[clang] [clang-tools-extra] [clang] Don't preserve the typo expr in the recovery expr for invalid VarDecls (PR #90948)

[Haojian Wu via cfe-commits]

https://github.com/hokein updated https://github.com/llvm/llvm-project/pull/90948

>From 2f29011bae5bf1b285c2ab1700c887d74eaec4b0 Mon Sep 17 00:00:00 2001
From: Haojian Wu <hokein.wu at gmail.com>
Date: Fri, 3 May 2024 10:06:39 +0200
Subject: [PATCH 1/2] [clang] Don't preserve the typo expr in the recovery expr
 for invalid VarDecls.

With the commit d5308949cf884d8e4b971d51a8b4f73584c4adec, we now
preserve the initializer for invalid decls with the recovery-expr.

However there is a chance that the original init expr is a typo-expr, we
should not preserve it in the final AST, as typo-expr is an internal AST
nodes. We should use the one after the typo correction.

This is spotted by a clangd hover crash on the testcase.
---
 clang-tools-extra/clangd/unittests/HoverTests.cpp | 13 +++++++++++++
 clang/lib/Sema/SemaDecl.cpp                       |  7 +++++--
 clang/test/AST/ast-dump-recovery.cpp              |  5 +++++
 3 files changed, 23 insertions(+), 2 deletions(-)

diff --git a/clang-tools-extra/clangd/unittests/HoverTests.cpp b/clang-tools-extra/clangd/unittests/HoverTests.cpp
index 5ead74748f550c..28df24f34827c0 100644
--- a/clang-tools-extra/clangd/unittests/HoverTests.cpp
+++ b/clang-tools-extra/clangd/unittests/HoverTests.cpp
@@ -965,6 +965,19 @@ class Foo final {})cpp";
          // Bindings are in theory public members of an anonymous struct.
          HI.AccessSpecifier = "public";
        }},
+      {// Don't crash on invalid decl with invalid init expr.
+       R"cpp(
+          Unknown [[^abc]] = invalid;
+          // error-ok
+          )cpp",
+       [](HoverInfo &HI) {
+         HI.Name = "abc";
+         HI.Kind = index::SymbolKind::Variable;
+         HI.NamespaceScope = "";
+         HI.Definition = "int abc = <recovery - expr>()";
+         HI.Type = "int";
+         HI.AccessSpecifier = "public";
+       }},
       {// Extra info for function call.
        R"cpp(
           void fun(int arg_a, int &arg_b) {};
diff --git a/clang/lib/Sema/SemaDecl.cpp b/clang/lib/Sema/SemaDecl.cpp
index 19968452f0d566..169df60b56bb4b 100644
--- a/clang/lib/Sema/SemaDecl.cpp
+++ b/clang/lib/Sema/SemaDecl.cpp
@@ -13530,9 +13530,12 @@ void Sema::AddInitializerToDecl(Decl *RealDecl, Expr *Init, bool DirectInit) {
   }
 
   if (VDecl->isInvalidDecl()) {
-    CorrectDelayedTyposInExpr(Init, VDecl);
+    ExprResult Res = CorrectDelayedTyposInExpr(Init, VDecl);
+    std::vector<Expr *> SubExprs;
+    if (Res.isUsable())
+      SubExprs.push_back(Res.get());
     ExprResult Recovery =
-        CreateRecoveryExpr(Init->getBeginLoc(), Init->getEndLoc(), {Init});
+        CreateRecoveryExpr(Init->getBeginLoc(), Init->getEndLoc(), SubExprs);
     if (Expr *E = Recovery.get())
       VDecl->setInit(E);
     return;
diff --git a/clang/test/AST/ast-dump-recovery.cpp b/clang/test/AST/ast-dump-recovery.cpp
index 77527743fe8577..a88dff471d9f04 100644
--- a/clang/test/AST/ast-dump-recovery.cpp
+++ b/clang/test/AST/ast-dump-recovery.cpp
@@ -419,6 +419,11 @@ void InitializerOfInvalidDecl() {
   // CHECK:      VarDecl {{.*}} invalid InvalidDecl
   // CHECK-NEXT: `-RecoveryExpr {{.*}} '<dependent type>' contains-errors
   // CHECK-NEXT:   `-DeclRefExpr {{.*}} 'int' lvalue Var {{.*}} 'ValidDecl'
+
+  Unknown InvalidDeclWithInvalidInit = Invalid;
+  // CHECK:      VarDecl {{.*}} invalid InvalidDeclWithInvalidInit
+  // CHECK-NEXT: `-RecoveryExpr {{.*}} '<dependent type>' contains-errors
+  // CHECK-NOT:    `-TypoExpr
 }
 
 void RecoverToAnInvalidDecl() {

>From 06c30958b7bb2c664440e47bd2257e068f72c2b1 Mon Sep 17 00:00:00 2001
From: Haojian Wu <hokein.wu at gmail.com>
Date: Mon, 6 May 2024 20:16:05 +0200
Subject: [PATCH 2/2] address review comments.

---
 clang/lib/Sema/SemaDecl.cpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/clang/lib/Sema/SemaDecl.cpp b/clang/lib/Sema/SemaDecl.cpp
index 169df60b56bb4b..590f37837eb2df 100644
--- a/clang/lib/Sema/SemaDecl.cpp
+++ b/clang/lib/Sema/SemaDecl.cpp
@@ -13531,7 +13531,7 @@ void Sema::AddInitializerToDecl(Decl *RealDecl, Expr *Init, bool DirectInit) {
 
   if (VDecl->isInvalidDecl()) {
     ExprResult Res = CorrectDelayedTyposInExpr(Init, VDecl);
-    std::vector<Expr *> SubExprs;
+    SmallVector<Expr *> SubExprs;
     if (Res.isUsable())
       SubExprs.push_back(Res.get());
     ExprResult Recovery =