Merge pull request #1481 from gregomni/switch-cases

Improve var decl completion in switch cases

Author: gregomni

Diff for: include/swift/AST/Stmt.h

@@ -985,6 +985,9 @@ class CaseStmt final : public Stmt,
 
   SourceLoc getStartLoc() const { return getLoc(); }
   SourceLoc getEndLoc() const { return getBody()->getEndLoc(); }
+  SourceRange getLabelItemsRange() const {
+    return ColonLoc.isValid() ? SourceRange(getLoc(), ColonLoc) : getSourceRange();
+  }
 
   bool isDefault() { return getCaseLabelItems()[0].isDefault(); }
 

Diff for: lib/AST/NameLookupImpl.h

@@ -223,12 +223,23 @@ class FindLocalVal : public StmtVisitor<FindLocalVal> {
   void visitCaseStmt(CaseStmt *S) {
     if (!isReferencePointInRange(S->getSourceRange()))
       return;
-    for (const auto &CLI : S->getCaseLabelItems()) {
-      auto *P = CLI.getPattern();
-      if (!isReferencePointInRange(P->getSourceRange()))
-        checkPattern(P, DeclVisibilityKind::LocalVariable);
+    // Pattern names aren't visible in the patterns themselves,
+    // just in the body or in where guards.
+    auto body = S->getBody();
+    bool inPatterns = isReferencePointInRange(S->getLabelItemsRange());
+    auto items = S->getCaseLabelItems();
+    if (inPatterns) {
+      for (const auto &CLI : items) {
+        auto guard = CLI.getGuardExpr();
+        if (guard && isReferencePointInRange(guard->getSourceRange())) {
+          inPatterns = false;
+          break;
+        }
+      }
     }
-    visit(S->getBody());
+    if (!inPatterns && items.size() > 0)
+      checkPattern(items[0].getPattern(), DeclVisibilityKind::LocalVariable);
+    visit(body);
   }
 
   void visitDoCatchStmt(DoCatchStmt *S) {

Diff for: test/IDE/complete_pattern.swift

@@ -23,6 +23,7 @@
 // RUN: %target-swift-ide-test -code-completion -source-filename %s -code-completion-token=MULTI_PATTERN_1 | FileCheck %s -check-prefix=MULTI_PATTERN_1
 // RUN: %target-swift-ide-test -code-completion -source-filename %s -code-completion-token=MULTI_PATTERN_2 | FileCheck %s -check-prefix=MULTI_PATTERN_2
 // RUN: %target-swift-ide-test -code-completion -source-filename %s -code-completion-token=MULTI_PATTERN_3 | FileCheck %s -check-prefix=MULTI_PATTERN_3
+// RUN: %target-swift-ide-test -code-completion -source-filename %s -code-completion-token=MULTI_PATTERN_4 | FileCheck %s -check-prefix=MULTI_PATTERN_4
 
 
 //===--- Helper types that are used in this test
@@ -155,13 +156,13 @@ func test_multiple_patterns1(x: Int) {
 }
 
 // MULTI_PATTERN_1: Begin completions
-// FIXME: ideally we wouldn't offer 'a' here, without 'let' first:
-// xxxMULTI_PATTERN_1-NOT: Decl[LocalVar]/Local: a[#Int#]{{; name=.+$}}
+// MULTI_PATTERN_1-NOT: Decl[LocalVar]/Local: a[#Int#]{{; name=.+$}}
+// MULTI_PATTERN_1-DAG: Decl[LocalVar]/Local: x[#Int#]{{; name=.+$}}
 // MULTI_PATTERN_1: End completions
 
 func test_multiple_patterns2(x: Int) {
     switch (x, x) {
-    case let (0, let a), (let a, 0):
+    case (0, let a), (let a, 0):
         #^MULTI_PATTERN_2^#
     }
 }
@@ -173,7 +174,7 @@ func test_multiple_patterns2(x: Int) {
 
 func test_multiple_patterns3(x: Int) {
     switch (x, x) {
-    case let (0, let a), (let b, 0):
+    case (0, let a), (let b, 0):
         #^MULTI_PATTERN_3^#
     }
 }
@@ -182,4 +183,15 @@ func test_multiple_patterns3(x: Int) {
 // MULTI_PATTERN_3-DAG: Decl[LocalVar]/Local: x[#Int#]{{; name=.+$}}
 // MULTI_PATTERN_3: End completions
 
+func test_multiple_patterns4(x: Int) {
+    switch (x, x) {
+    case (0, let a) where #^MULTI_PATTERN_4^#
+        
+    }
+}
+
+// MULTI_PATTERN_4: Begin completions
+// MULTI_PATTERN_4-DAG: Decl[LocalVar]/Local: a[#Int#]{{; name=.+$}}
+// MULTI_PATTERN_4-DAG: Decl[LocalVar]/Local: x[#Int#]{{; name=.+$}}
+// MULTI_PATTERN_4: End completions