傳遞至規則或切面實作函式的結構定義物件。可存取分析目前目標所需的資訊和方法。
具體來說,這可讓實作函式存取目前目標的標籤、屬性、設定,以及其依附元件的提供者。這個類別提供方法,可宣告輸出檔案和產生這些檔案的動作。
內容物件基本上會在呼叫實作函式的期間保留。在相關聯函式以外存取這些物件並無實用性。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
- file
- files
- 片段
- genfiles_dir
- info_file
- label
- outputs
- resolve_command
- resolve_tools
- rule
- runfiles
- split_attr
- super
- target_platform_has_constraint
- toolchains
- 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
屬性的規則例項的上下文,讀取這個值會導致錯誤。設定
configuration ctx.configuration
coverage_instrumented
bool ctx.coverage_instrumented(target=None)
target
的話) 由該目標指定的規則時,產生程式碼涵蓋率檢測工具。(如果提供非規則或 Starlark 規則目標,則會傳回 False)。檢查目前規則的來源 (如果未提供目標) 或目標來源是否應根據 --instrumentation_filter 和 --instrument_test_targets 設定進行檢測。這與設定中的 coverage_enabled
不同,後者會指出是否要為整個執行作業啟用涵蓋率資料收集,但不會指出是否要為特定目標進行檢測。
參數
參數 | 說明 |
---|---|
target
|
Target 或 None ;預設為 None 。指定規則的 Target。如果未提供,則預設為目前的規則。 |
created_actions
StarlarkValue ctx.created_actions()
True
,這項作業會傳回 Actions
供應器,代表目前規則至今為止所建立的所有動作。針對所有其他規則,則傳回 None
。請注意,在建立後續動作時,供應器不會更新,因此如果您想檢查這些動作,就必須再次呼叫這個函式。這有助於為規則實作輔助函式編寫測試,這些函式可能會接收
ctx
物件,並在該物件上建立動作。
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
包含在標籤類型屬性中定義的執行檔,並標示為 executable=True
。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
,系統就不會產生對應的 struct 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 $(location ...)
範本。展開功能僅適用於指向此規則直接依附元件的標籤,或是在選用引數 targets
中明確列出的標籤。如果參照的目標有多個輸出項目,$(location ...)
就會導致錯誤。在這種情況下,請使用 $(locations ...)
,因為它會產生以空格分隔的輸出路徑清單。這也可以安全地用於單一輸出檔案。使用者可以使用此函式在 BUILD 檔案中指定指令 (例如
genrule
)。在其他情況下,建議您直接控管標籤。
參數
參數 | 說明 |
---|---|
input
|
required String to be expanded. |
targets
|
Target 的序列;預設為 [] 。 列出其他查詢資訊的目標。 |
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,會傳回字串。變數必須採用下列格式:
$(VAR_NAME)
。此外,$$VAR_NAME
expands to $VAR_NAME
. Examples:ctx.expand_make_variables("cmd", "$(MY_VAR)", {"MY_VAR": "Hi"}) # == "Hi" ctx.expand_make_variables("cmd", "$$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