Move semantic logic into Semantics, fix missing tag for safe amp operator, using functional methods rather than clunky inline closure

6 files changed, 112 insertions, 105 deletions

diff --git a/crates/ra_hir/src/semantics.rs b/crates/ra_hir/src/semantics.rs
index 1072b3971..f706a186e 100644
--- a/crates/ra_hir/src/semantics.rs
+++ b/crates/ra_hir/src/semantics.rs
@@ -25,7 +25,8 @@ use crate::{
     semantics::source_to_def::{ChildContainer, SourceToDefCache, SourceToDefCtx},
     source_analyzer::{resolve_hir_path, resolve_hir_path_qualifier, SourceAnalyzer},
     AssocItem, Callable, Crate, Field, Function, HirFileId, ImplDef, InFile, Local, MacroDef,
-    Module, ModuleDef, Name, Origin, Path, ScopeDef, Trait, Type, TypeAlias, TypeParam, VariantDef,
+    Module, ModuleDef, Name, Origin, Path, ScopeDef, Trait, Type, TypeAlias, TypeParam, TypeRef,
+    VariantDef,
 };
 use resolver::TypeNs;
 
@@ -280,45 +281,84 @@ impl<'db, DB: HirDatabase> Semantics<'db, DB> {
         self.imp.assert_contains_node(node)
     }
 
-    pub fn is_unsafe_pat(&self, pat: &ast::Pat) -> bool {
-        let ty = (|| {
-            let parent = match pat {
-                ast::Pat::BindPat(bind_pat) => bind_pat.syntax().parent()?,
-                _ => return None,
-            };
-
-            // `BindPat` can live under `RecordPat` directly under `RecordFieldPat` or
-            // `RecordFieldPatList`. `RecordFieldPat` also lives under `RecordFieldPatList`,
-            // so this tries to lookup the `BindPat` anywhere along that structure to the
-            // `RecordPat` so we can get the containing type.
-            let record_pat = ast::RecordFieldPat::cast(parent.clone())
-                .and_then(|record_pat| record_pat.syntax().parent())
-                .or_else(|| Some(parent.clone()))
-                .and_then(|parent| {
-                    ast::RecordFieldPatList::cast(parent)?
-                        .syntax()
-                        .parent()
-                        .and_then(ast::RecordPat::cast)
-                });
-
-            // If this doesn't match a `RecordPat`, fallback to a `LetStmt` to see if
-            // this is initialized from a `FieldExpr`.
-            if let Some(record_pat) = record_pat {
-                self.type_of_pat(&ast::Pat::RecordPat(record_pat))
-            } else if let Some(let_stmt) = ast::LetStmt::cast(parent) {
-                let field_expr = match let_stmt.initializer()? {
-                    ast::Expr::FieldExpr(field_expr) => field_expr,
-                    _ => return None,
-                };
+    pub fn is_unsafe_method_call(&self, method_call_expr: ast::MethodCallExpr) -> Option<()> {
+        let expr = method_call_expr.expr()?;
+        let field_expr =
+            if let ast::Expr::FieldExpr(field_expr) = expr { field_expr } else { return None };
+        let ty = self.type_of_expr(&field_expr.expr()?)?;
+        if !ty.is_packed(self.db) {
+            return None;
+        }
 
-                self.type_of_expr(&field_expr.expr()?)
+        let func = self.resolve_method_call(&method_call_expr)?;
+        if func.has_self_param(self.db) {
+            let params = func.params(self.db);
+            if matches!(params.into_iter().next(), Some(TypeRef::Reference(..))) {
+                Some(())
             } else {
                 None
             }
-        })();
+        } else {
+            None
+        }
+    }
 
-        // Binding a reference to a packed type is possibly unsafe.
-        ty.map(|ty| ty.is_packed(self.db)).unwrap_or(false)
+    pub fn is_unsafe_ref_expr(&self, ref_expr: &ast::RefExpr) -> bool {
+        ref_expr
+            .expr()
+            .and_then(|expr| {
+                let field_expr = match expr {
+                    ast::Expr::FieldExpr(field_expr) => field_expr,
+                    _ => return None,
+                };
+                let expr = field_expr.expr()?;
+                self.type_of_expr(&expr)
+            })
+            // Binding a reference to a packed type is possibly unsafe.
+            .map(|ty| ty.is_packed(self.db))
+            .unwrap_or(false)
+
+        // FIXME This needs layout computation to be correct. It will highlight
+        // more than it should with the current implementation.
+    }
+
+    pub fn is_unsafe_bind_pat(&self, bind_pat: &ast::BindPat) -> bool {
+        bind_pat
+            .syntax()
+            .parent()
+            .and_then(|parent| {
+                // `BindPat` can live under `RecordPat` directly under `RecordFieldPat` or
+                // `RecordFieldPatList`. `RecordFieldPat` also lives under `RecordFieldPatList`,
+                // so this tries to lookup the `BindPat` anywhere along that structure to the
+                // `RecordPat` so we can get the containing type.
+                let record_pat = ast::RecordFieldPat::cast(parent.clone())
+                    .and_then(|record_pat| record_pat.syntax().parent())
+                    .or_else(|| Some(parent.clone()))
+                    .and_then(|parent| {
+                        ast::RecordFieldPatList::cast(parent)?
+                            .syntax()
+                            .parent()
+                            .and_then(ast::RecordPat::cast)
+                    });
+
+                // If this doesn't match a `RecordPat`, fallback to a `LetStmt` to see if
+                // this is initialized from a `FieldExpr`.
+                if let Some(record_pat) = record_pat {
+                    self.type_of_pat(&ast::Pat::RecordPat(record_pat))
+                } else if let Some(let_stmt) = ast::LetStmt::cast(parent) {
+                    let field_expr = match let_stmt.initializer()? {
+                        ast::Expr::FieldExpr(field_expr) => field_expr,
+                        _ => return None,
+                    };
+
+                    self.type_of_expr(&field_expr.expr()?)
+                } else {
+                    None
+                }
+            })
+            // Binding a reference to a packed type is possibly unsafe.
+            .map(|ty| ty.is_packed(self.db))
+            .unwrap_or(false)
     }
 }
 
diff --git a/crates/ra_ide/src/syntax_highlighting.rs b/crates/ra_ide/src/syntax_highlighting.rs
index cf93205b6..e29f65a78 100644
--- a/crates/ra_ide/src/syntax_highlighting.rs
+++ b/crates/ra_ide/src/syntax_highlighting.rs
@@ -565,29 +565,21 @@ fn highlight_element(
                 _ => h,
             }
         }
-        T![&] => {
-            let ref_expr = element.parent().and_then(ast::RefExpr::cast)?;
-            let expr = ref_expr.expr()?;
-            let field_expr = match expr {
-                ast::Expr::FieldExpr(fe) => fe,
-                _ => return None,
-            };
-
-            let expr = field_expr.expr()?;
-            let ty = sema.type_of_expr(&expr)?;
-            if !ty.is_packed(db) {
-                return None;
-            }
-
-            // FIXME This needs layout computation to be correct. It will highlight
-            // more than it should with the current implementation.
-
-            HighlightTag::Operator | HighlightModifier::Unsafe
-        }
         p if p.is_punct() => match p {
-            T![::] | T![->] | T![=>] | T![&] | T![..] | T![=] | T![@] => {
-                HighlightTag::Operator.into()
+            T![&] => {
+                let h = HighlightTag::Operator.into();
+                let is_unsafe = element
+                    .parent()
+                    .and_then(ast::RefExpr::cast)
+                    .map(|ref_expr| sema.is_unsafe_ref_expr(&ref_expr))
+                    .unwrap_or(false);
+                if is_unsafe {
+                    h | HighlightModifier::Unsafe
+                } else {
+                    h
+                }
             }
+            T![::] | T![->] | T![=>] | T![..] | T![=] | T![@] => HighlightTag::Operator.into(),
             T![!] if element.parent().and_then(ast::MacroCall::cast).is_some() => {
                 HighlightTag::Macro.into()
             }
@@ -668,22 +660,18 @@ fn highlight_element(
                         HighlightTag::SelfKeyword.into()
                     }
                 }
-                T![ref] => {
-                    let modifier: Option<HighlightModifier> = (|| {
-                        let bind_pat = element.parent().and_then(ast::BindPat::cast)?;
-                        if sema.is_unsafe_pat(&ast::Pat::BindPat(bind_pat)) {
+                T![ref] => element
+                    .parent()
+                    .and_then(ast::BindPat::cast)
+                    .and_then(|bind_pat| {
+                        if sema.is_unsafe_bind_pat(&bind_pat) {
                             Some(HighlightModifier::Unsafe)
                         } else {
                             None
                         }
-                    })();
-
-                    if let Some(modifier) = modifier {
-                        h | modifier
-                    } else {
-                        h
-                    }
-                }
+                    })
+                    .map(|modifier| h | modifier)
+                    .unwrap_or(h),
                 _ => h,
             }
         }
@@ -713,31 +701,6 @@ fn is_child_of_impl(element: &SyntaxElement) -> bool {
     }
 }
 
-fn is_method_call_unsafe(
-    sema: &Semantics<RootDatabase>,
-    method_call_expr: ast::MethodCallExpr,
-) -> Option<()> {
-    let expr = method_call_expr.expr()?;
-    let field_expr =
-        if let ast::Expr::FieldExpr(field_expr) = expr { field_expr } else { return None };
-    let ty = sema.type_of_expr(&field_expr.expr()?)?;
-    if !ty.is_packed(sema.db) {
-        return None;
-    }
-
-    let func = sema.resolve_method_call(&method_call_expr)?;
-    if func.has_self_param(sema.db) {
-        let params = func.params(sema.db);
-        if matches!(params.into_iter().next(), Some(TypeRef::Reference(..))) {
-            Some(())
-        } else {
-            None
-        }
-    } else {
-        None
-    }
-}
-
 fn highlight_name(
     sema: &Semantics<RootDatabase>,
     db: &RootDatabase,
@@ -767,7 +730,7 @@ fn highlight_name(
                     let is_unsafe = name_ref
                         .and_then(|name_ref| name_ref.syntax().parent())
                         .and_then(ast::MethodCallExpr::cast)
-                        .and_then(|method_call_expr| is_method_call_unsafe(sema, method_call_expr));
+                        .and_then(|method_call_expr| sema.is_unsafe_method_call(method_call_expr));
                     if is_unsafe.is_some() {
                         h |= HighlightModifier::Unsafe;
                     }
@@ -846,7 +809,7 @@ fn highlight_name_ref_by_syntax(name: ast::NameRef, sema: &Semantics<RootDatabas
         METHOD_CALL_EXPR => {
             let mut h = Highlight::new(HighlightTag::Function);
             let is_unsafe = ast::MethodCallExpr::cast(parent)
-                .and_then(|method_call_expr| is_method_call_unsafe(sema, method_call_expr));
+                .and_then(|method_call_expr| sema.is_unsafe_method_call(method_call_expr));
 
             if is_unsafe.is_some() {
                 h |= HighlightModifier::Unsafe;
@@ -866,7 +829,11 @@ fn highlight_name_ref_by_syntax(name: ast::NameRef, sema: &Semantics<RootDatabas
                     })
                 })
                 .unwrap_or(false);
-            if is_union { h | HighlightModifier::Unsafe } else { h.into() }
+            if is_union {
+                h | HighlightModifier::Unsafe
+            } else {
+                h.into()
+            }
         }
         PATH_SEGMENT => {
             let path = match parent.parent().and_then(ast::Path::cast) {
diff --git a/crates/ra_ide/test_data/highlight_doctest.html b/crates/ra_ide/test_data/highlight_doctest.html
index 46c1e0a11..6322d404f 100644
--- a/crates/ra_ide/test_data/highlight_doctest.html
+++ b/crates/ra_ide/test_data/highlight_doctest.html
@@ -87,7 +87,7 @@ pre                 { color: #DCDCCC; background: #3F3F3F; font-size: 22px; padd
     <span class="comment documentation">/// ```sh</span>
     <span class="comment documentation">/// echo 1</span>
     <span class="comment documentation">/// ```</span>
-    <span class="keyword">pub</span> <span class="keyword">fn</span> <span class="function declaration">foo</span><span class="punctuation">(</span>&<span class="self_keyword">self</span><span class="punctuation">)</span> <span class="operator">-&gt;</span> <span class="builtin_type">bool</span> <span class="punctuation">{</span>
+    <span class="keyword">pub</span> <span class="keyword">fn</span> <span class="function declaration">foo</span><span class="punctuation">(</span><span class="operator">&</span><span class="self_keyword">self</span><span class="punctuation">)</span> <span class="operator">-&gt;</span> <span class="builtin_type">bool</span> <span class="punctuation">{</span>
         <span class="bool_literal">true</span>
     <span class="punctuation">}</span>
 <span class="punctuation">}</span>
diff --git a/crates/ra_ide/test_data/highlight_injection.html b/crates/ra_ide/test_data/highlight_injection.html
index 60c394399..18addd00d 100644
--- a/crates/ra_ide/test_data/highlight_injection.html
+++ b/crates/ra_ide/test_data/highlight_injection.html
@@ -35,7 +35,7 @@ pre                 { color: #DCDCCC; background: #3F3F3F; font-size: 22px; padd
 
 .unresolved_reference { color: #FC5555; text-decoration: wavy underline; }
 </style>
-<pre><code><span class="keyword">fn</span> <span class="function declaration">fixture</span><span class="punctuation">(</span><span class="value_param declaration">ra_fixture</span><span class="punctuation">:</span> &<span class="builtin_type">str</span><span class="punctuation">)</span> <span class="punctuation">{</span><span class="punctuation">}</span>
+<pre><code><span class="keyword">fn</span> <span class="function declaration">fixture</span><span class="punctuation">(</span><span class="value_param declaration">ra_fixture</span><span class="punctuation">:</span> <span class="operator">&</span><span class="builtin_type">str</span><span class="punctuation">)</span> <span class="punctuation">{</span><span class="punctuation">}</span>
 
 <span class="keyword">fn</span> <span class="function declaration">main</span><span class="punctuation">(</span><span class="punctuation">)</span> <span class="punctuation">{</span>
     <span class="function">fixture</span><span class="punctuation">(</span><span class="string_literal">r#"</span>
diff --git a/crates/ra_ide/test_data/highlight_unsafe.html b/crates/ra_ide/test_data/highlight_unsafe.html
index 454ff6d5f..a2df2c27e 100644
--- a/crates/ra_ide/test_data/highlight_unsafe.html
+++ b/crates/ra_ide/test_data/highlight_unsafe.html
@@ -45,7 +45,7 @@ pre                 { color: #DCDCCC; background: #3F3F3F; font-size: 22px; padd
 <span class="keyword">struct</span> <span class="struct declaration">HasUnsafeFn</span><span class="punctuation">;</span>
 
 <span class="keyword">impl</span> <span class="struct">HasUnsafeFn</span> <span class="punctuation">{</span>
-    <span class="keyword unsafe">unsafe</span> <span class="keyword">fn</span> <span class="function declaration unsafe">unsafe_method</span><span class="punctuation">(</span>&<span class="self_keyword">self</span><span class="punctuation">)</span> <span class="punctuation">{</span><span class="punctuation">}</span>
+    <span class="keyword unsafe">unsafe</span> <span class="keyword">fn</span> <span class="function declaration unsafe">unsafe_method</span><span class="punctuation">(</span><span class="operator">&</span><span class="self_keyword">self</span><span class="punctuation">)</span> <span class="punctuation">{</span><span class="punctuation">}</span>
 <span class="punctuation">}</span>
 
 <span class="keyword">struct</span> <span class="struct declaration">TypeForStaticMut</span> <span class="punctuation">{</span>
@@ -55,7 +55,7 @@ pre                 { color: #DCDCCC; background: #3F3F3F; font-size: 22px; padd
 <span class="keyword">static</span> <span class="keyword">mut</span> <span class="static declaration mutable unsafe">global_mut</span><span class="punctuation">:</span> <span class="struct">TypeForStaticMut</span> <span class="operator">=</span> <span class="struct">TypeForStaticMut</span> <span class="punctuation">{</span> <span class="field">a</span><span class="punctuation">:</span> <span class="numeric_literal">0</span> <span class="punctuation">}</span><span class="punctuation">;</span>
 
 <span class="keyword">fn</span> <span class="function declaration">main</span><span class="punctuation">(</span><span class="punctuation">)</span> <span class="punctuation">{</span>
-    <span class="keyword">let</span> <span class="variable declaration">x</span> <span class="operator">=</span> &<span class="numeric_literal">5</span> <span class="keyword">as</span> <span class="keyword">*</span><span class="keyword">const</span> <span class="punctuation">_</span> <span class="keyword">as</span> <span class="keyword">*</span><span class="keyword">const</span> <span class="builtin_type">usize</span><span class="punctuation">;</span>
+    <span class="keyword">let</span> <span class="variable declaration">x</span> <span class="operator">=</span> <span class="operator">&</span><span class="numeric_literal">5</span> <span class="keyword">as</span> <span class="keyword">*</span><span class="keyword">const</span> <span class="punctuation">_</span> <span class="keyword">as</span> <span class="keyword">*</span><span class="keyword">const</span> <span class="builtin_type">usize</span><span class="punctuation">;</span>
     <span class="keyword">let</span> <span class="variable declaration">u</span> <span class="operator">=</span> <span class="union">Union</span> <span class="punctuation">{</span> <span class="field">b</span><span class="punctuation">:</span> <span class="numeric_literal">0</span> <span class="punctuation">}</span><span class="punctuation">;</span>
     <span class="keyword unsafe">unsafe</span> <span class="punctuation">{</span>
         <span class="comment">// unsafe fn and method calls</span>
diff --git a/crates/ra_ide/test_data/highlighting.html b/crates/ra_ide/test_data/highlighting.html
index 678cf9bd3..8e0160eee 100644
--- a/crates/ra_ide/test_data/highlighting.html
+++ b/crates/ra_ide/test_data/highlighting.html
@@ -45,11 +45,11 @@ pre                 { color: #DCDCCC; background: #3F3F3F; font-size: 22px; padd
 <span class="punctuation">}</span>
 
 <span class="keyword">trait</span> <span class="trait declaration">Bar</span> <span class="punctuation">{</span>
-    <span class="keyword">fn</span> <span class="function declaration">bar</span><span class="punctuation">(</span>&<span class="self_keyword">self</span><span class="punctuation">)</span> <span class="operator">-&gt;</span> <span class="builtin_type">i32</span><span class="punctuation">;</span>
+    <span class="keyword">fn</span> <span class="function declaration">bar</span><span class="punctuation">(</span><span class="operator">&</span><span class="self_keyword">self</span><span class="punctuation">)</span> <span class="operator">-&gt;</span> <span class="builtin_type">i32</span><span class="punctuation">;</span>
 <span class="punctuation">}</span>
 
 <span class="keyword">impl</span> <span class="trait">Bar</span> <span class="keyword">for</span> <span class="struct">Foo</span> <span class="punctuation">{</span>
-    <span class="keyword">fn</span> <span class="function declaration">bar</span><span class="punctuation">(</span>&<span class="self_keyword">self</span><span class="punctuation">)</span> <span class="operator">-&gt;</span> <span class="builtin_type">i32</span> <span class="punctuation">{</span>
+    <span class="keyword">fn</span> <span class="function declaration">bar</span><span class="punctuation">(</span><span class="operator">&</span><span class="self_keyword">self</span><span class="punctuation">)</span> <span class="operator">-&gt;</span> <span class="builtin_type">i32</span> <span class="punctuation">{</span>
         <span class="self_keyword">self</span><span class="punctuation">.</span><span class="field">x</span>
     <span class="punctuation">}</span>
 <span class="punctuation">}</span>
@@ -59,7 +59,7 @@ pre                 { color: #DCDCCC; background: #3F3F3F; font-size: 22px; padd
         <span class="self_keyword">self</span><span class="punctuation">.</span><span class="field">x</span>
     <span class="punctuation">}</span>
 
-    <span class="keyword">fn</span> <span class="function declaration">qux</span><span class="punctuation">(</span>&<span class="keyword">mut</span> <span class="self_keyword mutable">self</span><span class="punctuation">)</span> <span class="punctuation">{</span>
+    <span class="keyword">fn</span> <span class="function declaration">qux</span><span class="punctuation">(</span><span class="operator">&</span><span class="keyword">mut</span> <span class="self_keyword mutable">self</span><span class="punctuation">)</span> <span class="punctuation">{</span>
         <span class="self_keyword mutable">self</span><span class="punctuation">.</span><span class="field">x</span> <span class="operator">=</span> <span class="numeric_literal">0</span><span class="punctuation">;</span>
     <span class="punctuation">}</span>
 <span class="punctuation">}</span>
@@ -107,8 +107,8 @@ pre                 { color: #DCDCCC; background: #3F3F3F; font-size: 22px; padd
     <span class="macro">noop!</span><span class="punctuation">(</span><span class="macro">noop</span><span class="macro">!</span><span class="punctuation">(</span><span class="numeric_literal">1</span><span class="punctuation">)</span><span class="punctuation">)</span><span class="punctuation">;</span>
 
     <span class="keyword">let</span> <span class="keyword">mut</span> <span class="variable declaration mutable">x</span> <span class="operator">=</span> <span class="numeric_literal">42</span><span class="punctuation">;</span>
-    <span class="keyword">let</span> <span class="variable declaration mutable">y</span> <span class="operator">=</span> &<span class="keyword">mut</span> <span class="variable mutable">x</span><span class="punctuation">;</span>
-    <span class="keyword">let</span> <span class="variable declaration">z</span> <span class="operator">=</span> &<span class="variable mutable">y</span><span class="punctuation">;</span>
+    <span class="keyword">let</span> <span class="variable declaration mutable">y</span> <span class="operator">=</span> <span class="operator">&</span><span class="keyword">mut</span> <span class="variable mutable">x</span><span class="punctuation">;</span>
+    <span class="keyword">let</span> <span class="variable declaration">z</span> <span class="operator">=</span> <span class="operator">&</span><span class="variable mutable">y</span><span class="punctuation">;</span>
 
     <span class="keyword">let</span> <span class="struct">Foo</span> <span class="punctuation">{</span> <span class="field">x</span><span class="punctuation">:</span> <span class="variable declaration">z</span><span class="punctuation">,</span> <span class="field">y</span> <span class="punctuation">}</span> <span class="operator">=</span> <span class="struct">Foo</span> <span class="punctuation">{</span> <span class="field">x</span><span class="punctuation">:</span> <span class="variable">z</span><span class="punctuation">,</span> <span class="field">y</span> <span class="punctuation">}</span><span class="punctuation">;</span>