[clang] ed9007d - Revert "[Bounds-Safety] Temporarily relax a `counted_by` attribute restriction on flexible array members"

Vitaly Buka via cfe-commits cfe-commits at lists.llvm.org
Sun May 19 05:45:00 PDT 2024


Author: Vitaly Buka
Date: 2024-05-19T05:44:40-07:00
New Revision: ed9007d0d219726db01f211e9c9ab72fbfe4ecb1

URL: https://github.com/llvm/llvm-project/commit/ed9007d0d219726db01f211e9c9ab72fbfe4ecb1
DIFF: https://github.com/llvm/llvm-project/commit/ed9007d0d219726db01f211e9c9ab72fbfe4ecb1.diff

LOG: Revert "[Bounds-Safety] Temporarily relax a `counted_by` attribute restriction on flexible array members"

Together with 0ec3b972e58bcbcdc1bebe1696ea37f2931287c3
breaks https://lab.llvm.org/buildbot/#/builders/5/builds/43403

Issue #92687

This reverts commit cef6387e52578366c2332275dad88b9953b55336.

Added: 
    

Modified: 
    clang/include/clang/Basic/DiagnosticGroups.td
    clang/include/clang/Basic/DiagnosticSemaKinds.td
    clang/lib/Sema/SemaDeclAttr.cpp
    clang/test/Sema/attr-counted-by-vla.c

Removed: 
    


################################################################################
diff  --git a/clang/include/clang/Basic/DiagnosticGroups.td b/clang/include/clang/Basic/DiagnosticGroups.td
index 4fad4d1a0eca7..4cb4f3d999f7a 100644
--- a/clang/include/clang/Basic/DiagnosticGroups.td
+++ b/clang/include/clang/Basic/DiagnosticGroups.td
@@ -1447,10 +1447,6 @@ def FunctionMultiVersioning
 
 def NoDeref : DiagGroup<"noderef">;
 
-// -fbounds-safety and bounds annotation related warnings
-def BoundsSafetyCountedByEltTyUnknownSize :
-  DiagGroup<"bounds-safety-counted-by-elt-type-unknown-size">;
-
 // A group for cross translation unit static analysis related warnings.
 def CrossTU : DiagGroup<"ctu">;
 

diff  --git a/clang/include/clang/Basic/DiagnosticSemaKinds.td b/clang/include/clang/Basic/DiagnosticSemaKinds.td
index 1efa3af121c10..8e6596410c5d0 100644
--- a/clang/include/clang/Basic/DiagnosticSemaKinds.td
+++ b/clang/include/clang/Basic/DiagnosticSemaKinds.td
@@ -6552,7 +6552,7 @@ def err_counted_by_attr_refer_to_union : Error<
 def note_flexible_array_counted_by_attr_field : Note<
   "field %0 declared here">;
 def err_counted_by_attr_pointee_unknown_size : Error<
-  "'counted_by' %select{cannot|should not}3 be applied to %select{"
+  "'counted_by' cannot be applied to %select{"
     "a pointer with pointee|" // pointer
     "an array with element}0" // array
   " of unknown size because %1 is %select{"
@@ -6561,14 +6561,8 @@ def err_counted_by_attr_pointee_unknown_size : Error<
     "a function type|"     // CountedByInvalidPointeeTypeKind::FUNCTION
     // CountedByInvalidPointeeTypeKind::FLEXIBLE_ARRAY_MEMBER
     "a struct type with a flexible array member"
-    "%select{|. This will be an error in a future compiler version}3"
-    ""
   "}2">;
 
-def warn_counted_by_attr_elt_type_unknown_size :
-  Warning<err_counted_by_attr_pointee_unknown_size.Summary>,
-  InGroup<BoundsSafetyCountedByEltTyUnknownSize>;
-
 let CategoryName = "ARC Semantic Issue" in {
 
 // ARC-mode diagnostics.

diff  --git a/clang/lib/Sema/SemaDeclAttr.cpp b/clang/lib/Sema/SemaDeclAttr.cpp
index e816ea3647a7c..c8b71631076ba 100644
--- a/clang/lib/Sema/SemaDeclAttr.cpp
+++ b/clang/lib/Sema/SemaDeclAttr.cpp
@@ -8687,7 +8687,6 @@ static bool CheckCountedByAttrOnField(
   // Note: The `Decl::isFlexibleArrayMemberLike` check earlier on means
   // only `PointeeTy->isStructureTypeWithFlexibleArrayMember()` is reachable
   // when `FieldTy->isArrayType()`.
-  bool ShouldWarn = false;
   if (PointeeTy->isIncompleteType()) {
     InvalidTypeKind = CountedByInvalidPointeeTypeKind::INCOMPLETE;
   } else if (PointeeTy->isSizelessType()) {
@@ -8695,25 +8694,13 @@ static bool CheckCountedByAttrOnField(
   } else if (PointeeTy->isFunctionType()) {
     InvalidTypeKind = CountedByInvalidPointeeTypeKind::FUNCTION;
   } else if (PointeeTy->isStructureTypeWithFlexibleArrayMember()) {
-    if (FieldTy->isArrayType()) {
-      // This is a workaround for the Linux kernel that has already adopted
-      // `counted_by` on a FAM where the pointee is a struct with a FAM. This
-      // should be an error because computing the bounds of the array cannot be
-      // done correctly without manually traversing every struct object in the
-      // array at runtime. To allow the code to be built this error is
-      // downgraded to a warning.
-      ShouldWarn = true;
-    }
     InvalidTypeKind = CountedByInvalidPointeeTypeKind::FLEXIBLE_ARRAY_MEMBER;
   }
 
   if (InvalidTypeKind != CountedByInvalidPointeeTypeKind::VALID) {
-    unsigned DiagID = ShouldWarn
-                          ? diag::warn_counted_by_attr_elt_type_unknown_size
-                          : diag::err_counted_by_attr_pointee_unknown_size;
-    S.Diag(FD->getBeginLoc(), DiagID)
+    S.Diag(FD->getBeginLoc(), diag::err_counted_by_attr_pointee_unknown_size)
         << SelectPtrOrArr << PointeeTy << (int)InvalidTypeKind
-        << (ShouldWarn ? 1 : 0) << FD->getSourceRange();
+        << FD->getSourceRange();
     return true;
   }
 

diff  --git a/clang/test/Sema/attr-counted-by-vla.c b/clang/test/Sema/attr-counted-by-vla.c
index b25f719f3b95a..3de6bd55e2d8e 100644
--- a/clang/test/Sema/attr-counted-by-vla.c
+++ b/clang/test/Sema/attr-counted-by-vla.c
@@ -173,24 +173,21 @@ struct has_annotated_VLA {
 
 struct buffer_of_structs_with_unnannotated_vla {
   int count;
-  // Treating this as a warning is a temporary fix for existing attribute adopters. It **SHOULD BE AN ERROR**.
-  // expected-warning at +1{{'counted_by' should not be applied to an array with element of unknown size because 'struct has_unannotated_VLA' is a struct type with a flexible array member. This will be an error in a future compiler version}}
+  // expected-error at +1{{'counted_by' cannot be applied to an array with element of unknown size because 'struct has_unannotated_VLA' is a struct type with a flexible array member}}
   struct has_unannotated_VLA Arr[] __counted_by(count);
 };
 
 
 struct buffer_of_structs_with_annotated_vla {
   int count;
-  // Treating this as a warning is a temporary fix for existing attribute adopters. It **SHOULD BE AN ERROR**.
-  // expected-warning at +1{{'counted_by' should not be applied to an array with element of unknown size because 'struct has_annotated_VLA' is a struct type with a flexible array member. This will be an error in a future compiler version}}
+  // expected-error at +1{{'counted_by' cannot be applied to an array with element of unknown size because 'struct has_annotated_VLA' is a struct type with a flexible array member}}
   struct has_annotated_VLA Arr[] __counted_by(count);
 };
 
 struct buffer_of_const_structs_with_annotated_vla {
   int count;
-  // Treating this as a warning is a temporary fix for existing attribute adopters. It **SHOULD BE AN ERROR**.
   // Make sure the `const` qualifier is printed when printing the element type.
-  // expected-warning at +1{{'counted_by' should not be applied to an array with element of unknown size because 'const struct has_annotated_VLA' is a struct type with a flexible array member. This will be an error in a future compiler version}}
+  // expected-error at +1{{'counted_by' cannot be applied to an array with element of unknown size because 'const struct has_annotated_VLA' is a struct type with a flexible array member}}
   const struct has_annotated_VLA Arr[] __counted_by(count);
 };
 


        


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