makefile - GNU 使 "Removing intermediate files"

Question

我有以下规则

define compile_c
$(ECHO) "CC $<"
$(Q)$(CC) $(CFLAGS) -c -MD -o $@ $<
@# The following fixes the dependency file.
@# See http://make.paulandlesley.org/autodep.html for details.
@# Regex adjusted from the above to play better with Windows paths, etc.
@$(CP) $(@:.o=.d) $(@:.o=.P); \
  $(SED) -e 's/#.*//' -e 's/^.*:  *//' -e 's/ *\\$$//' \
      -e '/^$$/ d' -e 's/$$/ :/' < $(@:.o=.d) >> $(@:.o=.P); \
  $(RM) -f $(@:.o=.d)
endef

vpath %.c . $(TOP)
$(BUILD)/%.o: %.c $(BUILD)/%.pp
    $(call compile_c)

vpath %.c . $(TOP)

$(BUILD)/%.pp: %.c
    $(ECHO) "PreProcess $<"
    $(Q)$(CC) $(CFLAGS) -E -Wp,-C,-dD,-dI -o $@ $<

构建完成后，GNU make 说 Removing intermediate files...并删除所有 .pp我做的文件 不是 想。

为什么要这样做？
我该如何阻止？

Answer 1

由于您使用的是 GNU Make，您可以对 Makefile 进行以下调整:

.PRECIOUS: $(BUILD)/%.pp  # ADD THIS LINE
$(BUILD)/%.pp: %.c
    $(ECHO) "PreProcess $<"
    $(Q)$(CC) $(CFLAGS) -E -Wp,-C,-dD,-dI -o $@ $<

documentation关于 .PRECIOUS有这个说法吗指令:

The targets which .PRECIOUS depends on are given the following special treatment: if make is killed or interrupted during the execution of their recipes, the target is not deleted.

[...]

Also, if the target is an intermediate file, it will not be deleted after it is no longer needed, as is normally done.

[...]

You can also list the target pattern of an implicit rule (such as ‘%.o’) as a prerequisite file of the special target .PRECIOUS to preserve intermediate files created by rules whose target patterns match that file's name.

这样做的好处是不会创建不需要的附加规则。您尝试做的事情也更清楚:保留重新创建可能很昂贵的宝贵中间文件。