[PATCH v2 3/5] Makefile.compiler: replace cc-ifversion with compiler-specific macros
Nick Desaulniers
ndesaulniers at google.com
Wed Aug 31 18:44:06 UTC 2022
cc-ifversion is GCC specific. Replace it with compiler specific
variants. Update the users of cc-ifversion to use these new macros.
Provide a helper for checking compiler versions for GCC and Clang
simultaneously, that will be used in a follow up patch.
Cc: Jonathan Corbet <corbet at lwn.net>
Cc: linux-doc at vger.kernel.org
Cc: amd-gfx at lists.freedesktop.org
Cc: dri-devel at lists.freedesktop.org
Link: https://github.com/ClangBuiltLinux/linux/issues/350
Link: https://lore.kernel.org/llvm/CAGG=3QWSAUakO42kubrCap8fp-gm1ERJJAYXTnP1iHk_wrH=BQ@mail.gmail.com/
Suggested-by: Bill Wendling <morbo at google.com>
Signed-off-by: Nick Desaulniers <ndesaulniers at google.com>
---
Changes v1 -> v2:
* New patch.
Documentation/kbuild/makefiles.rst | 44 +++++++++++++++------
Makefile | 4 +-
drivers/gpu/drm/amd/display/dc/dml/Makefile | 12 ++----
scripts/Makefile.compiler | 15 +++++--
4 files changed, 49 insertions(+), 26 deletions(-)
diff --git a/Documentation/kbuild/makefiles.rst b/Documentation/kbuild/makefiles.rst
index 11a296e52d68..e46f5b45c422 100644
--- a/Documentation/kbuild/makefiles.rst
+++ b/Documentation/kbuild/makefiles.rst
@@ -682,22 +682,42 @@ more details, with real examples.
In the above example, -Wno-unused-but-set-variable will be added to
KBUILD_CFLAGS only if gcc really accepts it.
- cc-ifversion
- cc-ifversion tests the version of $(CC) and equals the fourth parameter
- if version expression is true, or the fifth (if given) if the version
- expression is false.
+ gcc-min-version
+ gcc-min-version tests if the value of $(CONFIG_GCC_VERSION) is greater than
+ or equal to the provided value and evaluates to y if so.
Example::
- #fs/reiserfs/Makefile
- ccflags-y := $(call cc-ifversion, -lt, 0402, -O1)
+ cflags-$(call gcc-min-version, 70100) := -foo
- In this example, ccflags-y will be assigned the value -O1 if the
- $(CC) version is less than 4.2.
- cc-ifversion takes all the shell operators:
- -eq, -ne, -lt, -le, -gt, and -ge
- The third parameter may be a text as in this example, but it may also
- be an expanded variable or a macro.
+ In this example, cflags-y will be assigned the value -foo if $(CC) is gcc and
+ $(CONFIG_GCC_VERSION) is >= 7.1.
+
+ clang-min-version
+ clang-min-version tests if the value of $(CONFIG_CLANG_VERSION) is greater
+ than or equal to the provided value and evaluates to y if so.
+
+ Example::
+
+ cflags-$(call clang-min-version, 110000) := -foo
+
+ In this example, cflags-y will be assigned the value -foo if $(CC) is clang
+ and $(CONFIG_CLANG_VERSION) is >= 11.0.0.
+
+ cc-min-version
+ cc-min-version tests if the value of $(CONFIG_GCC_VERSION) is greater
+ than or equal to the first value provided, or if the value of
+ $(CONFIG_CLANG_VERSION) is greater than or equal to the second value
+ provided, and evaluates
+ to y if so.
+
+ Example::
+
+ cflags-$(call cc-min-version, 70100, 110000) := -foo
+
+ In this example, cflags-y will be assigned the value -foo if $(CC) is gcc and
+ $(CONFIG_GCC_VERSION) is >= 7.1, or if $(CC) is clang and
+ $(CONFIG_CLANG_VERSION) is >= 11.0.0.
cc-cross-prefix
cc-cross-prefix is used to check if there exists a $(CC) in path with
diff --git a/Makefile b/Makefile
index 952d354069a4..caa39ecb1136 100644
--- a/Makefile
+++ b/Makefile
@@ -972,7 +972,7 @@ ifdef CONFIG_CC_IS_GCC
KBUILD_CFLAGS += -Wno-maybe-uninitialized
endif
-ifdef CONFIG_CC_IS_GCC
+ifeq ($(call gcc-min-version, 90100),y)
# The allocators already balk at large sizes, so silence the compiler
# warnings for bounds checks involving those possible values. While
# -Wno-alloc-size-larger-than would normally be used here, earlier versions
@@ -984,7 +984,7 @@ ifdef CONFIG_CC_IS_GCC
# ignored, continuing to default to PTRDIFF_MAX. So, left with no other
# choice, we must perform a versioned check to disable this warning.
# https://lore.kernel.org/lkml/20210824115859.187f272f@canb.auug.org.au
-KBUILD_CFLAGS += $(call cc-ifversion, -ge, 0901, -Wno-alloc-size-larger-than)
+KBUILD_CFLAGS += -Wno-alloc-size-larger-than
endif
# disable invalid "can't wrap" optimizations for signed / pointers
diff --git a/drivers/gpu/drm/amd/display/dc/dml/Makefile b/drivers/gpu/drm/amd/display/dc/dml/Makefile
index 86a3b5bfd699..d8ee4743b2e3 100644
--- a/drivers/gpu/drm/amd/display/dc/dml/Makefile
+++ b/drivers/gpu/drm/amd/display/dc/dml/Makefile
@@ -33,20 +33,14 @@ ifdef CONFIG_PPC64
dml_ccflags := -mhard-float -maltivec
endif
-ifdef CONFIG_CC_IS_GCC
-ifeq ($(call cc-ifversion, -lt, 0701, y), y)
-IS_OLD_GCC = 1
-endif
-endif
-
ifdef CONFIG_X86
-ifdef IS_OLD_GCC
+ifeq ($(call gcc-min-version, 70100),y)
+dml_ccflags += -msse2
+else
# Stack alignment mismatch, proceed with caution.
# GCC < 7.1 cannot compile code using `double` and -mpreferred-stack-boundary=3
# (8B stack alignment).
dml_ccflags += -mpreferred-stack-boundary=4
-else
-dml_ccflags += -msse2
endif
endif
diff --git a/scripts/Makefile.compiler b/scripts/Makefile.compiler
index d1739f0d3ce3..13dade724fa3 100644
--- a/scripts/Makefile.compiler
+++ b/scripts/Makefile.compiler
@@ -61,9 +61,18 @@ cc-option-yn = $(call try-run,\
cc-disable-warning = $(call try-run,\
$(CC) -Werror $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS) -W$(strip $(1)) -c -x c /dev/null -o "$$TMP",-Wno-$(strip $(1)))
-# cc-ifversion
-# Usage: EXTRA_CFLAGS += $(call cc-ifversion, -lt, 0402, -O1)
-cc-ifversion = $(shell [ $(CONFIG_GCC_VERSION)0 $(1) $(2)000 ] && echo $(3) || echo $(4))
+# gcc-min-version
+# Usage: cflags-$(call gcc-min-version, 70100) += -foo
+gcc-min-version = $(shell [ $(CONFIG_GCC_VERSION) -ge $(1) ] && echo y)
+
+# clang-min-version
+# Usage: cflags-$(call clang-min-version, 110000) += -foo
+clang-min-version = $(shell [ $(CONFIG_CLANG_VERSION) -ge $(1) ] && echo y)
+
+# cc-min-version
+# Usage: cflags-$(call cc-min-version, 701000, 110000)
+# ^ GCC ^ Clang
+cc-min-version = $(filter y, $(call gcc-min-version, $(1)), $(call clang-min-version, $(2)))
# ld-option
# Usage: KBUILD_LDFLAGS += $(call ld-option, -X, -Y)
--
2.37.2.672.g94769d06f0-goog
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