Invert use_target_has_atomic cfg

This way, a build system that does not want to run Cargo build scripts
can build serde without any cfgs defined, and get the most modern
feature set.

serde/build.rs

@@ -95,9 +95,8 @@ fn main() {
     // Whitelist of archs that support std::sync::atomic module. Ideally we
     // would use #[cfg(target_has_atomic = "...")] but it is not stable yet.
     // Instead this is based on rustc's compiler/rustc_target/src/spec/*.rs.
-    if minor >= 60 {
-        println!("cargo:rustc-cfg=use_target_has_atomic");
-    } else {
+    if minor < 60 {
+        println!("cargo:rustc-cfg=no_target_has_atomic");
         let has_atomic64 = target.starts_with("x86_64")
             || target.starts_with("i686")
             || target.starts_with("aarch64")

serde/src/de/impls.rs

@@ -2660,7 +2660,7 @@ where
     }
 }
 
-#[cfg(all(feature = "std", not(use_target_has_atomic), not(no_std_atomic)))]
+#[cfg(all(feature = "std", no_target_has_atomic, not(no_std_atomic)))]
 macro_rules! atomic_impl {
     ($($ty:ident)*) => {
         $(
@@ -2676,7 +2676,7 @@ macro_rules! atomic_impl {
     };
 }
 
-#[cfg(all(feature = "std", use_target_has_atomic))]
+#[cfg(all(feature = "std", not(no_target_has_atomic)))]
 macro_rules! atomic_impl {
     ($($ty:ident $size:expr),*) => {
         $(
@@ -2693,19 +2693,19 @@ macro_rules! atomic_impl {
     };
 }
 
-#[cfg(all(feature = "std", not(use_target_has_atomic), not(no_std_atomic)))]
+#[cfg(all(feature = "std", no_target_has_atomic, not(no_std_atomic)))]
 atomic_impl! {
     AtomicBool
     AtomicI8 AtomicI16 AtomicI32 AtomicIsize
     AtomicU8 AtomicU16 AtomicU32 AtomicUsize
 }
 
-#[cfg(all(feature = "std", not(use_target_has_atomic), not(no_std_atomic64)))]
+#[cfg(all(feature = "std", no_target_has_atomic, not(no_std_atomic64)))]
 atomic_impl! {
     AtomicI64 AtomicU64
 }
 
-#[cfg(all(feature = "std", use_target_has_atomic))]
+#[cfg(all(feature = "std", not(no_target_has_atomic)))]
 atomic_impl! {
     AtomicBool "8",
     AtomicI8 "8",

serde/src/lib.rs

@@ -236,25 +236,25 @@ mod lib {
     #[cfg(not(no_range_inclusive))]
     pub use self::core::ops::RangeInclusive;
 
-    #[cfg(all(feature = "std", not(use_target_has_atomic), not(no_std_atomic)))]
+    #[cfg(all(feature = "std", no_target_has_atomic, not(no_std_atomic)))]
     pub use std::sync::atomic::{
         AtomicBool, AtomicI16, AtomicI32, AtomicI8, AtomicIsize, AtomicU16, AtomicU32, AtomicU8,
         AtomicUsize, Ordering,
     };
-    #[cfg(all(feature = "std", not(use_target_has_atomic), not(no_std_atomic64)))]
+    #[cfg(all(feature = "std", no_target_has_atomic, not(no_std_atomic64)))]
     pub use std::sync::atomic::{AtomicI64, AtomicU64};
 
-    #[cfg(all(feature = "std", use_target_has_atomic))]
+    #[cfg(all(feature = "std", not(no_target_has_atomic)))]
     pub use std::sync::atomic::Ordering;
-    #[cfg(all(feature = "std", use_target_has_atomic, target_has_atomic = "8"))]
+    #[cfg(all(feature = "std", not(no_target_has_atomic), target_has_atomic = "8"))]
     pub use std::sync::atomic::{AtomicBool, AtomicI8, AtomicU8};
-    #[cfg(all(feature = "std", use_target_has_atomic, target_has_atomic = "16"))]
+    #[cfg(all(feature = "std", not(no_target_has_atomic), target_has_atomic = "16"))]
     pub use std::sync::atomic::{AtomicI16, AtomicU16};
-    #[cfg(all(feature = "std", use_target_has_atomic, target_has_atomic = "32"))]
+    #[cfg(all(feature = "std", not(no_target_has_atomic), target_has_atomic = "32"))]
     pub use std::sync::atomic::{AtomicI32, AtomicU32};
-    #[cfg(all(feature = "std", use_target_has_atomic, target_has_atomic = "64"))]
+    #[cfg(all(feature = "std", not(no_target_has_atomic), target_has_atomic = "64"))]
     pub use std::sync::atomic::{AtomicI64, AtomicU64};
-    #[cfg(all(feature = "std", use_target_has_atomic, target_has_atomic = "ptr"))]
+    #[cfg(all(feature = "std", not(no_target_has_atomic), target_has_atomic = "ptr"))]
     pub use std::sync::atomic::{AtomicIsize, AtomicUsize};
 
     #[cfg(any(feature = "std", not(no_core_duration)))]

serde/src/ser/impls.rs

@@ -945,7 +945,7 @@ where
 
 ////////////////////////////////////////////////////////////////////////////////
 
-#[cfg(all(feature = "std", not(use_target_has_atomic), not(no_std_atomic)))]
+#[cfg(all(feature = "std", no_target_has_atomic, not(no_std_atomic)))]
 macro_rules! atomic_impl {
     ($($ty:ident)*) => {
         $(
@@ -962,7 +962,7 @@ macro_rules! atomic_impl {
     }
 }
 
-#[cfg(all(feature = "std", use_target_has_atomic))]
+#[cfg(all(feature = "std", not(no_target_has_atomic)))]
 macro_rules! atomic_impl {
     ($($ty:ident $size:expr),*) => {
         $(
@@ -980,19 +980,19 @@ macro_rules! atomic_impl {
     }
 }
 
-#[cfg(all(feature = "std", not(use_target_has_atomic), not(no_std_atomic)))]
+#[cfg(all(feature = "std", no_target_has_atomic, not(no_std_atomic)))]
 atomic_impl! {
     AtomicBool
     AtomicI8 AtomicI16 AtomicI32 AtomicIsize
     AtomicU8 AtomicU16 AtomicU32 AtomicUsize
 }
 
-#[cfg(all(feature = "std", not(use_target_has_atomic), not(no_std_atomic64)))]
+#[cfg(all(feature = "std", no_target_has_atomic, not(no_std_atomic64)))]
 atomic_impl! {
     AtomicI64 AtomicU64
 }
 
-#[cfg(all(feature = "std", use_target_has_atomic))]
+#[cfg(all(feature = "std", not(no_target_has_atomic)))]
 atomic_impl! {
     AtomicBool "8",
     AtomicI8 "8",