When filling in value initializations within an initializer list, be

sure to fill in the initialized member of a union when a member was
explicitly designated. Fixes PR5843.

llvm-svn: 91858

clang/lib/Sema/SemaInit.cpp

@@ -345,6 +345,9 @@ class InitListChecker {
   int numArrayElements(QualType DeclType);
   int numStructUnionElements(QualType DeclType);
 
+  void FillInValueInitForField(unsigned Init, FieldDecl *Field,
+                               const InitializedEntity &ParentEntity,
+                               InitListExpr *ILE, bool &RequiresSecondPass);
   void FillInValueInitializations(const InitializedEntity &Entity,
                                   InitListExpr *ILE, bool &RequiresSecondPass);
 public:
@@ -358,33 +361,14 @@ public:
 };
 } // end anonymous namespace
 
-/// Recursively replaces NULL values within the given initializer list
+void InitListChecker::FillInValueInitForField(unsigned Init, FieldDecl *Field,
-/// with expressions that perform value-initialization of the
+                                        const InitializedEntity &ParentEntity,
-/// appropriate type.
-void 
-InitListChecker::FillInValueInitializations(const InitializedEntity &Entity,
                                               InitListExpr *ILE, 
                                               bool &RequiresSecondPass) {
-  assert((ILE->getType() != SemaRef.Context.VoidTy) &&
-         "Should not have void type");
   SourceLocation Loc = ILE->getSourceRange().getBegin();
-  if (ILE->getSyntacticForm())
+  unsigned NumInits = ILE->getNumInits();
-    Loc = ILE->getSyntacticForm()->getSourceRange().getBegin();
-
-  if (const RecordType *RType = ILE->getType()->getAs<RecordType>()) {
-    unsigned Init = 0, NumInits = ILE->getNumInits();
-    for (RecordDecl::field_iterator
-           Field = RType->getDecl()->field_begin(),
-           FieldEnd = RType->getDecl()->field_end();
-         Field != FieldEnd; ++Field) {
-      if (Field->isUnnamedBitfield())
-        continue;
-
-      if (hadError)
-        return;
-
   InitializedEntity MemberEntity 
-        = InitializedEntity::InitializeMember(*Field, &Entity);
+    = InitializedEntity::InitializeMember(Field, &ParentEntity);
   if (Init >= NumInits || !ILE->getInit(Init)) {
     // FIXME: We probably don't need to handle references
     // specially here, since value-initialization of references is
@@ -437,12 +421,49 @@ InitListChecker::FillInValueInitializations(const InitializedEntity &Entity,
                = dyn_cast<InitListExpr>(ILE->getInit(Init)))
     FillInValueInitializations(MemberEntity, InnerILE, 
                                RequiresSecondPass);  
+}
+
+/// Recursively replaces NULL values within the given initializer list
+/// with expressions that perform value-initialization of the
+/// appropriate type.
+void 
+InitListChecker::FillInValueInitializations(const InitializedEntity &Entity,
+                                            InitListExpr *ILE,
+                                            bool &RequiresSecondPass) {
+  assert((ILE->getType() != SemaRef.Context.VoidTy) &&
+         "Should not have void type");
+  SourceLocation Loc = ILE->getSourceRange().getBegin();
+  if (ILE->getSyntacticForm())
+    Loc = ILE->getSyntacticForm()->getSourceRange().getBegin();
+
+  if (const RecordType *RType = ILE->getType()->getAs<RecordType>()) {
+    if (RType->getDecl()->isUnion() &&
+        ILE->getInitializedFieldInUnion())
+      FillInValueInitForField(0, ILE->getInitializedFieldInUnion(),
+                              Entity, ILE, RequiresSecondPass);
+    else {
+      unsigned Init = 0;
+      for (RecordDecl::field_iterator
+             Field = RType->getDecl()->field_begin(),
+             FieldEnd = RType->getDecl()->field_end();
+           Field != FieldEnd; ++Field) {
+        if (Field->isUnnamedBitfield())
+          continue;
+
+        if (hadError)
+          return;
+
+        FillInValueInitForField(Init, *Field, Entity, ILE, RequiresSecondPass);
+        if (hadError)
+          return;
+
         ++Init;
 
         // Only look at the first initialization of a union.
         if (RType->getDecl()->isUnion())
           break;
       }
+    }
 
     return;
   }

clang/test/Sema/designated-initializers.c

@@ -231,4 +231,21 @@ int crazy_Y[] = {
   [ 0 ? crazy_x : 4] = 1
 };
 
+// PR5843
+struct expr {
+  int nargs;
+  union {
+    unsigned long int num;
+    struct expr *args[3];
+  } val;
+};
 
+struct expr expr0 = { 
+  .nargs = 2,
+  .val = {
+    .args = { 
+      [0] = (struct expr *)0, 
+      [1] = (struct expr *)0 
+    }
+  }
+};