[7.4.0] Repo context cherry-picks (#23389)

Cherry-picks the following commits:
* Clarify /rules/lib/builtins/repository_ctx description of default
working_directory for execute()
(fa2fbcd)
* Normalize repository starlark API docs
(8f16990)
* Document source of truth for `rctx.download*` cache key
(d4b416f)
* Make `get_default_canonical_id` public
(6052ad6)
* No longer eagerly fetch labels in repo rule
(6fabb1f)

Closes #23372

---------

Co-authored-by: David Sanderson <32687193+dws@users.noreply.github.com>
Co-authored-by: Jordan Mele <SiliconSoldier@outlook.com.au>
Co-authored-by: Jordan Mele <jordan.mele@outlook.com.au>

src/main/java/com/google/devtools/build/lib/bazel/repository/starlark/StarlarkExecutionResult.java

@@ -50,9 +50,11 @@
     name = "exec_result",
     category = DocCategory.BUILTIN,
     doc =
-        "A structure storing result of repository_ctx.execute() method. It contains the standard"
-            + " output stream content, the standard error stream content and the execution return"
-            + " code.")
+        """
+        A structure storing result of repository_ctx.execute() method. It contains the standard \
+        output stream content, the standard error stream content and the execution return \
+        code.
+        """)
 final class StarlarkExecutionResult implements StarlarkValue {
   private final int returnCode;
   private final String stdout;
@@ -73,9 +75,11 @@ public boolean isImmutable() {
       name = "return_code",
       structField = true,
       doc =
-          "The return code returned after the execution of the program. 256 if the process was"
-              + " terminated by a time out; values larger than 128 indicate termination by a"
-              + " signal.")
+          """
+          The return code returned after the execution of the program. 256 if the process was \
+          terminated by a time out; values larger than 128 indicate termination by a \
+          signal.
+          """)
   public int getReturnCode() {
     return returnCode;
   }

src/main/java/com/google/devtools/build/lib/bazel/repository/starlark/StarlarkOS.java

@@ -46,12 +46,14 @@ public boolean isImmutable() {
       name = "environ",
       structField = true,
       doc =
-          "The dictionary of environment variables."
-              + "<p><b>NOTE</b>: Retrieving an environment variable from this dictionary does not "
-              + "establish a dependency from a repository rule or module extension to the "
-              + "environment variable.  To establish a dependency when looking up an "
-              + "environment variable, use either <code>repository_ctx.getenv</code> or "
-              + "<code>module_ctx.getenv</code> instead.")
+          """
+          The dictionary of environment variables. \
+          <p><b>NOTE</b>: Retrieving an environment variable from this dictionary does not \
+          establish a dependency from a repository rule or module extension to the \
+          environment variable. To establish a dependency when looking up an \
+          environment variable, use either <code>repository_ctx.getenv</code> or \
+          <code>module_ctx.getenv</code> instead.
+          """)
   public ImmutableMap<String, String> getEnvironmentVariables() {
     return environ;
   }
@@ -60,8 +62,10 @@ public ImmutableMap<String, String> getEnvironmentVariables() {
       name = "name",
       structField = true,
       doc =
-          "A string identifying the operating system Bazel is running on (the value of the"
-              + " \"os.name\" Java property converted to lower case).")
+          """
+          A string identifying the operating system Bazel is running on (the value of the \
+          <code>"os.name"</code> Java property converted to lower case).
+          """)
   public String getName() {
     return System.getProperty("os.name").toLowerCase(Locale.ROOT);
   }
@@ -70,8 +74,10 @@ public String getName() {
       name = "arch",
       structField = true,
       doc =
-          "A string identifying the architecture Bazel is running on (the value of the \"os.arch\""
-              + " Java property converted to lower case).")
+          """
+          A string identifying the architecture Bazel is running on (the value of the \
+          <code>"os.arch"</code> Java property converted to lower case).
+          """)
   public String getArch() {
     return System.getProperty("os.arch").toLowerCase(Locale.ROOT);
   }

src/main/java/com/google/devtools/build/lib/bazel/repository/starlark/StarlarkPath.java

@@ -84,24 +84,27 @@ public String getBasename() {
   @StarlarkMethod(
       name = "readdir",
       doc =
-          "Returns the list of entries in the directory denoted by this path. Each entry is a "
-              + "<code>path</code> object itself.",
+          """
+          Returns the list of entries in the directory denoted by this path. Each entry is a \
+          <code>path</code> object itself.
+          """,
       parameters = {
         @Param(
             name = "watch",
             defaultValue = "'auto'",
             positional = false,
             named = true,
             doc =
-                "whether Bazel should watch the list of entries in this directory and refetch the "
-                    + "repository or re-evaluate the module extension next time when any changes "
-                    + "are detected. Changes to detect include entry creation, deletion, and "
-                    + "renaming. Note that this doesn't watch the <em>contents</em> of any entries "
-                    + "in the directory.<p>Can be the string 'yes', 'no', or 'auto'. If set to "
-                    + "'auto', Bazel will only watch this directory when it is legal to do so (see "
-                    + "<a "
-                    + "href=\"repository_ctx.html#watch\"><code>repository_ctx.watch()</code></a> "
-                    + "docs for more information)."),
+                """
+                whether Bazel should watch the list of entries in this directory and refetch the \
+                repository or re-evaluate the module extension next time when any changes \
+                are detected. Changes to detect include entry creation, deletion, and \
+                renaming. Note that this doesn't watch the <em>contents</em> of any entries \
+                in the directory.<p>Can be the string 'yes', 'no', or 'auto'. If set to \
+                'auto', Bazel will only watch this directory when it is legal to do so (see \
+                <a href="repository_ctx.html#watch"><code>repository_ctx.watch()</code></a> \
+                docs for more information).
+                """),
       })
   public ImmutableList<StarlarkPath> readdir(String watch)
       throws EvalException, RepositoryFunctionException, InterruptedException {
@@ -138,8 +141,10 @@ public StarlarkPath getDirname() {
           @Param(
               name = "relative_paths",
               doc =
-                  "Zero or more relative path strings to append to this path with path separators"
-                      + "added as needed."))
+                  """
+                  Zero or more relative path strings to append to this path with path separators \
+                  added as needed.
+                  """))
   public StarlarkPath getChild(Tuple relativePaths) throws EvalException {
     return new StarlarkPath(
         ctx,
@@ -153,10 +158,12 @@ public StarlarkPath getChild(Tuple relativePaths) throws EvalException {
       name = "exists",
       structField = true,
       doc =
-          "Returns true if the file or directory denoted by this path exists.<p>Note that "
-              + "accessing this field does <em>not</em> cause the path to be watched. If you'd "
-              + "like the repo rule or module extension to be sensitive to the path's existence, "
-              + "use the <code>watch()</code> method on the context object.")
+          """
+          Returns true if the file or directory denoted by this path exists.<p>Note that \
+          accessing this field does <em>not</em> cause the path to be watched. If you'd \
+          like the repo rule or module extension to be sensitive to the path's existence, \
+          use the <code>watch()</code> method on the context object.
+          """)
   public boolean exists() {
     return path.exists();
   }
@@ -165,10 +172,12 @@ public boolean exists() {
       name = "is_dir",
       structField = true,
       doc =
-          "Returns true if this path points to a directory.<p>Note that accessing this field does "
-              + "<em>not</em> cause the path to be watched. If you'd like the repo rule or module "
-              + "extension to be sensitive to whether the path is a directory or a file, use the "
-              + "<code>watch()</code> method on the context object.")
+          """
+          Returns true if this path points to a directory.<p>Note that accessing this field does \
+          <em>not</em> cause the path to be watched. If you'd like the repo rule or module \
+          extension to be sensitive to whether the path is a directory or a file, use the \
+          <code>watch()</code> method on the context object.
+          """)
   public boolean isDir() {
     return path.isDirectory();
   }
@@ -177,8 +186,10 @@ public boolean isDir() {
       name = "realpath",
       structField = true,
       doc =
-          "Returns the canonical path for this path by repeatedly replacing all symbolic links "
-              + "with their referents.")
+          """
+          Returns the canonical path for this path by repeatedly replacing all symbolic links \
+          with their referents.
+          """)
   public StarlarkPath realpath() throws IOException {
     return new StarlarkPath(ctx, path.resolveSymbolicLinks());
   }