Auto merge of #996 - alexeyzab:add-no-partialeq-command, r=fitzgen

Add --no-partialeq <regex> flag

Related to #965.

- [x] Add a new RegexSet member to bindgen::Builder (similar to the whitelisted_types set).

- [x] A Builder method to add strings to that RegexSet.

- [x] Plumbing in src/options.rs to convert --no-partialeq <regex> CLI flags into invocations of the builder method.

- [x] Make the MonotoneFramework::constrain function in src/ir/analysis/derive_partialeq.rs check if the given item is explicitly marked not to be Partialeq, and if so, insert it into the self.cannot_derive_partialeq set via return self.insert(id).

- [x] Tests!

- [x] When the no-partialeq type is transitively referenced by a whitelisted item

- [x] When the no-partialeq type is explicitly whitelisted

- [x] When the no-partialeq type is marked opaque

This is my first pass at implementing this functionality, I haven't implemented the tests yet. I wanted to make sure I am on the right track, particularly when it comes to updating `MonotoneFramework::constrain`.

r? @fitzgen

Author: bors-servo

src/ir/analysis/derive_partial_eq_or_partial_ord.rs

@@ -128,6 +128,10 @@ impl<'ctx> MonotoneFramework for CannotDerivePartialEqOrPartialOrd<'ctx> {
             }
         };
 
+        if self.ctx.no_partialeq_by_name(&item) {
+            return self.insert(id)
+        }
+
         trace!("ty: {:?}", ty);
         if item.is_opaque(self.ctx, &()) {
             let layout_can_derive = ty.layout(self.ctx).map_or(true, |l| {

src/ir/context.rs

@@ -2213,6 +2213,12 @@ impl BindgenContext {
         // float or not.
         self.has_float.as_ref().unwrap().contains(id)
     }
+
+    /// Check if `--no-partialeq` flag is enabled for this item.
+    pub fn no_partialeq_by_name(&self, item: &Item) -> bool {
+        let name = item.canonical_path(self)[1..].join("::");
+        self.options().no_partialeq_types.matches(&name)
+    }
 }
 
 /// A builder struct for configuring item resolution options.

src/lib.rs

@@ -504,6 +504,20 @@ impl Builder {
             output_vector.push(path.into());
         }
 
+        self.options
+            .no_partialeq_types
+            .get_items()
+            .iter()
+            .map(|item| {
+                output_vector.push("--no-partialeq".into());
+                output_vector.push(
+                    item.trim_left_matches("^")
+                        .trim_right_matches("$")
+                        .into(),
+                );
+            })
+            .count();
+
         output_vector
     }
 
@@ -1123,6 +1137,13 @@ impl Builder {
             ))
         }
     }
+
+    /// Don't derive `PartialEq` for a given type. Regular
+    /// expressions are supported.
+    pub fn no_partialeq(mut self, arg: String) -> Builder {
+        self.options.no_partialeq_types.insert(arg);
+        self
+    }
 }
 
 /// Configuration options for generated bindings.
@@ -1301,7 +1322,11 @@ struct BindgenOptions {
 
     /// The absolute path to the rustfmt configuration file, if None, the standard rustfmt
     /// options are used.
+
     rustfmt_configuration_file: Option<PathBuf>,
+
+    /// The set of types that we should not derive `PartialEq` for.
+    no_partialeq_types: RegexSet,
 }
 
 /// TODO(emilio): This is sort of a lie (see the error message that results from
@@ -1319,6 +1344,7 @@ impl BindgenOptions {
         self.bitfield_enums.build();
         self.constified_enum_modules.build();
         self.rustified_enums.build();
+        self.no_partialeq_types.build();
     }
 
     /// Update rust target version
@@ -1388,6 +1414,7 @@ impl Default for BindgenOptions {
             time_phases: false,
             rustfmt_bindings: false,
             rustfmt_configuration_file: None,
+            no_partialeq_types: Default::default(),
         }
     }
 }

src/options.rs

@@ -270,6 +270,13 @@ where
                 .takes_value(true)
                 .multiple(false)
                 .number_of_values(1),
+            Arg::with_name("no-partialeq")
+                .long("no-partialeq")
+                .help("Avoid deriving PartialEq for types matching <regex>.")
+                .value_name("regex")
+                .takes_value(true)
+                .multiple(true)
+                .number_of_values(1),
         ]) // .args()
         .get_matches_from(args);
 
@@ -546,6 +553,12 @@ where
         builder = builder.rustfmt_configuration_file(Some(path));
     }
 
+    if let Some(no_partialeq) = matches.values_of("no-partialeq") {
+        for regex in no_partialeq {
+            builder = builder.no_partialeq(String::from(regex));
+        }
+    }
+
     let verbose = matches.is_present("verbose");
 
     Ok((builder, output, verbose))

tests/expectations/tests/no-partialeq-opaque.rs

@@ -0,0 +1,29 @@
+/* automatically generated by rust-bindgen */
+
+
+#![allow(dead_code, non_snake_case, non_camel_case_types, non_upper_case_globals)]
+
+
+#[repr(C)]
+#[derive(Debug, Default, Copy)]
+pub struct NoPartialEq {
+    pub _bindgen_opaque_blob: u32,
+}
+#[test]
+fn bindgen_test_layout_NoPartialEq() {
+    assert_eq!(
+        ::std::mem::size_of::<NoPartialEq>(),
+        4usize,
+        concat!("Size of: ", stringify!(NoPartialEq))
+    );
+    assert_eq!(
+        ::std::mem::align_of::<NoPartialEq>(),
+        4usize,
+        concat!("Alignment of ", stringify!(NoPartialEq))
+    );
+}
+impl Clone for NoPartialEq {
+    fn clone(&self) -> Self {
+        *self
+    }
+}

tests/expectations/tests/no-partialeq-whitelisted.rs

@@ -0,0 +1,39 @@
+/* automatically generated by rust-bindgen */
+
+
+#![allow(dead_code, non_snake_case, non_camel_case_types, non_upper_case_globals)]
+
+
+#[repr(C)]
+#[derive(Debug, Default, Copy)]
+pub struct NoPartialEq {
+    pub i: ::std::os::raw::c_int,
+}
+#[test]
+fn bindgen_test_layout_NoPartialEq() {
+    assert_eq!(
+        ::std::mem::size_of::<NoPartialEq>(),
+        4usize,
+        concat!("Size of: ", stringify!(NoPartialEq))
+    );
+    assert_eq!(
+        ::std::mem::align_of::<NoPartialEq>(),
+        4usize,
+        concat!("Alignment of ", stringify!(NoPartialEq))
+    );
+    assert_eq!(
+        unsafe { &(*(0 as *const NoPartialEq)).i as *const _ as usize },
+        0usize,
+        concat!(
+            "Alignment of field: ",
+            stringify!(NoPartialEq),
+            "::",
+            stringify!(i)
+        )
+    );
+}
+impl Clone for NoPartialEq {
+    fn clone(&self) -> Self {
+        *self
+    }
+}

tests/expectations/tests/whitelisted-item-references-no-partialeq.rs

@@ -0,0 +1,62 @@
+/* automatically generated by rust-bindgen */
+
+
+#![allow(dead_code, non_snake_case, non_camel_case_types, non_upper_case_globals)]
+
+
+#[repr(C)]
+#[derive(Debug, Default, Copy)]
+pub struct NoPartialEq {
+    pub _address: u8,
+}
+#[test]
+fn bindgen_test_layout_NoPartialEq() {
+    assert_eq!(
+        ::std::mem::size_of::<NoPartialEq>(),
+        1usize,
+        concat!("Size of: ", stringify!(NoPartialEq))
+    );
+    assert_eq!(
+        ::std::mem::align_of::<NoPartialEq>(),
+        1usize,
+        concat!("Alignment of ", stringify!(NoPartialEq))
+    );
+}
+impl Clone for NoPartialEq {
+    fn clone(&self) -> Self {
+        *self
+    }
+}
+#[repr(C)]
+#[derive(Debug, Default, Copy)]
+pub struct WhitelistMe {
+    pub a: NoPartialEq,
+}
+#[test]
+fn bindgen_test_layout_WhitelistMe() {
+    assert_eq!(
+        ::std::mem::size_of::<WhitelistMe>(),
+        1usize,
+        concat!("Size of: ", stringify!(WhitelistMe))
+    );
+    assert_eq!(
+        ::std::mem::align_of::<WhitelistMe>(),
+        1usize,
+        concat!("Alignment of ", stringify!(WhitelistMe))
+    );
+    assert_eq!(
+        unsafe { &(*(0 as *const WhitelistMe)).a as *const _ as usize },
+        0usize,
+        concat!(
+            "Alignment of field: ",
+            stringify!(WhitelistMe),
+            "::",
+            stringify!(a)
+        )
+    );
+}
+impl Clone for WhitelistMe {
+    fn clone(&self) -> Self {
+        *self
+    }
+}

tests/headers/no-partialeq-opaque.hpp

@@ -0,0 +1,5 @@
+// bindgen-flags: --with-derive-partialeq --opaque-type "NoPartialEq" --no-partialeq "NoPartialEq"
+
+class NoPartialEq {
+  int i;
+};

tests/headers/no-partialeq-whitelisted.hpp

@@ -0,0 +1,5 @@
+// bindgen-flags: --with-derive-partialeq --whitelist-type "NoPartialEq" --no-partialeq "NoPartialEq"
+
+class NoPartialEq {
+  int i;
+};

tests/headers/whitelisted-item-references-no-partialeq.hpp

@@ -0,0 +1,7 @@
+// bindgen-flags: --with-derive-partialeq --whitelist-type "WhitelistMe" --no-partialeq "NoPartialEq"
+
+struct NoPartialEq {};
+
+class WhitelistMe {
+  NoPartialEq a;
+};