Move alignment config from declare_data to define_data

cranelift/module/src/backend.rs

@@ -62,7 +62,6 @@ where
         linkage: Linkage,
         writable: bool,
         tls: bool,
-        align: Option<u8>,
     ) -> ModuleResult<DataId>;
 
     /// Define a function, producing the function body from the given `Context`.

cranelift/module/src/data_context.rs

@@ -50,6 +50,8 @@ pub struct DataDescription {
     pub data_relocs: Vec<(CodeOffset, ir::GlobalValue, Addend)>,
     /// Object file section
     pub custom_segment_section: Option<(String, String)>,
+    /// Alignment
+    pub align: Option<u64>,
 }
 
 /// This is to data objects what cranelift_codegen::Context is to functions.
@@ -68,6 +70,7 @@ impl DataContext {
                 function_relocs: vec![],
                 data_relocs: vec![],
                 custom_segment_section: None,
+                align: None,
             },
         }
     }
@@ -79,6 +82,8 @@ impl DataContext {
         self.description.data_decls.clear();
         self.description.function_relocs.clear();
         self.description.data_relocs.clear();
+        self.description.custom_segment_section = None;
+        self.description.align = None;
     }
 
     /// Define a zero-initialized object with the given size.
@@ -100,6 +105,12 @@ impl DataContext {
         self.description.custom_segment_section = Some((seg.to_owned(), sec.to_owned()))
     }
 
+    /// Set the alignment for data. The alignment must be a power of two.
+    pub fn set_align(&mut self, align: u64) {
+        assert!(align.is_power_of_two());
+        self.description.align = Some(align);
+    }
+
     /// Declare an external function import.
     ///
     /// Users of the `Module` API generally should call

cranelift/module/src/module.rs

@@ -182,14 +182,12 @@ pub struct DataDeclaration {
     pub linkage: Linkage,
     pub writable: bool,
     pub tls: bool,
-    pub align: Option<u8>,
 }
 
 impl DataDeclaration {
-    fn merge(&mut self, linkage: Linkage, writable: bool, tls: bool, align: Option<u8>) {
+    fn merge(&mut self, linkage: Linkage, writable: bool, tls: bool) {
         self.linkage = Linkage::merge(self.linkage, linkage);
         self.writable = self.writable || writable;
-        self.align = self.align.max(align);
         assert_eq!(
             self.tls, tls,
             "Can't change TLS data object to normal or in the opposite way",
@@ -291,7 +289,6 @@ impl ModuleDeclarations {
         linkage: Linkage,
         writable: bool,
         tls: bool,
-        align: Option<u8>, // An alignment bigger than 128 is unlikely
     ) -> ModuleResult<(DataId, &DataDeclaration)> {
         // TODO: Can we avoid allocating names so often?
         use super::hash_map::Entry::*;
@@ -299,7 +296,7 @@ impl ModuleDeclarations {
             Occupied(entry) => match *entry.get() {
                 FuncOrDataId::Data(id) => {
                     let existing = &mut self.data_objects[id];
-                    existing.merge(linkage, writable, tls, align);
+                    existing.merge(linkage, writable, tls);
                     Ok((id, existing))
                 }
 
@@ -313,7 +310,6 @@ impl ModuleDeclarations {
                     linkage,
                     writable,
                     tls,
-                    align,
                 });
                 entry.insert(FuncOrDataId::Data(id));
                 Ok((id, &self.data_objects[id]))
@@ -410,10 +406,9 @@ where
         linkage: Linkage,
         writable: bool,
         tls: bool,
-        align: Option<u8>, // An alignment bigger than 128 is unlikely
     ) -> ModuleResult<DataId> {
         self.backend
-            .declare_data(name, linkage, writable, tls, align)
+            .declare_data(name, linkage, writable, tls)
     }
 
     /// Use this when you're building the IR of a function to reference a function.