[PATCH] D77041: [AST] Fix a crash on invalid constexpr Ctorinitializer when building RecoveryExpr.

[Haojian Wu via Phabricator via cfe-commits]

hokein updated this revision to Diff 254170.
hokein added a comment.

refine the fix based on the comment:

now constexpr ctor with error initializers is still a valid decl but not
constant-evaluate.


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D77041/new/

https://reviews.llvm.org/D77041

Files:
  clang/lib/AST/ExprConstant.cpp
  clang/lib/Sema/SemaDecl.cpp
  clang/test/SemaCXX/invalid-constructor-init.cpp


Index: clang/test/SemaCXX/invalid-constructor-init.cpp
===================================================================
--- /dev/null
+++ clang/test/SemaCXX/invalid-constructor-init.cpp
@@ -0,0 +1,23 @@
+// RUN: %clang_cc1 -frecovery-ast -verify %s
+
+struct X {
+  int Y;
+  constexpr X() // expected-error {{constexpr constructor never produces}}
+      : Y(foo()) {} // expected-error {{use of undeclared identifier 'foo'}}
+};
+// no crash on evaluating the constexpr ctor.
+constexpr int Z = X().Y; // expected-error {{constexpr variable 'Z' must be initialized by a constant expression}}
+
+struct X2 {
+  int Y = foo();    // expected-error {{use of undeclared identifier 'foo'}} \
+                 // expected-note {{subexpression not valid in a constant expression}}
+  constexpr X2() {} // expected-error {{constexpr constructor never produces a constant expression}}
+};
+
+struct CycleDelegate {
+  int Y;
+  CycleDelegate(int)
+      : Y(foo()) {} // expected-error {{use of undeclared identifier 'foo'}}
+  // no bogus "delegation cycle" diagnostic
+  CycleDelegate(float) : CycleDelegate(1) {}
+};
Index: clang/lib/Sema/SemaDecl.cpp
===================================================================
--- clang/lib/Sema/SemaDecl.cpp
+++ clang/lib/Sema/SemaDecl.cpp
@@ -45,6 +45,7 @@
 #include "clang/Sema/Template.h"
 #include "llvm/ADT/SmallString.h"
 #include "llvm/ADT/Triple.h"
+#include "llvm/Support/Casting.h"
 #include <algorithm>
 #include <cstring>
 #include <functional>
Index: clang/lib/AST/ExprConstant.cpp
===================================================================
--- clang/lib/AST/ExprConstant.cpp
+++ clang/lib/AST/ExprConstant.cpp
@@ -4975,6 +4975,13 @@
     return false;
   }
 
+  if (const auto *CtorDecl = dyn_cast_or_null<CXXConstructorDecl>(Definition)) {
+    for (const auto *InitExpr : CtorDecl->inits()) {
+      if (InitExpr->getInit() && InitExpr->getInit()->containsErrors())
+        return false;
+    }
+  }
+
   // Can we evaluate this function call?
   if (Definition && Definition->isConstexpr() && Body)
     return true;
@@ -14736,6 +14743,15 @@
   if (FD->isDependentContext())
     return true;
 
+  // Bail out if a constexpr constructor has an initializer that contains an
+  // error. We deliberately don't produce a diagnostic, as we have produced a
+  // relevant diagnostic when parsing the error initializer.
+  if (const auto *Ctor = dyn_cast<CXXConstructorDecl>(FD)) {
+    for (const auto *InitExpr : Ctor->inits()) {
+      if (InitExpr->getInit() && InitExpr->getInit()->containsErrors())
+        return false;
+    }
+  }
   Expr::EvalStatus Status;
   Status.Diag = &Diags;
 


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