[clang] 9108897 - [clang] Report missing designated initializers in C++
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cfe-commits at lists.llvm.org
Mon Aug 21 02:07:16 PDT 2023
Author: Podchishchaeva, Mariya
Date: 2023-08-21T02:05:34-07:00
New Revision: 91088978d712cd7b33610c59f69d87d5a39e3113
URL: https://github.com/llvm/llvm-project/commit/91088978d712cd7b33610c59f69d87d5a39e3113
DIFF: https://github.com/llvm/llvm-project/commit/91088978d712cd7b33610c59f69d87d5a39e3113.diff
LOG: [clang] Report missing designated initializers in C++
Prior to this change clang didn't emit missing-field-initializers
warning for designated initializers. The comments say that it is done to
match gcc behavior. However, gcc behaves so only for C. For C++ warnings
are emitted.
Fixes https://github.com/llvm/llvm-project/issues/56628
Reviewed By: aaron.ballman
Differential Revision: https://reviews.llvm.org/D157879
Added:
Modified:
clang/docs/ReleaseNotes.rst
clang/lib/Sema/SemaInit.cpp
clang/test/SemaCXX/cxx2a-initializer-aggregates.cpp
Removed:
################################################################################
diff --git a/clang/docs/ReleaseNotes.rst b/clang/docs/ReleaseNotes.rst
index d76005692aa809..94418a08671d78 100644
--- a/clang/docs/ReleaseNotes.rst
+++ b/clang/docs/ReleaseNotes.rst
@@ -154,6 +154,9 @@ Bug Fixes in This Version
- Fix a hang on valid C code passing a function type as an argument to
``typeof`` to form a function declaration.
(`#64713 <https://github.com/llvm/llvm-project/issues/64713>_`)
+- Clang now reports missing-field-initializers warning for missing designated
+ initializers in C++.
+ (`#56628 <https://github.com/llvm/llvm-project/issues/56628>`_)
Bug Fixes to Compiler Builtins
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
diff --git a/clang/lib/Sema/SemaInit.cpp b/clang/lib/Sema/SemaInit.cpp
index ab68029fb35e96..a21fdb771a4d66 100644
--- a/clang/lib/Sema/SemaInit.cpp
+++ b/clang/lib/Sema/SemaInit.cpp
@@ -2252,6 +2252,8 @@ void InitListChecker::CheckStructUnionTypes(
!IList->isIdiomaticZeroInitializer(SemaRef.getLangOpts());
bool HasDesignatedInit = false;
+ llvm::SmallPtrSet<FieldDecl *, 4> InitializedFields;
+
while (Index < IList->getNumInits()) {
Expr *Init = IList->getInit(Index);
SourceLocation InitLoc = Init->getBeginLoc();
@@ -2267,20 +2269,23 @@ void InitListChecker::CheckStructUnionTypes(
// Handle this designated initializer. Field will be updated to
// the next field that we'll be initializing.
- if (CheckDesignatedInitializer(Entity, IList, DIE, 0,
- DeclType, &Field, nullptr, Index,
- StructuredList, StructuredIndex,
- true, TopLevelObject))
+ bool DesignatedInitFailed = CheckDesignatedInitializer(
+ Entity, IList, DIE, 0, DeclType, &Field, nullptr, Index,
+ StructuredList, StructuredIndex, true, TopLevelObject);
+ if (DesignatedInitFailed)
hadError = true;
- else if (!VerifyOnly) {
- // Find the field named by the designated initializer.
- RecordDecl::field_iterator F = RD->field_begin();
- while (std::next(F) != Field)
- ++F;
- QualType ET = SemaRef.Context.getBaseElementType(F->getType());
- if (checkDestructorReference(ET, InitLoc, SemaRef)) {
- hadError = true;
- return;
+
+ // Find the field named by the designated initializer.
+ DesignatedInitExpr::Designator *D = DIE->getDesignator(0);
+ if (!VerifyOnly && D->isFieldDesignator()) {
+ FieldDecl *F = D->getFieldDecl();
+ InitializedFields.insert(F);
+ if (!DesignatedInitFailed) {
+ QualType ET = SemaRef.Context.getBaseElementType(F->getType());
+ if (checkDestructorReference(ET, InitLoc, SemaRef)) {
+ hadError = true;
+ return;
+ }
}
}
@@ -2288,7 +2293,8 @@ void InitListChecker::CheckStructUnionTypes(
// Disable check for missing fields when designators are used.
// This matches gcc behaviour.
- CheckForMissingFields = false;
+ if (!SemaRef.getLangOpts().CPlusPlus)
+ CheckForMissingFields = false;
continue;
}
@@ -2367,6 +2373,7 @@ void InitListChecker::CheckStructUnionTypes(
CheckSubElementType(MemberEntity, IList, Field->getType(), Index,
StructuredList, StructuredIndex);
InitializedSomething = true;
+ InitializedFields.insert(*Field);
if (RD->isUnion() && StructuredList) {
// Initialize the first field within the union.
@@ -2378,15 +2385,20 @@ void InitListChecker::CheckStructUnionTypes(
// Emit warnings for missing struct field initializers.
if (!VerifyOnly && InitializedSomething && CheckForMissingFields &&
- Field != FieldEnd && !Field->getType()->isIncompleteArrayType() &&
!RD->isUnion()) {
// It is possible we have one or more unnamed bitfields remaining.
// Find first (if any) named field and emit warning.
- for (RecordDecl::field_iterator it = Field, end = RD->field_end();
+ for (RecordDecl::field_iterator it = HasDesignatedInit ? RD->field_begin()
+ : Field,
+ end = RD->field_end();
it != end; ++it) {
+ if (HasDesignatedInit && InitializedFields.count(*it))
+ continue;
+
if (!it->isUnnamedBitfield() && !it->hasInClassInitializer()) {
SemaRef.Diag(IList->getSourceRange().getEnd(),
- diag::warn_missing_field_initializers) << *it;
+ diag::warn_missing_field_initializers)
+ << *it;
break;
}
}
diff --git a/clang/test/SemaCXX/cxx2a-initializer-aggregates.cpp b/clang/test/SemaCXX/cxx2a-initializer-aggregates.cpp
index eaca12a5f5c0c0..60cd2547ee417a 100644
--- a/clang/test/SemaCXX/cxx2a-initializer-aggregates.cpp
+++ b/clang/test/SemaCXX/cxx2a-initializer-aggregates.cpp
@@ -4,6 +4,7 @@
// RUN: %clang_cc1 -std=c++20 %s -verify=cxx20,expected,reorder -Wno-c99-designator -Werror=reorder-init-list -Wno-initializer-overrides
// RUN: %clang_cc1 -std=c++20 %s -verify=cxx20,expected,override -Wno-c99-designator -Wno-reorder-init-list -Werror=initializer-overrides
// RUN: %clang_cc1 -std=c++20 %s -verify=cxx20,expected -Wno-c99-designator -Wno-reorder-init-list -Wno-initializer-overrides
+// RUN: %clang_cc1 -std=c++20 %s -verify=cxx20,expected,wmissing -Wmissing-field-initializers -Wno-c99-designator -Wno-reorder-init-list -Wno-initializer-overrides
namespace class_with_ctor {
@@ -49,15 +50,17 @@ A a3 = {
A a4 = {
.x = 1, // override-note {{previous}}
.x = 1 // override-error {{overrides prior initialization}}
-};
+}; // wmissing-warning {{missing field 'y' initializer}}
A a5 = {
.y = 1, // override-note {{previous}}
.y = 1 // override-error {{overrides prior initialization}}
-};
+}; // wmissing-warning {{missing field 'x' initializer}}
B b2 = {.a = 1}; // pedantic-error {{brace elision for designated initializer is a C99 extension}}
+ // wmissing-warning at -1 {{missing field 'y' initializer}}
B b3 = {.a = 1, 2}; // pedantic-error {{mixture of designated and non-designated}} pedantic-note {{first non-designated}} pedantic-error {{brace elision}}
B b4 = {.a = 1, 2, 3}; // pedantic-error {{mixture of designated and non-designated}} pedantic-note {{first non-designated}} pedantic-error {{brace elision}} expected-error {{excess elements}}
B b5 = {.a = nullptr}; // expected-error {{cannot initialize}}
+ // wmissing-warning at -1 {{missing field 'y' initializer}}
struct C { int :0, x, :0, y, :0; };
C c = {
.x = 1, // override-note {{previous}}
@@ -67,6 +70,13 @@ C c = {
.x = 1, // reorder-error {{declaration order}} override-error {{overrides prior initialization}} override-note {{previous}}
.x = 1, // override-error {{overrides prior initialization}}
};
+
+struct Foo { int a, b; };
+
+struct Foo foo0 = { 1 }; // wmissing-warning {{missing field 'b' initializer}}
+struct Foo foo1 = { .a = 1 }; // wmissing-warning {{missing field 'b' initializer}}
+struct Foo foo2 = { .b = 1 }; // wmissing-warning {{missing field 'a' initializer}}
+
}
namespace base_class {
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