傳遞至規則或切面實作函式的內容物件。這個程式庫可存取分析目前目標所需的資訊和方法。
特別是,它可讓實作函式存取目前目標的標籤、屬性、設定和其依附元件的提供者。其中包含宣告輸出檔案的方法和產生這些檔案的動作。
情境物件在呼叫實作函式的期間基本上有效。在關聯函式以外的地方存取這些物件並不實用。詳情請參閱規則頁面。
成員
- 動作
- aspect_ids
- attr
- bin_dir
- build_file_path
- build_setting_value
- 設定
- coverage_instrumented
- created_actions
- disabled_features
- exec_groups
- 可執行
- expand_location
- expand_make_variables
- 功能
- 檔案
- 檔案
- 片段
- genfiles_dir
- info_file
- 標籤
- 輸出內容
- resolve_command
- resolve_tools
- 規則
- runfiles
- split_attr
- 超級
- target_platform_has_constraint
- 工具鍊
- var
- version_file
- workspace_name
作業
actions ctx.actions
aspect_ids
list ctx.aspect_ids
attr
struct ctx.attr
rule
函式的 attrs
字典的鍵和值。查看使用範例。
bin_dir
root ctx.bin_dir
build_file_path
string ctx.build_file_path
build_setting_value
unknown ctx.build_setting_value
build_setting
屬性的規則例項,則系統會顯示錯誤訊息。
設定
configuration ctx.configuration
coverage_instrumented
bool ctx.coverage_instrumented(target=None)
target
,則傳回該目標指定的規則。(如果提供了非規則或 Starlark 規則目標,則會傳回 False。)檢查目前規則的來源 (若未提供目標) 或目標來源是否應根據 --instrumentation_filter 和 --instrument_test_targets 配置設定進行檢測。這與設定中的 coverage_enabled
不同,後者會指出整個執行作業是否已啟用涵蓋範圍資料收集功能,但不會對特定目標進行檢測。
參數
參數 | 說明 |
---|---|
target
|
Target;或 None ;
預設值為 None 指定規則的目標。如未提供,則會預設為目前的規則。 |
created_actions
StarlarkValue ctx.created_actions()
True
,則會傳回 Actions
供應器,代表目前已根據目前規則建立的所有動作。針對所有其他規則,則傳回 None
。請注意,後續動作建立時不會更新供應器,因此如要檢查,您必須再次呼叫這個函式。這是為了協助編寫規則實作輔助函式的測試,測試會接收
ctx
物件並建立動作。
disabled_features
list ctx.disabled_features
exec_groups
ExecGroupCollection ctx.exec_groups
ctx.exec_groups[name_of_group]
」存取。
執行檔
struct ctx.executable
struct
,包含以標籤類型屬性定義且標示為 executable=True
的可執行檔。struct 欄位對應的是屬性名稱。結構中的每個值都是 File
或 None
。如果規則中未指定選用屬性,則對應的結構值會是 None
。如果標籤類型未標示為 executable=True
,則不會產生相對應的結構體欄位。查看使用範例。
expand_location
string ctx.expand_location(input, targets=[])
$(location //x)
替換為目標 //x 的輸出檔案路徑,展開指定字串中的所有 $(location ...)
範本。擴充功能僅適用於指向這項規則的直接依附性標籤,或是明確列於選用引數 targets
中的標籤。$(location ...)
如果參照的目標有多項輸出內容,就會發生錯誤。在這種情況下,請使用 $(locations ...)
,因為這會產生以空格分隔的輸出路徑清單。這也可以安全用於單一輸出檔案。這個函式可用來讓使用者在 BUILD 檔案中指定指令 (例如
genrule
)。在其他情況下,建議您直接操控標籤。
參數
參數 | 說明 |
---|---|
input
|
必要 要展開的字串。 |
targets
|
目標的序列;
預設值為 [] 列出其他查詢資訊的目標清單。 |
None
。
expand_make_variables
string ctx.expand_make_variables(attribute_name, command, additional_substitutions)
在展開所有「Make 變數」參照後傳回字串。變數必須採用下列格式:
$(VAR_NAME)
。其他班次:$$VAR_NAME
expands to $VAR_NAME
. Examples:ctx.expand_make_variables("cmd", "$(MY_VAR)", {"MY_VAR": "Hi"}) # == "Hi" ctx.expand_make_variables("cmd", "$$PWD", {}) # == "$PWD" Additional variables may come from other places, such as configurations. Note that this function is experimental.Parameters
Parameter | Description |
---|---|
attribute_name
|
required The attribute name. Used for error reporting. |
command
|
required The expression to expand. It can contain references to "Make variables". |
additional_substitutions
|
required Additional substitutions to make beyond the default make variables. |
features
list ctx.features
file
struct ctx.file
struct
containing files defined in label type attributes marked as allow_single_file
. The struct fields correspond to the attribute names. The struct value is always a File
or None
. If an optional attribute is not specified in the rule then the corresponding struct value is None
. If a label type is not marked as allow_single_file
, no corresponding struct field is generated. It is a shortcut for:list(ctx.attr.<ATTR>.files)[0]
file
to access the (singular) default output of a dependency. See example of use.
files
struct ctx.files
struct
containing files defined in label or label list type attributes. The struct fields correspond to the attribute names. The struct values are list
of File
s. It is a shortcut for:[f for t in ctx.attr.<ATTR> for f in t.files]
files
to access the default outputs of a dependency. See example of use.
fragments
fragments ctx.fragments
genfiles_dir
root ctx.genfiles_dir
info_file
File ctx.info_file
label
Label ctx.label
outputs
structure ctx.outputs
File
objects. See the Rules page for more information and examples.This field does not exist on aspect contexts, since aspects do not have predeclared outputs.
The fields of this object are defined as follows. It is an error if two outputs produce the same field name or have the same label.
- If the rule declares an
outputs
dict, then for every entry in the dict, there is a field whose name is the key and whose value is the correspondingFile
. - For every attribute of type
attr.output
that the rule declares, there is a field whose name is the attribute's name. If the target specified a label for that attribute, then the field value is the correspondingFile
; otherwise the field value isNone
. - For every attribute of type
attr.output_list
that the rule declares, there is a field whose name is the attribute's name. The field value is a list ofFile
objects corresponding to the labels given for that attribute in the target, or an empty list if the attribute was not specified in the target. - (Deprecated) If the rule is marked
executable
ortest
, there is a field named"executable"
, which is the default executable. It is recommended that instead of using this, you pass another file (either predeclared or not) to theexecutable
arg ofDefaultInfo
.
resolve_command
tuple ctx.resolve_command(command='', attribute=None, expand_locations=False, make_variables=None, tools=[], label_dict={}, execution_requirements={})
(inputs, command, input_manifests)
of the list of resolved inputs, the argv list for the resolved command, and the runfiles metadata required to run the command, all of them suitable for passing as the same-named arguments of the ctx.action
method.Note for Windows users: this method requires Bash (MSYS2). Consider using
resolve_tools()
instead (if that fits your needs).
Parameters
Parameter | Description |
---|---|
command
|
default is '' Command to resolve. |
attribute
|
string; or None ;
default is None Name of the associated attribute for which to issue an error, or None. |
expand_locations
|
default is False Shall we expand $(location) variables? See ctx.expand_location() for more details. |
make_variables
|
dict; or None ;
default is None Make variables to expand, or None. |
tools
|
sequence of Targets;
default is [] List of tools (list of targets). |
label_dict
|
default is {} Dictionary of resolved labels and the corresponding list of Files (a dict of Label : list of Files). |
execution_requirements
|
default is {} Information for scheduling the action to resolve this command. See tags for useful keys. |
resolve_tools
tuple ctx.resolve_tools(tools=[])
(inputs, input_manifests)
of the depset of resolved inputs and the runfiles metadata required to run the tools, both of them suitable for passing as the same-named arguments of the ctx.actions.run
method.In contrast to
ctx.resolve_command
, this method does not require that Bash be installed on the machine, so it's suitable for rules built on Windows.
Parameters
Parameter | Description |
---|---|
tools
|
sequence of Targets;
default is [] List of tools (list of targets). |
rule
rule_attributes ctx.rule
runfiles
runfiles ctx.runfiles(files=[], transitive_files=None, collect_data=False, collect_default=False, symlinks={}, root_symlinks={})
Parameters
Parameter | Description |
---|---|
files
|
sequence of Files;
default is [] The list of files to be added to the runfiles. |
transitive_files
|
depset of Files; or None ;
default is None The (transitive) set of files to be added to the runfiles. The depset should use the default order (which, as the name implies, is the default).
|
collect_data
|
default is False Use of this parameter is not recommended. See runfiles guide. Whether to collect the data runfiles from the dependencies in srcs, data and deps attributes. |
collect_default
|
default is False Use of this parameter is not recommended. See runfiles guide. Whether to collect the default runfiles from the dependencies in srcs, data and deps attributes. |
symlinks
|
dict; or depset of SymlinkEntrys;
default is {} Either a SymlinkEntry depset or the map of symlinks to be added to the runfiles. Symlinks are always added under the main workspace's runfiles directory (e.g. <runfiles_root>/_main/<symlink_path> , not the directory corresponding to the current target's repository. See Runfiles symlinks in the rules guide.
|
root_symlinks
|
dict; or depset of SymlinkEntrys;
default is {} Either a SymlinkEntry depset or a map of symlinks to be added to the runfiles. See Runfiles symlinks in the rules guide. |
split_attr
struct ctx.split_attr
super
unknown ctx.super()
target_platform_has_constraint
bool ctx.target_platform_has_constraint(constraintValue)
Parameters
Parameter | Description |
---|---|
constraintValue
|
required The constraint value to check the target platform against. |
toolchains
ToolchainContext ctx.toolchains
var
dict ctx.var
version_file
File ctx.version_file
workspace_name
string ctx.workspace_name