我使用过一些rake(一个Ruby make程序),它有一个选项,可以获得所有可用目标的列表,例如

> rake --tasks
rake db:charset      # retrieve the charset for your data...
rake db:collation    # retrieve the collation for your da...
rake db:create       # Creates the databases defined in y...
rake db:drop         # Drops the database for your curren...
...

但是在GNU make中似乎没有这样做的选项。

显然,代码几乎已经有了,截至2007年- http://www.mail-archive.com/help-make@gnu.org/msg06434.html。

不管怎样,我做了一个小hack来从makefile中提取目标,你可以将它包含在makefile中。

list:
    @grep '^[^#[:space:]].*:' Makefile

它会给你一个已定义目标的列表。这只是一个开始——例如,它并没有过滤掉依赖关系。

> make list
list:
copy:
run:
plot:
turnin:

当前回答

专注于描述make目标的简单语法,并有一个干净的输出,我选择了以下方法:

help:
    @grep -B1 -E "^[a-zA-Z0-9_-]+\:([^\=]|$$)" Makefile \
     | grep -v -- -- \
     | sed 'N;s/\n/###/' \
     | sed -n 's/^#: \(.*\)###\(.*\):.*/\2###\1/p' \
     | column -t  -s '###'


#: Starts the container stack
up: a b
  command

#: Pulls in new container images
pull: c d 
    another command

make-target-not-shown:

# this does not count as a description, so leaving
# your implementation comments alone, e.g TODOs
also-not-shown:

因此,将上面的文件作为Makefile来处理并运行它会给您带来类似于

> make help
up          Starts the container stack
pull        Pulls in new container images

命令链的解释:

First, grep all targets and their preceeding line, see https://unix.stackexchange.com/a/320709/223029. Then, get rid of the group separator, see https://stackoverflow.com/a/2168139/1242922. Then, we collapse each pair of lines to parse it later, see https://stackoverflow.com/a/9605559/1242922. Then, we parse for valid lines and remove those which do not match, see https://stackoverflow.com/a/8255627/1242922, and also give the output our desired order: command, then description. Lastly, we arrange the output like a table.

其他回答

我把这两个答案结合起来:https://stackoverflow.com/a/9524878/86967和https://stackoverflow.com/a/7390874/86967 并做了一些转义,以便可以从makefile中使用。

.PHONY: no_targets__ list
no_targets__:
list:
    sh -c "$(MAKE) -p no_targets__ | awk -F':' '/^[a-zA-Z0-9][^\$$#\/\\t=]*:([^=]|$$)/ {split(\$$1,A,/ /);for(i in A)print A[i]}' | grep -v '__\$$' | sort"

.

$ make -s list
build
clean
default
distclean
doc
fresh
install
list
makefile ## this is kind of extraneous, but whatever...
run

在Bash下(至少),这可以通过制表符自动完成:

可我会spacetabtab

我个人为我构建的每个Makefile复制粘贴相同的帮助目标。

.SILENT:

.PHONY: help
## This help screen
help:
    printf "Available targets\n\n"
    awk '/^[a-zA-Z\-\_0-9]+:/ { \
        helpMessage = match(lastLine, /^## (.*)/); \
        if (helpMessage) { \
            helpCommand = substr($$1, 0, index($$1, ":")-1); \
            helpMessage = substr(lastLine, RSTART + 3, RLENGTH); \
            printf "%-30s %s\n", helpCommand, helpMessage; \
        } \
    } \
    { lastLine = $$0 }' $(MAKEFILE_LIST)

我也在这个Github要点中保留了它的副本: https://gist.github.com/Olshansk/689fc2dee28a44397c6e31a0776ede30

我用这个:

make -npq .DEFAULT 2> /dev/null | \
      awk -v RS= -F: '$1 ~ /^[^#%]+$/ { print $1 }'

它是bash补全脚本功能的一个非常简化的版本。

这可能会产生很多假阳性,但就我的目的而言,我宁愿有假阳性而不是假阴性。

Make默认情况下不支持此功能,其他回答已经展示了如何自动提取可能目标的列表。

然而,如果您想对清单有更多的控制,而不产生任何副作用(例如使用. phony目标标记文档,这阻止了使用目标名称作为Make用来决定需要重建哪些目标的实际文件的逻辑),您可以为文档发明自己的语法。我更喜欢这样使用###:

CPUS ?= $(shell nproc)
MAKEFLAGS += -j $(CPUS) -l $(CPUS) -s

# Basic paths
PREFIX  ?= usr
BINDIR  ?= $(PREFIX)/bin
ETCDIR  ?= etc
MANDIR  ?= $(PREFIX)/share/man
# ...

### help: Show help message (default target)
# use "help" as the default target (first target in the Makefile)
.PHONY: help
help:
    @printf "%s\n\n" "make: List of possible targets:"
    @grep '^### .*:' $(lastword $(MAKEFILE_LIST)) | sed 's/^### \([^:]*\): \(.*\)/\1:\t\2/' | column -ts "$$(printf '\t')"

### install: Install all files in $PREFIX (used by debian binary package build scripts)
install:
    install -D -o root -g root -m 755 ...
    ...

### release: Increase package version number
release:
    debchange --release

(像往常一样,缩进文件必须精确地从一个制表器开始,但stackoverflow不能正确地再现该细节。)

输出如下所示:

$ make
make: List of possible targets:

help:      Show help message (default target)
install:   Install all files in $PREFIX (used by debian binary package build scripts)
release:   Increase package version number

This works because only lines starting with ### and having a : character are considered as the documentation to output. Note that this intentionally does not extract the actual target name but fully trusts the documentation lines only. This allows always emitting correct output for very complex Makefile tricks, too. Also note that this avoids needing to put the documentation line on any specific position relative to actual rule. I also intentionally avoid sorting the output because the order of output can be fully controlled from the Makefile itself simply by listing the documentation lines in preferred order.

显然,您可以发明任何其他您喜欢的语法,甚至可以做一些

### en: install: Install all files in $PREFIX
### fi: asennus: asenna kaikki tiedostot hakemistoon $PREFIX

并且只打印与当前语言环境匹配的行,以支持多种语言,并具有别名来本地化目标名称:

.PHONY: asennus
asennus: install

最重要的问题是为什么要列出目标?您想要实际的文档还是某种调试信息?