[clang] [Clang] Fix missing diagnostic for non-standard layout type in `offsetof` (PR #65246)

via cfe-commits cfe-commits at lists.llvm.org
Mon Sep 4 21:36:38 PDT 2023


https://github.com/kasuga-fj updated https://github.com/llvm/llvm-project/pull/65246:

>From d15196f5148194c5cb2f59c438d06f9fa61c8b4a Mon Sep 17 00:00:00 2001
From: "kasuga.ryotaro" <kasuga.ryotaro at fujitsu.com>
Date: Wed, 30 Aug 2023 13:26:31 +0900
Subject: [PATCH 1/5] [Clang] Fix missing diagnostic for non-standard layout
 type in `offsetof`

Fixes #64619

Clang warns diagnostic for non-standard layout types in `offsetof` only
if they are in evaluated context. With this patch, you'll also get
  diagnostic if you use `offsetof` on non-standard layout types in any
  other contexts
---
 clang/lib/Sema/SemaExpr.cpp         |  9 ++++-----
 clang/test/SemaCXX/class-layout.cpp | 30 ++++++++++++++---------------
 clang/test/SemaCXX/ms_struct.cpp    |  5 ++---
 clang/test/SemaCXX/offsetof.cpp     | 10 +++++-----
 4 files changed, 26 insertions(+), 28 deletions(-)

diff --git a/clang/lib/Sema/SemaExpr.cpp b/clang/lib/Sema/SemaExpr.cpp
index f9badf4ede847f..d78d823e15e62d 100644
--- a/clang/lib/Sema/SemaExpr.cpp
+++ b/clang/lib/Sema/SemaExpr.cpp
@@ -16750,12 +16750,11 @@ ExprResult Sema::BuildBuiltinOffsetOf(SourceLocation BuiltinLoc,
         LangOpts.CPlusPlus11? diag::ext_offsetof_non_standardlayout_type
                             : diag::ext_offsetof_non_pod_type;
 
-      if (!IsSafe && !DidWarnAboutNonPOD &&
-          DiagRuntimeBehavior(BuiltinLoc, nullptr,
-                              PDiag(DiagID)
-                              << SourceRange(Components[0].LocStart, OC.LocEnd)
-                              << CurrentType))
+      if (!IsSafe && !DidWarnAboutNonPOD) {
+        Diag(BuiltinLoc, DiagID)
+            << SourceRange(Components[0].LocStart, OC.LocEnd) << CurrentType;
         DidWarnAboutNonPOD = true;
+      }
     }
 
     // Look for the field.
diff --git a/clang/test/SemaCXX/class-layout.cpp b/clang/test/SemaCXX/class-layout.cpp
index 3ccd0ad25d7e75..a5660e10fe725a 100644
--- a/clang/test/SemaCXX/class-layout.cpp
+++ b/clang/test/SemaCXX/class-layout.cpp
@@ -1,18 +1,18 @@
-// RUN: %clang_cc1 -triple x86_64-unknown-unknown %s -fsyntax-only -verify -std=c++98 -Wno-inaccessible-base -Wno-c++11-extensions
-// RUN: %clang_cc1 -triple x86_64-unknown-unknown %s -fsyntax-only -verify -std=c++11 -Wno-inaccessible-base
-// RUN: %clang_cc1 -triple x86_64-apple-darwin    %s -fsyntax-only -verify -std=c++11 -Wno-inaccessible-base -DCLANG_ABI_COMPAT=15
-// RUN: %clang_cc1 -triple x86_64-scei-ps4        %s -fsyntax-only -verify -std=c++11 -Wno-inaccessible-base -DCLANG_ABI_COMPAT=6
-// RUN: %clang_cc1 -triple x86_64-sie-ps5         %s -fsyntax-only -verify -std=c++11 -Wno-inaccessible-base -DCLANG_ABI_COMPAT=6
-// RUN: %clang_cc1 -triple x86_64-unknown-unknown %s -fsyntax-only -verify -std=c++11 -Wno-inaccessible-base -fclang-abi-compat=6 -DCLANG_ABI_COMPAT=6
-// RUN: %clang_cc1 -triple x86_64-unknown-unknown %s -fsyntax-only -verify -std=c++11 -Wno-inaccessible-base -fclang-abi-compat=14 -DCLANG_ABI_COMPAT=14
-// RUN: %clang_cc1 -triple x86_64-unknown-unknown %s -fsyntax-only -verify -std=c++11 -Wno-inaccessible-base -fclang-abi-compat=15 -DCLANG_ABI_COMPAT=15
-// RUN: %clang_cc1 -triple x86_64-unknown-unknown %s -fsyntax-only -verify -std=c++11 -Wno-inaccessible-base -fclang-abi-compat=16 -DCLANG_ABI_COMPAT=16
-// RUN: %clang_cc1 -triple powerpc-ibm-aix7.3.0.0 %s -fsyntax-only -verify -std=c++11 -Wno-inaccessible-base -DCLANG_ABI_COMPAT=15
-// RUN: %clang_cc1 -triple powerpc-ibm-aix7.3.0.0 %s -fsyntax-only -verify -std=c++11 -Wno-inaccessible-base -fclang-abi-compat=15 -DCLANG_ABI_COMPAT=15
-// RUN: %clang_cc1 -triple powerpc64-ibm-aix7.3.0.0 %s -fsyntax-only -verify -std=c++11 -Wno-inaccessible-base -DCLANG_ABI_COMPAT=15
-// RUN: %clang_cc1 -triple powerpc64-ibm-aix7.3.0.0 %s -fsyntax-only -verify -std=c++11 -Wno-inaccessible-base -fclang-abi-compat=15 -DCLANG_ABI_COMPAT=15
-// RUN: %clang_cc1 -triple s390x-none-zos %s -fsyntax-only -verify -std=c++11 -Wno-inaccessible-base
-// RUN: %clang_cc1 -triple s390x-none-zos %s -fsyntax-only -verify -std=c++11 -Wno-inaccessible-base -fclang-abi-compat=15 -DCLANG_ABI_COMPAT=15
+// RUN: %clang_cc1 -triple x86_64-unknown-unknown %s -fsyntax-only -verify -std=c++98 -Wno-inaccessible-base -Wno-invalid-offsetof -Wno-c++11-extensions
+// RUN: %clang_cc1 -triple x86_64-unknown-unknown %s -fsyntax-only -verify -std=c++11 -Wno-inaccessible-base -Wno-invalid-offsetof
+// RUN: %clang_cc1 -triple x86_64-apple-darwin    %s -fsyntax-only -verify -std=c++11 -Wno-inaccessible-base -Wno-invalid-offsetof -DCLANG_ABI_COMPAT=15
+// RUN: %clang_cc1 -triple x86_64-scei-ps4        %s -fsyntax-only -verify -std=c++11 -Wno-inaccessible-base -Wno-invalid-offsetof -DCLANG_ABI_COMPAT=6
+// RUN: %clang_cc1 -triple x86_64-sie-ps5         %s -fsyntax-only -verify -std=c++11 -Wno-inaccessible-base -Wno-invalid-offsetof -DCLANG_ABI_COMPAT=6
+// RUN: %clang_cc1 -triple x86_64-unknown-unknown %s -fsyntax-only -verify -std=c++11 -Wno-inaccessible-base -Wno-invalid-offsetof -fclang-abi-compat=6 -DCLANG_ABI_COMPAT=6
+// RUN: %clang_cc1 -triple x86_64-unknown-unknown %s -fsyntax-only -verify -std=c++11 -Wno-inaccessible-base -Wno-invalid-offsetof -fclang-abi-compat=14 -DCLANG_ABI_COMPAT=14
+// RUN: %clang_cc1 -triple x86_64-unknown-unknown %s -fsyntax-only -verify -std=c++11 -Wno-inaccessible-base -Wno-invalid-offsetof -fclang-abi-compat=15 -DCLANG_ABI_COMPAT=15
+// RUN: %clang_cc1 -triple x86_64-unknown-unknown %s -fsyntax-only -verify -std=c++11 -Wno-inaccessible-base -Wno-invalid-offsetof -fclang-abi-compat=16 -DCLANG_ABI_COMPAT=16
+// RUN: %clang_cc1 -triple powerpc-ibm-aix7.3.0.0 %s -fsyntax-only -verify -std=c++11 -Wno-inaccessible-base -Wno-invalid-offsetof -DCLANG_ABI_COMPAT=15
+// RUN: %clang_cc1 -triple powerpc-ibm-aix7.3.0.0 %s -fsyntax-only -verify -std=c++11 -Wno-inaccessible-base -Wno-invalid-offsetof -fclang-abi-compat=15 -DCLANG_ABI_COMPAT=15
+// RUN: %clang_cc1 -triple powerpc64-ibm-aix7.3.0.0 %s -fsyntax-only -verify -std=c++11 -Wno-inaccessible-base -Wno-invalid-offsetof -DCLANG_ABI_COMPAT=15
+// RUN: %clang_cc1 -triple powerpc64-ibm-aix7.3.0.0 %s -fsyntax-only -verify -std=c++11 -Wno-inaccessible-base -Wno-invalid-offsetof -fclang-abi-compat=15 -DCLANG_ABI_COMPAT=15
+// RUN: %clang_cc1 -triple s390x-none-zos %s -fsyntax-only -verify -std=c++11 -Wno-inaccessible-base -Wno-invalid-offsetof
+// RUN: %clang_cc1 -triple s390x-none-zos %s -fsyntax-only -verify -std=c++11 -Wno-inaccessible-base -Wno-invalid-offsetof -fclang-abi-compat=15 -DCLANG_ABI_COMPAT=15
 
 // expected-no-diagnostics
 
diff --git a/clang/test/SemaCXX/ms_struct.cpp b/clang/test/SemaCXX/ms_struct.cpp
index 122819c3eeade1..c553253d54fd8e 100644
--- a/clang/test/SemaCXX/ms_struct.cpp
+++ b/clang/test/SemaCXX/ms_struct.cpp
@@ -25,6 +25,7 @@ struct B : public A {
 
 static_assert(__builtin_offsetof(B, d) == 12,
   "We can't allocate the bitfield into the padding under ms_struct");
+// expected-warning at -2 {{offset of on non-standard-layout type 'B'}}
 
 // rdar://16178895
 struct C {
@@ -39,6 +40,4 @@ struct C {
 
 static_assert(__builtin_offsetof(C, n) == 8,
               "long long field in ms_struct should be 8-byte aligned");
-#if !defined(TEST_FOR_ERROR) && !defined(TEST_FOR_WARNING)
-// expected-no-diagnostics
-#endif
+// expected-warning at -2 {{offset of on non-standard-layout type 'C'}}
\ No newline at end of file
diff --git a/clang/test/SemaCXX/offsetof.cpp b/clang/test/SemaCXX/offsetof.cpp
index 39ea3804dce311..4b9da20a2789e0 100644
--- a/clang/test/SemaCXX/offsetof.cpp
+++ b/clang/test/SemaCXX/offsetof.cpp
@@ -17,7 +17,7 @@ struct Base { int x; };
 struct Derived : Base { int y; };
 int o = __builtin_offsetof(Derived, x); // expected-warning{{offset of on non-POD type}}
 
-const int o2 = sizeof(__builtin_offsetof(Derived, x));
+const int o2 = sizeof(__builtin_offsetof(Derived, x)); // expected-warning{{offset of on non-POD type 'Derived'}}
 
 struct HasArray {
   int array[17];
@@ -50,9 +50,9 @@ struct Derived2 : public Base1, public Base2 {
   int z; 
 };
 
-int derived1[__builtin_offsetof(Derived2, x) == 0? 1 : -1];
-int derived2[__builtin_offsetof(Derived2, y)  == 4? 1 : -1];
-int derived3[__builtin_offsetof(Derived2, z)  == 8? 1 : -1];
+int derived1[__builtin_offsetof(Derived2, x) == 0? 1 : -1]; // expected-warning{{offset of on non-POD type 'Derived2'}}
+int derived2[__builtin_offsetof(Derived2, y)  == 4? 1 : -1]; // expected-warning{{offset of on non-POD type 'Derived2'}}
+int derived3[__builtin_offsetof(Derived2, z)  == 8? 1 : -1]; // expected-warning{{offset of on non-POD type 'Derived2'}}
 
 // offsetof referring to anonymous struct in base.
 // PR7769
@@ -65,7 +65,7 @@ struct foo {
 struct bar : public foo  {
 };
 
-int anonstruct[__builtin_offsetof(bar, x) == 0 ? 1 : -1];
+int anonstruct[__builtin_offsetof(bar, x) == 0 ? 1 : -1]; // expected-warning{{offset of on non-POD type 'bar'}}
 
 struct LtoRCheck {
   int a[10];

>From 6262bb88e4f35f6a2649418a15b0adef9b51cd31 Mon Sep 17 00:00:00 2001
From: "kasuga.ryotaro" <kasuga.ryotaro at fujitsu.com>
Date: Mon, 4 Sep 2023 16:06:56 +0900
Subject: [PATCH 2/5] fixup! [Clang] Fix missing diagnostic for non-standard
 layout type in `offsetof`

---
 clang/docs/ReleaseNotes.rst | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/clang/docs/ReleaseNotes.rst b/clang/docs/ReleaseNotes.rst
index 6dc3c1c5fbcef8..ac277c9429ce6e 100644
--- a/clang/docs/ReleaseNotes.rst
+++ b/clang/docs/ReleaseNotes.rst
@@ -155,6 +155,8 @@ Improvements to Clang's diagnostics
   (`#64871: <https://github.com/llvm/llvm-project/issues/64871>`_).
   Also clang no longer emits false positive warnings about the output length of
   ``%g`` format specifier.
+- Clang now always diagnoses when using non-standard layout types in ``offsetof`` .
+  (`#64619: <https://github.com/llvm/llvm-project/issues/64619>`_)
 
 Bug Fixes in This Version
 -------------------------

>From 20b1883ce199dd98a338b3f35b8b48f4d953e5b3 Mon Sep 17 00:00:00 2001
From: "kasuga.ryotaro" <kasuga.ryotaro at fujitsu.com>
Date: Mon, 4 Sep 2023 18:22:06 +0900
Subject: [PATCH 3/5] fixup! [Clang] Fix missing diagnostic for non-standard
 layout type in `offsetof`

---
 clang/test/SemaCXX/ms_struct.cpp | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/clang/test/SemaCXX/ms_struct.cpp b/clang/test/SemaCXX/ms_struct.cpp
index c553253d54fd8e..94b245ec8df626 100644
--- a/clang/test/SemaCXX/ms_struct.cpp
+++ b/clang/test/SemaCXX/ms_struct.cpp
@@ -40,4 +40,5 @@ struct C {
 
 static_assert(__builtin_offsetof(C, n) == 8,
               "long long field in ms_struct should be 8-byte aligned");
-// expected-warning at -2 {{offset of on non-standard-layout type 'C'}}
\ No newline at end of file
+// expected-warning at -2 {{offset of on non-standard-layout type 'C'}}
+

>From b9c767a6a128f57858273eb43d4383e83d0d086b Mon Sep 17 00:00:00 2001
From: "kasuga.ryotaro" <kasuga.ryotaro at fujitsu.com>
Date: Tue, 5 Sep 2023 13:39:12 +0900
Subject: [PATCH 5/5] fixup! [Clang] Fix missing diagnostic for non-standard
 layout type in `offsetof`

---
 clang/test/SemaCXX/offsetof.cpp | 1 +
 1 file changed, 1 insertion(+)

diff --git a/clang/test/SemaCXX/offsetof.cpp b/clang/test/SemaCXX/offsetof.cpp
index 4b9da20a2789e0..54ffb05fe94462 100644
--- a/clang/test/SemaCXX/offsetof.cpp
+++ b/clang/test/SemaCXX/offsetof.cpp
@@ -67,6 +67,7 @@ struct bar : public foo  {
 
 int anonstruct[__builtin_offsetof(bar, x) == 0 ? 1 : -1]; // expected-warning{{offset of on non-POD type 'bar'}}
 
+
 struct LtoRCheck {
   int a[10];
   int f();



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