Cache the result of Item::path_for_whitelisting.

5 files changed, 19 insertions, 3 deletions

diff --git a/Cargo.lock b/Cargo.lock
index e5b9dfdd..bbe27eff 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -37,6 +37,7 @@ dependencies = [
  "diff 0.1.11 (registry+https://github.com/rust-lang/crates.io-index)",
  "env_logger 0.7.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "lazy_static 1.4.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "lazycell 1.2.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "log 0.4.8 (registry+https://github.com/rust-lang/crates.io-index)",
  "peeking_take_while 0.1.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "proc-macro2 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -135,6 +136,11 @@ version = "1.4.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
 [[package]]
+name = "lazycell"
+version = "1.2.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
+[[package]]
 name = "libc"
 version = "0.2.62"
 source = "registry+https://github.com/rust-lang/crates.io-index"
@@ -334,6 +340,7 @@ dependencies = [
 "checksum glob 0.3.0 (registry+https://github.com/rust-lang/crates.io-index)" = "9b919933a397b79c37e33b77bb2aa3dc8eb6e165ad809e58ff75bc7db2e34574"
 "checksum humantime 1.3.0 (registry+https://github.com/rust-lang/crates.io-index)" = "df004cfca50ef23c36850aaaa59ad52cc70d0e90243c3c7737a4dd32dc7a3c4f"
 "checksum lazy_static 1.4.0 (registry+https://github.com/rust-lang/crates.io-index)" = "e2abad23fbc42b3700f2f279844dc832adb2b2eb069b2df918f455c4e18cc646"
+"checksum lazycell 1.2.1 (registry+https://github.com/rust-lang/crates.io-index)" = "b294d6fa9ee409a054354afc4352b0b9ef7ca222c69b8812cbea9e7d2bf3783f"
 "checksum libc 0.2.62 (registry+https://github.com/rust-lang/crates.io-index)" = "34fcd2c08d2f832f376f4173a231990fa5aef4e99fb569867318a227ef4c06ba"
 "checksum libloading 0.5.2 (registry+https://github.com/rust-lang/crates.io-index)" = "f2b111a074963af1d37a139918ac6d49ad1d0d5e47f72fd55388619691a7d753"
 "checksum log 0.4.8 (registry+https://github.com/rust-lang/crates.io-index)" = "14b6052be84e6b71ab17edffc2eeabf5c2c3ae1fdb464aae35ac50c67a44e1f7"
diff --git a/Cargo.toml b/Cargo.toml
index a73c5dd0..9a71b277 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -50,6 +50,7 @@ cfg-if = "0.1.0"
 # This kinda sucks: https://github.com/rust-lang/cargo/issues/1982
 clap = { version = "2", optional = true }
 clang-sys = { version = "0.28.0", features = ["runtime", "clang_6_0"] }
+lazycell = "1"
 lazy_static = "1"
 peeking_take_while = "0.1.2"
 quote = { version = "1", default-features = false }
diff --git a/src/ir/context.rs b/src/ir/context.rs
index 292383f5..6158d02d 100644
--- a/src/ir/context.rs
+++ b/src/ir/context.rs
@@ -2327,7 +2327,7 @@ If you encounter an error missing from this list, please file an issue or a PR!"
                             }
 
                             let mut prefix_path =
-                                parent.path_for_whitelisting(self);
+                                parent.path_for_whitelisting(self).clone();
                             enum_.variants().iter().any(|variant| {
                                 prefix_path.push(variant.name().into());
                                 let name = prefix_path[1..].join("::");
diff --git a/src/ir/item.rs b/src/ir/item.rs
index 1e12424e..267522a5 100644
--- a/src/ir/item.rs
+++ b/src/ir/item.rs
@@ -20,6 +20,7 @@ use super::traversal::{EdgeKind, Trace, Tracer};
 use super::ty::{Type, TypeKind};
 use clang;
 use clang_sys;
+use lazycell::LazyCell;
 use parse::{ClangItemParser, ClangSubItemParser, ParseError, ParseResult};
 use regex;
 use std::cell::{Cell, RefCell};
@@ -398,6 +399,10 @@ pub struct Item {
     /// considerably faster in those cases.
     canonical_name_cache: RefCell<Option<String>>,
 
+    /// The path to use for whitelisting and other name-based checks, as
+    /// returned by `path_for_whitelisting`, lazily constructed.
+    path_for_whitelisting: LazyCell<Vec<String>>,
+
     /// A doc comment over the item, if any.
     comment: Option<String>,
     /// Annotations extracted from the doc comment, or the default ones
@@ -434,6 +439,7 @@ impl Item {
             local_id: Cell::new(None),
             next_child_local_id: Cell::new(1),
             canonical_name_cache: RefCell::new(None),
+            path_for_whitelisting: LazyCell::new(),
             parent_id: parent_id,
             comment: comment,
             annotations: annotations.unwrap_or_default(),
@@ -972,8 +978,9 @@ impl Item {
 
     /// Returns the path we should use for whitelisting / blacklisting, which
     /// doesn't include user-mangling.
-    pub fn path_for_whitelisting(&self, ctx: &BindgenContext) -> Vec<String> {
-        self.compute_path(ctx, UserMangled::No)
+    pub fn path_for_whitelisting(&self, ctx: &BindgenContext) -> &Vec<String> {
+        self.path_for_whitelisting
+            .borrow_with(|| self.compute_path(ctx, UserMangled::No))
     }
 
     fn compute_path(
diff --git a/src/lib.rs b/src/lib.rs
index f5a30468..297421e5 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -24,6 +24,7 @@ extern crate cexpr;
 extern crate cfg_if;
 extern crate clang_sys;
 extern crate rustc_hash;
+extern crate lazycell;
 #[macro_use]
 extern crate lazy_static;
 extern crate peeking_take_while;