rust: use native Meson support for clippy and rustdoc

Meson has support for invoking clippy and rustdoc on all crates (1.7.0 for
clippy, 1.8.0 for rustdoc).  Use it instead of the homegrown version; this
requires disabling the multiple_crate_versions lint (the only one that was
enabled from the "cargo" group)---which was not particularly useful anyway
because all dependencies are converted by hand into Meson subprojects.

rustfmt is still not supported.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

clippy.toml

@@ -1,3 +1,3 @@
-doc-valid-idents = ["PrimeCell", ".."]
+doc-valid-idents = ["IrDA", "PrimeCell", ".."]
 allow-mixed-uninlined-format-args = false
 msrv = "1.77.0"

docs/devel/rust.rst

@@ -37,12 +37,16 @@ output directory (typically ``rust/target/``).  A vanilla invocation
 of Cargo will complain that it cannot find the generated sources,
 which can be fixed in different ways:
 
-* by using special shorthand targets in the QEMU build directory::
+* by using Makefile targets, provided by Meson, that run ``clippy`` or
+  ``rustdoc``:
 
     make clippy
-    make rustfmt
     make rustdoc
 
+A target for ``rustfmt`` is also declared in ``rust/meson.build``:
+
+    make rustfmt
+
 * by invoking ``cargo`` through the Meson `development environment`__
   feature::
 
@@ -50,7 +54,7 @@ which can be fixed in different ways:
     pyvenv/bin/meson devenv -w ../rust cargo fmt
 
   If you are going to use ``cargo`` repeatedly, ``pyvenv/bin/meson devenv``
-  will enter a shell where commands like ``cargo clippy`` just work.
+  will enter a shell where commands like ``cargo fmt`` just work.
 
 __ https://mesonbuild.com/Commands.html#devenv
 

meson.build

@@ -4404,7 +4404,7 @@ foreach target : target_dirs
                               build_by_default: true,
                               build_always_stale: true)
       rlib = static_library('rust_' + target.underscorify(),
-                            rlib_rs,
+                            structured_sources([], {'.': rlib_rs}),
                             dependencies: target_rust.dependencies(),
                             override_options: ['rust_std=2021', 'build.rust_std=2021'],
                             rust_abi: 'c')

rust/Cargo.toml

@@ -63,7 +63,6 @@ ignored_unit_patterns = "deny"
 implicit_clone = "deny"
 macro_use_imports = "deny"
 missing_safety_doc = "deny"
-multiple_crate_versions = "deny"
 mut_mut = "deny"
 needless_bitwise_bool = "deny"
 needless_pass_by_ref_mut = "deny"

rust/meson.build

@@ -24,21 +24,9 @@ subdir('hw')
 cargo = find_program('cargo', required: false)
 
 if cargo.found()
-  run_target('clippy',
-    command: [config_host['MESON'], 'devenv',
-              '--workdir', '@CURRENT_SOURCE_DIR@',
-              cargo, 'clippy', '--tests'],
-    depends: bindings_rs)
-
   run_target('rustfmt',
     command: [config_host['MESON'], 'devenv',
               '--workdir', '@CURRENT_SOURCE_DIR@',
               cargo, 'fmt'],
     depends: bindings_rs)
-
-  run_target('rustdoc',
-    command: [config_host['MESON'], 'devenv',
-              '--workdir', '@CURRENT_SOURCE_DIR@',
-              cargo, 'doc', '--no-deps', '--document-private-items'],
-    depends: bindings_rs)
 endif

scripts/rust/rustc_args.py

@@ -104,10 +104,7 @@ def generate_lint_flags(cargo_toml: CargoTOML, strict_lints: bool) -> Iterable[s
             else:
                 raise Exception(f"invalid level {level} for {prefix}{lint}")
 
-            # This may change if QEMU ever invokes clippy-driver or rustdoc by
-            # hand.  For now, check the syntax but do not add non-rustc lints to
-            # the command line.
-            if k == "rust" and not (strict_lints and lint in STRICT_LINTS):
+            if not (strict_lints and lint in STRICT_LINTS):
                 lint_list.append(LintFlag(flags=[flag, prefix + lint], priority=priority))
 
     if strict_lints: