add clippy-json targetclippy-json

Add a clippy-json target to the ninja script.

This is useful for rust-analyzer, which requires an "external check
command" to function when not using cargo.

This also changes the --emit option in the clippy script to "emit",
without this, clippy will fail with errors about missing
libraries. These would normally be created with the normal compilation
target, but we can't rely on that, because if it fails, clippy-json
never runs, and you won't get error messages to the LSP.

2 files changed, 17 insertions, 3 deletions

diff --git a/mesonbuild/backend/ninjabackend.py b/mesonbuild/backend/ninjabackend.py
index 086d19566..34d1b9aac 100644
--- a/mesonbuild/backend/ninjabackend.py
+++ b/mesonbuild/backend/ninjabackend.py
@@ -3947,6 +3947,17 @@ https://gcc.gnu.org/bugzilla/show_bug.cgi?id=47485'''))
         elem.add_dep(list(self.all_structured_sources))
         self.add_build(elem)
 
+    def generate_clippy_json(self) -> None:
+        if 'clippy-json' in self.all_outputs or not self.have_language('rust'):
+            return
+
+        cmd = self.environment.get_build_command() + \
+            ['--internal', 'clippy', self.environment.build_dir, '--error-format=json']
+        elem = self.create_phony_target('clippy-json', 'CUSTOM_COMMAND', 'PHONY')
+        elem.add_item('COMMAND', cmd)
+        elem.add_item('pool', 'console')
+        self.add_build(elem)        
+
     def generate_rustdoc(self) -> None:
         if 'rustdoc' in self.all_outputs or not self.have_language('rust'):
             return
@@ -4036,6 +4047,7 @@ https://gcc.gnu.org/bugzilla/show_bug.cgi?id=47485'''))
         self.generate_clangformat()
         self.generate_clangtidy()
         self.generate_clippy()
+        self.generate_clippy_json()        
         self.generate_rustdoc()
         self.generate_tags('etags', 'TAGS')
         self.generate_tags('ctags', 'ctags')
diff --git a/mesonbuild/scripts/clippy.py b/mesonbuild/scripts/clippy.py
index 0ea7a3429..0a8d85779 100644
--- a/mesonbuild/scripts/clippy.py
+++ b/mesonbuild/scripts/clippy.py
@@ -15,7 +15,7 @@ if T.TYPE_CHECKING:
     from ..compilers.rust import RustCompiler
 
 class ClippyDriver:
-    def __init__(self, build: build.Build, tempdir: str):
+    def __init__(self, build: build.Build, tempdir: str, args: list[str]):
         self.tools: PerMachine[T.List[str]] = PerMachine([], [])
         self.warned: T.DefaultDict[str, bool] = defaultdict(lambda: False)
         self.tempdir = tempdir
@@ -24,6 +24,7 @@ class ClippyDriver:
             if 'rust' in compilers:
                 compiler = T.cast('RustCompiler', compilers['rust'])
                 self.tools[machine] = compiler.get_rust_tool('clippy-driver')
+        self.args = args
 
     def warn_missing_clippy(self, machine: str) -> None:
         if self.warned[machine]:
@@ -64,13 +65,14 @@ class ClippyDriver:
                 # and --emit dep-info= is not enough for clippy to do
                 # enough analysis, so use --emit metadata.
                 cmdlist.append('--emit')
-                cmdlist.append('metadata')
+                cmdlist.append('link')
                 cmdlist.append('--out-dir')
                 cmdlist.append(self.tempdir)
+                cmdlist += self.args
                 yield run_with_buffered_output(cmdlist)
 
 def run(args: T.List[str]) -> int:
     os.chdir(args[0])
     build_data = build.load(os.getcwd())
     with tempfile.TemporaryDirectory() as d:
-        return run_tool_on_targets(ClippyDriver(build_data, d))
+        return run_tool_on_targets(ClippyDriver(build_data, d, args[1:]))