Fix generated constants: f64::INFINITY, f64::NEG_ INFINITY, f64::NAN

#2853

Author: Gabi Ganam

bindgen/codegen/helpers.rs

@@ -131,6 +131,7 @@ pub(crate) mod ast_ty {
     use crate::ir::function::FunctionSig;
     use crate::ir::layout::Layout;
     use crate::ir::ty::{FloatKind, IntKind};
+    use crate::RustTarget;
     use proc_macro2::TokenStream;
     use std::str::FromStr;
 
@@ -312,35 +313,44 @@ pub(crate) mod ast_ty {
         }
 
         let prefix = ctx.trait_prefix();
+        let rust_target = ctx.options().rust_target;
 
         if f.is_nan() {
-            return Ok(quote! {
-                if rust_target >= RustTarget::Stable_1_43 {
+            let tokens = if rust_target >= RustTarget::Stable_1_43 {
+                quote! {
                     f64::NAN
-                } else {
+                }
+            } else {
+                quote! {
                     ::#prefix::f64::NAN
                 }
-            });
+            };
+            return Ok(tokens);
         }
 
         if f.is_infinite() {
-            return Ok(if f.is_sign_positive() {
-                quote! {
-                    if rust_target >= RustTarget::Stable_1_43 {
+            let tokens = if f.is_sign_positive() {
+                if rust_target >= RustTarget::Stable_1_43 {
+                    quote! {
                         f64::INFINITY
-                    } else {
+                    }
+                } else {
+                    quote! {
                         ::#prefix::f64::INFINITY
                     }
                 }
-            } else {
-                quote! {
-                    if rust_target >= RustTarget::Stable_1_43 {
+            } else { // sign_negative
+                if rust_target >= RustTarget::Stable_1_43 {
+                    quote! {
                         f64::NEG_INFINITY
-                    } else {
+                    }
+                } else {
+                    quote! {
                         ::#prefix::f64::NEG_INFINITY
                     }
                 }
-            });
+            };
+            return Ok(tokens);
         }
 
         warn!("Unknown non-finite float number: {:?}", f);

bindgen/features.rs

@@ -106,7 +106,8 @@ define_rust_targets! {
     Stable_1_64(64) => { core_ffi_c: #94503 },
     Stable_1_59(59) => { const_cstr: #54745 },
     Stable_1_47(47) => { larger_arrays: #74060 },
-    Stable_1_40(40) => { non_exhaustive: #44109 },
+    Stable_1_43(43) => { non_exhaustive: #44109 },
+    Stable_1_40(40) => {},
     Stable_1_36(36) => { maybe_uninit: #60445 },
     Stable_1_33(33) => { repr_packed_n: #57049 },
     #[deprecated]