[Xen-devel] [PATCH for-4.13] x86: re-order clang no integrated assembler tests

[Roger Pau Monne <roger.pau@xxxxxxxxxx>]

The tests to check whether the integrated assembler is capable of
building Xen should be performed before testing any assembler
features, or else the feature specific tests would be stale if the
integrated assembler is disabled afterwards.

Fixes: ef286f67787a ('x86: move and fix clang .skip check')
Reported-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
Reported-by: Doug Goldstein <cardoe@xxxxxxxxxx>
signed-off-by: Roger Pau Monné <roger.pau@xxxxxxxxxx>
---
Cc: Juergen Gross <jgross@xxxxxxxx>
---
 xen/arch/x86/Rules.mk | 43 ++++++++++++++++++++++++-------------------
 1 file changed, 24 insertions(+), 19 deletions(-)

diff --git a/xen/arch/x86/Rules.mk b/xen/arch/x86/Rules.mk
index a3c5eb9de7..92fdbe9d68 100644
--- a/xen/arch/x86/Rules.mk
+++ b/xen/arch/x86/Rules.mk
@@ -12,6 +12,30 @@ CFLAGS += '-D__OBJECT_LABEL__=$(subst /,$$,$(subst 
-,_,$(subst $(BASEDIR)/,,$(CU
 # Prevent floating-point variables from creeping into Xen.
 CFLAGS += -msoft-float
 
+ifeq ($(clang),y)
+# Note: Any test which adds -no-integrated-as will cause subsequent tests to
+# succeed, and not trigger further additions.
+#
+# The tests to select whether the integrated assembler is usable need to happen
+# before testing any assembler features, or else the result of the tests would
+# be stale if the integrated assembler is not used.
+
+# Older clang's built-in assembler doesn't understand .skip with labels:
+# https://bugs.llvm.org/show_bug.cgi?id=27369
+$(call as-option-add,CFLAGS,CC,".L0: .L1: .skip (.L1 - .L0)",,\
+                     -no-integrated-as)
+
+# Check whether clang asm()-s support .include.
+$(call as-option-add,CFLAGS,CC,".include \"asm/indirect_thunk_asm.h\"",,\
+                     -no-integrated-as)
+
+# Check whether clang keeps .macro-s between asm()-s:
+# https://bugs.llvm.org/show_bug.cgi?id=36110
+$(call as-option-add,CFLAGS,CC,\
+                     ".macro FOO;.endm"$$(close); asm volatile $$(open)".macro 
FOO;.endm",\
+                     -no-integrated-as)
+endif
+
 $(call cc-options-add,CFLAGS,CC,$(EMBEDDED_EXTRA_CFLAGS))
 $(call cc-option-add,CFLAGS,CC,-Wnested-externs)
 $(call as-option-add,CFLAGS,CC,"vmcall",-DHAVE_AS_VMX)
@@ -70,22 +94,3 @@ endif
 # Set up the assembler include path properly for older toolchains.
 CFLAGS += -Wa,-I$(BASEDIR)/include
 
-ifeq ($(clang),y)
-# Note: Any test which adds -no-integrated-as will cause subsequent tests to
-# succeed, and not trigger further additions.
-
-# Older clang's built-in assembler doesn't understand .skip with labels:
-# https://bugs.llvm.org/show_bug.cgi?id=27369
-$(call as-option-add,CFLAGS,CC,".L0: .L1: .skip (.L1 - .L0)",,\
-                     -no-integrated-as)
-
-# Check whether clang asm()-s support .include.
-$(call as-option-add,CFLAGS,CC,".include \"asm/indirect_thunk_asm.h\"",,\
-                     -no-integrated-as)
-
-# Check whether clang keeps .macro-s between asm()-s:
-# https://bugs.llvm.org/show_bug.cgi?id=36110
-$(call as-option-add,CFLAGS,CC,\
-                     ".macro FOO;.endm"$$(close); asm volatile $$(open)".macro 
FOO;.endm",\
-                     -no-integrated-as)
-endif
-- 
2.24.0


_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxxx
https://lists.xenproject.org/mailman/listinfo/xen-devel