From fde6479c6a743216c188668c76cb64f4ee0f7b7a Mon Sep 17 00:00:00 2001
From: yancy <email@yancy.lol>
Date: Sat, 28 Oct 2023 11:41:27 +0200
Subject: [PATCH] Create uniform build script

Previously, each unique compiler cfg attribute that appeared in the
codebase was hard coded and emitted to stdout at compile time. This
meant keeping the file up to date as different compiler cfg attributes
changed. It's inconsequential to emit a compiler version that's not
used, so this change just emits all possibilities to reduce the
maintenance burden of the build script.
---
 bitcoin/build.rs   | 18 ++++++++++--------
 internals/build.rs | 10 ++++------
 2 files changed, 14 insertions(+), 14 deletions(-)

diff --git a/bitcoin/build.rs b/bitcoin/build.rs
index 4621b7f1..b5e2f5f6 100644
--- a/bitcoin/build.rs
+++ b/bitcoin/build.rs
@@ -1,10 +1,13 @@
+const MSRV_MINOR: u64 = 48;
+
 fn main() {
-    let rustc = std::env::var_os("RUSTC").unwrap_or_else(|| "rustc".into());
+    let rustc = std::env::var_os("RUSTC");
+    let rustc = rustc.as_ref().map(std::path::Path::new).unwrap_or_else(|| "rustc".as_ref());
     let output = std::process::Command::new(rustc)
         .arg("--version")
         .output()
-        .expect("Failed to run rustc --version");
-    assert!(output.status.success(), "Failed to get rust version");
+        .unwrap_or_else(|error| panic!("Failed to run `{:?} --version`: {:?}", rustc, error));
+    assert!(output.status.success(), "{:?} -- version returned non-zero exit code", rustc);
     let stdout = String::from_utf8(output.stdout).expect("rustc produced non-UTF-8 output");
     let version_prefix = "rustc ";
     if !stdout.starts_with(version_prefix) {
@@ -16,16 +19,15 @@ fn main() {
     let version = &version[..end];
     let mut version_components = version.split('.');
     let major = version_components.next().unwrap();
-    assert_eq!(major, "1", "Unexpected Rust version");
+    assert_eq!(major, "1", "Unexpected Rust major version");
     let minor = version_components
         .next()
         .unwrap_or("0")
         .parse::<u64>()
         .expect("invalid Rust minor version");
 
-    for activate_version in &[53, 60] {
-        if minor >= *activate_version {
-            println!("cargo:rustc-cfg=rust_v_1_{}", activate_version);
-        }
+    // print cfg for all interesting versions less than or equal to minor
+    for version in MSRV_MINOR..=minor {
+        println!("cargo:rustc-cfg=rust_v_1_{}", version);
     }
 }
diff --git a/internals/build.rs b/internals/build.rs
index ab1f0411..b5e2f5f6 100644
--- a/internals/build.rs
+++ b/internals/build.rs
@@ -1,3 +1,5 @@
+const MSRV_MINOR: u64 = 48;
+
 fn main() {
     let rustc = std::env::var_os("RUSTC");
     let rustc = rustc.as_ref().map(std::path::Path::new).unwrap_or_else(|| "rustc".as_ref());
@@ -25,11 +27,7 @@ fn main() {
         .expect("invalid Rust minor version");
 
     // print cfg for all interesting versions less than or equal to minor
-    // 46 adds `track_caller`
-    // 55 adds `kind()` to `ParseIntError`
-    for version in &[46, 55] {
-        if *version <= minor {
-            println!("cargo:rustc-cfg=rust_v_1_{}", version);
-        }
+    for version in MSRV_MINOR..=minor {
+        println!("cargo:rustc-cfg=rust_v_1_{}", version);
     }
 }