[clang] dfb85c3 - [Clang][Interp] Diagnose uninitialized ctor of global record arrays

[Takuya Shimizu via cfe-commits]

Author: Takuya Shimizu
Date: 2023-06-21T19:03:01+09:00
New Revision: dfb85c3ce09a7bd1a059a3e821390b5111454f9e

URL: https://github.com/llvm/llvm-project/commit/dfb85c3ce09a7bd1a059a3e821390b5111454f9e
DIFF: https://github.com/llvm/llvm-project/commit/dfb85c3ce09a7bd1a059a3e821390b5111454f9e.diff

LOG: [Clang][Interp] Diagnose uninitialized ctor of global record arrays

This patch adds a check for uninitialized subobjects of global variables that are record arrays.
e.g. `constexpr Foo f[2];`

Reviewed By: tbaeder

Differential Revision: https://reviews.llvm.org/D152548

Added: 
    

Modified: 
    clang/lib/AST/Interp/ByteCodeExprGen.h
    clang/lib/AST/Interp/Interp.cpp
    clang/test/AST/Interp/cxx20.cpp

Removed: 
    


################################################################################
diff  --git a/clang/lib/AST/Interp/ByteCodeExprGen.h b/clang/lib/AST/Interp/ByteCodeExprGen.h
index 8708bf99d91e7..83bafeb9aac61 100644
--- a/clang/lib/AST/Interp/ByteCodeExprGen.h
+++ b/clang/lib/AST/Interp/ByteCodeExprGen.h
@@ -166,7 +166,8 @@ class ByteCodeExprGen : public ConstStmtVisitor<ByteCodeExprGen<Emitter>, bool>,
     if (!visitInitializer(Init))
       return false;
 
-    if (Init->getType()->isRecordType() && !this->emitCheckGlobalCtor(Init))
+    if ((Init->getType()->isArrayType() || Init->getType()->isRecordType()) &&
+        !this->emitCheckGlobalCtor(Init))
       return false;
 
     return this->emitPopPtr(Init);

diff  --git a/clang/lib/AST/Interp/Interp.cpp b/clang/lib/AST/Interp/Interp.cpp
index 8d7f191ebaa09..f646e876554ca 100644
--- a/clang/lib/AST/Interp/Interp.cpp
+++ b/clang/lib/AST/Interp/Interp.cpp
@@ -456,8 +456,11 @@ static bool CheckFieldsInitialized(InterpState &S, CodePtr OpPC,
 
 bool CheckCtorCall(InterpState &S, CodePtr OpPC, const Pointer &This) {
   assert(!This.isZero());
-  const Record *R = This.getRecord();
-  return CheckFieldsInitialized(S, OpPC, This, R);
+  if (const Record *R = This.getRecord())
+    return CheckFieldsInitialized(S, OpPC, This, R);
+  const auto *CAT =
+      cast<ConstantArrayType>(This.getType()->getAsArrayTypeUnsafe());
+  return CheckArrayInitialized(S, OpPC, This, CAT);
 }
 
 bool CheckFloatResult(InterpState &S, CodePtr OpPC, APFloat::opStatus Status) {

diff  --git a/clang/test/AST/Interp/cxx20.cpp b/clang/test/AST/Interp/cxx20.cpp
index 5d9fa90b482ea..87c32e42d053e 100644
--- a/clang/test/AST/Interp/cxx20.cpp
+++ b/clang/test/AST/Interp/cxx20.cpp
@@ -138,14 +138,43 @@ static_assert(!b4); // ref-error {{not an integral constant expression}} \
 namespace UninitializedFields {
   class A {
   public:
-    int a; // expected-note 3{{subobject declared here}} \
-           // ref-note 3{{subobject declared here}}
+    int a; // expected-note 4{{subobject declared here}} \
+           // ref-note 4{{subobject declared here}}
     constexpr A() {}
   };
   constexpr A a; // expected-error {{must be initialized by a constant expression}} \
                  // expected-note {{subobject 'a' is not initialized}} \
                  // ref-error {{must be initialized by a constant expression}} \
                  // ref-note {{subobject 'a' is not initialized}}
+  constexpr A aarr[2]; // expected-error {{must be initialized by a constant expression}} \
+                       // expected-note {{subobject 'a' is not initialized}} \
+                       // ref-error {{must be initialized by a constant expression}} \
+                       // ref-note {{subobject 'a' is not initialized}}
+  class F {
+    public:
+      int f; // expected-note 3{{subobject declared here}} \
+             // ref-note 3{{subobject declared here}}
+
+      constexpr F() {}
+      constexpr F(bool b) {
+        if (b)
+          f = 42;
+      }
+  };
+
+  constexpr F foo[2] = {true}; // expected-error {{must be initialized by a constant expression}} \
+                               // expected-note {{subobject 'f' is not initialized}} \
+                               // ref-error {{must be initialized by a constant expression}} \
+                               // ref-note {{subobject 'f' is not initialized}}
+  constexpr F foo2[3] = {true, false, true}; // expected-error {{must be initialized by a constant expression}} \
+                                             // expected-note {{subobject 'f' is not initialized}} \
+                                             // ref-error {{must be initialized by a constant expression}} \
+                                             // ref-note {{subobject 'f' is not initialized}}
+  constexpr F foo3[3] = {true, true, F()}; // expected-error {{must be initialized by a constant expression}} \
+                                           // expected-note {{subobject 'f' is not initialized}} \
+                                           // ref-error {{must be initialized by a constant expression}} \
+                                           // ref-note {{subobject 'f' is not initialized}}
+
 
 
   class Base {