servo: Merge #13911 - Use nsACString to pass string params for bindings (from upsuper:bug1312338); r=Manishearth

Use nsACString to pass string params for bindings

This is the Servo side change of [bug 1312338](https://bugzilla.mozilla.org/show_bug.cgi?id=1312338) which has been reviewed by @Manishearth.

r? @Manishearth

(This should not be merged before the Gecko side code lands in m-c)

Source-Repo: https://github.com/servo/servo
Source-Revision: a9715c1f02ee63d9e96aed620e5289e8ae9cee7b

servo/components/style/binding_tools/regen.py

@@ -233,7 +233,13 @@ COMPILATION_TARGETS = {
     # Generation of the ffi bindings.
     "bindings": {
         "target_dir": "../gecko_bindings",
-        "raw_lines": [],
+        "blacklist_types": [
+            "nsACString_internal",
+        ],
+        "raw_lines": [
+            "pub use nsstring::nsACString;",
+            "type nsACString_internal = nsACString;",
+        ],
         "flags": [
             "--ignore-methods",
         ],

servo/components/style/gecko_bindings/bindings.rs

@@ -1,5 +1,7 @@
 /* automatically generated by rust-bindgen */
 
+pub use nsstring::nsACString;
+type nsACString_internal = nsACString;
 pub type ServoComputedValuesStrong = ::gecko_bindings::sugar::ownership::Strong<ServoComputedValues>;
 pub type ServoComputedValuesBorrowedOrNull<'a> = Option<&'a ServoComputedValues>;
 pub type ServoComputedValuesBorrowed<'a> = &'a ServoComputedValues;
@@ -837,10 +839,10 @@ extern "C" {
     pub fn Servo_Node_ClearNodeData(node: RawGeckoNodeBorrowed);
 }
 extern "C" {
-    pub fn Servo_StyleSheet_FromUTF8Bytes(bytes: *const u8, length: u32,
+    pub fn Servo_StyleSheet_FromUTF8Bytes(data: *const nsACString_internal,
                                           parsing_mode: SheetParsingMode,
-                                          base_bytes: *const u8,
-                                          base_length: u32,
+                                          base_url:
+                                              *const nsACString_internal,
                                           base: *mut ThreadSafeURIHolder,
                                           referrer: *mut ThreadSafeURIHolder,
                                           principal:
@@ -876,10 +878,9 @@ extern "C" {
                                                      RawServoStyleSheetBorrowed);
 }
 extern "C" {
-    pub fn Servo_ParseProperty(property_bytes: *const u8,
-                               property_length: u32, value_bytes: *const u8,
-                               value_length: u32, base_bytes: *const u8,
-                               base_length: u32,
+    pub fn Servo_ParseProperty(property: *const nsACString_internal,
+                               value: *const nsACString_internal,
+                               base_url: *const nsACString_internal,
                                base: *mut ThreadSafeURIHolder,
                                referrer: *mut ThreadSafeURIHolder,
                                principal: *mut ThreadSafePrincipalHolder)
@@ -893,7 +894,7 @@ extern "C" {
      -> ServoComputedValuesStrong;
 }
 extern "C" {
-    pub fn Servo_ParseStyleAttribute(bytes: *const u8, length: u32)
+    pub fn Servo_ParseStyleAttribute(data: *const nsACString_internal)
      -> RawServoDeclarationBlockStrong;
 }
 extern "C" {
@@ -907,8 +908,8 @@ extern "C" {
                                                     buffer: *mut nsString);
 }
 extern "C" {
-    pub fn Servo_CSSSupports(name: *const u8, name_length: u32,
-                             value: *const u8, value_length: u32) -> bool;
+    pub fn Servo_CSSSupports(name: *const nsACString_internal,
+                             value: *const nsACString_internal) -> bool;
 }
 extern "C" {
     pub fn Servo_ComputedValues_Get(node: RawGeckoNodeBorrowed)

servo/components/style/gecko_bindings/nsstring_vendor/src/lib.rs

@@ -144,6 +144,7 @@ use std::ptr;
 use std::mem;
 use std::fmt;
 use std::cmp;
+use std::str;
 use std::u32;
 
 //////////////////////////////////
@@ -569,6 +570,10 @@ impl nsACString {
             Gecko_AppendUTF16toCString(self as *mut _, other as *const _);
         }
     }
+
+    pub unsafe fn as_str_unchecked(&self) -> &str {
+        str::from_utf8_unchecked(self)
+    }
 }
 
 impl<'a> From<&'a str> for nsCString<'a> {

servo/ports/geckolib/glue.rs

@@ -8,8 +8,6 @@ use env_logger;
 use euclid::Size2D;
 use parking_lot::RwLock;
 use std::mem::transmute;
-use std::slice;
-use std::str::from_utf8_unchecked;
 use std::sync::{Arc, Mutex};
 use style::arc_ptr_eq;
 use style::context::{LocalStyleContextCreationInfo, ReflowGoal, SharedStyleContext};
@@ -29,6 +27,7 @@ use style::gecko_bindings::bindings::{RawServoStyleSheetStrong, ServoComputedVal
 use style::gecko_bindings::bindings::{ThreadSafePrincipalHolder, ThreadSafeURIHolder};
 use style::gecko_bindings::bindings::Gecko_Utf8SliceToString;
 use style::gecko_bindings::bindings::ServoComputedValuesBorrowedOrNull;
+use style::gecko_bindings::bindings::nsACString;
 use style::gecko_bindings::structs::{SheetParsingMode, nsIAtom};
 use style::gecko_bindings::structs::ServoElementSnapshot;
 use style::gecko_bindings::structs::nsRestyleHint;
@@ -161,16 +160,14 @@ pub extern "C" fn Servo_Node_ClearNodeData(node: RawGeckoNodeBorrowed) -> () {
 }
 
 #[no_mangle]
-pub extern "C" fn Servo_StyleSheet_FromUTF8Bytes(bytes: *const u8,
-                                                length: u32,
-                                                mode: SheetParsingMode,
-                                                base_bytes: *const u8,
-                                                base_length: u32,
-                                                base: *mut ThreadSafeURIHolder,
-                                                referrer: *mut ThreadSafeURIHolder,
-                                                principal: *mut ThreadSafePrincipalHolder)
-                                                -> RawServoStyleSheetStrong {
-    let input = unsafe { from_utf8_unchecked(slice::from_raw_parts(bytes, length as usize)) };
+pub extern "C" fn Servo_StyleSheet_FromUTF8Bytes(data: *const nsACString,
+                                                 mode: SheetParsingMode,
+                                                 base_url: *const nsACString,
+                                                 base: *mut ThreadSafeURIHolder,
+                                                 referrer: *mut ThreadSafeURIHolder,
+                                                 principal: *mut ThreadSafePrincipalHolder)
+                                                 -> RawServoStyleSheetStrong {
+    let input = unsafe { data.as_ref().unwrap().as_str_unchecked() };
 
     let origin = match mode {
         SheetParsingMode::eAuthorSheetFeatures => Origin::Author,
@@ -178,7 +175,7 @@ pub extern "C" fn Servo_StyleSheet_FromUTF8Bytes(bytes: *const u8,
         SheetParsingMode::eAgentSheetFeatures => Origin::UserAgent,
     };
 
-    let base_str = unsafe { from_utf8_unchecked(slice::from_raw_parts(base_bytes, base_length as usize)) };
+    let base_str = unsafe { base_url.as_ref().unwrap().as_str_unchecked() };
     let url = Url::parse(base_str).unwrap();
     let extra_data = unsafe { ParserContextExtraData {
         base: Some(GeckoArcURI::new(base)),
@@ -367,23 +364,14 @@ pub extern "C" fn Servo_StyleSet_Drop(data: RawServoStyleSetOwned) -> () {
 
 
 #[no_mangle]
-pub extern "C" fn Servo_ParseProperty(property_bytes: *const u8,
-                                      property_length: u32,
-                                      value_bytes: *const u8,
-                                      value_length: u32,
-                                      base_bytes: *const u8,
-                                      base_length: u32,
-                                      base: *mut ThreadSafeURIHolder,
+pub extern "C" fn Servo_ParseProperty(property: *const nsACString, value: *const nsACString,
+                                      base_url: *const nsACString, base: *mut ThreadSafeURIHolder,
                                       referrer: *mut ThreadSafeURIHolder,
                                       principal: *mut ThreadSafePrincipalHolder)
                                       -> RawServoDeclarationBlockStrong {
-    // All this string wrangling is temporary until the Gecko string bindings land (bug 1294742).
-    let name = unsafe { from_utf8_unchecked(slice::from_raw_parts(property_bytes,
-                                                                  property_length as usize)) };
-    let value_str = unsafe { from_utf8_unchecked(slice::from_raw_parts(value_bytes,
-                                                                       value_length as usize)) };
-    let base_str = unsafe { from_utf8_unchecked(slice::from_raw_parts(base_bytes,
-                                                                      base_length as usize)) };
+    let name = unsafe { property.as_ref().unwrap().as_str_unchecked() };
+    let value = unsafe { value.as_ref().unwrap().as_str_unchecked() };
+    let base_str = unsafe { base_url.as_ref().unwrap().as_str_unchecked() };
     let base_url = Url::parse(base_str).unwrap();
     let extra_data = unsafe { ParserContextExtraData {
         base: Some(GeckoArcURI::new(base)),
@@ -396,7 +384,7 @@ pub extern "C" fn Servo_ParseProperty(property_bytes: *const u8,
                                                      extra_data);
 
     let mut results = vec![];
-    match PropertyDeclaration::parse(name, &context, &mut Parser::new(value_str),
+    match PropertyDeclaration::parse(name, &context, &mut Parser::new(value),
                                      &mut results, false) {
         PropertyDeclarationParseResult::ValidOrIgnoredDeclaration => {},
         _ => return RawServoDeclarationBlockStrong::null(),
@@ -411,9 +399,8 @@ pub extern "C" fn Servo_ParseProperty(property_bytes: *const u8,
 }
 
 #[no_mangle]
-pub extern "C" fn Servo_ParseStyleAttribute(bytes: *const u8, length: u32)
-                                            -> RawServoDeclarationBlockStrong {
-    let value = unsafe { from_utf8_unchecked(slice::from_raw_parts(bytes, length as usize)) };
+pub extern "C" fn Servo_ParseStyleAttribute(data: *const nsACString) -> RawServoDeclarationBlockStrong {
+    let value = unsafe { data.as_ref().unwrap().as_str_unchecked() };
     Arc::new(RwLock::new(GeckoElement::parse_style_attribute(value))).into_strong()
 }
 
@@ -467,10 +454,9 @@ pub extern "C" fn Servo_DeclarationBlock_SerializeOneValue(
 }
 
 #[no_mangle]
-pub extern "C" fn Servo_CSSSupports(property: *const u8, property_length: u32,
-                                    value: *const u8, value_length: u32) -> bool {
-    let property = unsafe { from_utf8_unchecked(slice::from_raw_parts(property, property_length as usize)) };
-    let value    = unsafe { from_utf8_unchecked(slice::from_raw_parts(value, value_length as usize)) };
+pub extern "C" fn Servo_CSSSupports(property: *const nsACString, value: *const nsACString) -> bool {
+    let property = unsafe { property.as_ref().unwrap().as_str_unchecked() };
+    let value = unsafe { value.as_ref().unwrap().as_str_unchecked() };
 
     let base_url = &*DUMMY_BASE_URL;
     let extra_data = ParserContextExtraData::default();