Fix race condition in clang_macro_fallback

bindgen/Cargo.toml

@@ -41,6 +41,7 @@ regex = { workspace = true, features = ["std", "unicode-perl"] }
 rustc-hash.workspace = true
 shlex.workspace = true
 syn = { workspace = true, features = ["full", "extra-traits", "visit-mut"] }
+tempfile.workspace = true
 
 [features]
 default = ["logging", "prettyplease", "runtime"]

bindgen/clang.rs

@@ -7,6 +7,8 @@
 use crate::ir::context::BindgenContext;
 use clang_sys::*;
 use std::cmp;
+use std::path::{Path, PathBuf};
+use tempfile::TempDir;
 
 use std::ffi::{CStr, CString};
 use std::fmt;
@@ -246,11 +248,10 @@ impl Cursor {
     pub(crate) fn is_toplevel(&self) -> bool {
         let mut semantic_parent = self.fallible_semantic_parent();
 
-        while semantic_parent.is_some() &&
-            (semantic_parent.unwrap().kind() == CXCursor_Namespace ||
-                semantic_parent.unwrap().kind() ==
-                    CXCursor_NamespaceAlias ||
-                semantic_parent.unwrap().kind() == CXCursor_NamespaceRef)
+        while semantic_parent.is_some()
+            && (semantic_parent.unwrap().kind() == CXCursor_Namespace
+                || semantic_parent.unwrap().kind() == CXCursor_NamespaceAlias
+                || semantic_parent.unwrap().kind() == CXCursor_NamespaceRef)
         {
             semantic_parent =
                 semantic_parent.unwrap().fallible_semantic_parent();
@@ -267,9 +268,9 @@ impl Cursor {
     pub(crate) fn is_template_like(&self) -> bool {
         matches!(
             self.kind(),
-            CXCursor_ClassTemplate |
-                CXCursor_ClassTemplatePartialSpecialization |
-                CXCursor_TypeAliasTemplateDecl
+            CXCursor_ClassTemplate
+                | CXCursor_ClassTemplatePartialSpecialization
+                | CXCursor_TypeAliasTemplateDecl
         )
     }
 
@@ -296,9 +297,9 @@ impl Cursor {
     /// Is the referent a fully specialized template specialization without any
     /// remaining free template arguments?
     pub(crate) fn is_fully_specialized_template(&self) -> bool {
-        self.is_template_specialization() &&
-            self.kind() != CXCursor_ClassTemplatePartialSpecialization &&
-            self.num_template_args().unwrap_or(0) > 0
+        self.is_template_specialization()
+            && self.kind() != CXCursor_ClassTemplatePartialSpecialization
+            && self.num_template_args().unwrap_or(0) > 0
     }
 
     /// Is the referent a template specialization that still has remaining free
@@ -324,9 +325,9 @@ impl Cursor {
     pub(crate) fn is_template_parameter(&self) -> bool {
         matches!(
             self.kind(),
-            CXCursor_TemplateTemplateParameter |
-                CXCursor_TemplateTypeParameter |
-                CXCursor_NonTypeTemplateParameter
+            CXCursor_TemplateTemplateParameter
+                | CXCursor_TemplateTypeParameter
+                | CXCursor_NonTypeTemplateParameter
         )
     }
 
@@ -664,9 +665,9 @@ impl Cursor {
         // inline function without a definition, and it's not a defaulted
         // function, we can reasonably safely conclude that it's a deleted
         // function.
-        self.is_inlined_function() &&
-            self.definition().is_none() &&
-            !self.is_defaulted_function()
+        self.is_inlined_function()
+            && self.definition().is_none()
+            && !self.is_defaulted_function()
     }
 
     /// Is the referent a bit field declaration?
@@ -788,11 +789,11 @@ impl Cursor {
                 let found_attr = &mut found_attrs[idx];
                 if !*found_attr {
                     // `attr.name` and` attr.token_kind` are checked against unexposed attributes only.
-                    if attr.kind == Some(kind) ||
-                        (kind == CXCursor_UnexposedAttr &&
-                            cur.tokens().iter().any(|t| {
-                                t.kind == attr.token_kind &&
-                                    t.spelling() == attr.name
+                    if attr.kind == Some(kind)
+                        || (kind == CXCursor_UnexposedAttr
+                            && cur.tokens().iter().any(|t| {
+                                t.kind == attr.token_kind
+                                    && t.spelling() == attr.name
                             }))
                     {
                         *found_attr = true;
@@ -1408,12 +1409,12 @@ impl Type {
     /// to.
     pub(crate) fn pointee_type(&self) -> Option<Type> {
         match self.kind() {
-            CXType_Pointer |
-            CXType_RValueReference |
-            CXType_LValueReference |
-            CXType_MemberPointer |
-            CXType_BlockPointer |
-            CXType_ObjCObjectPointer => {
+            CXType_Pointer
+            | CXType_RValueReference
+            | CXType_LValueReference
+            | CXType_MemberPointer
+            | CXType_BlockPointer
+            | CXType_ObjCObjectPointer => {
                 let ret = Type {
                     x: unsafe { clang_getPointeeType(self.x) },
                 };
@@ -1516,12 +1517,12 @@ impl Type {
         // Yep, the spelling of this containing type-parameter is extremely
         // nasty... But can happen in <type_traits>. Unfortunately I couldn't
         // reduce it enough :(
-        self.template_args().is_some_and(|args| args.len() > 0) &&
-            !matches!(
+        self.template_args().is_some_and(|args| args.len() > 0)
+            && !matches!(
                 self.declaration().kind(),
-                CXCursor_ClassTemplatePartialSpecialization |
-                    CXCursor_TypeAliasTemplateDecl |
-                    CXCursor_TemplateTemplateParameter
+                CXCursor_ClassTemplatePartialSpecialization
+                    | CXCursor_TypeAliasTemplateDecl
+                    | CXCursor_TemplateTemplateParameter
             )
     }
 
@@ -1546,9 +1547,9 @@ impl Type {
                 .is_match(spelling.as_ref())
         }
 
-        self.kind() == CXType_Unexposed &&
-            (hacky_parse_associated_type(self.spelling()) ||
-                hacky_parse_associated_type(
+        self.kind() == CXType_Unexposed
+            && (hacky_parse_associated_type(self.spelling())
+                || hacky_parse_associated_type(
                     self.canonical_type().spelling(),
                 ))
     }
@@ -1822,12 +1823,15 @@ impl TranslationUnit {
     /// Parse a source file into a translation unit.
     pub(crate) fn parse(
         ix: &Index,
-        file: &str,
+        file: Option<&Path>,
         cmd_args: &[Box<str>],
         unsaved: &[UnsavedFile],
         opts: CXTranslationUnit_Flags,
     ) -> Option<TranslationUnit> {
-        let fname = CString::new(file).unwrap();
+        let fname = match file {
+            Some(file) => path_to_cstring(file),
+            None => CString::new(vec![]).unwrap(),
+        };
         let _c_args: Vec<CString> = cmd_args
             .iter()
             .map(|s| CString::new(s.as_bytes()).unwrap())
@@ -1879,10 +1883,8 @@ impl TranslationUnit {
     }
 
     /// Save a translation unit to the given file.
-    pub(crate) fn save(&mut self, file: &str) -> Result<(), CXSaveError> {
-        let Ok(file) = CString::new(file) else {
-            return Err(CXSaveError_Unknown);
-        };
+    pub(crate) fn save(&mut self, file: &Path) -> Result<(), CXSaveError> {
+        let file = path_to_cstring(file);
         let ret = unsafe {
             clang_saveTranslationUnit(
                 self.x,
@@ -1913,8 +1915,9 @@ impl Drop for TranslationUnit {
 
 /// Translation unit used for macro fallback parsing
 pub(crate) struct FallbackTranslationUnit {
-    file_path: String,
-    pch_path: String,
+    temp_dir: TempDir,
+    file_path: PathBuf,
+    pch_path: PathBuf,
     idx: Box<Index>,
     tu: TranslationUnit,
 }
@@ -1928,8 +1931,9 @@ impl fmt::Debug for FallbackTranslationUnit {
 impl FallbackTranslationUnit {
     /// Create a new fallback translation unit
     pub(crate) fn new(
-        file: String,
-        pch_path: String,
+        temp_dir: TempDir,
+        file: PathBuf,
+        pch_path: PathBuf,
         c_args: &[Box<str>],
     ) -> Option<Self> {
         // Create empty file
@@ -1943,12 +1947,13 @@ impl FallbackTranslationUnit {
         let f_index = Box::new(Index::new(true, false));
         let f_translation_unit = TranslationUnit::parse(
             &f_index,
-            &file,
+            Some(&file),
             c_args,
             &[],
             CXTranslationUnit_None,
         )?;
         Some(FallbackTranslationUnit {
+            temp_dir,
             file_path: file,
             pch_path,
             tu: f_translation_unit,
@@ -1985,13 +1990,6 @@ impl FallbackTranslationUnit {
     }
 }
 
-impl Drop for FallbackTranslationUnit {
-    fn drop(&mut self) {
-        let _ = std::fs::remove_file(&self.file_path);
-        let _ = std::fs::remove_file(&self.pch_path);
-    }
-}
-
 /// A diagnostic message generated while parsing a translation unit.
 pub(crate) struct Diagnostic {
     x: CXDiagnostic,
@@ -2032,9 +2030,9 @@ pub(crate) struct UnsavedFile {
 }
 
 impl UnsavedFile {
-    /// Construct a new unsaved file with the given `name` and `contents`.
-    pub(crate) fn new(name: &str, contents: &str) -> UnsavedFile {
-        let name = CString::new(name.as_bytes()).unwrap();
+    /// Construct a new unsaved file with the given `path` and `contents`.
+    pub(crate) fn new(path: &Path, contents: &str) -> UnsavedFile {
+        let name = path_to_cstring(path);
         let contents = CString::new(contents.as_bytes()).unwrap();
         let x = CXUnsavedFile {
             Filename: name.as_ptr(),
@@ -2309,8 +2307,8 @@ impl EvalResult {
         {
             let mut found_cant_eval = false;
             cursor.visit(|c| {
-                if c.kind() == CXCursor_TypeRef &&
-                    c.cur_type().canonical_type().kind() == CXType_Unexposed
+                if c.kind() == CXCursor_TypeRef
+                    && c.cur_type().canonical_type().kind() == CXType_Unexposed
                 {
                     found_cant_eval = true;
                     return CXChildVisit_Break;
@@ -2446,3 +2444,7 @@ impl TargetInfo {
         }
     }
 }
+
+fn path_to_cstring(path: &Path) -> CString {
+    CString::new(path.to_string_lossy().as_bytes()).unwrap()
+}