feat: add `rustc_flags` attr to `rust_doc` rule (#1458)
**Context**
When building [rustdocs](https://doc.rust-lang.org/rustdoc/what-is-rustdoc.html) it is very useful to pass `-Dwarnings`. This allows you to easily assert things like [intra-doc-links](https://doc.rust-lang.org/rustdoc/write-documentation/linking-to-items-by-name.html) aren't broken. As far as I can tell, passing flags to `rustdoc` isn't possible today.
**Solution**
Add the `rustc_flags` attr to the `rust_doc` rule. `rustc_flags` is already parsed in [`construct_arguments(...)`](https://github.com/bazelbuild/rules_rust/blob/main/rust/private/rustc.bzl#L601) which `rust_doc` calls into.
diff --git a/docs/flatten.md b/docs/flatten.md
index f524f26..822c2dd 100644
--- a/docs/flatten.md
+++ b/docs/flatten.md
@@ -431,7 +431,8 @@
## rust_doc
<pre>
-rust_doc(<a href="#rust_doc-name">name</a>, <a href="#rust_doc-crate">crate</a>, <a href="#rust_doc-html_after_content">html_after_content</a>, <a href="#rust_doc-html_before_content">html_before_content</a>, <a href="#rust_doc-html_in_header">html_in_header</a>, <a href="#rust_doc-markdown_css">markdown_css</a>)
+rust_doc(<a href="#rust_doc-name">name</a>, <a href="#rust_doc-crate">crate</a>, <a href="#rust_doc-html_after_content">html_after_content</a>, <a href="#rust_doc-html_before_content">html_before_content</a>, <a href="#rust_doc-html_in_header">html_in_header</a>, <a href="#rust_doc-markdown_css">markdown_css</a>,
+ <a href="#rust_doc-rustc_flags">rustc_flags</a>)
</pre>
Generates code documentation.
@@ -482,6 +483,7 @@
| <a id="rust_doc-html_before_content"></a>html_before_content | File to add in <code><body></code>, before content. | <a href="https://bazel.build/docs/build-ref.html#labels">Label</a> | optional | None |
| <a id="rust_doc-html_in_header"></a>html_in_header | File to add to <code><head></code>. | <a href="https://bazel.build/docs/build-ref.html#labels">Label</a> | optional | None |
| <a id="rust_doc-markdown_css"></a>markdown_css | CSS files to include via <code><link></code> in a rendered Markdown file. | <a href="https://bazel.build/docs/build-ref.html#labels">List of labels</a> | optional | [] |
+| <a id="rust_doc-rustc_flags"></a>rustc_flags | List of compiler flags passed to <code>rustc</code>.<br><br>These strings are subject to Make variable expansion for predefined source/output path variables like <code>$location</code>, <code>$execpath</code>, and <code>$rootpath</code>. This expansion is useful if you wish to pass a generated file of arguments to rustc: <code>@$(location //package:target)</code>. | List of strings | optional | [] |
<a id="rust_doc_test"></a>
diff --git a/docs/rust_doc.md b/docs/rust_doc.md
index 633bf09..009172f 100644
--- a/docs/rust_doc.md
+++ b/docs/rust_doc.md
@@ -9,7 +9,8 @@
## rust_doc
<pre>
-rust_doc(<a href="#rust_doc-name">name</a>, <a href="#rust_doc-crate">crate</a>, <a href="#rust_doc-html_after_content">html_after_content</a>, <a href="#rust_doc-html_before_content">html_before_content</a>, <a href="#rust_doc-html_in_header">html_in_header</a>, <a href="#rust_doc-markdown_css">markdown_css</a>)
+rust_doc(<a href="#rust_doc-name">name</a>, <a href="#rust_doc-crate">crate</a>, <a href="#rust_doc-html_after_content">html_after_content</a>, <a href="#rust_doc-html_before_content">html_before_content</a>, <a href="#rust_doc-html_in_header">html_in_header</a>, <a href="#rust_doc-markdown_css">markdown_css</a>,
+ <a href="#rust_doc-rustc_flags">rustc_flags</a>)
</pre>
Generates code documentation.
@@ -60,6 +61,7 @@
| <a id="rust_doc-html_before_content"></a>html_before_content | File to add in <code><body></code>, before content. | <a href="https://bazel.build/docs/build-ref.html#labels">Label</a> | optional | None |
| <a id="rust_doc-html_in_header"></a>html_in_header | File to add to <code><head></code>. | <a href="https://bazel.build/docs/build-ref.html#labels">Label</a> | optional | None |
| <a id="rust_doc-markdown_css"></a>markdown_css | CSS files to include via <code><link></code> in a rendered Markdown file. | <a href="https://bazel.build/docs/build-ref.html#labels">List of labels</a> | optional | [] |
+| <a id="rust_doc-rustc_flags"></a>rustc_flags | List of compiler flags passed to <code>rustc</code>.<br><br>These strings are subject to Make variable expansion for predefined source/output path variables like <code>$location</code>, <code>$execpath</code>, and <code>$rootpath</code>. This expansion is useful if you wish to pass a generated file of arguments to rustc: <code>@$(location //package:target)</code>. | List of strings | optional | [] |
<a id="rust_doc_test"></a>
diff --git a/rust/private/rustdoc.bzl b/rust/private/rustdoc.bzl
index a35bcd7..7da57e5 100644
--- a/rust/private/rustdoc.bzl
+++ b/rust/private/rustdoc.bzl
@@ -281,6 +281,16 @@
doc = "CSS files to include via `<link>` in a rendered Markdown file.",
allow_files = [".css"],
),
+ "rustc_flags": attr.string_list(
+ doc = dedent("""\
+ List of compiler flags passed to `rustc`.
+
+ These strings are subject to Make variable expansion for predefined
+ source/output path variables like `$location`, `$execpath`, and
+ `$rootpath`. This expansion is useful if you wish to pass a generated
+ file of arguments to rustc: `@$(location //package:target)`.
+ """),
+ ),
"_cc_toolchain": attr.label(
doc = "In order to use find_cpp_toolchain, you must define the '_cc_toolchain' attribute on your rule or aspect.",
default = Label("@bazel_tools//tools/cpp:current_cc_toolchain"),
