Auto merge of #1427 - emilio:const-static, r=emilio

codegen: Teach bindgen to respect constness of statics. ```c const extern struct Foo gFoo; ``` Should never generate a `static mut`.
rust-lang · Oct 22, 2018 · 0d0a245 · 0d0a245
2 parents d7a74ba + 710cbc0
commit 0d0a245
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Showing 10 changed files with 80 additions and 18 deletions.
diff --git a/Cargo.lock b/Cargo.lock
diff --git a/Cargo.toml b/Cargo.toml
@@ -14,7 +14,7 @@ readme = "README.md"
 repository = "https://github.com/rust-lang-nursery/rust-bindgen"
 documentation = "https://docs.rs/bindgen"
 homepage = "https://rust-lang-nursery.github.io/rust-bindgen/"
-version = "0.42.3"
+version = "0.43.0"
 build = "build.rs"
 
 include = [
@@ -44,7 +44,7 @@ shlex = "0.1"
 
 [dependencies]
 bitflags = "1.0.3"
-cexpr = "0.3"
+cexpr = "0.3.3"
 cfg-if = "0.1.0"
 # This kinda sucks: https://github.com/rust-lang/cargo/issues/1982
 clap = "2"

diff --git a/src/codegen/mod.rs b/src/codegen/mod.rs
@@ -575,10 +575,16 @@ impl CodeGenerator for Var {
                 attrs.push(attributes::link_name(self.name()));
             }
 
+            let maybe_mut = if self.is_const() {
+                quote! { }
+            } else {
+                quote! { mut }
+            };
+
             let mut tokens = quote!(
                 extern "C" {
                     #(#attrs)*
-                    pub static mut #canonical_ident: #ty;
+                    pub static #maybe_mut #canonical_ident: #ty;
                 }
             );
 

diff --git a/tests/expectations/tests/extern-const-struct.rs b/tests/expectations/tests/extern-const-struct.rs
@@ -0,0 +1,46 @@
+/* automatically generated by rust-bindgen */
+
+#![allow(
+    dead_code,
+    non_snake_case,
+    non_camel_case_types,
+    non_upper_case_globals
+)]
+
+#[repr(C)]
+#[derive(Copy, Clone)]
+pub struct nsFoo {
+    pub details: [f32; 400usize],
+}
+#[test]
+fn bindgen_test_layout_nsFoo() {
+    assert_eq!(
+        ::std::mem::size_of::<nsFoo>(),
+        1600usize,
+        concat!("Size of: ", stringify!(nsFoo))
+    );
+    assert_eq!(
+        ::std::mem::align_of::<nsFoo>(),
+        4usize,
+        concat!("Alignment of ", stringify!(nsFoo))
+    );
+    assert_eq!(
+        unsafe { &(*(::std::ptr::null::<nsFoo>())).details as *const _ as usize },
+        0usize,
+        concat!(
+            "Offset of field: ",
+            stringify!(nsFoo),
+            "::",
+            stringify!(details)
+        )
+    );
+}
+impl Default for nsFoo {
+    fn default() -> Self {
+        unsafe { ::std::mem::zeroed() }
+    }
+}
+extern "C" {
+    #[link_name = "\u{1}gDetails"]
+    pub static gDetails: nsFoo;
+}
diff --git a/tests/expectations/tests/issue-511.rs b/tests/expectations/tests/issue-511.rs
@@ -1,6 +1,11 @@
 /* automatically generated by rust-bindgen */
 
-#![allow(dead_code, non_snake_case, non_camel_case_types, non_upper_case_globals)]
+#![allow(
+    dead_code,
+    non_snake_case,
+    non_camel_case_types,
+    non_upper_case_globals
+)]
 
 extern "C" {
     #[link_name = "\u{1}a"]
@@ -12,9 +17,9 @@ extern "C" {
 }
 extern "C" {
     #[link_name = "\u{1}c"]
-    pub static mut c: *mut ::std::os::raw::c_char;
+    pub static c: *mut ::std::os::raw::c_char;
 }
 extern "C" {
     #[link_name = "\u{1}d"]
-    pub static mut d: *const ::std::os::raw::c_char;
+    pub static d: *const ::std::os::raw::c_char;
 }
diff --git a/tests/expectations/tests/libclang-3.8/auto.rs b/tests/expectations/tests/libclang-3.8/auto.rs
@@ -11,7 +11,7 @@ pub struct Foo {
 }
 extern "C" {
     #[link_name = "\u{1}_ZN3Foo4kFooE"]
-    pub static mut Foo_kFoo: bool;
+    pub static Foo_kFoo: bool;
 }
 #[test]
 fn bindgen_test_layout_Foo() {

diff --git a/tests/expectations/tests/libclang-3.8/const_bool.rs b/tests/expectations/tests/libclang-3.8/const_bool.rs
@@ -6,7 +6,7 @@
 
 extern "C" {
     #[link_name = "\u{1}_ZL1k"]
-    pub static mut k: bool;
+    pub static k: bool;
 }
 #[repr(C)]
 #[derive(Debug, Default, Copy, Clone)]
@@ -15,7 +15,7 @@ pub struct A {
 }
 extern "C" {
     #[link_name = "\u{1}_ZN1A1kE"]
-    pub static mut A_k: bool;
+    pub static A_k: bool;
 }
 #[test]
 fn bindgen_test_layout_A() {
@@ -33,5 +33,5 @@ fn bindgen_test_layout_A() {
 pub type foo = bool;
 extern "C" {
     #[link_name = "\u{1}_ZL2k2"]
-    pub static mut k2: foo;
+    pub static k2: foo;
 }
diff --git a/tests/expectations/tests/libclang-3.8/constant-evaluate.rs b/tests/expectations/tests/libclang-3.8/constant-evaluate.rs
@@ -13,27 +13,27 @@ pub type EasyToOverflow = ::std::os::raw::c_ulonglong;
 pub const k: EasyToOverflow = 2147483648;
 extern "C" {
     #[link_name = "\u{1}k_expr"]
-    pub static mut k_expr: EasyToOverflow;
+    pub static k_expr: EasyToOverflow;
 }
 extern "C" {
     #[link_name = "\u{1}wow"]
-    pub static mut wow: EasyToOverflow;
+    pub static wow: EasyToOverflow;
 }
 extern "C" {
     #[link_name = "\u{1}BAZ"]
-    pub static mut BAZ: ::std::os::raw::c_longlong;
+    pub static BAZ: ::std::os::raw::c_longlong;
 }
 extern "C" {
     #[link_name = "\u{1}fuzz"]
-    pub static mut fuzz: f64;
+    pub static fuzz: f64;
 }
 extern "C" {
     #[link_name = "\u{1}BAZZ"]
-    pub static mut BAZZ: ::std::os::raw::c_char;
+    pub static BAZZ: ::std::os::raw::c_char;
 }
 extern "C" {
     #[link_name = "\u{1}WAT"]
-    pub static mut WAT: ::std::os::raw::c_char;
+    pub static WAT: ::std::os::raw::c_char;
 }
 extern "C" {
     #[link_name = "\u{1}bytestring"]

diff --git a/tests/expectations/tests/libclang-3.9/constant-evaluate.rs b/tests/expectations/tests/libclang-3.9/constant-evaluate.rs
@@ -17,7 +17,7 @@ pub const k: EasyToOverflow = 2147483648;
 pub const k_expr: EasyToOverflow = 0;
 extern "C" {
     #[link_name = "\u{1}wow"]
-    pub static mut wow: EasyToOverflow;
+    pub static wow: EasyToOverflow;
 }
 pub const BAZ: ::std::os::raw::c_longlong = 24;
 pub const fuzz: f64 = 51.0;

diff --git a/tests/headers/extern-const-struct.h b/tests/headers/extern-const-struct.h
@@ -0,0 +1,5 @@
+struct nsFoo {
+  float details[400];
+};
+
+extern const struct nsFoo gDetails;