rustc_llvm/build.rs: improve comment for NetBSD/i386 targets

he32 · he32 · commit 391b472a370a · 2023-10-26T17:10:16.000Z
...explaining why we need -latomic (gcc &amp; g++ built for i486,
and LLVM insisting on use of 64-bit atomics).
diff --git a/compiler/rustc_llvm/build.rs b/compiler/rustc_llvm/build.rs
@@ -258,7 +258,9 @@ fn main() {
     {
         println!("cargo:rustc-link-lib=z");
     } else if target.contains("netbsd") {
-        // Building for i586 or i686, we need -latomic for 64-bit atomics
+        // On NetBSD/i386, gcc and g++ is built for i486 (to maximize backward compat)
+        // However, LLVM insists on using 64-bit atomics.
+        // This gives rise to a need to link rust itself with -latomic for these targets
         if target.starts_with("i586")
            || target.starts_with("i686")
         {

Original file line number	Diff line number	Diff line change
`@@ -258,7 +258,9 @@ fn main() {`
`258`	`258`	`{`
`259`	`259`	`println!("cargo:rustc-link-lib=z");`
`260`	`260`	`} else if target.contains("netbsd") {`
`261`		`- // Building for i586 or i686, we need -latomic for 64-bit atomics`
	`261`	`+ // On NetBSD/i386, gcc and g++ is built for i486 (to maximize backward compat)`
	`262`	`+ // However, LLVM insists on using 64-bit atomics.`
	`263`	`+ // This gives rise to a need to link rust itself with -latomic for these targets`
`262`	`264`	`if target.starts_with("i586")`
`263`	`265`	`\|\| target.starts_with("i686")`
`264`	`266`	`{`