOTHROW;
@@ -90,8 +90,8 @@ int _stat32(const char* path, struct _stat32* buf);
 int _stat64(const char* path, struct _stat64* buf);
 int _stat32i64(const char* path, struct _stat32i64* buf);
 int _stat64i32(const char* path, struct _stat64i32* buf);
-#else
-int stat(const char* path, struct stat* buf) NOTHROW;
+#elif !defined(__linux__)
+extern int stat(const char* path, struct stat* buf) NOTHROW;
 #endif
 int symlink(const char* oldpath, const char* newpath) NOTHROW;
 int umount(const char* path) NOTHROW;
diff --git a/native_client_sdk/src/tools/host_gcc.mk b/native_client_sdk/src/tools/host_gcc.mk
index fad4a87..f474054 100644
--- a/native_client_sdk/src/tools/host_gcc.mk
+++ b/native_client_sdk/src/tools/host_gcc.mk
@@ -14,17 +14,17 @@
 # We use the C++ compiler for everything and then use the -Wl,-as-needed flag
 # in the linker to drop libc++ unless it's actually needed.
 #
-HOST_CC ?= $(NACL_COMPILER_PREFIX) gcc
-HOST_CXX ?= $(NACL_COMPILER_PREFIX) g++
-HOST_LINK ?= g++
-HOST_LIB ?= ar
-HOST_STRIP ?= strip
+CC ?= $(NACL_COMPILER_PREFIX) gcc
+CXX ?= $(NACL_COMPILER_PREFIX) g++
+LINK ?= $(CXX)
+LIB ?= ar
+STRIP ?= strip
 
 # Adding -Wl,-Bsymbolic means that symbols defined within the module are always
 # used by the moulde, and not shadowed by symbols already loaded in, for
 # exmaple, libc.  Without this the libc symbols (or anything injected with
 # LD_PRELOAD will take precedence).
-LDFLAGS ?= -Wl,-Map,$(OUTDIR)/$(TARGET).map -Wl,-Bsymbolic
+HOST_LDFLAGS ?= -Wl,-Map,$(OUTDIR)/$(TARGET).map -Wl,-Bsymbolic
 
 ifeq (,$(findstring gcc,$(shell $(WHICH) gcc)))
 $(warning To skip the host build use:)
@@ -32,9 +32,8 @@ $(warning "make all_versions NO_HOST_BUILDS=1")
 $(error Unable to find gcc in PATH while building Host build)
 endif
 
-
-LINUX_WARNINGS ?= -Wno-long-long -Wall -Werror
-LINUX_CFLAGS = -fPIC -pthread $(LINUX_WARNINGS) -I$(NACL_SDK_ROOT)/include -I$(NACL_SDK_ROOT)/include/linux
+HOST_WARNINGS ?= -Wno-long-long -Wall -Werror
+HOST_CFLAGS = -fPIC -pthread $(HOST_WARNINGS) -I$(NACL_SDK_ROOT)/include -I$(NACL_SDK_ROOT)/include/linux
 
 
 #
@@ -46,14 +45,14 @@ LINUX_CFLAGS = -fPIC -pthread $(LINUX_WARNINGS) -I$(NACL_SDK_ROOT)/include -I$(N
 define C_COMPILER_RULE
 -include $(call SRC_TO_DEP,$(1))
 $(call SRC_TO_OBJ,$(1)): $(1) $(TOP_MAKE) | $(dir $(call SRC_TO_OBJ,$(1)))dir.stamp
-	$(call LOG,CC  ,$$@,$(HOST_CC) -o $$@ -c $$< -fPIC $(POSIX_FLAGS) $(LINUX_CFLAGS) $(2))
+	$(call LOG,CC  ,$$@,$(CC) -o $$@ -c $$< -fPIC $(POSIX_FLAGS) $(HOST_CFLAGS) $(2))
 	@$(FIXDEPS) $(call SRC_TO_DEP_PRE_FIXUP,$(1))
 endef
 
 define CXX_COMPILER_RULE
 -include $(call SRC_TO_DEP,$(1))
 $(call SRC_TO_OBJ,$(1)): $(1) $(TOP_MAKE) | $(dir $(call SRC_TO_OBJ,$(1)))dir.stamp
-	$(call LOG,CXX ,$$@,$(HOST_CXX) -o $$@ -c $$< -fPIC $(POSIX_FLAGS) $(LINUX_CFLAGS) $(2))
+	$(call LOG,CXX ,$$@,$(CXX) -o $$@ -c $$< -fPIC $(POSIX_FLAGS) $(HOST_CFLAGS) $(2))
 	@$(FIXDEPS) $(call SRC_TO_DEP_PRE_FIXUP,$(1))
 endef
 
@@ -100,7 +99,7 @@ all: $(LIBDIR)/$(OSNAME)_host/$(CONFIG)/lib$(1).a
 $(LIBDIR)/$(OSNAME)_host/$(CONFIG)/lib$(1).a: $(foreach src,$(2),$(call SRC_TO_OBJ,$(src)))
 	$(MKDIR) -p $$(dir $$@)
 	$(RM) -f $$@
-	$(call LOG,LIB,$$@,$(HOST_LIB) -cr $$@ $$^)
+	$(call LOG,LIB,$$@,$(LIB) -cr $$@ $$^)
 endef
 
 
@@ -112,19 +111,19 @@ endef
 # $3 = List of libs
 # $4 = List of deps
 # $5 = List of lib dirs
-# $6 = Other Linker Args
+# $6 = Linker Args
 #
 ifdef STANDALONE
 define LINKER_RULE
 all: $(1)
 $(1): $(2) $(foreach dep,$(4),$(STAMPDIR)/$(dep).stamp)
-	$(call LOG,LINK,$$@,$(HOST_LINK) -o $(1) $(2) $(LDFLAGS) $(NACL_LDFLAGS) $(foreach path,$(5),-L$(path)/$(OSNAME)_host)/$(CONFIG) $(foreach lib,$(3),-l$(lib)) $(6))
+	$(call LOG,LINK,$$@,$(LINK) -o $(1) $(2) $(HOST_LDFLAGS) $(NACL_LDFLAGS) $(LDFLAGS) $(foreach path,$(5),-L$(path)/$(OSNAME)_host)/$(CONFIG) $(foreach lib,$(3),-l$(lib)) $(6))
 endef
 else
 define LINKER_RULE
 all: $(1)
 $(1): $(2) $(foreach dep,$(4),$(STAMPDIR)/$(dep).stamp)
-	$(call LOG,LINK,$$@,$(HOST_LINK) -shared -o $(1) $(2) $(LDFLAGS) $(NACL_LDFLAGS) $(foreach path,$(5),-L$(path)/$(OSNAME)_host)/$(CONFIG) $(foreach lib,$(3),-l$(lib)) $(6))
+	$(call LOG,LINK,$$@,$(LINK) -shared -o $(1) $(2) $(HOST_LDFLAGS) $(NACL_LDFLAGS) $(LDFLAGS) $(foreach path,$(5),-L$(path)/$(OSNAME)_host)/$(CONFIG) $(foreach lib,$(3),-l$(lib)) $(6))
 endef
 endif
 
@@ -157,7 +156,7 @@ all: $(LIB_LIST) $(DEPS_LIST)
 define STRIP_RULE
 all: $(OUTDIR)/$(1)$(HOST_EXT)
 $(OUTDIR)/$(1)$(HOST_EXT): $(OUTDIR)/$(2)$(HOST_EXT)
-	$(call LOG,STRIP,$$@,$(HOST_STRIP) --strip-debug -o $$@ $$^)
+	$(call LOG,STRIP,$$@,$(STRIP) --strip-debug -o $$@ $$^)
 endef
 
 
diff --git a/native_client_sdk/src/tools/nacl_gcc.mk b/native_client_sdk/src/tools/nacl_gcc.mk
index d758a88..2f51e36 100644
--- a/native_client_sdk/src/tools/nacl_gcc.mk
+++ b/native_client_sdk/src/tools/nacl_gcc.mk
@@ -178,7 +178,7 @@ define SO_LINKER_RULE
 ifneq (,$(findstring x86_32,$(ARCHES)))
 all: $(OUTDIR)/lib$(1)_x86_32.so
 $(OUTDIR)/lib$(1)_x86_32.so: $(foreach src,$(2),$(call SRC_TO_OBJ,$(src),_x86_32_pic)) $(foreach dep,$(4),$(STAMPDIR)/$(dep).stamp)
-	$(call LOG,LINK,$$@,$(X86_32_LINK) -o $$@ $$(filter %.o,$$^) $(LDFLAGS_SHARED) -m32 $(NACL_LDFLAGS) $(X86_32_LDFLAGS) $(foreach path,$(5),-L$(path)/$(TOOLCHAIN)_x86_32/$(CONFIG)) $(foreach lib,$(3),-l$(lib)))
+	$(call LOG,LINK,$$@,$(X86_32_LINK) -o $$@ $$(filter %.o,$$^) $(LDFLAGS_SHARED) -m32 $(NACL_LDFLAGS) $(X86_32_LDFLAGS) $(LDFLAGS) $(foreach path,$(5),-L$(path)/$(TOOLCHAIN)_x86_32/$(CONFIG)) $(foreach lib,$(3),-l$(lib)))
 	$(call LOG,VALIDATE,$$@,$(NCVAL) $$@)
 
 $(STAMPDIR)/$(1).stamp: $(LIBDIR)/$(TOOLCHAIN)_x86_32/$(CONFIG)/lib$(1).so
@@ -195,7 +195,7 @@ endif
 ifneq (,$(findstring x86_64,$(ARCHES)))
 all: $(OUTDIR)/lib$(1)_x86_64.so
 $(OUTDIR)/lib$(1)_x86_64.so: $(foreach src,$(2),$(call SRC_TO_OBJ,$(src),_x86_64_pic)) $(foreach dep,$(4),$(STAMPDIR)/$(dep).stamp)
-	$(call LOG,LINK,$$@,$(X86_32_LINK) -o $$@ $$(filter %.o,$$^) $(LDFLAGS_SHARED) -m64 $(NACL_LDFLAGS) $(X86_64_LDFLAGS) $(foreach path,$(5),-L$(path)/$(TOOLCHAIN)_x86_64/$(CONFIG)) $(foreach lib,$(3),-l$(lib)))
+	$(call LOG,LINK,$$@,$(X86_32_LINK) -o $$@ $$(filter %.o,$$^) $(LDFLAGS_SHARED) -m64 $(NACL_LDFLAGS) $(X86_64_LDFLAGS) $(LDFLAGS) $(foreach path,$(5),-L$(path)/$(TOOLCHAIN)_x86_64/$(CONFIG)) $(foreach lib,$(3),-l$(lib)))
 	$(call LOG,VALIDATE,$$@,$(NCVAL) $$@)
 
 $(STAMPDIR)/$(1).stamp: $(LIBDIR)/$(TOOLCHAIN)_x86_64/$(CONFIG)/lib$(1).so
@@ -288,7 +288,7 @@ endef
 # $2 = List of Sources
 # $3 = List of LIBS
 # $4 = List of DEPS
-# $5 = POSIX Link Flags
+# $5 = Link Flags
 # $6 = Library Paths
 #
 define LINKER_RULE