[clang-tools-extra] 7212977 - [clangd] Always desugar type aliases in hover

[Kadir Cetinkaya via cfe-commits]

Author: Kadir Cetinkaya
Date: 2022-06-15T16:10:49+02:00
New Revision: 7212977fbb41bcffaf28a33a70c2df2b40492524

URL: https://github.com/llvm/llvm-project/commit/7212977fbb41bcffaf28a33a70c2df2b40492524
DIFF: https://github.com/llvm/llvm-project/commit/7212977fbb41bcffaf28a33a70c2df2b40492524.diff

LOG: [clangd] Always desugar type aliases in hover

The alias itself is already included in the definition section of the
hover (it's printed as spelled in source code). So it doesn't provide any value
when we print the aliases as-is.
Fixes https://github.com/clangd/clangd/issues/1134.

Differential Revision: https://reviews.llvm.org/D127832

Added: 
    

Modified: 
    clang-tools-extra/clangd/Hover.cpp
    clang-tools-extra/clangd/unittests/HoverTests.cpp

Removed: 
    


################################################################################
diff  --git a/clang-tools-extra/clangd/Hover.cpp b/clang-tools-extra/clangd/Hover.cpp
index fcf3af756184..07552c5869fa 100644
--- a/clang-tools-extra/clangd/Hover.cpp
+++ b/clang-tools-extra/clangd/Hover.cpp
@@ -623,7 +623,8 @@ HoverInfo getHoverContents(const NamedDecl *D, const PrintingPolicy &PP,
     HI.Type =
         printType(VT->getTemplatedDecl()->getType(), VT->getASTContext(), PP);
   else if (const auto *TN = dyn_cast<TypedefNameDecl>(D))
-    HI.Type = printType(TN->getUnderlyingType(), TN->getASTContext(), PP);
+    HI.Type = printType(TN->getUnderlyingType().getDesugaredType(Ctx),
+                        TN->getASTContext(), PP);
   else if (const auto *TAT = dyn_cast<TypeAliasTemplateDecl>(D))
     HI.Type = printType(TAT->getTemplatedDecl()->getUnderlyingType(),
                         TAT->getASTContext(), PP);

diff  --git a/clang-tools-extra/clangd/unittests/HoverTests.cpp b/clang-tools-extra/clangd/unittests/HoverTests.cpp
index 25ce19b2c580..0f149b724296 100644
--- a/clang-tools-extra/clangd/unittests/HoverTests.cpp
+++ b/clang-tools-extra/clangd/unittests/HoverTests.cpp
@@ -3206,6 +3206,30 @@ TEST(Hover, HideBigInitializers) {
   ASSERT_TRUE(H);
   EXPECT_EQ(H->Definition, "int arr[]");
 }
+
+TEST(Hover, Typedefs) {
+  Annotations T(R"cpp(
+  template <bool X, typename T, typename F>
+  struct cond { using type = T; };
+  template <typename T, typename F>
+  struct cond<false, T, F> { using type = F; };
+
+  template <bool X, typename T, typename F>
+  using type = typename cond<X, T, F>::type;
+
+  void foo() {
+    using f^oo = type<true, int, double>;
+  }
+  )cpp");
+
+  TestTU TU = TestTU::withCode(T.code());
+  auto AST = TU.build();
+  auto H = getHover(AST, T.point(), format::getLLVMStyle(), nullptr);
+
+  ASSERT_TRUE(H && H->Type);
+  EXPECT_EQ(H->Type->Type, "int");
+  EXPECT_EQ(H->Definition, "using foo = type<true, int, double>");
+}
 } // namespace
 } // namespace clangd
 } // namespace clang