Begin synthesizing spans (#1746)

I consulted other rust-lang devs and they agree proc-macros should use
what I refer to as "synthetic" spans. These spans have their root
context derived from `Span::mixed_site()` or `Span::call_site()` but
have been given a location in the code somewhere.

- Fixes remaining `used_underscore_binding` warnings.
- Closes #1667

Author: workingjubilee

.github/workflows/tests.yml

@@ -434,7 +434,7 @@ jobs:
 
       # We can't do this with other lints because we need $PGRX_HOME
       - name: Clippy -Awarnings
-        run: cargo clippy -p pgrx --features pg$PG_VER -- -Awarnings
+        run: cargo clippy --tests --features pg$PG_VER --no-default-features -- -Awarnings
 
       # This also requires $PGRX_HOME
       - name: Check doc-links

pgrx-macros/src/rewriter.rs

@@ -9,7 +9,7 @@
 //LICENSE Use of this source code is governed by the MIT license that can be found in the LICENSE file.
 extern crate proc_macro;
 
-use quote::{format_ident, quote, quote_spanned};
+use quote::{quote, quote_spanned};
 use std::mem;
 use std::ops::Deref;
 use std::str::FromStr;
@@ -20,6 +20,14 @@ use syn::{
     Visibility,
 };
 
+macro_rules! format_ident {
+    ($s:literal, $e:expr) => {{
+        let mut synthetic = $e.clone();
+        synthetic.set_span(proc_macro2::Span::call_site().located_at($e.span()));
+        quote::format_ident!($s, synthetic)
+    }};
+}
+
 pub fn extern_block(block: ItemForeignMod) -> proc_macro2::TokenStream {
     let mut stream = proc_macro2::TokenStream::new();
 
@@ -60,6 +68,7 @@ pub fn item_fn_without_rewrite(mut func: ItemFn) -> syn::Result<proc_macro2::Tok
 
     let arg_list = build_arg_list(&sig, false)?;
     let func_name = func.sig.ident.clone();
+    let func_name = format_ident!("{}", func_name);
 
     let prolog = if input_func_name == "__pgrx_private_shmem_hook"
         || input_func_name == "__pgrx_private_shmem_request_hook"
@@ -90,7 +99,9 @@ pub fn item_fn_without_rewrite(mut func: ItemFn) -> syn::Result<proc_macro2::Tok
         quote! { #func_name::<#ty>(#arg_list) }
     };
 
-    Ok(quote_spanned! {func.span()=>
+    let synthetic = proc_macro2::Span::mixed_site().located_at(func.span());
+
+    Ok(quote_spanned! {synthetic=>
         #prolog
         #(#attrs)*
         #vis #sig {
@@ -149,6 +160,7 @@ fn build_arg_list(sig: &Signature, suffix_arg_name: bool) -> syn::Result<proc_ma
                         let ident = format_ident!("{}_", ident.ident);
                         arg_list.extend(quote! { #ident, });
                     } else {
+                        let ident = format_ident!("{}", ident.ident);
                         arg_list.extend(quote! { #ident, });
                     }
                 } else {

pgrx-sql-entity-graph/src/finfo.rs

@@ -27,7 +27,10 @@ pub fn finfo_v1_extern_c(
     let original_name = &original.sig.ident;
     let wrapper_symbol = format_ident!("{}_wrapper", original_name);
 
-    let tokens = quote_spanned! { original.sig.span() =>
+    let synthetic = proc_macro2::Span::mixed_site();
+    let synthetic = synthetic.located_at(original.sig.span());
+
+    let tokens = quote_spanned! { synthetic =>
         #[no_mangle]
         #[doc(hidden)]
         pub unsafe extern "C" fn #wrapper_symbol(#fcinfo: ::pgrx::pg_sys::FunctionCallInfo) -> ::pgrx::pg_sys::Datum {

pgrx-sql-entity-graph/src/pg_extern/mod.rs

@@ -40,12 +40,30 @@ use operator::{PgrxOperatorAttributeWithIdent, PgrxOperatorOpName};
 use search_path::SearchPathList;
 
 use proc_macro2::{Ident, Span, TokenStream as TokenStream2};
-use quote::{format_ident, quote, quote_spanned};
+use quote::quote;
 use syn::parse::{Parse, ParseStream, Parser};
 use syn::punctuated::Punctuated;
 use syn::spanned::Spanned;
 use syn::{Meta, Token};
 
+macro_rules! quote_spanned {
+    ($span:expr=> $($expansion:tt)*) => {
+        {
+            let synthetic = Span::mixed_site();
+            let synthetic = synthetic.located_at($span);
+            quote::quote_spanned! {synthetic=> $($expansion)* }
+        }
+    };
+}
+
+macro_rules! format_ident {
+    ($s:literal, $e:expr) => {{
+        let mut synthetic = $e.clone();
+        synthetic.set_span(Span::call_site().located_at($e.span()));
+        quote::format_ident!($s, synthetic)
+    }};
+}
+
 /// A parsed `#[pg_extern]` item.
 ///
 /// It should be used with [`syn::parse::Parse`] functions.
@@ -377,7 +395,8 @@ impl PgExtern {
         let signature = &self.func.sig;
         let func_name = &signature.ident;
         // we do this odd dance so we can pass the same ident to macros that don't know each other
-        let fcinfo_ident = syn::Ident::new("fcinfo", signature.ident.span());
+        let synthetic_ident_span = Span::mixed_site().located_at(signature.ident.span());
+        let fcinfo_ident = syn::Ident::new("fcinfo", synthetic_ident_span);
         let mut lifetimes = signature
             .generics
             .lifetimes()

pgrx-sql-entity-graph/src/pg_trigger/mod.rs

@@ -22,7 +22,7 @@ use crate::enrich::{ToEntityGraphTokens, ToRustCodeTokens};
 use crate::finfo::{finfo_v1_extern_c, finfo_v1_tokens};
 use crate::{CodeEnrichment, ToSqlConfig};
 use attribute::PgTriggerAttribute;
-use proc_macro2::{Ident, TokenStream as TokenStream2};
+use proc_macro2::{Ident, Span, TokenStream as TokenStream2};
 use quote::{format_ident, quote};
 use syn::{spanned::Spanned, ItemFn, Token};
 
@@ -70,7 +70,8 @@ impl PgTrigger {
 
     pub fn wrapper_tokens(&self) -> Result<ItemFn, syn::Error> {
         let function_ident = self.func.sig.ident.clone();
-        let fcinfo_ident = Ident::new("_fcinfo", function_ident.span());
+        let fcinfo_ident =
+            Ident::new("_fcinfo", Span::mixed_site().located_at(function_ident.span()));
 
         let tokens = quote! {
             fn _internal(fcinfo: ::pgrx::pg_sys::FunctionCallInfo) -> ::pgrx::pg_sys::Datum {

pgrx-tests/src/tests/attributes_tests.rs

@@ -18,7 +18,7 @@ mod tests {
     #[pg_test]
     #[ignore = "This test should be ignored."]
     fn test_for_ignore_attribute() {
-        assert_eq!(true, true);
+        assert_eq!(true, false);
     }
 
     #[pg_test]

pgrx-tests/tests/compile-fail/aggregate-functions-dont-run-forever.stderr

@@ -9,7 +9,7 @@ error[E0521]: borrowed data escapes outside of function
    | lifetime `'fcx` defined here
    | argument requires that `'fcx` must outlive `'static`
    |
-   = note: this error originates in the attribute macro `pg_aggregate` (in Nightly builds, run with -Z macro-backtrace for more info)
+   = note: this error originates in the attribute macro `::pgrx::pg_extern` (in Nightly builds, run with -Z macro-backtrace for more info)
 
 error[E0521]: borrowed data escapes outside of function
   --> tests/compile-fail/aggregate-functions-dont-run-forever.rs:47:1
@@ -22,7 +22,7 @@ error[E0521]: borrowed data escapes outside of function
    | lifetime `'fcx` defined here
    | argument requires that `'fcx` must outlive `'static`
    |
-   = note: this error originates in the attribute macro `pg_aggregate` (in Nightly builds, run with -Z macro-backtrace for more info)
+   = note: this error originates in the attribute macro `::pgrx::pg_extern` (in Nightly builds, run with -Z macro-backtrace for more info)
 
 error[E0521]: borrowed data escapes outside of function
   --> tests/compile-fail/aggregate-functions-dont-run-forever.rs:70:1
@@ -35,7 +35,7 @@ error[E0521]: borrowed data escapes outside of function
    | lifetime `'fcx` defined here
    | argument requires that `'fcx` must outlive `'static`
    |
-   = note: this error originates in the attribute macro `pg_aggregate` (in Nightly builds, run with -Z macro-backtrace for more info)
+   = note: this error originates in the attribute macro `::pgrx::pg_extern` (in Nightly builds, run with -Z macro-backtrace for more info)
 
 error[E0521]: borrowed data escapes outside of function
    --> tests/compile-fail/aggregate-functions-dont-run-forever.rs:113:1
@@ -48,7 +48,7 @@ error[E0521]: borrowed data escapes outside of function
     | lifetime `'fcx` defined here
     | argument requires that `'fcx` must outlive `'static`
     |
-    = note: this error originates in the attribute macro `pg_aggregate` (in Nightly builds, run with -Z macro-backtrace for more info)
+    = note: this error originates in the attribute macro `::pgrx::pg_extern` (in Nightly builds, run with -Z macro-backtrace for more info)
 
 error[E0521]: borrowed data escapes outside of function
    --> tests/compile-fail/aggregate-functions-dont-run-forever.rs:141:1
@@ -61,4 +61,4 @@ error[E0521]: borrowed data escapes outside of function
     | lifetime `'fcx` defined here
     | argument requires that `'fcx` must outlive `'static`
     |
-    = note: this error originates in the attribute macro `pg_aggregate` (in Nightly builds, run with -Z macro-backtrace for more info)
+    = note: this error originates in the attribute macro `::pgrx::pg_extern` (in Nightly builds, run with -Z macro-backtrace for more info)

pgrx-tests/tests/compile-fail/eq-for-postgres_hash.stderr

@@ -39,7 +39,7 @@ note: required by a bound in `brokentype_hash`
   |                                                ^^^^^^^^^^^^ required by this bound in `brokentype_hash`
 5 | pub struct BrokenType {
   |            ---------- required by a bound in this function
-  = note: this error originates in the derive macro `PostgresHash` (in Nightly builds, run with -Z macro-backtrace for more info)
+  = note: this error originates in the attribute macro `::pgrx::pgrx_macros::pg_extern` which comes from the expansion of the derive macro `PostgresHash` (in Nightly builds, run with -Z macro-backtrace for more info)
 help: consider annotating `BrokenType` with `#[derive(Hash)]`
   |
 5 + #[derive(Hash)]
@@ -59,7 +59,7 @@ note: required by a bound in `brokentype_hash`
   |                                                ^^^^^^^^^^^^ required by this bound in `brokentype_hash`
 5 | pub struct BrokenType {
   |            ---------- required by a bound in this function
-  = note: this error originates in the derive macro `PostgresHash` (in Nightly builds, run with -Z macro-backtrace for more info)
+  = note: this error originates in the attribute macro `::pgrx::pgrx_macros::pg_extern` which comes from the expansion of the derive macro `PostgresHash` (in Nightly builds, run with -Z macro-backtrace for more info)
 help: consider annotating `BrokenType` with `#[derive(Eq)]`
   |
 5 + #[derive(Eq)]

pgrx-tests/tests/compile-fail/postgres-strings-arent-immortal.stderr

@@ -2,7 +2,10 @@ error[E0521]: borrowed data escapes outside of function
  --> tests/compile-fail/postgres-strings-arent-immortal.rs:4:67
   |
 3 |   #[pg_extern]
-  |   ------------ lifetime `'fcx` defined here
+  |   ------------
+  |   |
+  |   lifetime `'fcx` defined here
+  |   in this procedural macro expansion
 4 |   fn split(input: &'static str, pattern: &str) -> Vec<&'static str> {
   |  ___________________________________________________________________^
 5 | |     input.split_terminator(pattern).collect()
@@ -12,3 +15,5 @@ error[E0521]: borrowed data escapes outside of function
   | | `fcinfo` is a reference that is only valid in the function body
   | |_`fcinfo` escapes the function body here
   |   argument requires that `'fcx` must outlive `'static`
+  |
+  = note: this error originates in the attribute macro `pg_extern` (in Nightly builds, run with -Z macro-backtrace for more info)

pgrx-tests/tests/compile-fail/table-iterators-arent-immortal.stderr

@@ -2,7 +2,10 @@ error[E0521]: borrowed data escapes outside of function
  --> tests/compile-fail/table-iterators-arent-immortal.rs:6:78
   |
 3 |   #[pg_extern]
-  |   ------------ lifetime `'fcx` defined here
+  |   ------------
+  |   |
+  |   lifetime `'fcx` defined here
+  |   in this procedural macro expansion
 ...
 6 |   ) -> TableIterator<(name!(a, &'static str), name!(b, Option<&'static str>))> {
   |  ______________________________________________________________________________^
@@ -13,3 +16,5 @@ error[E0521]: borrowed data escapes outside of function
   | | `fcinfo` is a reference that is only valid in the function body
   | |_`fcinfo` escapes the function body here
   |   argument requires that `'fcx` must outlive `'static`
+  |
+  = note: this error originates in the attribute macro `pg_extern` (in Nightly builds, run with -Z macro-backtrace for more info)