From ee441391a7781e6522f429b3e4da6399c606753b Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Emilio=20Cobos=20=C3=81lvarez?= <emilio@crisal.io>
Date: Mon, 2 Sep 2024 15:40:37 +0200
Subject: [PATCH] ir: Dig into atomic types.

Fixes #2920
---
 .../tests/expectations/tests/atomic-constant.rs      |  7 +++++++
 .../expectations/tests/libclang-9/atomic-constant.rs |  4 ++++
 bindgen-tests/tests/headers/atomic-constant.h        |  2 ++
 bindgen/Cargo.toml                                   |  2 +-
 bindgen/clang.rs                                     |  9 +++++++++
 bindgen/ir/ty.rs                                     | 12 ++++++++++++
 bindgen/ir/var.rs                                    |  3 ++-
 7 files changed, 37 insertions(+), 2 deletions(-)
 create mode 100644 bindgen-tests/tests/expectations/tests/atomic-constant.rs
 create mode 100644 bindgen-tests/tests/expectations/tests/libclang-9/atomic-constant.rs
 create mode 100644 bindgen-tests/tests/headers/atomic-constant.h

diff --git a/bindgen-tests/tests/expectations/tests/atomic-constant.rs b/bindgen-tests/tests/expectations/tests/atomic-constant.rs
new file mode 100644
index 0000000000..bd3c18697b
--- /dev/null
+++ b/bindgen-tests/tests/expectations/tests/atomic-constant.rs
@@ -0,0 +1,7 @@
+#![allow(dead_code, non_snake_case, non_camel_case_types, non_upper_case_globals)]
+extern "C" {
+    pub static mut a: ::std::os::raw::c_int;
+}
+extern "C" {
+    pub static mut b: ::std::os::raw::c_int;
+}
diff --git a/bindgen-tests/tests/expectations/tests/libclang-9/atomic-constant.rs b/bindgen-tests/tests/expectations/tests/libclang-9/atomic-constant.rs
new file mode 100644
index 0000000000..ce12eaad3a
--- /dev/null
+++ b/bindgen-tests/tests/expectations/tests/libclang-9/atomic-constant.rs
@@ -0,0 +1,4 @@
+#![allow(dead_code, non_snake_case, non_camel_case_types, non_upper_case_globals)]
+extern "C" {
+    pub static mut b: ::std::os::raw::c_int;
+}
diff --git a/bindgen-tests/tests/headers/atomic-constant.h b/bindgen-tests/tests/headers/atomic-constant.h
new file mode 100644
index 0000000000..b28f76f7e4
--- /dev/null
+++ b/bindgen-tests/tests/headers/atomic-constant.h
@@ -0,0 +1,2 @@
+_Atomic(int) a;
+int b;
diff --git a/bindgen/Cargo.toml b/bindgen/Cargo.toml
index 9eddd5157d..1c19cc3539 100644
--- a/bindgen/Cargo.toml
+++ b/bindgen/Cargo.toml
@@ -28,7 +28,7 @@ path = "lib.rs"
 annotate-snippets = { version = "0.9.1", features = ["color"], optional = true }
 bitflags = "2.2.1"
 cexpr = "0.6"
-clang-sys = { version = "1", features = ["clang_6_0"] }
+clang-sys = { version = "1", features = ["clang_11_0"] }
 itertools = { version = ">=0.10,<0.14", default-features = false }
 log = { version = "0.4", optional = true }
 prettyplease = { version = "0.2.7", optional = true, features = ["verbatim"] }
diff --git a/bindgen/clang.rs b/bindgen/clang.rs
index 47c7b1704a..e585fb31bd 100644
--- a/bindgen/clang.rs
+++ b/bindgen/clang.rs
@@ -1493,6 +1493,15 @@ impl Type {
         }
     }
 
+    /// For atomic types, get the underlying type.
+    pub(crate) fn atomic_value_type(&self) -> Type {
+        unsafe {
+            Type {
+                x: clang_Type_getValueType(self.x),
+            }
+        }
+    }
+
     /// Is this a valid type?
     pub(crate) fn is_valid(&self) -> bool {
         self.kind() != CXType_Invalid
diff --git a/bindgen/ir/ty.rs b/bindgen/ir/ty.rs
index 2a24dd0291..6d4c5666dc 100644
--- a/bindgen/ir/ty.rs
+++ b/bindgen/ir/ty.rs
@@ -1167,6 +1167,18 @@ impl Type {
                     .expect("Not able to resolve array element?");
                     TypeKind::Array(inner, ty.num_elements().unwrap())
                 }
+                CXType_Atomic => {
+                    // TODO(emilio): Maybe we can preserve the "is atomic" bit somehow and generate
+                    // something more useful... But for now this is better than panicking or
+                    // generating nothing.
+                    return Self::from_clang_ty(
+                        potential_id,
+                        &ty.atomic_value_type(),
+                        location,
+                        parent_id,
+                        ctx,
+                    );
+                }
                 CXType_Elaborated => {
                     return Self::from_clang_ty(
                         potential_id,
diff --git a/bindgen/ir/var.rs b/bindgen/ir/var.rs
index 40a061e16c..b8fffc7d66 100644
--- a/bindgen/ir/var.rs
+++ b/bindgen/ir/var.rs
@@ -320,7 +320,8 @@ impl ClangSubItemParser for Var {
                             matches!(ty.kind(), CXType_Auto | CXType_Unexposed),
                             "Couldn't resolve constant type, and it \
                              wasn't an nondeductible auto type or unexposed \
-                             type!"
+                             type: {:?}",
+                            ty
                         );
                         return Err(e);
                     }