chore(benchmarks): measure builder usage in compilation benchmarks

benchmarks/compilation/codegen/src/main.rs

@@ -1,4 +1,4 @@
-use proc_macro2::TokenStream;
+use proc_macro2::{Literal, TokenStream};
 use quote::{format_ident, quote};
 use std::path::PathBuf;
 
@@ -10,15 +10,14 @@ fn main() -> anyhow::Result<()> {
 
     let src_dir = bench_dir.join("src");
 
-    let structs_number = 10;
-    let fields_number = 50;
-
-    std::fs::write(
-        src_dir.join(format!(
-            "structs_{structs_number}_fields_{fields_number}.rs"
-        )),
-        structs_n_fields_n(structs_number, fields_number).to_string(),
-    )?;
+    for (structs_number, fields_number) in [(100, 10), (10, 50)] {
+        std::fs::write(
+            src_dir.join(format!(
+                "structs_{structs_number}_fields_{fields_number}.rs"
+            )),
+            structs_n_fields_n(structs_number, fields_number).to_string(),
+        )?;
+    }
 
     println!("Running cargo fmt in {}", bench_dir.display());
 
@@ -38,10 +37,20 @@ fn structs_n_fields_n(structs_number: usize, fields_number: usize) -> TokenStrea
         .map(|i| format_ident!("x{i}"))
         .collect::<Vec<_>>();
 
+    let field_values = (1..=fields_number)
+        .map(Literal::usize_unsuffixed)
+        .collect::<Vec<_>>();
+
     (1..=structs_number)
         .map(move |i| {
             let struct_name = format_ident!("Struct{i}");
+            let builder_name = format_ident!("Struct{i}Builder");
+            let usage_fn = format_ident!("struct{i}");
 
+            // Every struct is built once with all setters called. This way
+            // the benchmark measures the cost of the builder usage in addition
+            // to the cost of the builder definition. The `cfg`s follow the
+            // same order of priority as the `Builder` import in `lib.rs`.
             quote! {
                 #[cfg_attr(
                     any(
@@ -54,6 +63,35 @@ fn structs_n_fields_n(structs_number: usize, fields_number: usize) -> TokenStrea
                 pub struct #struct_name {
                     #( #field_names: i32, )*
                 }
+
+                #[cfg(any(feature = "bon", feature = "typed-builder"))]
+                pub fn #usage_fn() -> #struct_name {
+                    #struct_name::builder()
+                        #( .#field_names(#field_values) )*
+                        .build()
+                }
+
+                #[cfg(all(
+                    feature = "derive_builder",
+                    not(any(feature = "bon", feature = "typed-builder")),
+                ))]
+                pub fn #usage_fn() -> #struct_name {
+                    #builder_name::default()
+                        #( .#field_names(#field_values) )*
+                        .build()
+                        .unwrap()
+                }
+
+                #[cfg(not(any(
+                    feature = "bon",
+                    feature = "typed-builder",
+                    feature = "derive_builder",
+                )))]
+                pub fn #usage_fn() -> #struct_name {
+                    #struct_name {
+                        #( #field_names: #field_values, )*
+                    }
+                }
             }
         })
         .collect()

benchmarks/compilation/results.md

@@ -1,10 +1,10 @@
 | Command                                |      Mean [s] | Min [s] | Max [s] |     Relative |
 | :------------------------------------- | ------------: | ------: | ------: | -----------: |
-| `structs_100_fields_10 bon`            | 2.340 ± 0.019 |   2.315 |   2.364 | 20.86 ± 1.37 |
-| `structs_100_fields_10 typed-builder`  | 1.831 ± 0.015 |   1.806 |   1.859 | 16.32 ± 1.07 |
-| `structs_100_fields_10 derive_builder` | 1.026 ± 0.013 |   1.009 |   1.048 |  9.14 ± 0.61 |
-| `structs_100_fields_10 `               | 0.113 ± 0.010 |   0.092 |   0.125 |  1.01 ± 0.11 |
-| `structs_10_fields_50 bon`             | 2.096 ± 0.009 |   2.080 |   2.109 | 18.69 ± 1.22 |
-| `structs_10_fields_50 typed-builder`   | 2.088 ± 0.014 |   2.067 |   2.115 | 18.61 ± 1.22 |
-| `structs_10_fields_50 derive_builder`  | 0.449 ± 0.022 |   0.391 |   0.470 |  4.00 ± 0.33 |
-| `structs_10_fields_50 `                | 0.112 ± 0.007 |   0.086 |   0.116 |         1.00 |
+| `structs_100_fields_10 bon`            | 2.321 ± 0.023 |   2.282 |   2.351 | 21.40 ± 1.92 |
+| `structs_100_fields_10 typed-builder`  | 1.677 ± 0.023 |   1.649 |   1.726 | 15.47 ± 1.40 |
+| `structs_100_fields_10 derive_builder` | 1.043 ± 0.023 |   1.013 |   1.084 |  9.62 ± 0.88 |
+| `structs_100_fields_10 `               | 0.135 ± 0.015 |   0.114 |   0.162 |  1.24 ± 0.18 |
+| `structs_10_fields_50 bon`             | 2.098 ± 0.022 |   2.065 |   2.135 | 19.35 ± 1.74 |
+| `structs_10_fields_50 typed-builder`   | 1.996 ± 0.021 |   1.970 |   2.029 | 18.41 ± 1.65 |
+| `structs_10_fields_50 derive_builder`  | 0.434 ± 0.012 |   0.415 |   0.450 |  4.00 ± 0.37 |
+| `structs_10_fields_50 `                | 0.108 ± 0.010 |   0.096 |   0.129 |         1.00 |

benchmarks/compilation/src/lib.rs

@@ -2,7 +2,8 @@
     missing_docs,
     missing_debug_implementations,
     dead_code,
-    rustdoc::missing_crate_level_docs
+    rustdoc::missing_crate_level_docs,
+    clippy::must_use_candidate
 )]
 
 cfg_if::cfg_if! {