GNU Make Cheatsheet

Based on https://www.gnu.org/software/make/manual/html_node/Quick-Reference.html

Directives ¶

Directive	Description
`define variable` `define variable =` `define variable :=` `define variable ::=` `define variable +=` `define variable ?=` `endef`	Define multi-line variables.
`undefine variable`	Undefining variables.
`ifdef variable` `ifndef variable` `ifeq (a,b)` `ifeq "a" "b"` `ifeq 'a' 'b'` `ifneq (a,b)` `ifneq "a" "b"` `ifneq 'a' 'b'` `else` `endif`	Conditionally evaluate part of the makefile.
`include file` `-include file` `sinclude file`	Include another makefile.
`override variable-assignment`	Define a variable, overriding any previous definition, even one from the command line.
`export`	Tell make to export all variables to child processes by default.
`export variable` `export variable-assignment` `unexport variable`	Tell make whether or not to export a particular variable to child processes.
`private variable-assignment`	Do not allow this variable assignment to be inherited by prerequisites.
`vpath pattern path`	Specify a search path for files matching a ‘%’ pattern.
`vpath pattern`	Remove all search paths previously specified for pattern.
`vpath`	Remove all search paths previously specified in any vpath directive.

Built-in Functions ¶

Function	Description
`$(subst from,to,text)`	Replace `from` with `to` in `text`.
`$(patsubst pattern,replacement,text)`	Replace words matching `pattern` with `replacement` in `text`.
`$(strip string)`	Remove excess whitespace characters from `string`.
`$(findstring find,text)`	Locate find in `text`.
`$(filter pattern…,text)`	Select words in `text` that match one of the `pattern` words.
`$(filter-out pattern…,text)`	Select words in `text` that do not match any of the `pattern` words.
`$(sort list)`	Sort the words in `list` lexicographically, removing duplicates.
`$(word n,text)`	Extract the `n`-th word (one-origin) of `text`.
`$(words text)`	Count the number of words in `text`.
`$(wordlist s,e,text)`	Returns the list of words in `text` from `s` to `e`.
`$(firstword names…)`	Extract the first word of `names`.
`$(lastword names…)`	Extract the last word of `names`.
`$(dir names…)`	Extract the directory part of each file name.
`$(notdir names…)`	Extract the non-directory part of each file name.
`$(suffix names…)`	Extract the suffix (the last ‘.’ and following characters) of each file name.
`$(basename names…)`	Extract the base name (name without suffix) of each file name.
`$(addsuffix suffix,names…)`	Append `suffix` to each word in `names`.
`$(addprefix prefix,names…)`	Prepend `prefix` to each word in `names`.
`$(join list1,list2)`	Join two parallel lists of words.
`$(wildcard pattern…)`	Find file names matching a shell file name pattern (not a ‘%’ pattern).
`$(realpath names…)`	For each file name in `names`, expand to an absolute name that does not contain any ., .., nor symlinks.
`$(abspath names…)`	For each file name in `names`, expand to an absolute name that does not contain any . or .. components, but preserves symlinks.
`$(error text…)`	When this function is evaluated, make generates a fatal error with the message `text`.
`$(warning text…)`	When this function is evaluated, make generates a warning with the message `text`.
`$(shell command)`	Execute a shell command and return its output.
`$(origin variable)`	Return a string describing how the make variable `variable` was defined.
`$(flavor variable)`	Return a string describing the flavor of the make variable `variable`.
`$(foreach var,words,text)`	Evaluate `text` with `var` bound to each word in `words`, and concatenate the results.
`$(if cond,then-part[,else-part])`	Evaluate `cond`; if it’s non-empty substitute the expansion of the `then-part` otherwise substitute the expansion of the `else-part`.
`$(or cond1[,cond2[,cond3…]])`	Evaluate `condN` one at a time; substitute the first non-empty expansion. If all expansions are empty, substitute the empty string.
`$(and cond1[,cond2[,cond3…]])`	Evaluate `condN` one at a time; if any results in empty string substitute the empty string. Otherwise substitute the expansion of the last `condN`.
`$(call var,param,…)`	Evaluate the variable `var` replacing any references to `$(1)`, `$(2)` with the first, second, etc. param values.
`$(eval text)`	Evaluate `text` then read the results as makefile commands; expands to the empty string.
`$(file op filename,text)`	Expand the arguments, then open the file `filename` using mode `op` and write `text` to that file.
`$(value var)`	Evaluates to the contents of the variable `var`, with no expansion performed on it.

Automatic Variables ¶

Variable	Description
`$@`	The file name of the target.
`$%`	The target member name, when the target is an archive member.
`$<`	The name of the first prerequisite.
`$?`	The names of all the prerequisites newer than the target, with spaces between them. For prerequisites which are archive members, only the named member is used (see Archives).
`$^` `$+`	The names of all the prerequisites, with spaces between them. For prerequisites which are archive members, only the named member is used (see Archives). The value of $^ omits duplicate prerequisites, while $+ retains them and preserves their order.
`$*`	The stem with which an implicit rule matches (see How Patterns Match).
`$(@D)` `$(@F)`	The directory part and the file-within-directory part of `$@`.
`$(D)` `$(F)`	The directory part and the file-within-directory part of `$*`.
`$(%D)` `$(%F)`	The directory part and the file-within-directory part of `$%`.
`$(<D)` `$(<F)`	The directory part and the file-within-directory part of `$<`.
`$(^D)` `$(^F)`	The directory part and the file-within-directory part of `$^`.
`$(+D)` `$(+F)`	The directory part and the file-within-directory part of `$+`.
`$(?D)` `$(?F)`	The directory part and the file-within-directory part of `$?`.

Special Variables ¶

Variables	Description
`MAKEFILES`	Makefiles to be read on every invocation of make.
`VPATH`	Directory search path for files not found in the current directory.
`SHELL`	The name of the system default command interpreter, usually `/bin/sh`.
`MAKESHELL`	The name of the command interpreter that is to be used by make, taking precedence over `SHELL` (MS-DOS only).
`MAKE`	The name with which make was invoked (using this variable in recipes has special meaning).
`MAKE_VERSION`	The built-in variable `MAKE_VERSION` expands to the version number of the GNU make program.
`MAKE_HOST`	The built-in variable `MAKE_HOST` expands to a string representing the host that GNU make was built to run on.
`MAKELEVEL`	The number of levels of recursion (sub-makes).
`MAKEFLAGS`	The flags given to make. You can set this in the environment or a makefile to set flags. It is never appropriate to use MAKEFLAGS directly in a recipe line: its contents may not be quoted correctly for use in the shell. Always allow recursive make’s to obtain these values through the environment from its parent.
`GNUMAKEFLAGS`	Other flags parsed by make. You can set this in the environment or a makefile to set make command-line flags. GNU make never sets this variable itself. This variable is only needed if you’d like to set GNU make-specific flags in a POSIX-compliant makefile. This variable will be seen by GNU make and ignored by other make implementations. It’s not needed if you only use GNU make; just use MAKEFLAGS directly. See Communicating Options to a Sub-make.
`MAKECMDGOALS`	The targets given to make on the command line. Setting this variable has no effect on the operation of make.
`CURDIR`	Set to the absolute pathname of the current working directory (after all -C options are processed, if any). Setting this variable has no effect on the operation of make.
`SUFFIXES`	The default list of suffixes before make reads any makefiles.
`.LIBPATTERNS`	Defines the naming of the libraries make searches for, and their order.