clang-parser: better extra_args defaults

1 files changed, 23 insertions, 15 deletions

diff --git a/src/parser/clang/config.rs b/src/parser/clang/config.rs
index 05fe3ab..1d9c6ba 100644
--- a/src/parser/clang/config.rs
+++ b/src/parser/clang/config.rs
@@ -17,31 +17,39 @@ pub(crate) struct ProvidedConfig {
     #[structopt(long = "clang-compile-commands-location")]
     pub(super) compile_commands_location: Option<PathBuf>,
     #[structopt(long = "clang-extra-args", number_of_values = 1)]
-    #[serde(default)]
-    pub(super) extra_args: Vec<String>,
+    pub(super) extra_args: Option<Vec<String>>,
 }
 
 impl Default for Config {
     fn default() -> Self {
-        Config::from_merge(
-            ProvidedConfig::default(),
-            ProvidedConfig::default(),
-        )
-        // Currently errors out only on CLI parse fail with clang's extra args
-        .unwrap()
+        Config::from_merge(ProvidedConfig::default(), ProvidedConfig::default())
+            // Currently errors out only on CLI parse fail with clang's extra args
+            .unwrap()
     }
 }
 
+fn default_extra_args() -> Vec<String> {
+    vec![
+        // We don't parse function bodies so libclang report every arguments/functions/etc. as unused.
+        String::from("-Wno-unused-const-variable"),
+        String::from("-Wno-unused-function"),
+        String::from("-Wno-unused-parameter"),
+        String::from("-Wno-unused-private-field"),
+        String::from("-Wno-unused-variable"),
+        // We don't "link" so every linker arguments from the compile_commands.json gets reported
+        String::from("-Qunused-arguments"),
+    ]
+}
+
 impl Config {
-    pub(crate) fn from_merge(
-        cli: ProvidedConfig,
-        mut config: ProvidedConfig,
-    ) -> Result<Self> {
+    pub(crate) fn from_merge(cli: ProvidedConfig, config: ProvidedConfig) -> Result<Self> {
         let mut extra_args = Vec::new();
-        for args in cli.extra_args {
-            extra_args.append(&mut ::shell_words::split(&args)?);
+        if let Some(cli_extra_args) = cli.extra_args {
+            for args in cli_extra_args {
+                extra_args.append(&mut ::shell_words::split(&args)?);
+            }
         }
-        extra_args.append(&mut config.extra_args);
+        extra_args.append(&mut config.extra_args.unwrap_or_else(default_extra_args));
         Ok(Self {
             compile_commands_location: cli
                 .compile_commands_location