break up lints.rs into separate files

6 files changed, 393 insertions, 0 deletions

diff --git a/components/plugins/lints/inheritance_integrity.rs b/components/plugins/lints/inheritance_integrity.rs
new file mode 100644
index 00000000000..d3ea6ee280d
--- /dev/null
+++ b/components/plugins/lints/inheritance_integrity.rs
@@ -0,0 +1,90 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+use syntax::{ast, ast_util};
+use rustc::lint::{Context, LintPass, LintArray, Level};
+use rustc::middle::{ty, def};
+use rustc::middle::typeck::astconv::AstConv;
+
+use utils::match_lang_ty;
+
+declare_lint!(INHERITANCE_INTEGRITY, Deny,
+              "Ensures that struct fields are properly laid out for inheritance to work")
+
+/// Lint for ensuring proper layout of DOM structs
+///
+/// A DOM struct must have one Reflector field or one field
+/// which itself is a DOM struct (in which case it must be the first field).
+pub struct InheritancePass;
+
+impl LintPass for InheritancePass {
+    fn get_lints(&self) -> LintArray {
+        lint_array!(INHERITANCE_INTEGRITY)
+    }
+
+    fn check_struct_def(&mut self, cx: &Context, def: &ast::StructDef, _i: ast::Ident, _gen: &ast::Generics, id: ast::NodeId) {
+        // Lints are run post expansion, so it's fine to use
+        // #[_dom_struct_marker] here without also checking for #[dom_struct]
+        if ty::has_attr(cx.tcx, ast_util::local_def(id), "_dom_struct_marker") {
+            // Find the reflector, if any
+            let reflector_span = def.fields.iter().enumerate()
+                                    .find(|&(ctr, f)| {
+                                        if match_lang_ty(cx, &*f.node.ty, "reflector") {
+                                            if ctr > 0 {
+                                                cx.span_lint(INHERITANCE_INTEGRITY, f.span,
+                                                             "The Reflector should be the first field of the DOM struct");
+                                            }
+                                            return true;
+                                        }
+                                        false
+                                    })
+                                    .map(|(_, f)| f.span);
+            // Find all #[dom_struct] fields
+            let dom_spans: Vec<_> = def.fields.iter().enumerate().filter_map(|(ctr, f)| {
+                if let ast::TyPath(_, _, ty_id) = f.node.ty.node {
+                    if let Some(def::DefTy(def_id, _)) = cx.tcx.def_map.borrow().get(&ty_id).cloned() {
+                        if ty::has_attr(cx.tcx, def_id, "_dom_struct_marker") {
+                            // If the field is not the first, it's probably
+                            // being misused (a)
+                            if ctr > 0 {
+                                cx.span_lint(INHERITANCE_INTEGRITY, f.span,
+                                             "Bare DOM structs should only be used as the first field of a \
+                                              DOM struct. Consider using JS<T> instead.");
+                            }
+                            return Some(f.span)
+                        }
+                    }
+                }
+                None
+            }).collect();
+
+            // We should not have both a reflector and a dom struct field
+            if let Some(sp) = reflector_span {
+                if dom_spans.len() > 0 {
+                    cx.span_lint(INHERITANCE_INTEGRITY, cx.tcx.map.expect_item(id).span,
+                                 "This DOM struct has both Reflector and bare DOM struct members");
+                    if cx.current_level(INHERITANCE_INTEGRITY) != Level::Allow {
+                        let sess = cx.sess();
+                        sess.span_note(sp, "Reflector found here");
+                        for span in dom_spans.iter() {
+                            sess.span_note(*span, "Bare DOM struct found here");
+                        }
+                    }
+                }
+            // Nor should we have more than one dom struct field
+            } else if dom_spans.len() > 1 {
+                cx.span_lint(INHERITANCE_INTEGRITY, cx.tcx.map.expect_item(id).span,
+                             "This DOM struct has multiple DOM struct members, only one is allowed");
+                if cx.current_level(INHERITANCE_INTEGRITY) != Level::Allow {
+                    for span in dom_spans.iter() {
+                        cx.sess().span_note(*span, "Bare DOM struct found here");
+                    }
+                }
+            } else if dom_spans.len() == 0 {
+                cx.span_lint(INHERITANCE_INTEGRITY, cx.tcx.map.expect_item(id).span,
+                             "This DOM struct has no reflector or parent DOM struct");
+            }
+        }
+    }
+}
diff --git a/components/plugins/lints/mod.rs b/components/plugins/lints/mod.rs
new file mode 100644
index 00000000000..af7083e5b5f
--- /dev/null
+++ b/components/plugins/lints/mod.rs
@@ -0,0 +1,9 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+ pub mod inheritance_integrity;
+ pub mod privatize;
+ pub mod str_to_string;
+ pub mod transmute_type;
+ pub mod unrooted_must_root;
diff --git a/components/plugins/lints/privatize.rs b/components/plugins/lints/privatize.rs
new file mode 100644
index 00000000000..07e7ca594da
--- /dev/null
+++ b/components/plugins/lints/privatize.rs
@@ -0,0 +1,38 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+use syntax::{ast, ast_util};
+use syntax::ast::Public;
+use syntax::attr::AttrMetaMethods;
+use rustc::lint::{Context, LintPass, LintArray};
+use rustc::middle::ty;
+use rustc::middle::typeck::astconv::AstConv;
+
+declare_lint!(PRIVATIZE, Deny,
+              "Allows to enforce private fields for struct definitions")
+
+/// Lint for keeping DOM fields private
+///
+/// This lint (disable with `-A privatize`/`#[allow(privatize)]`) ensures all types marked with `#[privatize]` have no private fields
+pub struct PrivatizePass;
+
+impl LintPass for PrivatizePass {
+    fn get_lints(&self) -> LintArray {
+        lint_array!(PRIVATIZE)
+    }
+
+    fn check_struct_def(&mut self, cx: &Context, def: &ast::StructDef, _i: ast::Ident, _gen: &ast::Generics, id: ast::NodeId) {
+        if ty::has_attr(cx.tcx, ast_util::local_def(id), "privatize") {
+            for field in def.fields.iter() {
+                match field.node {
+                    ast::StructField_ { kind: ast::NamedField(ident, visibility), .. } if visibility == Public => {
+                        cx.span_lint(PRIVATIZE, field.span,
+                                     format!("Field {} is public where only private fields are allowed", ident.name).as_slice());
+                    }
+                    _ => {}
+                }
+            }
+        }
+    }
+}
diff --git a/components/plugins/lints/str_to_string.rs b/components/plugins/lints/str_to_string.rs
new file mode 100644
index 00000000000..79c2d917139
--- /dev/null
+++ b/components/plugins/lints/str_to_string.rs
@@ -0,0 +1,48 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+use syntax::ast;
+use rustc::lint::{Context, LintPass, LintArray};
+use rustc::middle::ty::expr_ty;
+use rustc::middle::ty;
+use rustc::middle::typeck::astconv::AstConv;
+
+declare_lint!(STR_TO_STRING, Deny,
+              "Warn when a String could use into_string() instead of to_string()")
+
+/// Prefer str.into_string() over str.to_string()
+///
+/// The latter creates a `Formatter` and is 5x slower than the former
+pub struct StrToStringPass;
+
+impl LintPass for StrToStringPass {
+    fn get_lints(&self) -> LintArray {
+        lint_array!(STR_TO_STRING)
+    }
+
+    fn check_expr(&mut self, cx: &Context, expr: &ast::Expr) {
+        match expr.node {
+            ast::ExprMethodCall(ref method, _, ref args)
+                if method.node.as_str() == "to_string"
+                && is_str(cx, &*args[0]) => {
+                cx.span_lint(STR_TO_STRING, expr.span,
+                             "str.into_string() is more efficient than str.to_string(), please use it instead");
+            },
+            _ => ()
+        }
+
+        fn is_str(cx: &Context, expr: &ast::Expr) -> bool {
+            fn walk_ty<'t>(ty: ty::t) -> ty::t {
+                match ty::get(ty).sty {
+                    ty::ty_ptr(ref tm) | ty::ty_rptr(_, ref tm) => walk_ty(tm.ty),
+                    _ => ty
+                }
+            }
+            match ty::get(walk_ty(expr_ty(cx.tcx, expr))).sty {
+                ty::ty_str => true,
+                _ => false
+            }
+        }
+    }
+}
diff --git a/components/plugins/lints/transmute_type.rs b/components/plugins/lints/transmute_type.rs
new file mode 100644
index 00000000000..a5d6ec55ba3
--- /dev/null
+++ b/components/plugins/lints/transmute_type.rs
@@ -0,0 +1,48 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+use syntax::ast;
+use syntax::attr::AttrMetaMethods;
+use rustc::lint::{Context, LintPass, LintArray};
+use rustc::middle::ty::expr_ty;
+use rustc::middle::typeck::astconv::AstConv;
+use rustc::util::ppaux::Repr;
+
+declare_lint!(TRANSMUTE_TYPE_LINT, Allow,
+              "Warn and report types being transmuted")
+
+/// Lint for auditing transmutes
+///
+/// This lint (off by default, enable with `-W transmute-type-lint`) warns about all the transmutes
+/// being used, along with the types they transmute to/from.
+pub struct TransmutePass;
+
+impl LintPass for TransmutePass {
+    fn get_lints(&self) -> LintArray {
+        lint_array!(TRANSMUTE_TYPE_LINT)
+    }
+
+    fn check_expr(&mut self, cx: &Context, ex: &ast::Expr) {
+        match ex.node {
+            ast::ExprCall(ref expr, ref args) => {
+                match expr.node {
+                    ast::ExprPath(ref path) => {
+                        if path.segments.last()
+                                        .map_or(false, |ref segment| segment.identifier.name.as_str() == "transmute")
+                           && args.len() == 1 {
+                            let tcx = cx.tcx();
+                            cx.span_lint(TRANSMUTE_TYPE_LINT, ex.span,
+                                         format!("Transmute to {} from {} detected",
+                                                 expr_ty(tcx, ex).repr(tcx),
+                                                 expr_ty(tcx, &**args.get(0).unwrap()).repr(tcx)
+                                        ).as_slice());
+                        }
+                    }
+                    _ => {}
+                }
+            }
+            _ => {}
+        }
+    }
+}
diff --git a/components/plugins/lints/unrooted_must_root.rs b/components/plugins/lints/unrooted_must_root.rs
new file mode 100644
index 00000000000..582d1502fa3
--- /dev/null
+++ b/components/plugins/lints/unrooted_must_root.rs
@@ -0,0 +1,160 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+use syntax::{ast, codemap, visit};
+use syntax::attr::AttrMetaMethods;
+use rustc::lint::{Context, LintPass, LintArray};
+use rustc::middle::ty::expr_ty;
+use rustc::middle::{ty, def};
+use rustc::middle::typeck::astconv::AstConv;
+use rustc::util::ppaux::Repr;
+use utils::unsafe_context;
+
+declare_lint!(UNROOTED_MUST_ROOT, Deny,
+              "Warn and report usage of unrooted jsmanaged objects")
+
+/// Lint for ensuring safe usage of unrooted pointers
+///
+/// This lint (disable with `-A unrooted-must-root`/`#[allow(unrooted_must_root)]`) ensures that `#[must_root]` values are used correctly.
+/// "Incorrect" usage includes:
+///
+///  - Not being used in a struct/enum field which is not `#[must_root]` itself
+///  - Not being used as an argument to a function (Except onces named `new` and `new_inherited`)
+///  - Not being bound locally in a `let` statement, assignment, `for` loop, or `match` statement.
+///
+/// This helps catch most situations where pointers like `JS<T>` are used in a way that they can be invalidated by a GC pass.
+pub struct UnrootedPass;
+
+// Checks if a type has the #[must_root] annotation.
+// Unwraps pointers as well
+// TODO (#3874, sort of): unwrap other types like Vec/Option/HashMap/etc
+fn lint_unrooted_ty(cx: &Context, ty: &ast::Ty, warning: &str) {
+    match ty.node {
+        ast::TyVec(ref t) | ast::TyFixedLengthVec(ref t, _) |
+        ast::TyPtr(ast::MutTy { ty: ref t, ..}) | ast::TyRptr(_, ast::MutTy { ty: ref t, ..}) => lint_unrooted_ty(cx, &**t, warning),
+        ast::TyPath(_, _, id) => {
+                match cx.tcx.def_map.borrow()[id].clone() {
+                    def::DefTy(def_id, _) => {
+                        if ty::has_attr(cx.tcx, def_id, "must_root") {
+                            cx.span_lint(UNROOTED_MUST_ROOT, ty.span, warning);
+                        }
+                    }
+                    _ => (),
+                }
+            }
+            _ => (),
+    };
+}
+
+impl LintPass for UnrootedPass {
+    fn get_lints(&self) -> LintArray {
+        lint_array!(UNROOTED_MUST_ROOT)
+    }
+    /// All structs containing #[must_root] types must be #[must_root] themselves
+    fn check_struct_def(&mut self, cx: &Context, def: &ast::StructDef, _i: ast::Ident, _gen: &ast::Generics, id: ast::NodeId) {
+        if cx.tcx.map.expect_item(id).attrs.iter().all(|a| !a.check_name("must_root")) {
+            for ref field in def.fields.iter() {
+                lint_unrooted_ty(cx, &*field.node.ty,
+                                 "Type must be rooted, use #[must_root] on the struct definition to propagate");
+            }
+        }
+    }
+    /// All enums containing #[must_root] types must be #[must_root] themselves
+    fn check_variant(&mut self, cx: &Context, var: &ast::Variant, _gen: &ast::Generics) {
+        let ref map = cx.tcx.map;
+        if map.expect_item(map.get_parent(var.node.id)).attrs.iter().all(|a| !a.check_name("must_root")) {
+            match var.node.kind {
+                ast::TupleVariantKind(ref vec) => {
+                    for ty in vec.iter() {
+                        lint_unrooted_ty(cx, &*ty.ty,
+                                         "Type must be rooted, use #[must_root] on the enum definition to propagate")
+                    }
+                }
+                _ => () // Struct variants already caught by check_struct_def
+            }
+        }
+    }
+    /// Function arguments that are #[must_root] types are not allowed
+    fn check_fn(&mut self, cx: &Context, kind: visit::FnKind, decl: &ast::FnDecl,
+                block: &ast::Block, _span: codemap::Span, id: ast::NodeId) {
+        match kind {
+            visit::FkItemFn(i, _, _, _) |
+            visit::FkMethod(i, _, _) if i.as_str() == "new" || i.as_str() == "new_inherited" => {
+                return;
+            },
+            visit::FkItemFn(_, _, style, _) => match style {
+                ast::UnsafeFn => return,
+                _ => ()
+            },
+            _ => ()
+        }
+
+        if unsafe_context(&cx.tcx.map, id) {
+            return;
+        }
+
+        match block.rules {
+            ast::DefaultBlock => {
+                for arg in decl.inputs.iter() {
+                    lint_unrooted_ty(cx, &*arg.ty,
+                                     "Type must be rooted")
+                }
+            }
+            _ => () // fn is `unsafe`
+        }
+    }
+
+    // Partially copied from rustc::middle::lint::builtin
+    // Catches `let` statements and assignments which store a #[must_root] value
+    // Expressions which return out of blocks eventually end up in a `let` or assignment
+    // statement or a function return (which will be caught when it is used elsewhere)
+    fn check_stmt(&mut self, cx: &Context, s: &ast::Stmt) {
+
+        match s.node {
+            ast::StmtDecl(_, id) |
+            ast::StmtExpr(_, id) |
+            ast::StmtSemi(_, id) if unsafe_context(&cx.tcx.map, id) => {
+                return
+            },
+            _ => ()
+        };
+
+        let expr = match s.node {
+            // Catch a `let` binding
+            ast::StmtDecl(ref decl, _) => match decl.node {
+                ast::DeclLocal(ref loc) => match loc.init {
+                    Some(ref e) => &**e,
+                    _ => return
+                },
+                _ => return
+            },
+            ast::StmtExpr(ref expr, _) => match expr.node {
+                // This catches deferred `let` statements
+                ast::ExprAssign(_, ref e) |
+                // Match statements allow you to bind onto the variable later in an arm
+                // We need not check arms individually since enum/struct fields are already
+                // linted in `check_struct_def` and `check_variant`
+                // (so there is no way of destructuring out a `#[must_root]` field)
+                ast::ExprMatch(ref e, _, _) |
+                // For loops allow you to bind a return value locally
+                ast::ExprForLoop(_, ref e, _, _) => &**e,
+                // XXXManishearth look into `if let` once it lands in our rustc
+                _ => return
+            },
+            _ => return
+        };
+
+        let t = expr_ty(cx.tcx, &*expr);
+        match ty::get(t).sty {
+            ty::ty_struct(did, _) |
+            ty::ty_enum(did, _) => {
+                if ty::has_attr(cx.tcx, did, "must_root") {
+                    cx.span_lint(UNROOTED_MUST_ROOT, expr.span,
+                                 format!("Expression of type {} must be rooted", t.repr(cx.tcx)).as_slice());
+                }
+            }
+            _ => {}
+        }
+    }
+}