[PATCH] treewide: remove meaningless assignments in Makefiles

From: Masahiro Yamada
Date: Wed Feb 21 2024 - 08:42:26 EST

In Makefiles, $(error ), $(warning ), and $(info ) expand to the empty
string, as explained in the GNU Make manual [1]:
"The result of the expansion of this function is the empty string."

Therefore, they are no-op except for logging purposes.

$(shell ...) expands to the output of the command. It expands to the
empty string when the command does not print anything to stdout.
Hence, $(shell mkdir ...) is no-op except for creating the directory.

Remove meaningless assignments.

[1]: https://www.gnu.org/software/make/manual/make.html#Make-Control-Functions

Signed-off-by: Masahiro Yamada <masahiroy@xxxxxxxxxx>
---

This is a treewide cleanup, but in practice, this is touching mostly
perf Makefiles. I am sending this to perf subsystem.


tools/perf/Makefile.config | 90 ++++++++++++++--------------
tools/perf/Makefile.perf | 4 +-
tools/perf/arch/arm64/Makefile | 2 +-
tools/perf/arch/loongarch/Makefile | 2 +-
tools/perf/arch/mips/Makefile | 2 +-
tools/perf/arch/powerpc/Makefile | 2 +-
tools/perf/arch/s390/Makefile | 2 +-
tools/perf/arch/x86/Makefile | 2 +-
tools/scripts/Makefile.include | 2 +-
tools/testing/selftests/kvm/Makefile | 4 +-
10 files changed, 56 insertions(+), 56 deletions(-)

diff --git a/tools/perf/Makefile.config b/tools/perf/Makefile.config
index aa55850fbc21..6edf9916d41c 100644
--- a/tools/perf/Makefile.config
+++ b/tools/perf/Makefile.config
@@ -209,11 +209,11 @@ endif
include $(srctree)/tools/scripts/utilities.mak

ifeq ($(call get-executable,$(FLEX)),)
- dummy := $(error Error: $(FLEX) is missing on this system, please install it)
+ $(error Error: $(FLEX) is missing on this system, please install it)
endif

ifeq ($(call get-executable,$(BISON)),)
- dummy := $(error Error: $(BISON) is missing on this system, please install it)
+ $(error Error: $(BISON) is missing on this system, please install it)
endif

ifneq ($(OUTPUT),)
@@ -438,46 +438,46 @@ else
LIBC_SUPPORT := 1
endif
ifeq ($(LIBC_SUPPORT),1)
- msg := $(error ERROR: No libelf found. Disables 'probe' tool, jvmti and BPF support. Please install libelf-dev, libelf-devel, elfutils-libelf-devel or build with NO_LIBELF=1.)
+ $(error ERROR: No libelf found. Disables 'probe' tool, jvmti and BPF support. Please install libelf-dev, libelf-devel, elfutils-libelf-devel or build with NO_LIBELF=1.)
else
ifneq ($(filter s% -fsanitize=address%,$(EXTRA_CFLAGS),),)
ifneq ($(shell ldconfig -p | grep libasan >/dev/null 2>&1; echo $$?), 0)
- msg := $(error No libasan found, please install libasan);
+ $(error No libasan found, please install libasan)
endif
endif

ifneq ($(filter s% -fsanitize=undefined%,$(EXTRA_CFLAGS),),)
ifneq ($(shell ldconfig -p | grep libubsan >/dev/null 2>&1; echo $$?), 0)
- msg := $(error No libubsan found, please install libubsan);
+ $(error No libubsan found, please install libubsan)
endif
endif

ifneq ($(filter s% -static%,$(LDFLAGS),),)
- msg := $(error No static glibc found, please install glibc-static);
+ $(error No static glibc found, please install glibc-static)
else
- msg := $(error No gnu/libc-version.h found, please install glibc-dev[el]);
+ $(error No gnu/libc-version.h found, please install glibc-dev[el])
endif
endif
else
ifndef NO_LIBDW_DWARF_UNWIND
ifneq ($(feature-libdw-dwarf-unwind),1)
NO_LIBDW_DWARF_UNWIND := 1
- msg := $(warning No libdw DWARF unwind found, Please install elfutils-devel/libdw-dev >= 0.158 and/or set LIBDW_DIR);
+ $(warning No libdw DWARF unwind found, Please install elfutils-devel/libdw-dev >= 0.158 and/or set LIBDW_DIR)
endif
endif
ifneq ($(feature-dwarf), 1)
ifndef NO_DWARF
- msg := $(warning No libdw.h found or old libdw.h found or elfutils is older than 0.138, disables dwarf support. Please install new elfutils-devel/libdw-dev);
+ $(warning No libdw.h found or old libdw.h found or elfutils is older than 0.138, disables dwarf support. Please install new elfutils-devel/libdw-dev)
NO_DWARF := 1
endif
else
ifneq ($(feature-dwarf_getlocations), 1)
- msg := $(warning Old libdw.h, finding variables at given 'perf probe' point will not work, install elfutils-devel/libdw-dev >= 0.157);
+ $(warning Old libdw.h, finding variables at given 'perf probe' point will not work, install elfutils-devel/libdw-dev >= 0.157)
else
CFLAGS += -DHAVE_DWARF_GETLOCATIONS_SUPPORT
endif # dwarf_getlocations
ifneq ($(feature-dwarf_getcfi), 1)
- msg := $(warning Old libdw.h, finding variables at given 'perf probe' point will not work, install elfutils-devel/libdw-dev >= 0.142);
+ $(warning Old libdw.h, finding variables at given 'perf probe' point will not work, install elfutils-devel/libdw-dev >= 0.142)
else
CFLAGS += -DHAVE_DWARF_CFI_SUPPORT
endif # dwarf_getcfi
@@ -525,7 +525,7 @@ ifdef CORESIGHT
endif
endif
else
- dummy := $(error Error: No libopencsd library found or the version is not up-to-date. Please install recent libopencsd to build with CORESIGHT=1)
+ $(error Error: No libopencsd library found or the version is not up-to-date. Please install recent libopencsd to build with CORESIGHT=1)
endif
endif

@@ -551,7 +551,7 @@ ifndef NO_LIBELF
ifeq ($(feature-libelf-gelf_getnote), 1)
CFLAGS += -DHAVE_GELF_GETNOTE_SUPPORT
else
- msg := $(warning gelf_getnote() not found on libelf, SDT support disabled);
+ $(warning gelf_getnote() not found on libelf, SDT support disabled)
endif

ifeq ($(feature-libelf-getshdrstrndx), 1)
@@ -568,7 +568,7 @@ ifndef NO_LIBELF

ifndef NO_DWARF
ifeq ($(origin PERF_HAVE_DWARF_REGS), undefined)
- msg := $(warning DWARF register mappings have not been defined for architecture $(SRCARCH), DWARF support disabled);
+ $(warning DWARF register mappings have not been defined for architecture $(SRCARCH), DWARF support disabled)
NO_DWARF := 1
else
CFLAGS += -DHAVE_DWARF_SUPPORT $(LIBDW_CFLAGS)
@@ -590,11 +590,11 @@ ifndef NO_LIBELF
$(call detected,CONFIG_LIBBPF)
$(call detected,CONFIG_LIBBPF_DYNAMIC)
else
- dummy := $(error Error: No libbpf devel library found or older than v1.0, please install/update libbpf-devel);
+ $(error Error: No libbpf devel library found or older than v1.0, please install/update libbpf-devel)
endif
else
ifeq ($(NO_ZLIB), 1)
- dummy := $(warning Warning: Statically building libbpf not possible as zlib is missing)
+ $(warning Warning: Statically building libbpf not possible as zlib is missing)
NO_LIBBPF := 1
else
# Libbpf will be built as a static library from tools/lib/bpf.
@@ -609,7 +609,7 @@ endif # NO_LIBELF

ifndef NO_SDT
ifneq ($(feature-sdt), 1)
- msg := $(warning No sys/sdt.h found, no SDT events are defined, please install systemtap-sdt-devel or systemtap-sdt-dev);
+ $(warning No sys/sdt.h found, no SDT events are defined, please install systemtap-sdt-devel or systemtap-sdt-dev)
NO_SDT := 1;
else
CFLAGS += -DHAVE_SDT_EVENT
@@ -651,13 +651,13 @@ ifndef NO_LIBUNWIND
have_libunwind = 1
$(call feature_check,libunwind-debug-frame-aarch64)
ifneq ($(feature-libunwind-debug-frame-aarch64), 1)
- msg := $(warning No debug_frame support found in libunwind-aarch64);
+ $(warning No debug_frame support found in libunwind-aarch64)
CFLAGS += -DNO_LIBUNWIND_DEBUG_FRAME_AARCH64
endif
endif

ifneq ($(feature-libunwind), 1)
- msg := $(warning No libunwind found. Please install libunwind-dev[el] >= 1.1 and/or set LIBUNWIND_DIR);
+ $(warning No libunwind found. Please install libunwind-dev[el] >= 1.1 and/or set LIBUNWIND_DIR)
NO_LOCAL_LIBUNWIND := 1
else
have_libunwind := 1
@@ -673,7 +673,7 @@ endif

ifndef NO_LIBBPF
ifneq ($(feature-bpf), 1)
- msg := $(warning BPF API too old. Please install recent kernel headers. BPF support in 'perf record' is disabled.)
+ $(warning BPF API too old. Please install recent kernel headers. BPF support in 'perf record' is disabled.)
NO_LIBBPF := 1
endif
endif
@@ -686,28 +686,28 @@ endif

ifeq ($(BUILD_BPF_SKEL),1)
ifeq ($(filter -DHAVE_LIBELF_SUPPORT, $(CFLAGS)),)
- dummy := $(warning Warning: Disabled BPF skeletons as libelf is required by bpftool)
+ $(warning Warning: Disabled BPF skeletons as libelf is required by bpftool)
BUILD_BPF_SKEL := 0
else ifeq ($(filter -DHAVE_ZLIB_SUPPORT, $(CFLAGS)),)
- dummy := $(warning Warning: Disabled BPF skeletons as zlib is required by bpftool)
+ $(warning Warning: Disabled BPF skeletons as zlib is required by bpftool)
BUILD_BPF_SKEL := 0
else ifeq ($(filter -DHAVE_LIBBPF_SUPPORT, $(CFLAGS)),)
- dummy := $(warning Warning: Disabled BPF skeletons as libbpf is required)
+ $(warning Warning: Disabled BPF skeletons as libbpf is required)
BUILD_BPF_SKEL := 0
else ifeq ($(call get-executable,$(CLANG)),)
- dummy := $(warning Warning: Disabled BPF skeletons as clang ($(CLANG)) is missing)
+ $(warning Warning: Disabled BPF skeletons as clang ($(CLANG)) is missing)
BUILD_BPF_SKEL := 0
else
CLANG_VERSION := $(shell $(CLANG) --version | head -1 | sed 's/.*clang version \([[:digit:]]\+.[[:digit:]]\+.[[:digit:]]\+\).*/\1/g')
ifeq ($(call version-lt3,$(CLANG_VERSION),12.0.1),1)
- dummy := $(warning Warning: Disabled BPF skeletons as reliable BTF generation needs at least $(CLANG) version 12.0.1)
+ $(warning Warning: Disabled BPF skeletons as reliable BTF generation needs at least $(CLANG) version 12.0.1)
BUILD_BPF_SKEL := 0
endif
endif
ifeq ($(BUILD_BPF_SKEL),1)
$(call feature_check,clang-bpf-co-re)
ifeq ($(feature-clang-bpf-co-re), 0)
- dummy := $(warning Warning: Disabled BPF skeletons as clang is too old)
+ $(warning Warning: Disabled BPF skeletons as clang is too old)
BUILD_BPF_SKEL := 0
endif
endif
@@ -727,7 +727,7 @@ dwarf-post-unwind-text := BUG
# setup DWARF post unwinder
ifdef NO_LIBUNWIND
ifdef NO_LIBDW_DWARF_UNWIND
- msg := $(warning Disabling post unwind, no support found.);
+ $(warning Disabling post unwind, no support found.)
dwarf-post-unwind := 0
else
dwarf-post-unwind-text := libdw
@@ -753,7 +753,7 @@ ifndef NO_LOCAL_LIBUNWIND
ifeq ($(SRCARCH),$(filter $(SRCARCH),arm arm64))
$(call feature_check,libunwind-debug-frame)
ifneq ($(feature-libunwind-debug-frame), 1)
- msg := $(warning No debug_frame support found in libunwind);
+ $(warning No debug_frame support found in libunwind)
CFLAGS += -DNO_LIBUNWIND_DEBUG_FRAME
endif
else
@@ -782,7 +782,7 @@ ifneq ($(NO_LIBTRACEEVENT),1)
ifndef NO_LIBAUDIT
$(call feature_check,libaudit)
ifneq ($(feature-libaudit), 1)
- msg := $(warning No libaudit.h found, disables 'trace' tool, please install audit-libs-devel or libaudit-dev);
+ $(warning No libaudit.h found, disables 'trace' tool, please install audit-libs-devel or libaudit-dev)
NO_LIBAUDIT := 1
else
CFLAGS += -DHAVE_LIBAUDIT_SUPPORT
@@ -795,7 +795,7 @@ endif

ifndef NO_LIBCRYPTO
ifneq ($(feature-libcrypto), 1)
- msg := $(warning No libcrypto.h found, disables jitted code injection, please install openssl-devel or libssl-dev);
+ $(warning No libcrypto.h found, disables jitted code injection, please install openssl-devel or libssl-dev)
NO_LIBCRYPTO := 1
else
CFLAGS += -DHAVE_LIBCRYPTO_SUPPORT
@@ -807,7 +807,7 @@ endif
ifndef NO_SLANG
ifneq ($(feature-libslang), 1)
ifneq ($(feature-libslang-include-subdir), 1)
- msg := $(warning slang not found, disables TUI support. Please install slang-devel, libslang-dev or libslang2-dev);
+ $(warning slang not found, disables TUI support. Please install slang-devel, libslang-dev or libslang2-dev)
NO_SLANG := 1
else
CFLAGS += -DHAVE_SLANG_INCLUDE_SUBDIR
@@ -825,7 +825,7 @@ ifdef GTK2
FLAGS_GTK2=$(CFLAGS) $(LDFLAGS) $(EXTLIBS) $(shell $(PKG_CONFIG) --libs --cflags gtk+-2.0 2>/dev/null)
$(call feature_check,gtk2)
ifneq ($(feature-gtk2), 1)
- msg := $(warning GTK2 not found, disables GTK2 support. Please install gtk2-devel or libgtk2.0-dev);
+ $(warning GTK2 not found, disables GTK2 support. Please install gtk2-devel or libgtk2.0-dev)
NO_GTK2 := 1
else
$(call feature_check,gtk2-infobar)
@@ -854,7 +854,7 @@ else
ifneq ($(feature-libperl), 1)
CFLAGS += -DNO_LIBPERL
NO_LIBPERL := 1
- msg := $(warning Missing perl devel files. Disabling perl scripting support, please install perl-ExtUtils-Embed/libperl-dev);
+ $(warning Missing perl devel files. Disabling perl scripting support, please install perl-ExtUtils-Embed/libperl-dev)
else
LDFLAGS += $(PERL_EMBED_LDFLAGS)
EXTLIBS += $(PERL_EMBED_LIBADD)
@@ -869,7 +869,7 @@ endif
ifeq ($(feature-timerfd), 1)
CFLAGS += -DHAVE_TIMERFD_SUPPORT
else
- msg := $(warning No timerfd support. Disables 'perf kvm stat live');
+ $(warning No timerfd support. Disables 'perf kvm stat live')
endif

disable-python = $(eval $(disable-python_code))
@@ -903,7 +903,7 @@ else
PYTHON_EXTENSION_SUFFIX := $(shell $(PYTHON) -c 'from importlib import machinery; print(machinery.EXTENSION_SUFFIXES[0])')
LANG_BINDINGS += $(obj-perf)python/perf$(PYTHON_EXTENSION_SUFFIX)
else
- msg := $(warning Missing python setuptools, the python binding won't be built, please install python3-setuptools or equivalent);
+ $(warning Missing python setuptools, the python binding won't be built, please install python3-setuptools or equivalent)
endif
CFLAGS += -DHAVE_LIBPYTHON_SUPPORT
$(call detected,CONFIG_LIBPYTHON)
@@ -962,7 +962,7 @@ ifdef BUILD_NONDISTRO
ifeq ($(feature-libbfd-buildid), 1)
CFLAGS += -DHAVE_LIBBFD_BUILDID_SUPPORT
else
- msg := $(warning Old version of libbfd/binutils things like PE executable profiling will not be available);
+ $(warning Old version of libbfd/binutils things like PE executable profiling will not be available)
endif
endif

@@ -994,7 +994,7 @@ ifndef NO_LZMA
EXTLIBS += -llzma
$(call detected,CONFIG_LZMA)
else
- msg := $(warning No liblzma found, disables xz kernel module decompression, please install xz-devel/liblzma-dev);
+ $(warning No liblzma found, disables xz kernel module decompression, please install xz-devel/liblzma-dev)
NO_LZMA := 1
endif
endif
@@ -1007,7 +1007,7 @@ ifndef NO_LIBZSTD
EXTLIBS += -lzstd
$(call detected,CONFIG_ZSTD)
else
- msg := $(warning No libzstd found, disables trace compression, please install libzstd-dev[el] and/or set LIBZSTD_DIR);
+ $(warning No libzstd found, disables trace compression, please install libzstd-dev[el] and/or set LIBZSTD_DIR)
NO_LIBZSTD := 1
endif
endif
@@ -1018,7 +1018,7 @@ ifndef NO_LIBCAP
EXTLIBS += -lcap
$(call detected,CONFIG_LIBCAP)
else
- msg := $(warning No libcap found, disables capability support, please install libcap-devel/libcap-dev);
+ $(warning No libcap found, disables capability support, please install libcap-devel/libcap-dev)
NO_LIBCAP := 1
endif
endif
@@ -1031,11 +1031,11 @@ endif

ifndef NO_LIBNUMA
ifeq ($(feature-libnuma), 0)
- msg := $(warning No numa.h found, disables 'perf bench numa mem' benchmark, please install numactl-devel/libnuma-devel/libnuma-dev);
+ $(warning No numa.h found, disables 'perf bench numa mem' benchmark, please install numactl-devel/libnuma-devel/libnuma-dev)
NO_LIBNUMA := 1
else
ifeq ($(feature-numa_num_possible_cpus), 0)
- msg := $(warning Old numa library found, disables 'perf bench numa mem' benchmark, please install numactl-devel/libnuma-devel/libnuma-dev >= 2.0.8);
+ $(warning Old numa library found, disables 'perf bench numa mem' benchmark, please install numactl-devel/libnuma-devel/libnuma-dev >= 2.0.8)
NO_LIBNUMA := 1
else
CFLAGS += -DHAVE_LIBNUMA_SUPPORT
@@ -1090,14 +1090,14 @@ ifndef NO_LIBBABELTRACE
EXTLIBS += -lbabeltrace-ctf
$(call detected,CONFIG_LIBBABELTRACE)
else
- msg := $(warning No libbabeltrace found, disables 'perf data' CTF format support, please install libbabeltrace-dev[el]/libbabeltrace-ctf-dev);
+ $(warning No libbabeltrace found, disables 'perf data' CTF format support, please install libbabeltrace-dev[el]/libbabeltrace-ctf-dev)
endif
endif

ifndef NO_AUXTRACE
ifeq ($(SRCARCH),x86)
ifeq ($(feature-get_cpuid), 0)
- msg := $(warning Your gcc lacks the __get_cpuid() builtin, disables support for auxtrace/Intel PT, please install a newer gcc);
+ $(warning Your gcc lacks the __get_cpuid() builtin, disables support for auxtrace/Intel PT, please install a newer gcc)
NO_AUXTRACE := 1
endif
endif
@@ -1155,7 +1155,7 @@ ifndef NO_LIBPFM4
ASCIIDOC_EXTRA = -aHAVE_LIBPFM=1
$(call detected,CONFIG_LIBPFM4)
else
- msg := $(warning libpfm4 not found, disables libpfm4 support. Please install libpfm4-dev);
+ $(warning libpfm4 not found, disables libpfm4 support. Please install libpfm4-dev)
endif
endif

@@ -1173,7 +1173,7 @@ ifneq ($(NO_LIBTRACEEVENT),1)
CFLAGS += -DLIBTRACEEVENT_VERSION=$(LIBTRACEEVENT_VERSION_CPP)
$(call detected,CONFIG_LIBTRACEEVENT)
else
- dummy := $(error ERROR: libtraceevent is missing. Please install libtraceevent-dev/libtraceevent-devel or build with NO_LIBTRACEEVENT=1)
+ $(error ERROR: libtraceevent is missing. Please install libtraceevent-dev/libtraceevent-devel or build with NO_LIBTRACEEVENT=1)
endif

$(call feature_check,libtracefs)
diff --git a/tools/perf/Makefile.perf b/tools/perf/Makefile.perf
index f8774a9b1377..3707fed8dfde 100644
--- a/tools/perf/Makefile.perf
+++ b/tools/perf/Makefile.perf
@@ -482,7 +482,7 @@ drm_hdr_dir := $(srctree)/tools/include/uapi/drm
drm_ioctl_tbl := $(srctree)/tools/perf/trace/beauty/drm_ioctl.sh

# Create output directory if not already present
-_dummy := $(shell [ -d '$(beauty_ioctl_outdir)' ] || mkdir -p '$(beauty_ioctl_outdir)')
+$(shell [ -d '$(beauty_ioctl_outdir)' ] || mkdir -p '$(beauty_ioctl_outdir)')

$(drm_ioctl_array): $(drm_hdr_dir)/drm.h $(drm_hdr_dir)/i915_drm.h $(drm_ioctl_tbl)
$(Q)$(SHELL) '$(drm_ioctl_tbl)' $(drm_hdr_dir) > $@
@@ -672,7 +672,7 @@ tests-coresight-targets-clean:
all: shell_compatibility_test $(ALL_PROGRAMS) $(LANG_BINDINGS) $(OTHER_PROGRAMS) tests-coresight-targets

# Create python binding output directory if not already present
-_dummy := $(shell [ -d '$(OUTPUT)python' ] || mkdir -p '$(OUTPUT)python')
+$(shell [ -d '$(OUTPUT)python' ] || mkdir -p '$(OUTPUT)python')

$(OUTPUT)python/perf$(PYTHON_EXTENSION_SUFFIX): $(PYTHON_EXT_SRCS) $(PYTHON_EXT_DEPS) $(LIBPERF) $(LIBSUBCMD)
$(QUIET_GEN)LDSHARED="$(CC) -pthread -shared" \
diff --git a/tools/perf/arch/arm64/Makefile b/tools/perf/arch/arm64/Makefile
index fab3095fb5d0..5735ed4479bb 100644
--- a/tools/perf/arch/arm64/Makefile
+++ b/tools/perf/arch/arm64/Makefile
@@ -18,7 +18,7 @@ sysprf := $(srctree)/tools/perf/arch/arm64/entry/syscalls/
systbl := $(sysprf)/mksyscalltbl

# Create output directory if not already present
-_dummy := $(shell [ -d '$(out)' ] || mkdir -p '$(out)')
+$(shell [ -d '$(out)' ] || mkdir -p '$(out)')

$(header): $(sysdef) $(systbl)
$(Q)$(SHELL) '$(systbl)' '$(CC)' '$(HOSTCC)' $(incpath) $(sysdef) > $@
diff --git a/tools/perf/arch/loongarch/Makefile b/tools/perf/arch/loongarch/Makefile
index c392e7af4743..3992a67a87d9 100644
--- a/tools/perf/arch/loongarch/Makefile
+++ b/tools/perf/arch/loongarch/Makefile
@@ -17,7 +17,7 @@ sysprf := $(srctree)/tools/perf/arch/loongarch/entry/syscalls/
systbl := $(sysprf)/mksyscalltbl

# Create output directory if not already present
-_dummy := $(shell [ -d '$(out)' ] || mkdir -p '$(out)')
+$(shell [ -d '$(out)' ] || mkdir -p '$(out)')

$(header): $(sysdef) $(systbl)
$(Q)$(SHELL) '$(systbl)' '$(CC)' '$(HOSTCC)' $(incpath) $(sysdef) > $@
diff --git a/tools/perf/arch/mips/Makefile b/tools/perf/arch/mips/Makefile
index 8bc09072e3d6..cd0b011b3be5 100644
--- a/tools/perf/arch/mips/Makefile
+++ b/tools/perf/arch/mips/Makefile
@@ -11,7 +11,7 @@ sysdef := $(sysprf)/syscall_n64.tbl
systbl := $(sysprf)/mksyscalltbl

# Create output directory if not already present
-_dummy := $(shell [ -d '$(out)' ] || mkdir -p '$(out)')
+$(shell [ -d '$(out)' ] || mkdir -p '$(out)')

$(header): $(sysdef) $(systbl)
$(Q)$(SHELL) '$(systbl)' $(sysdef) > $@
diff --git a/tools/perf/arch/powerpc/Makefile b/tools/perf/arch/powerpc/Makefile
index 840ea0e59287..bf6d323574f6 100644
--- a/tools/perf/arch/powerpc/Makefile
+++ b/tools/perf/arch/powerpc/Makefile
@@ -19,7 +19,7 @@ sysdef := $(sysprf)/syscall.tbl
systbl := $(sysprf)/mksyscalltbl

# Create output directory if not already present
-_dummy := $(shell [ -d '$(out)' ] || mkdir -p '$(out)')
+$(shell [ -d '$(out)' ] || mkdir -p '$(out)')

$(header64): $(sysdef) $(systbl)
$(Q)$(SHELL) '$(systbl)' '64' $(sysdef) > $@
diff --git a/tools/perf/arch/s390/Makefile b/tools/perf/arch/s390/Makefile
index 74bffbea03e2..56994e63b43a 100644
--- a/tools/perf/arch/s390/Makefile
+++ b/tools/perf/arch/s390/Makefile
@@ -17,7 +17,7 @@ sysdef := $(sysprf)/syscall.tbl
systbl := $(sysprf)/mksyscalltbl

# Create output directory if not already present
-_dummy := $(shell [ -d '$(out)' ] || mkdir -p '$(out)')
+$(shell [ -d '$(out)' ] || mkdir -p '$(out)')

$(header): $(sysdef) $(systbl)
$(Q)$(SHELL) '$(systbl)' $(sysdef) > $@
diff --git a/tools/perf/arch/x86/Makefile b/tools/perf/arch/x86/Makefile
index 5a9f9a7bf07d..8952e00f9b60 100644
--- a/tools/perf/arch/x86/Makefile
+++ b/tools/perf/arch/x86/Makefile
@@ -17,7 +17,7 @@ sys := $(srctree)/tools/perf/arch/x86/entry/syscalls
systbl := $(sys)/syscalltbl.sh

# Create output directory if not already present
-_dummy := $(shell [ -d '$(out)' ] || mkdir -p '$(out)')
+$(shell [ -d '$(out)' ] || mkdir -p '$(out)')

$(header): $(sys)/syscall_64.tbl $(systbl)
$(Q)$(SHELL) '$(systbl)' $(sys)/syscall_64.tbl 'x86_64' > $@
diff --git a/tools/scripts/Makefile.include b/tools/scripts/Makefile.include
index 6fba29f3222d..0aa4005017c7 100644
--- a/tools/scripts/Makefile.include
+++ b/tools/scripts/Makefile.include
@@ -1,7 +1,7 @@
# SPDX-License-Identifier: GPL-2.0
ifneq ($(O),)
ifeq ($(origin O), command line)
- dummy := $(if $(shell cd $(PWD); test -d $(O) || echo $(O)),$(error O=$(O) does not exist),)
+ $(if $(shell cd $(PWD); test -d $(O) || echo $(O)),$(error O=$(O) does not exist),)
ABSOLUTE_O := $(shell cd $(PWD); cd $(O) ; pwd)
OUTPUT := $(ABSOLUTE_O)/$(if $(subdir),$(subdir)/)
COMMAND_O := O=$(ABSOLUTE_O)
diff --git a/tools/testing/selftests/kvm/Makefile b/tools/testing/selftests/kvm/Makefile
index 492e937fab00..14684aeb4b55 100644
--- a/tools/testing/selftests/kvm/Makefile
+++ b/tools/testing/selftests/kvm/Makefile
@@ -285,7 +285,7 @@ EXTRA_CLEAN += $(GEN_HDRS) \
$(TEST_GEN_OBJ) \
cscope.*

-x := $(shell mkdir -p $(sort $(dir $(LIBKVM_C_OBJ) $(LIBKVM_S_OBJ))))
+$(shell mkdir -p $(sort $(dir $(LIBKVM_C_OBJ) $(LIBKVM_S_OBJ))))
$(LIBKVM_C_OBJ): $(OUTPUT)/%.o: %.c $(GEN_HDRS)
$(CC) $(CFLAGS) $(CPPFLAGS) $(TARGET_ARCH) -c $< -o $@

@@ -298,7 +298,7 @@ $(LIBKVM_S_OBJ): $(OUTPUT)/%.o: %.S $(GEN_HDRS)
$(LIBKVM_STRING_OBJ): $(OUTPUT)/%.o: %.c
$(CC) $(CFLAGS) $(CPPFLAGS) $(TARGET_ARCH) -c -ffreestanding $< -o $@

-x := $(shell mkdir -p $(sort $(dir $(TEST_GEN_PROGS))))
+$(shell mkdir -p $(sort $(dir $(TEST_GEN_PROGS))))
$(SPLIT_TESTS_OBJS): $(GEN_HDRS)
$(TEST_GEN_PROGS): $(LIBKVM_OBJS)
$(TEST_GEN_PROGS_EXTENDED): $(LIBKVM_OBJS)
--
2.40.1