README ¶
Buildozer
Buildozer is a command line tool to rewrite multiple Bazel BUILD files using standard commands.
Installation
- Build a binary and put it into your $GOPATH/bin:
go get github.com/bazelbuild/buildtools/buildozer
Usage
buildozer [OPTIONS] ['command args' | -f FILE ] label-list
Here, label-list
is a comma-separated list of Bazel labels, for example
//path/to/pkg1:rule1, //path/to/pkg2:rule2
. Buildozer reads commands from
FILE
(-
for stdin (format: |
-separated command line arguments to buildozer,
excluding flags))
You should specify at least one command and one target. Buildozer will execute all commands on all targets. Commands are executed in order, files are processed in parallel.
Targets
Targets look like Bazel labels, but there can be some differences in presence of macros.
- Use the label notation to refer to a rule:
//buildtools/buildozer:edit
- Use the
__pkg__
suffix to refer to the package declaration://buildtools/buildozer:__pkg__
- Use an asterisk to refer to all rules in a file:
//pkg:*
- Use
...
to refer to all descendant BUILD files in a directory://pkg/...:*
- Use percent to refer to all rules of a certain kind:
//pkg:%java_library
- Use percent-and-number to refer to a rule that begins at a certain line:
//pkg:%123
. - Use
-
for the package name if you want to process standard input stream instead of a file:-:all_tests
.
Options
OPTIONS include the following options:
-stdout
: write changed BUILD file to stdout-buildifier
: format output using a specific buildifier binary. If empty, use built-in formatter.-k
: apply all commands, even if there are failures-quiet
: suppress informational messages-shorten_labels
: convert added labels to short form, e.g. //foo:bar => :bar-types
: Filter the targets, keeping only those of the given types, e.g.buildozer -types go_library,go_binary 'print rule' '//buildtools/buildozer:*'
-eol-comments=false
: When adding new comments, put them on a separate line.
See buildozer -help
for the full list.
Edit commands
Buildozer supports the following commands('command args'
):
add <attr> <value(s)>
: Adds value(s) to a list attribute of a rule. If a value is already present in the list, it is not added.new_load <path> <[to=]from(s)>
: Add a load statement for the given path, importing the symbols. Before using this, make sure to runbuildozer 'fix movePackageToTop'
. Afterwards, consider runningbuildozer 'fix unusedLoads'
.replace_load <path> <[to=]from(s)>
: Similar tonew_load
, but removes existing load statements for the requested symbols before adding new loads.substitute_load <old_regexp> <new_template>
Replaces modules of loads which matchold_regexp
according tonew_template
. The regular expression must follow RE2 syntax.new_template
may be a simple replacement string, but it may also expand numbered or named groups using$0
or$x
.comment <attr>? <value>? <comment>
: Add a comment to a rule, an attribute, or a specific value in a list. Spaces in the comment should be escaped with backslashes.print_comment <attr>? <value>?
delete
: Delete a rule.fix <fix(es)>?
: Apply a fix.move <old_attr> <new_attr> <value(s)>
: Movesvalue(s)
from the listold_attr
to the listnew_attr
. The wildcard*
matches all values.new <rule_kind> <rule_name> [(before|after) <relative_rule_name>]
: Add a new rule at the end of the BUILD file (before/after<relative_rule>
).print <attr(s)>
remove <attr>
: Removes attributeattr
.remove <attr> <value(s)>
: Removesvalue(s)
from the listattr
. The wildcard*
matches all attributes. Lists containing none of thevalue(s)
are not modified.remove_comment <attr>? <value>?
: Removes the comment attached to the rule, an attribute, or a specific value in a list.rename <old_attr> <new_attr>
: Rename theold_attr
tonew_attr
which must not yet exist.replace <attr> <old_value> <new_value>
: Replacesold_value
withnew_value
in the listattr
. Wildcard*
matches all attributes. Lists not containingold_value
are not modified.substitute <attr> <old_regexp> <new_template>
: Replaces strings which matchold_regexp
in the listattr
according tonew_template
. Wildcard*
matches all attributes. The regular expression must follow RE2 syntax.new_template
may be a simple replacement string, but it may also expand numbered or named groups using$0
or$x
. Lists without strings that matchold_regexp
are not modified.set <attr> <value(s)>
: Sets the value of an attribute. If the attribute was already present, its old value is replaced.set_if_absent <attr> <value(s)>
: Sets the value of an attribute. If the attribute was already present, no action is taken.set kind <value>
: Set the target type to value.copy <attr> <from_rule>
: Copies the value ofattr
between rules. If it exists in theto_rule
, it will be overwritten.copy_no_overwrite <attr> <from_rule>
: Copies the value ofattr
between rules. If it exists in theto_rule
, no action is taken.dict_add <attr> <(key:value)(s)>
: Sets the value of a key for the dict attributeattr
. If the key was already present, it will not be overwrittendict_set <attr> <(key:value)(s)>
: Sets the value of a key for the dict attributeattr
. If the key was already present, its old value is replaced.dict_delete <attr> <key(s)>
: Deletes the key for the dict attributeattr
.dict_list_add <attr> <key> <value(s)>
: Adds value(s) to the list in the dict attributeattr
.
Here, <attr>
represents an attribute (being add
ed/rename
d/delete
d etc.),
e.g.: srcs
, <value(s)>
represents values of the attribute and so on.
A '?' indicates that the preceding argument is optional.
The fix command without a fix specified applied to all eligible fixes.
Use //path/to/pkg:__pkg__
as label for file level changes like new_load
and
new
.
A transformation can be applied to all rules of a particular kind by using
%rule_kind
at the end of the label(see examples below).
Examples
# Edit //pkg:rule and //pkg:rule2, and add a dependency on //base
buildozer 'add deps //base' //pkg:rule //pkg:rule2
# A load for a skylark file in //pkg
buildozer 'new_load //tools/build_rules:build_test.bzl build_test' //pkg:__pkg__
# Replaces existing loads for build_test in //pkg
buildozer 'replace_load @rules_build//build:defs.bzl build_test' //pkg:__pkg__
# Replaces modules of loads using regular expressions.
#
# In this example
# load("@rules_foo//foo:defs.bzl", "foo_library", "foo_test")
# will be replaced with
# load("//third_party/build_defs/rules_foo/foo:defs.bzl", "foo_library", "foo_test")
buildozer 'substitute_load ^@([^/]*)//([^:].*)$ //third_party/build_defs/${1}/${2}' //pkg:__pkg__
# Change the default_visibility to public for the package //pkg
buildozer 'set default_visibility //visibility:public' //pkg:__pkg__
# Change all gwt_module targets to java_library in the package //pkg
buildozer 'set kind java_library' //pkg:%gwt_module
# Replace the dependency on pkg_v1 with a dependency on pkg_v2
buildozer 'replace deps //pkg_v1 //pkg_v2' //pkg:rule
# Replace all dependencies using regular expressions.
buildozer 'substitute deps //old/(.*) //new/${1}' //pkg:rule
# Delete the dependency on foo in every cc_library in the package
buildozer 'remove deps foo' //pkg:%cc_library
# Delete the testonly attribute in every rule in the package
buildozer 'remove testonly' '//pkg:*'
# Add a comment to the timeout attribute of //pkg:rule_test
buildozer 'comment timeout Delete\ this\ after\ 2015-12-31.' //pkg:rule_test
# Add a new rule at the end of the file
buildozer 'new java_library foo' //pkg:__pkg__
# Add a cc_binary rule named new_bin before the rule named tests
buildozer 'new cc_binary new_bin before tests' //:__pkg__
# Copy an attribute from `protolib` to `py_protolib`.
buildozer 'copy testonly protolib' //pkg:py_protolib
# Set two attributes in the same rule
buildozer 'set compile 1' 'set srcmap 1' //pkg:rule
# Make a default explicit in all soy_js rules in a package
buildozer 'set_if_absent allowv1syntax 1' //pkg:%soy_js
# Add an attribute new_attr with value "def_val" to all cc_binary rules
# Note that special characters will automatically be escaped in the string
buildozer 'add new_attr def_val' //:%cc_binary
Print commands
These commands are not modifying files, Buildifier returns 0 after a successful execution.
print <attribute(s)>
: For each target, prints the value of the attributes (see below).print_comment <attr>? <value>?
: Prints a comment associated with a rule, an attribute or a specific value in a list.
The print command prints the value of the attributes. If a target doesn't have the attribute, a warning is printed on stderr.
There are some special attributes in the print
command:
kind
: displays the name of the functionlabel
: the fully qualified labelrule
: the entire rule definitionstartline
: the line number on which the rule begins in the BUILD fileendline
: the line number on which the rule ends in the BUILD file
Examples
# Print the kind of a target
buildozer 'print kind' base # output: cc_library
# Print the name of all cc_library in //base
buildozer 'print name' base:%cc_library
# Get the default visibility of the //base package
buildozer 'print default_visibility' base:%package
# Print labels of cc_library targets in //base that have a deps attribute
buildozer 'print label deps' base:%cc_library 2>/dev/null | cut -d' ' -f1
# Print the list of labels in //base that explicitly set the testonly attribute:
buildozer 'print label testonly' 'base:*' 2>/dev/null
# Print the entire definition (including comments) of the //base:heapcheck rule:
buildozer 'print rule' //base:heapcheck
Converting labels
Buildozer works at the syntax-level. It doesn't evaluate the BUILD files. If you
need to query the information Bazel has, please use bazel query
. If you have a
list of Bazel labels, chances are that some of them are generated by BUILD
extensions. Labels in Buildozer are slightly different from labels in Bazel.
Bazel cares about the generated code, while Buildozer looks at the BUILD file
before macro expansion.
To see the expanded BUILD files, try:
bazel query --output=build //path/to/BUILD
Do multiple changes at once
Use buildozer -f <file>
to load a list of commands from a file. The usage is
just like arguments on the command-line, except that arguments are separated by
|
.
$ cat /tmp/cmds
new cc_library foo|//buildtools/buildozer/BUILD
add deps //base //strings|add srcs foo.cc|//buildtools/buildozer:foo
add deps :foo|//buildtools/buildozer
$ buildozer -f /tmp/cmds
fixed //buildtools/buildozer/BUILD
The list of commands will typically be generated and can be large. This is efficient: Commands are grouped so that each file is modified once. Files are processed in parallel.
Error code
The return code is:
0
on success, if changes were made or only readonly commands were executed1
when there is a usage error2
when at least one command has failed3
on success, when no changes were made
Source Structure
buildozer/main.go
: Entry point for the buildozer binaryedit/buildozer.go
: Implementation of functions for the buildozer commandsedit/edit.go
: Library functions to perform various operations on ASTs. These- functions are called by the impl functions in buildozer.go
edit/fix.go
: Functions for various fixes for thebuildozer 'fix <fix(es)>'
command, like cleaning unused loads, changing labels to canonical notation, etc.edit/types.go
: Type information for attributes
Documentation ¶
There is no documentation for this package.