makefile - 如何检测 GNU make 中使用的 shell？

Question

如何检测 gnu make 将使用的 shell？我希望我的产品在以下平台上运行:

• Linux
• window
• 带有 cygwin 的 Windows(请注意，在带有 cygwin 的 Windows 上，make 使用 cygwin shell)

然后我想检测 gcc 是否独立于操作系统存在于系统上。

Answer 1

到目前为止，我想出了这个解决方案:

# detect what shell is used
ifeq ($(findstring cmd.exe,$(SHELL)),cmd.exe)
$(info "shell Windows cmd.exe")
DEVNUL := NUL
WHICH := where
else
$(info "shell Bash")
DEVNUL := /dev/null
WHICH := which
endif

# detect platform independently if gcc is installed
ifeq ($(shell ${WHICH} gcc 2>${DEVNUL}),)
$(error "gcc is not in your system PATH")
else
$(info "gcc found")
endif

可选地，当我需要检测更多我可以使用的工具时:

EXECUTABLES = ls dd 
K := $(foreach myTestCommand,$(EXECUTABLES),\
        $(if $(shell ${WHICH} $(myTestCommand) 2>${DEVNUL} ),\
            $(myTestCommand) found,\
            $(error "No $(myTestCommand) in PATH)))
$(info ${K})