Re: [PATCH] treewide: remove meaningless assignments in Makefiles

Paolo Bonzini <pbonzini@xxxxxxxxxx> · Fri, 15 Mar 2024 11:49:48 +0100

On 2/21/24 14:42, Masahiro Yamada wrote:
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.

"Mostly" is not exclusively, and you did not even bother CCing the KVM 
mailing list.  We would have told you that we have changes in flight for 
6.9, and now there are conflicts in the file that you touched.

Next time please prepare a topic branch, or split the patch.

Paolo


  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)








