When cc-option and friends evaluate compiler flags, the temporary file $$TMP is created as an output object, and automatically cleaned up. The actual file path of $$TMP is .<pid>.tmp, here <pid> is the process ID of $(shell ....) invoked from cc-option. (Please note $$$$ is the escape sequence of $$). Such garbage files are cleaned up in most cases, but some compiler flags create additional output files. For example, -gsplit-dwarf creates a .dwo file. When CONFIG_DEBUG_INFO_SPLIT=y, you will see a bunch of .<pid>.dwo files left in the top of build directories. You may not notice them unless you do 'ls -a', but the garbage files will increase every time you run 'make'. This commit changes the temporary object path to .tmp_<pid>/tmp, and removes .tmp_<pid> directory when exiting. The additional files .tmp_<pid>/tmp.dwo, will be cleaned away altogether. When the compiler creates separate build artifacts, their file paths are usually determined based on the base name of the object. Another example is -ftest-coverage, which outputs the coverage data into <base-name-of-object>.gcno Signed-off-by: Masahiro Yamada <masahiroy@xxxxxxxxxx> --- scripts/Kbuild.include | 13 +++++++------ 1 file changed, 7 insertions(+), 6 deletions(-) diff --git a/scripts/Kbuild.include b/scripts/Kbuild.include index 0c3dc983439b..5dfd224599b7 100644 --- a/scripts/Kbuild.include +++ b/scripts/Kbuild.include @@ -86,20 +86,21 @@ cc-cross-prefix = $(firstword $(foreach c, $(1), \ $(if $(shell command -v -- $(c)gcc 2>/dev/null), $(c)))) # output directory for tests below -TMPOUT := $(if $(KBUILD_EXTMOD),$(firstword $(KBUILD_EXTMOD))/) +TMPOUT = $(if $(KBUILD_EXTMOD),$(firstword $(KBUILD_EXTMOD))/).tmp_$$$$ # try-run # Usage: option = $(call try-run, $(CC)...-o "$$TMP",option-ok,otherwise) -# Exit code chooses option. "$$TMP" serves as a temporary file and is +# Exit code chooses option. "$$TMP" serves as a temporary directory and is # automatically cleaned up. try-run = $(shell set -e; \ - TMP="$(TMPOUT).$$$$.tmp"; \ - TMPO="$(TMPOUT).$$$$.o"; \ + TMP=$(TMPOUT)/tmp; \ + TMPO=$(TMPOUT)/tmp.o; \ + mkdir -p $(TMPOUT); \ + trap "rm -rf $(TMPOUT)" EXIT; \ if ($(1)) >/dev/null 2>&1; \ then echo "$(2)"; \ else echo "$(3)"; \ - fi; \ - rm -f "$$TMP" "$$TMPO") + fi) # as-option # Usage: cflags-y += $(call as-option,-Wa$(comma)-isa=foo,) -- 2.25.1
