Kbuild fixes for v5.8 (3rd)

- do not use non-portable strsep() in a host program
 
  - fix single target builds for external modules
 
  - change Clang's --prefix option to make it work for the latest Clang
 -----BEGIN PGP SIGNATURE-----
 
 iQJJBAABCgAzFiEEbmPs18K1szRHjPqEPYsBB53g2wYFAl8d53AVHG1hc2FoaXJv
 eUBrZXJuZWwub3JnAAoJED2LAQed4NsGRdgQAJZLfQfQuKOpvtV7OBmVffbI8rdx
 anZKWJ/ILtrlc6UkAP5eHlMw6x/uP+UjaiOSDbfHiiP4OfuEHjlfUvS36+rWCKtb
 g0F3Pf1EqABYrNScL8/n0K8GS++REf6X8DUqZ7MYtJFftPVsbkaXuxIFM9Et1U6d
 vrfvxH8z4S4/LzgANcrYd2sR0eLZNnoLpQb6qBWLLIdNXtF4xNQ17y0B4Ihpr/o3
 PnQu9ttJ8Xoh1kCMfkQkQKh3oL6rT7Tay7KB5AfABb0RHX5eI/x7vSThAxtgTzNA
 dOUxKeBFpPInw3XG8rTjRnr0msRGhFbDxC2zygiAv5Y+nz7D/ct9m7tAtCK1Zurn
 lLTkkXAcchbdk3z57wzEiiRS3ylE/b+Jn38BIQIbefwPYJpuIkFCfcvbmo5Z2rXs
 d/0x1co/PYcSCvlZJlLp8VpeM9yeZ0xXlmERJbPjFXEyh7XQw9NwShzvTPhaNjV8
 Ax4ZZ+U9m9/IJsO103HOTdFlFo3gmhgR8uVCsZ0+VT1VZtZ5PN5olJKcgOv0YrW3
 4/nqK7NsNJLMZEPImyam7UMUIspi8V8x6ujwgglBPftRIaYpHpG6sQ75deyqGVMh
 MSxiw/fysexABBUEC3QEh65qvLEcwzc8YN59TfCaPLJiN/B+2/nayqns8ozfSVzl
 PAYnj3FFWjZ9ij/B
 =zebF
 -----END PGP SIGNATURE-----

Merge tag 'kbuild-fixes-v5.8-3' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild into master

Pull Kbuild fixes from Masahiro Yamada:

 - do not use non-portable strsep() in a host program

 - fix single target builds for external modules

 - change Clang's --prefix option to make it work for the latest Clang

* tag 'kbuild-fixes-v5.8-3' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild:
  Makefile: Fix GCC_TOOLCHAIN_DIR prefix for Clang cross compilation
  kbuild: fix single target builds for external modules
  modpost: remove use of non-standard strsep() in HOSTCC code

Makefile

@@ -567,7 +567,7 @@ ifneq ($(shell $(CC) --version 2>&1 | head -n 1 | grep clang),)
 ifneq ($(CROSS_COMPILE),)
 CLANG_FLAGS	+= --target=$(notdir $(CROSS_COMPILE:%-=%))
 GCC_TOOLCHAIN_DIR := $(dir $(shell which $(CROSS_COMPILE)elfedit))
-CLANG_FLAGS	+= --prefix=$(GCC_TOOLCHAIN_DIR)
+CLANG_FLAGS	+= --prefix=$(GCC_TOOLCHAIN_DIR)$(notdir $(CROSS_COMPILE))
 GCC_TOOLCHAIN	:= $(realpath $(GCC_TOOLCHAIN_DIR)/..)
 endif
 ifneq ($(GCC_TOOLCHAIN),)
@@ -1754,7 +1754,7 @@ PHONY += descend $(build-dirs)
 descend: $(build-dirs)
 $(build-dirs): prepare
 	$(Q)$(MAKE) $(build)=$@ \
-	single-build=$(if $(filter-out $@/, $(filter $@/%, $(single-no-ko))),1) \
+	single-build=$(if $(filter-out $@/, $(filter $@/%, $(KBUILD_SINGLE_TARGETS))),1) \
 	need-builtin=1 need-modorder=1
 
 clean-dirs := $(addprefix _clean_, $(clean-dirs))

scripts/mod/modpost.c

@@ -138,11 +138,19 @@ char *read_text_file(const char *filename)
 
 char *get_line(char **stringp)
 {
+	char *orig = *stringp, *next;
+
 	/* do not return the unwanted extra line at EOF */
-	if (*stringp && **stringp == '\0')
+	if (!orig || *orig == '\0')
 		return NULL;
 
-	return strsep(stringp, "\n");
+	next = strchr(orig, '\n');
+	if (next)
+		*next++ = '\0';
+
+	*stringp = next;
+
+	return orig;
 }
 
 /* A list of all modules we processed */