Allow rust_bindgen rules to disable rustfmt with an attr (bazelbuild#…

…1024)

* Disable rustfmt when toolchain lacks it as documented

* Add a parameter to rust_bindgen instead

* Regenerate documentation

* Also add to rust_bindgen_library

* Regenerate documentation

* Include an unformatted rust_bindgen_library test

* Override crate names to fix build

bindgen/bindgen.bzl

@@ -40,6 +40,7 @@ def rust_bindgen_library(
         cc_lib,
         bindgen_flags = None,
         clang_flags = None,
+        rustfmt = True,
         **kwargs):
     """Generates a rust source file for `header`, and builds a rust_library.
 
@@ -51,6 +52,7 @@ def rust_bindgen_library(
         cc_lib (str): The label of the cc_library that contains the .h file. This is used to find the transitive includes.
         bindgen_flags (list, optional): Flags to pass directly to the bindgen executable. See https://rust-lang.github.io/rust-bindgen/ for details.
         clang_flags (list, optional): Flags to pass directly to the clang executable.
+        rustfmt (bool, optional): Enable or disable running rustfmt on the generated file.
         **kwargs: Arguments to forward to the underlying `rust_library` rule.
     """
 
@@ -68,6 +70,7 @@ def rust_bindgen_library(
         cc_lib = cc_lib,
         bindgen_flags = bindgen_flags or [],
         clang_flags = clang_flags or [],
+        rustfmt = rustfmt,
         tags = tags,
     )
 
@@ -109,7 +112,7 @@ def _rust_bindgen_impl(ctx):
     system_include_directories = cc_lib[CcInfo].compilation_context.system_includes.to_list()
 
     # Vanilla usage of bindgen produces formatted output, here we do the same if we have `rustfmt` in our toolchain.
-    if rustfmt_bin:
+    if ctx.attr.rustfmt and rustfmt_bin:
         unformatted_output = ctx.actions.declare_file(output.basename + ".unformatted")
     else:
         unformatted_output = output
@@ -158,7 +161,7 @@ def _rust_bindgen_impl(ctx):
         tools = [clang_bin],
     )
 
-    if rustfmt_bin:
+    if ctx.attr.rustfmt and rustfmt_bin:
         rustfmt_args = ctx.actions.args()
         rustfmt_args.add("--stdout-file", output.path)
         rustfmt_args.add("--")
@@ -194,6 +197,10 @@ rust_bindgen = rule(
             doc = "The .h file to generate bindings for.",
             allow_single_file = True,
         ),
+        "rustfmt": attr.bool(
+            doc = "Enable or disable running rustfmt on the generated file.",
+            default = True,
+        ),
         "_cc_toolchain": attr.label(
             default = Label("@bazel_tools//tools/cpp:current_cc_toolchain"),
         ),
@@ -249,7 +256,7 @@ rust_bindgen_toolchain = rule(
             mandatory = False,
         ),
         "rustfmt": attr.label(
-            doc = "The label of a `rustfmt` executable. If this is provided, generated sources will be formatted.",
+            doc = "The label of a `rustfmt` executable. If this is not provided, falls back to the rust_toolchain rustfmt.",
             executable = True,
             cfg = "exec",
             mandatory = False,

docs/flatten.md

@@ -341,7 +341,7 @@ Hello world
 ## rust_bindgen
 
 <pre>
-rust_bindgen(<a href="#rust_bindgen-name">name</a>, <a href="#rust_bindgen-bindgen_flags">bindgen_flags</a>, <a href="#rust_bindgen-cc_lib">cc_lib</a>, <a href="#rust_bindgen-clang_flags">clang_flags</a>, <a href="#rust_bindgen-header">header</a>)
+rust_bindgen(<a href="#rust_bindgen-name">name</a>, <a href="#rust_bindgen-bindgen_flags">bindgen_flags</a>, <a href="#rust_bindgen-cc_lib">cc_lib</a>, <a href="#rust_bindgen-clang_flags">clang_flags</a>, <a href="#rust_bindgen-header">header</a>, <a href="#rust_bindgen-rustfmt">rustfmt</a>)
 </pre>
 
 Generates a rust source file from a cc_library and a header.
@@ -356,6 +356,7 @@ Generates a rust source file from a cc_library and a header.
 | <a id="rust_bindgen-cc_lib"></a>cc_lib |  The cc_library that contains the .h file. This is used to find the transitive includes.   | <a href="https://bazel.build/docs/build-ref.html#labels">Label</a> | optional | None |
 | <a id="rust_bindgen-clang_flags"></a>clang_flags |  Flags to pass directly to the clang executable.   | List of strings | optional | [] |
 | <a id="rust_bindgen-header"></a>header |  The .h file to generate bindings for.   | <a href="https://bazel.build/docs/build-ref.html#labels">Label</a> | optional | None |
+| <a id="rust_bindgen-rustfmt"></a>rustfmt |  Enable or disable running rustfmt on the generated file.   | Boolean | optional | True |
 
 
 <a id="#rust_bindgen_toolchain"></a>
@@ -378,7 +379,7 @@ The tools required for the `rust_bindgen` rule.
 | <a id="rust_bindgen_toolchain-clang"></a>clang |  The label of a <code>clang</code> executable.   | <a href="https://bazel.build/docs/build-ref.html#labels">Label</a> | optional | None |
 | <a id="rust_bindgen_toolchain-libclang"></a>libclang |  A cc_library that provides bindgen's runtime dependency on libclang.   | <a href="https://bazel.build/docs/build-ref.html#labels">Label</a> | optional | None |
 | <a id="rust_bindgen_toolchain-libstdcxx"></a>libstdcxx |  A cc_library that satisfies libclang's libstdc++ dependency. This is used to make the execution of clang hermetic. If None, system libraries will be used instead.   | <a href="https://bazel.build/docs/build-ref.html#labels">Label</a> | optional | None |
-| <a id="rust_bindgen_toolchain-rustfmt"></a>rustfmt |  The label of a <code>rustfmt</code> executable. If this is provided, generated sources will be formatted.   | <a href="https://bazel.build/docs/build-ref.html#labels">Label</a> | optional | None |
+| <a id="rust_bindgen_toolchain-rustfmt"></a>rustfmt |  The label of a <code>rustfmt</code> executable. If this is not provided, falls back to the rust_toolchain rustfmt.   | <a href="https://bazel.build/docs/build-ref.html#labels">Label</a> | optional | None |
 
 
 <a id="#rust_clippy"></a>
@@ -1675,7 +1676,7 @@ str: A json encoded struct of crate overrides
 ## rust_bindgen_library
 
 <pre>
-rust_bindgen_library(<a href="#rust_bindgen_library-name">name</a>, <a href="#rust_bindgen_library-header">header</a>, <a href="#rust_bindgen_library-cc_lib">cc_lib</a>, <a href="#rust_bindgen_library-bindgen_flags">bindgen_flags</a>, <a href="#rust_bindgen_library-clang_flags">clang_flags</a>, <a href="#rust_bindgen_library-kwargs">kwargs</a>)
+rust_bindgen_library(<a href="#rust_bindgen_library-name">name</a>, <a href="#rust_bindgen_library-header">header</a>, <a href="#rust_bindgen_library-cc_lib">cc_lib</a>, <a href="#rust_bindgen_library-bindgen_flags">bindgen_flags</a>, <a href="#rust_bindgen_library-clang_flags">clang_flags</a>, <a href="#rust_bindgen_library-rustfmt">rustfmt</a>, <a href="#rust_bindgen_library-kwargs">kwargs</a>)
 </pre>
 
 Generates a rust source file for `header`, and builds a rust_library.
@@ -1693,6 +1694,7 @@ Arguments are the same as `rust_bindgen`, and `kwargs` are passed directly to ru
 | <a id="rust_bindgen_library-cc_lib"></a>cc_lib |  The label of the cc_library that contains the .h file. This is used to find the transitive includes.   |  none |
 | <a id="rust_bindgen_library-bindgen_flags"></a>bindgen_flags |  Flags to pass directly to the bindgen executable. See https://rust-lang.github.io/rust-bindgen/ for details.   |  <code>None</code> |
 | <a id="rust_bindgen_library-clang_flags"></a>clang_flags |  Flags to pass directly to the clang executable.   |  <code>None</code> |
+| <a id="rust_bindgen_library-rustfmt"></a>rustfmt |  Enable or disable running rustfmt on the generated file.   |  <code>True</code> |
 | <a id="rust_bindgen_library-kwargs"></a>kwargs |  Arguments to forward to the underlying <code>rust_library</code> rule.   |  none |
 
 

docs/rust_bindgen.md

@@ -11,7 +11,7 @@
 ## rust_bindgen
 
 <pre>
-rust_bindgen(<a href="#rust_bindgen-name">name</a>, <a href="#rust_bindgen-bindgen_flags">bindgen_flags</a>, <a href="#rust_bindgen-cc_lib">cc_lib</a>, <a href="#rust_bindgen-clang_flags">clang_flags</a>, <a href="#rust_bindgen-header">header</a>)
+rust_bindgen(<a href="#rust_bindgen-name">name</a>, <a href="#rust_bindgen-bindgen_flags">bindgen_flags</a>, <a href="#rust_bindgen-cc_lib">cc_lib</a>, <a href="#rust_bindgen-clang_flags">clang_flags</a>, <a href="#rust_bindgen-header">header</a>, <a href="#rust_bindgen-rustfmt">rustfmt</a>)
 </pre>
 
 Generates a rust source file from a cc_library and a header.
@@ -26,6 +26,7 @@ Generates a rust source file from a cc_library and a header.
 | <a id="rust_bindgen-cc_lib"></a>cc_lib |  The cc_library that contains the .h file. This is used to find the transitive includes.   | <a href="https://bazel.build/docs/build-ref.html#labels">Label</a> | optional | None |
 | <a id="rust_bindgen-clang_flags"></a>clang_flags |  Flags to pass directly to the clang executable.   | List of strings | optional | [] |
 | <a id="rust_bindgen-header"></a>header |  The .h file to generate bindings for.   | <a href="https://bazel.build/docs/build-ref.html#labels">Label</a> | optional | None |
+| <a id="rust_bindgen-rustfmt"></a>rustfmt |  Enable or disable running rustfmt on the generated file.   | Boolean | optional | True |
 
 
 <a id="#rust_bindgen_toolchain"></a>
@@ -48,15 +49,15 @@ The tools required for the `rust_bindgen` rule.
 | <a id="rust_bindgen_toolchain-clang"></a>clang |  The label of a <code>clang</code> executable.   | <a href="https://bazel.build/docs/build-ref.html#labels">Label</a> | optional | None |
 | <a id="rust_bindgen_toolchain-libclang"></a>libclang |  A cc_library that provides bindgen's runtime dependency on libclang.   | <a href="https://bazel.build/docs/build-ref.html#labels">Label</a> | optional | None |
 | <a id="rust_bindgen_toolchain-libstdcxx"></a>libstdcxx |  A cc_library that satisfies libclang's libstdc++ dependency. This is used to make the execution of clang hermetic. If None, system libraries will be used instead.   | <a href="https://bazel.build/docs/build-ref.html#labels">Label</a> | optional | None |
-| <a id="rust_bindgen_toolchain-rustfmt"></a>rustfmt |  The label of a <code>rustfmt</code> executable. If this is provided, generated sources will be formatted.   | <a href="https://bazel.build/docs/build-ref.html#labels">Label</a> | optional | None |
+| <a id="rust_bindgen_toolchain-rustfmt"></a>rustfmt |  The label of a <code>rustfmt</code> executable. If this is not provided, falls back to the rust_toolchain rustfmt.   | <a href="https://bazel.build/docs/build-ref.html#labels">Label</a> | optional | None |
 
 
 <a id="#rust_bindgen_library"></a>
 
 ## rust_bindgen_library
 
 <pre>
-rust_bindgen_library(<a href="#rust_bindgen_library-name">name</a>, <a href="#rust_bindgen_library-header">header</a>, <a href="#rust_bindgen_library-cc_lib">cc_lib</a>, <a href="#rust_bindgen_library-bindgen_flags">bindgen_flags</a>, <a href="#rust_bindgen_library-clang_flags">clang_flags</a>, <a href="#rust_bindgen_library-kwargs">kwargs</a>)
+rust_bindgen_library(<a href="#rust_bindgen_library-name">name</a>, <a href="#rust_bindgen_library-header">header</a>, <a href="#rust_bindgen_library-cc_lib">cc_lib</a>, <a href="#rust_bindgen_library-bindgen_flags">bindgen_flags</a>, <a href="#rust_bindgen_library-clang_flags">clang_flags</a>, <a href="#rust_bindgen_library-rustfmt">rustfmt</a>, <a href="#rust_bindgen_library-kwargs">kwargs</a>)
 </pre>
 
 Generates a rust source file for `header`, and builds a rust_library.
@@ -74,6 +75,7 @@ Arguments are the same as `rust_bindgen`, and `kwargs` are passed directly to ru
 | <a id="rust_bindgen_library-cc_lib"></a>cc_lib |  The label of the cc_library that contains the .h file. This is used to find the transitive includes.   |  none |
 | <a id="rust_bindgen_library-bindgen_flags"></a>bindgen_flags |  Flags to pass directly to the bindgen executable. See https://rust-lang.github.io/rust-bindgen/ for details.   |  <code>None</code> |
 | <a id="rust_bindgen_library-clang_flags"></a>clang_flags |  Flags to pass directly to the clang executable.   |  <code>None</code> |
+| <a id="rust_bindgen_library-rustfmt"></a>rustfmt |  Enable or disable running rustfmt on the generated file.   |  <code>True</code> |
 | <a id="rust_bindgen_library-kwargs"></a>kwargs |  Arguments to forward to the underlying <code>rust_library</code> rule.   |  none |
 
 

examples/bindgen/BUILD.bazel

@@ -26,3 +26,27 @@ rust_test(
     name = "simple_test",
     crate = ":simple_example",
 )
+
+# Same as above, except disabling formatting on bindgen.
+rust_bindgen_library(
+    name = "simple_bindgen_unformatted",
+    bindgen_flags = [
+        "--allowlist-var=SIMPLE_.*",
+    ],
+    cc_lib = ":simple",
+    crate_name = "simple_bindgen",
+    header = "simple.h",
+    rustfmt = False,
+)
+
+rust_binary(
+    name = "simple_example_unformatted",
+    srcs = ["main.rs"],
+    crate_name = "simple_example",
+    deps = [":simple_bindgen_unformatted"],
+)
+
+rust_test(
+    name = "simple_test_unformatted",
+    crate = ":simple_example_unformatted",
+)