Merge pull request rust-lang#855 from photoszzt/move_dependency_out

Pull out the loop that generates dependency map into its own function.

Author: fitzgen

src/ir/analysis/derive_debug.rs

@@ -1,6 +1,6 @@
 //! Determining which types for which we can emit `#[derive(Debug)]`.
 
-use super::{ConstrainResult, MonotoneFramework};
+use super::{ConstrainResult, MonotoneFramework, generate_dependencies};
 use std::collections::HashSet;
 use std::collections::HashMap;
 use ir::context::{BindgenContext, ItemId};
@@ -9,7 +9,6 @@ use ir::traversal::EdgeKind;
 use ir::ty::RUST_DERIVE_IN_ARRAY_LIMIT;
 use ir::ty::TypeKind;
 use ir::comp::Field;
-use ir::traversal::Trace;
 use ir::comp::FieldMethods;
 use ir::derive::CanTriviallyDeriveDebug;
 use ir::comp::CompKind;
@@ -99,24 +98,7 @@ impl<'ctx, 'gen> MonotoneFramework for CannotDeriveDebug<'ctx, 'gen> {
 
     fn new(ctx: &'ctx BindgenContext<'gen>) -> CannotDeriveDebug<'ctx, 'gen> {
         let cannot_derive_debug = HashSet::new();
-        let mut dependencies = HashMap::new();
-
-        for &item in ctx.whitelisted_items() {
-            dependencies.entry(item).or_insert(vec![]);
-
-            {
-                // We reverse our natural IR graph edges to find dependencies
-                // between nodes.
-                item.trace(ctx, &mut |sub_item: ItemId, edge_kind| {
-                    if ctx.whitelisted_items().contains(&sub_item) &&
-                       Self::consider_edge(edge_kind) {
-                           dependencies.entry(sub_item)
-                               .or_insert(vec![])
-                               .push(item);
-                    }
-                }, &());
-            }
-        }
+        let dependencies = generate_dependencies(ctx, Self::consider_edge);
 
         CannotDeriveDebug {
             ctx,

src/ir/analysis/has_vtable.rs

@@ -1,11 +1,10 @@
 //! Determining which types has vtable
-use super::{ConstrainResult, MonotoneFramework};
+use super::{ConstrainResult, MonotoneFramework, generate_dependencies};
 use std::collections::HashSet;
 use std::collections::HashMap;
 use ir::context::{BindgenContext, ItemId};
 use ir::traversal::EdgeKind;
 use ir::ty::TypeKind;
-use ir::traversal::Trace;
 
 /// An analysis that finds for each IR item whether it has vtable or not
 ///
@@ -68,24 +67,7 @@ impl<'ctx, 'gen> MonotoneFramework for HasVtableAnalysis<'ctx, 'gen> {
 
     fn new(ctx: &'ctx BindgenContext<'gen>) -> HasVtableAnalysis<'ctx, 'gen> {
         let have_vtable = HashSet::new();
-        let mut dependencies = HashMap::new();
-
-        for &item in ctx.whitelisted_items() {
-            dependencies.entry(item).or_insert(vec![]);
-
-            {
-                // We reverse our natural IR graph edges to find dependencies
-                // between nodes.
-                item.trace(ctx, &mut |sub_item: ItemId, edge_kind| {
-                    if ctx.whitelisted_items().contains(&sub_item) &&
-                        Self::consider_edge(edge_kind) {
-                            dependencies.entry(sub_item)
-                                .or_insert(vec![])
-                                .push(item);
-                        }
-                }, &());
-            }
-        }
+        let dependencies = generate_dependencies(ctx, Self::consider_edge);
 
         HasVtableAnalysis {
             ctx,

src/ir/analysis/mod.rs

@@ -46,6 +46,9 @@ mod has_vtable;
 pub use self::has_vtable::HasVtableAnalysis;
 pub use self::has_vtable::HasVtable;
 
+use ir::context::{BindgenContext, ItemId};
+use ir::traversal::{EdgeKind, Trace};
+use std::collections::HashMap;
 use std::fmt;
 
 /// An analysis in the monotone framework.
@@ -134,6 +137,30 @@ pub fn analyze<Analysis>(extra: Analysis::Extra) -> Analysis::Output
     analysis.into()
 }
 
+/// Generate the dependency map for analysis
+pub fn generate_dependencies<F>(ctx: &BindgenContext, consider_edge: F) -> HashMap<ItemId, Vec<ItemId>>
+    where F: Fn(EdgeKind) -> bool {
+    let mut dependencies = HashMap::new();
+
+    for &item in ctx.whitelisted_items() {
+        dependencies.entry(item).or_insert(vec![]);
+
+        {
+            // We reverse our natural IR graph edges to find dependencies
+            // between nodes.
+            item.trace(ctx, &mut |sub_item: ItemId, edge_kind| {
+                if ctx.whitelisted_items().contains(&sub_item) &&
+                    consider_edge(edge_kind) {
+                        dependencies.entry(sub_item)
+                            .or_insert(vec![])
+                            .push(item);
+                    }
+            }, &());
+        }
+    }
+    dependencies
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;