clippy --fix pgrx libraries (#1366)

I backed out changes from inside sensitive files where they might make
semantics less clear, but the rest are fairly simple. Modulo those
holdbacks, this brings up to conformance with `clippy --fix`:
- pgrx
- pgrx-macros
- pgrx-pg-sys

pgrx-macros/src/lib.rs

@@ -102,8 +102,7 @@ pub fn pg_test(attr: TokenStream, item: TokenStream) -> TokenStream {
             };
 
             let sql_funcname = func.sig.ident.to_string();
-            let test_func_name =
-                Ident::new(&format!("pg_{}", func.sig.ident.to_string()), func.span());
+            let test_func_name = Ident::new(&format!("pg_{}", func.sig.ident), func.span());
 
             let attributes = func.attrs;
             let mut att_stream = proc_macro2::TokenStream::new();
@@ -1053,7 +1052,7 @@ Functions inside the `impl` may use the [`#[pgrx]`](macro@pgrx) attribute.
 pub fn pg_aggregate(_attr: TokenStream, item: TokenStream) -> TokenStream {
     // We don't care about `_attr` as we can find it in the `ItemMod`.
     fn wrapped(item_impl: ItemImpl) -> Result<TokenStream, syn::Error> {
-        let sql_graph_entity_item = PgAggregate::new(item_impl.into())?;
+        let sql_graph_entity_item = PgAggregate::new(item_impl)?;
 
         Ok(sql_graph_entity_item.to_token_stream().into())
     }

pgrx-macros/src/rewriter.rs

@@ -68,8 +68,7 @@ impl PgGuardRewriter {
         // nor do we need a visibility beyond "private"
         func.vis = Visibility::Inherited;
 
-        func.sig.ident =
-            Ident::new(&format!("{}_inner", func.sig.ident.to_string()), func.sig.ident.span());
+        func.sig.ident = Ident::new(&format!("{}_inner", func.sig.ident), func.sig.ident.span());
 
         let arg_list = PgGuardRewriter::build_arg_list(&sig, false)?;
         let func_name = PgGuardRewriter::build_func_name(&func.sig);

pgrx-pg-sys/build.rs

@@ -155,7 +155,7 @@ fn main() -> eyre::Result<()> {
     } else {
         let mut found = Vec::new();
         for pgver in SUPPORTED_VERSIONS() {
-            if let Some(_) = env_tracked(&format!("CARGO_FEATURE_PG{}", pgver.major)) {
+            if env_tracked(&format!("CARGO_FEATURE_PG{}", pgver.major)).is_some() {
                 found.push(pgver);
             }
         }
@@ -175,7 +175,7 @@ fn main() -> eyre::Result<()> {
                 return Err(eyre!(
                     "Multiple `pg$VERSION` features found.\n`--no-default-features` may be required.\nFound: {}",
                     versions
-                        .into_iter()
+                        .iter()
                         .map(|version| format!("pg{}", version.major))
                         .collect::<Vec<String>>()
                         .join(", ")
@@ -254,7 +254,7 @@ fn emit_rerun_if_changed() {
     println!("cargo:rerun-if-changed=cshim");
 
     if let Ok(pgrx_config) = Pgrx::config_toml() {
-        println!("cargo:rerun-if-changed={}", pgrx_config.display().to_string());
+        println!("cargo:rerun-if-changed={}", pgrx_config.display());
     }
 }
 
@@ -268,7 +268,7 @@ fn generate_bindings(
     include_h.push("include");
     include_h.push(format!("pg{}.h", major_version));
 
-    let bindgen_output = get_bindings(major_version, &pg_config, &include_h)
+    let bindgen_output = get_bindings(major_version, pg_config, &include_h)
         .wrap_err_with(|| format!("bindgen failed for pg{}", major_version))?;
 
     let oids = extract_oids(&bindgen_output);
@@ -350,8 +350,8 @@ fn write_rs_file(
     let mut contents = header;
     contents.extend(code);
 
-    std::fs::write(&file, contents.to_string())?;
-    rust_fmt(&file)
+    std::fs::write(file, contents.to_string())?;
+    rust_fmt(file)
 }
 
 /// Given a token stream representing a file, apply a series of transformations to munge
@@ -405,7 +405,7 @@ fn rewrite_oid_consts(
     oids: &BTreeMap<syn::Ident, Box<syn::Expr>>,
 ) -> Vec<syn::Item> {
     items
-        .into_iter()
+        .iter()
         .map(|item| match item {
             Item::Const(ItemConst { ident, ty, expr, .. })
                 if ty.to_token_stream().to_string() == "u32" && oids.get(ident) == Some(expr) =>
@@ -699,7 +699,7 @@ fn get_bindings(
     } else {
         let bindings = run_bindgen(major_version, pg_config, include_h)?;
         if let Some(path) = env_tracked("PGRX_PG_SYS_EXTRA_OUTPUT_PATH") {
-            std::fs::write(&path, &bindings)?;
+            std::fs::write(path, &bindings)?;
         }
         bindings
     };
@@ -719,7 +719,7 @@ fn run_bindgen(
     binder = add_derives(binder);
     let bindings = binder
         .header(include_h.display().to_string())
-        .clang_args(&extra_bindgen_clang_args(pg_config)?)
+        .clang_args(extra_bindgen_clang_args(pg_config)?)
         .clang_args(pg_target_include_flags(major_version, pg_config)?)
         .detect_include_paths(target_env_tracked("PGRX_BINDGEN_NO_DETECT_INCLUDES").is_none())
         .parse_callbacks(Box::new(PgrxOverrides::default()))
@@ -833,7 +833,7 @@ fn build_shim(shim_src: &PathBuf, shim_dst: &PathBuf, pg_config: &PgConfig) -> e
 
     eprintln!("libpgrx_cshim={}", libpgrx_cshim.display());
     // then build the shim for the version feature currently being built
-    build_shim_for_version(&shim_src, &shim_dst, pg_config)?;
+    build_shim_for_version(shim_src, shim_dst, pg_config)?;
 
     // no matter what, tell rustc to link to the library that was built for the feature we're currently building
     let envvar_name = format!("CARGO_FEATURE_PG{}", major_version);
@@ -1042,7 +1042,7 @@ fn apply_pg_guard(items: &Vec<syn::Item>) -> eyre::Result<proc_macro2::TokenStre
             Item::ForeignMod(block) => {
                 let abi = &block.abi;
                 let (mut extern_funcs, mut others) = (Vec::new(), Vec::new());
-                block.items.iter().cloned().filter(|item| !is_blocklisted_item(item)).for_each(
+                block.items.iter().filter(|&item| !is_blocklisted_item(item)).cloned().for_each(
                     |item| match item {
                         ForeignItem::Fn(func) => extern_funcs.push(func),
                         item => others.push(item),
@@ -1078,6 +1078,6 @@ fn rust_fmt(path: &PathBuf) -> eyre::Result<()> {
         {
             Err(e).wrap_err("Failed to run `rustfmt`, is it installed?")
         }
-        Err(e) => Err(e.into()),
+        Err(e) => Err(e),
     }
 }

pgrx-pg-sys/src/include.rs

@@ -4,34 +4,39 @@
 
 #[cfg(all(feature = "pg12", not(docsrs)))]
 pub(crate) mod pg12 {
+    #![allow(clippy::all)]
     include!(concat!(env!("OUT_DIR"), "/pg12.rs"));
 }
 #[cfg(all(feature = "pg12", docsrs))]
 pub(crate) mod pg12;
 
 #[cfg(all(feature = "pg13", not(docsrs)))]
 pub(crate) mod pg13 {
+    #![allow(clippy::all)]
     include!(concat!(env!("OUT_DIR"), "/pg13.rs"));
 }
 #[cfg(all(feature = "pg13", docsrs))]
 pub(crate) mod pg13;
 
 #[cfg(all(feature = "pg14", not(docsrs)))]
 pub(crate) mod pg14 {
+    #![allow(clippy::all)]
     include!(concat!(env!("OUT_DIR"), "/pg14.rs"));
 }
 #[cfg(all(feature = "pg14", docsrs))]
 pub(crate) mod pg14;
 
 #[cfg(all(feature = "pg15", not(docsrs)))]
 pub(crate) mod pg15 {
+    #![allow(clippy::all)]
     include!(concat!(env!("OUT_DIR"), "/pg15.rs"));
 }
 #[cfg(all(feature = "pg15", docsrs))]
 pub(crate) mod pg15;
 
 #[cfg(all(feature = "pg16", not(docsrs)))]
 pub(crate) mod pg16 {
+    #[allow(clippy::all)]
     include!(concat!(env!("OUT_DIR"), "/pg16.rs"));
 }
 #[cfg(all(feature = "pg16", docsrs))]

pgrx-pg-sys/src/port.rs

@@ -197,8 +197,7 @@ pub unsafe fn BufferGetBlock(buffer: crate::Buffer) -> crate::Block {
     if BufferIsLocal(buffer) {
         *crate::LocalBufferBlockPointers.offset(((-buffer) - 1) as isize)
     } else {
-        crate::BufferBlocks
-            .offset((((buffer as crate::Size) - 1) * crate::BLCKSZ as usize) as isize)
+        crate::BufferBlocks.add(((buffer as crate::Size) - 1) * crate::BLCKSZ as usize)
             as crate::Block
     }
 }

pgrx-pg-sys/src/submodules/datum.rs

@@ -214,7 +214,7 @@ impl TryFrom<NullableDatum> for Datum {
 impl From<NullableDatum> for Option<Datum> {
     #[inline]
     fn from(nd: NullableDatum) -> Option<Datum> {
-        Some(Datum::try_from(nd).ok()?)
+        Datum::try_from(nd).ok()
     }
 }
 
@@ -259,6 +259,6 @@ mod test {
 
         let val: usize = 123456;
         let datum = Datum::from(val);
-        assert_eq!(datum.value() as usize, val);
+        assert_eq!({ datum.value() }, val);
     }
 }

pgrx-pg-sys/src/submodules/errcodes.rs

@@ -1280,15 +1280,15 @@ impl From<isize> for PgSqlErrorCode {
 #[allow(non_snake_case)]
 #[inline]
 const fn PGSIXBIT(ch: i32) -> i32 {
-    (((ch) - '0' as i32) & 0x3F) as i32
+    ((ch) - '0' as i32) & 0x3F
 }
 
 #[allow(non_snake_case)]
 #[inline]
 const fn MAKE_SQLSTATE(ch1: char, ch2: char, ch3: char, ch4: char, ch5: char) -> i32 {
-    (PGSIXBIT(ch1 as i32)
+    PGSIXBIT(ch1 as i32)
         + (PGSIXBIT(ch2 as i32) << 6)
         + (PGSIXBIT(ch3 as i32) << 12)
         + (PGSIXBIT(ch4 as i32) << 18)
-        + (PGSIXBIT(ch5 as i32) << 24)) as i32
+        + (PGSIXBIT(ch5 as i32) << 24)
 }

pgrx-pg-sys/src/submodules/ffi.rs

@@ -123,7 +123,7 @@ unsafe fn pg_guard_ffi_boundary_impl<T, F: FnOnce() -> T>(f: F) -> T {
             pg_sys::PG_exception_stack = prev_exception_stack;
             pg_sys::error_context_stack = prev_error_context_stack;
 
-            return result;
+            result
         } else {
             // we're back here b/c of a longjmp originating in Postgres
 
@@ -148,13 +148,13 @@ unsafe fn pg_guard_ffi_boundary_impl<T, F: FnOnce() -> T>(f: F) -> T {
                 .is_null()
                 .then(|| String::from("<null error message>"))
                 .unwrap_or_else(|| CStr::from_ptr(errdata.message).to_string_lossy().to_string());
-            let detail = errdata.detail.is_null().then(|| None).unwrap_or_else(|| {
+            let detail = errdata.detail.is_null().then_some(None).unwrap_or_else(|| {
                 Some(CStr::from_ptr(errdata.detail).to_string_lossy().to_string())
             });
-            let hint = errdata.hint.is_null().then(|| None).unwrap_or_else(|| {
+            let hint = errdata.hint.is_null().then_some(None).unwrap_or_else(|| {
                 Some(CStr::from_ptr(errdata.hint).to_string_lossy().to_string())
             });
-            let funcname = errdata.funcname.is_null().then(|| None).unwrap_or_else(|| {
+            let funcname = errdata.funcname.is_null().then_some(None).unwrap_or_else(|| {
                 Some(CStr::from_ptr(errdata.funcname).to_string_lossy().to_string())
             });
             let file =

pgrx-pg-sys/src/submodules/htup.rs

@@ -393,13 +393,11 @@ unsafe fn fastgetattr(
             } else {
                 nocachegetattr(tup, attnum, tupleDesc)
             }
+        } else if att_isnull(attnum - 1, (*(*tup).t_data).t_bits.as_ptr()) {
+            *isnull = true;
+            Datum::from(0) // a NULL pointer
         } else {
-            if att_isnull(attnum - 1, (*(*tup).t_data).t_bits.as_ptr()) {
-                *isnull = true;
-                Datum::from(0) // a NULL pointer
-            } else {
-                nocachegetattr(tup, attnum, tupleDesc)
-            }
+            nocachegetattr(tup, attnum, tupleDesc)
         }
     }
 }

pgrx-pg-sys/src/submodules/panic.rs

@@ -224,7 +224,7 @@ impl ErrorReportWithLevel {
 
     /// Returns the name of the function that generated this error report, if we were able to figure it out
     pub fn function_name(&self) -> Option<&str> {
-        self.inner.location.funcname.as_ref().map(|s| s.as_str())
+        self.inner.location.funcname.as_deref()
     }
 
     /// Returns the context message of this error report, if any
@@ -282,12 +282,12 @@ impl ErrorReport {
 
     /// Returns the detail message of this error report
     pub fn detail(&self) -> Option<&str> {
-        self.detail.as_ref().map(|s| s.as_str())
+        self.detail.as_deref()
     }
 
     /// Returns the hint message of this error report
     pub fn hint(&self) -> Option<&str> {
-        self.hint.as_ref().map(|s| s.as_str())
+        self.hint.as_deref()
     }
 
     /// Report this [PgErrorReport], which will ultimately be reported by Postgres at the specified [PgLogLevel]