字元

7.3 · 7.2 · 7.1 · 7.0 · 6.5

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

作業

actions ctx.actions

包含宣告輸出檔案和產生這些檔案的動作的方法。

aspect_ids

list ctx.aspect_ids

套用至目標的所有面向 ID 清單。僅適用於面向切入點的實作函式。

attr

struct ctx.attr

用於存取屬性值的結構體。這些值由使用者提供 (如未提供，則會使用預設值)。結構的屬性和值類型會對應至提供給 rule 函式的 attrs 字典的鍵和值。查看使用範例。

bin_dir

root ctx.bin_dir

繫結目錄的根目錄。

build_file_path

string ctx.build_file_path

這項規則的 BUILD 檔案路徑 (相對於來源根目錄)。

build_setting_value

unknown ctx.build_setting_value

目前目標所代表的建構設定值。如果這不是設定 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

預設設定。詳情請參閱設定類型。

coverage_instrumented

bool ctx.coverage_instrumented(target=None)

傳回是否應在執行此規則或 (如果提供 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()

如果規則的 _skylark_testable 設為 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

使用者為這項規則明確停用的功能組合。

exec_groups

ExecGroupCollection ctx.exec_groups

這個規則可用的執行群組集合，並以名稱做為索引。使用 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=[])

將 $(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。
可能會傳回 None。

expand_make_variables

string ctx.expand_make_variables(attribute_name, command, additional_substitutions)

已淘汰。請改用 ctx.var 存取變數。
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


    The set of features that are explicitly enabled by the user for this rule. See example of use.


        
file

        
struct ctx.file


    A 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]
In other words, use file to access the (singular) default output of a dependency. See example of use.


        
files

        
struct ctx.files


    A 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 Files.  It is a shortcut for:
[f for t in ctx.attr.<ATTR> for f in t.files]
 In other words, use files to access the  default outputs of a dependency. See example of use.


        
fragments

        
fragments ctx.fragments


    Allows access to configuration fragments in target configuration.


        
genfiles_dir

        
root ctx.genfiles_dir


    The root corresponding to genfiles directory.


        
info_file

        
File ctx.info_file


    The file that is used to hold the non-volatile workspace status for the current build request. See documentation for --workspace_status_command for more information.


        
label

        
Label ctx.label


    The label of the target currently being analyzed.


        
outputs

        
structure ctx.outputs


    A pseudo-struct containing all the predeclared output files, represented by 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 corresponding File.
  • 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 corresponding File; otherwise the field value is None.
  • 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 of File 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 or test, 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 the executable arg of DefaultInfo.



        
resolve_command

        
tuple ctx.resolve_command(command='', attribute=None, expand_locations=False, make_variables=None, tools=[], label_dict={}, execution_requirements={})


    (Experimental) Returns a tuple (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=[])


    Returns a tuple (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


    Rule attributes descriptor for the rule that the aspect is applied to. Only available in aspect implementation functions.


        
runfiles

        
runfiles ctx.runfiles(files=[], transitive_files=None, collect_data=False, collect_default=False, symlinks={}, root_symlinks={})


    Creates a runfiles object.

          
      
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.
            

          

                  

            
            
                          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.
            		
          

                  

            
            
                          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


    A struct to access the values of attributes with split configurations. If the attribute is a label list, the value of split_attr is a dict of the keys of the split (as strings) to lists of the ConfiguredTargets in that branch of the split. If the attribute is a label, then the value of split_attr is a dict of the keys of the split (as strings) to single ConfiguredTargets. Attributes with split configurations still appear in the attr struct, but their values will be single lists with all the branches of the split merged together.


        
super

        
unknown ctx.super()


    Experimental: Calls parent's implementation function and returns its providers


        
target_platform_has_constraint

        
bool ctx.target_platform_has_constraint(constraintValue)


    Returns true if the given constraint value is part of the current target platform.

          
      
Parameters

      

        
          
          
        
        
          

            Parameter
            Description
          

        
        
                  

            
              constraintValue
            
            
                                     required

                          The constraint value to check the target platform against.
            		
          

                
      


        
toolchains

        
ToolchainContext ctx.toolchains


    Toolchains for the default exec group of this rule.


        
var

        
dict ctx.var


    Dictionary (String to String) of configuration variables.


        
version_file

        
File ctx.version_file


    The file that is used to hold the volatile workspace status for the current build request. See documentation for --workspace_status_command for more information.


        
workspace_name

        
string ctx.workspace_name


    The workspace name as defined in the WORKSPACE file.