void updated this revision to Diff 557415.
void added a comment.
Use CBA as an acronym of CountedByAttribute instead of EBA, which is oldspeak.
Repository:
rG LLVM Github Monorepo
CHANGES SINCE LAST ACTION
https://reviews.llvm.org/D148381/new/
https://reviews.llvm.org/D148381
Files:
clang/docs/ReleaseNotes.rst
clang/include/clang/AST/Decl.h
clang/include/clang/AST/DeclBase.h
clang/include/clang/Basic/Attr.td
clang/include/clang/Basic/AttrDocs.td
clang/include/clang/Basic/DiagnosticSemaKinds.td
clang/lib/AST/ASTImporter.cpp
clang/lib/AST/DeclBase.cpp
clang/lib/AST/Expr.cpp
clang/lib/CodeGen/CGBuiltin.cpp
clang/lib/CodeGen/CGExpr.cpp
clang/lib/CodeGen/CodeGenFunction.h
clang/lib/Sema/SemaDecl.cpp
clang/lib/Sema/SemaDeclAttr.cpp
clang/test/CodeGen/attr-counted-by.c
clang/test/Misc/pragma-attribute-supported-attributes-list.test
clang/test/Sema/attr-counted-by.c
Index: clang/test/Sema/attr-counted-by.c
===================================================================
--- /dev/null
+++ clang/test/Sema/attr-counted-by.c
@@ -0,0 +1,37 @@
+// RUN: %clang_cc1 -fstrict-flex-arrays=3 -fsyntax-only -verify %s
+
+#define __counted_by(f) __attribute__((counted_by(f)))
+
+struct bar;
+
+struct not_found {
+ int bork;
+ struct bar *fam[] __counted_by(blork); // expected-error {{field 'blork' in 'counted_by' not found}}
+};
+
+int global; // expected-note {{variable 'global' is declared here}}
+
+struct found_outside_of_struct {
+ int bork;
+ struct bar *fam[] __counted_by(global); // expected-error {{field 'global' in 'counted_by' is not found in struct}}
+};
+
+struct self_referrential {
+ int bork;
+ struct bar *self[] __counted_by(self); // expected-error {{field 'self' in 'counted_by' cannot refer to the flexible array}}
+};
+
+struct non_int {
+ double non_integer; // expected-error {{field 'non_integer' in 'counted_by' is not a non-boolean integer type}}
+ struct bar *fam[] __counted_by(non_integer); // expected-note {{field 'non_integer' declared here}}
+};
+
+struct array_of_ints {
+ int non_integer[2]; // expected-error {{field 'non_integer' in 'counted_by' is not a non-boolean integer type}}
+ struct bar *fam[] __counted_by(non_integer); // expected-note {{field 'non_integer' declared here}}
+};
+
+struct not_a_fam {
+ double non_integer;
+ struct bar *non_fam __counted_by(non_integer); // expected-error {{'counted_by' only applies to flexible array members}}
+};
Index: clang/test/Misc/pragma-attribute-supported-attributes-list.test
===================================================================
--- clang/test/Misc/pragma-attribute-supported-attributes-list.test
+++ clang/test/Misc/pragma-attribute-supported-attributes-list.test
@@ -56,6 +56,7 @@
// CHECK-NEXT: ConsumableAutoCast (SubjectMatchRule_record)
// CHECK-NEXT: ConsumableSetOnRead (SubjectMatchRule_record)
// CHECK-NEXT: Convergent (SubjectMatchRule_function)
+// CHECK-NEXT: CountedBy (SubjectMatchRule_field)
// CHECK-NEXT: DLLExport (SubjectMatchRule_function, SubjectMatchRule_variable, SubjectMatchRule_record, SubjectMatchRule_objc_interface)
// CHECK-NEXT: DLLImport (SubjectMatchRule_function, SubjectMatchRule_variable, SubjectMatchRule_record, SubjectMatchRule_objc_interface)
// CHECK-NEXT: Destructor (SubjectMatchRule_function)
Index: clang/test/CodeGen/attr-counted-by.c
===================================================================
--- /dev/null
+++ clang/test/CodeGen/attr-counted-by.c
@@ -0,0 +1,227 @@
+// NOTE: Assertions have been autogenerated by utils/update_cc_test_checks.py UTC_ARGS: --version 3
+// RUN: %clang_cc1 -triple x86_64-unknown-linux-gnu -DCOUNTED_BY -O2 -Wall -fsanitize=array-bounds,object-size,local-bounds -fstrict-flex-arrays=3 -emit-llvm -o - %s | FileCheck --check-prefix=SANITIZE-WITH-ATTR %s
+// RUN: %clang_cc1 -triple x86_64-unknown-linux-gnu -DCOUNTED_BY -O2 -Wall -fstrict-flex-arrays=3 -emit-llvm -o - %s | FileCheck --check-prefix=NO-SANITIZE-WITH-ATTR %s
+// RUN: %clang_cc1 -triple x86_64-unknown-linux-gnu -O2 -Wall -fsanitize=array-bounds,object-size,local-bounds -fstrict-flex-arrays=3 -emit-llvm -o - %s | FileCheck --check-prefix=SANITIZE-WITHOUT-ATTR %s
+// RUN: %clang_cc1 -triple x86_64-unknown-linux-gnu -O2 -Wall -fstrict-flex-arrays=3 -emit-llvm -o - %s | FileCheck --check-prefix=NO-SANITIZE-WITHOUT-ATTR %s
+
+#if !__has_attribute(counted_by)
+#error "has attribute broken"
+#endif
+
+#ifdef COUNTED_BY
+#define __counted_by(member) __attribute__((__counted_by__(member)))
+#else
+#define __counted_by(member)
+#endif
+
+typedef long unsigned int size_t;
+
+struct annotated {
+ unsigned long flags;
+ int count;
+ int array[] __counted_by(count);
+};
+
+// SANITIZE-WITH-ATTR-LABEL: define dso_local void @test1(
+// SANITIZE-WITH-ATTR-SAME: ptr noundef [[P:%.*]], i32 noundef [[INDEX:%.*]], i32 noundef [[VAL:%.*]]) local_unnamed_addr #[[ATTR0:[0-9]+]] {
+// SANITIZE-WITH-ATTR-NEXT: entry:
+// SANITIZE-WITH-ATTR-NEXT: [[COUNT:%.*]] = getelementptr inbounds [[STRUCT_ANNOTATED:%.*]], ptr [[P]], i64 0, i32 1
+// SANITIZE-WITH-ATTR-NEXT: [[TMP0:%.*]] = load i32, ptr [[COUNT]], align 8, !tbaa [[TBAA2:![0-9]+]]
+// SANITIZE-WITH-ATTR-NEXT: [[TMP1:%.*]] = sext i32 [[INDEX]] to i64, !nosanitize !6
+// SANITIZE-WITH-ATTR-NEXT: [[TMP2:%.*]] = zext i32 [[TMP0]] to i64, !nosanitize !6
+// SANITIZE-WITH-ATTR-NEXT: [[TMP3:%.*]] = icmp ult i64 [[TMP1]], [[TMP2]], !nosanitize !6
+// SANITIZE-WITH-ATTR-NEXT: br i1 [[TMP3]], label [[CONT7:%.*]], label [[HANDLER_OUT_OF_BOUNDS:%.*]], !prof [[PROF7:![0-9]+]], !nosanitize !6
+// SANITIZE-WITH-ATTR: handler.out_of_bounds:
+// SANITIZE-WITH-ATTR-NEXT: [[TMP4:%.*]] = zext i32 [[INDEX]] to i64, !nosanitize !6
+// SANITIZE-WITH-ATTR-NEXT: tail call void @__ubsan_handle_out_of_bounds_abort(ptr nonnull @[[GLOB2:[0-9]+]], i64 [[TMP4]]) #[[ATTR2:[0-9]+]], !nosanitize !6
+// SANITIZE-WITH-ATTR-NEXT: unreachable, !nosanitize !6
+// SANITIZE-WITH-ATTR: cont7:
+// SANITIZE-WITH-ATTR-NEXT: [[ARRAYIDX:%.*]] = getelementptr inbounds [[STRUCT_ANNOTATED]], ptr [[P]], i64 0, i32 2, i64 [[TMP1]]
+// SANITIZE-WITH-ATTR-NEXT: store i32 [[VAL]], ptr [[ARRAYIDX]], align 4, !tbaa [[TBAA2]]
+// SANITIZE-WITH-ATTR-NEXT: ret void
+//
+// NO-SANITIZE-WITH-ATTR-LABEL: define dso_local void @test1(
+// NO-SANITIZE-WITH-ATTR-SAME: ptr nocapture noundef writeonly [[P:%.*]], i32 noundef [[INDEX:%.*]], i32 noundef [[VAL:%.*]]) local_unnamed_addr #[[ATTR0:[0-9]+]] {
+// NO-SANITIZE-WITH-ATTR-NEXT: entry:
+// NO-SANITIZE-WITH-ATTR-NEXT: [[IDXPROM:%.*]] = sext i32 [[INDEX]] to i64
+// NO-SANITIZE-WITH-ATTR-NEXT: [[ARRAYIDX:%.*]] = getelementptr inbounds [[STRUCT_ANNOTATED:%.*]], ptr [[P]], i64 0, i32 2, i64 [[IDXPROM]]
+// NO-SANITIZE-WITH-ATTR-NEXT: store i32 [[VAL]], ptr [[ARRAYIDX]], align 4, !tbaa [[TBAA2:![0-9]+]]
+// NO-SANITIZE-WITH-ATTR-NEXT: ret void
+//
+// SANITIZE-WITHOUT-ATTR-LABEL: define dso_local void @test1(
+// SANITIZE-WITHOUT-ATTR-SAME: ptr noundef [[P:%.*]], i32 noundef [[INDEX:%.*]], i32 noundef [[VAL:%.*]]) local_unnamed_addr #[[ATTR0:[0-9]+]] {
+// SANITIZE-WITHOUT-ATTR-NEXT: entry:
+// SANITIZE-WITHOUT-ATTR-NEXT: [[IDXPROM:%.*]] = sext i32 [[INDEX]] to i64
+// SANITIZE-WITHOUT-ATTR-NEXT: [[ARRAYIDX:%.*]] = getelementptr inbounds [[STRUCT_ANNOTATED:%.*]], ptr [[P]], i64 0, i32 2, i64 [[IDXPROM]]
+// SANITIZE-WITHOUT-ATTR-NEXT: store i32 [[VAL]], ptr [[ARRAYIDX]], align 4, !tbaa [[TBAA2:![0-9]+]]
+// SANITIZE-WITHOUT-ATTR-NEXT: ret void
+//
+// NO-SANITIZE-WITHOUT-ATTR-LABEL: define dso_local void @test1(
+// NO-SANITIZE-WITHOUT-ATTR-SAME: ptr nocapture noundef writeonly [[P:%.*]], i32 noundef [[INDEX:%.*]], i32 noundef [[VAL:%.*]]) local_unnamed_addr #[[ATTR0:[0-9]+]] {
+// NO-SANITIZE-WITHOUT-ATTR-NEXT: entry:
+// NO-SANITIZE-WITHOUT-ATTR-NEXT: [[IDXPROM:%.*]] = sext i32 [[INDEX]] to i64
+// NO-SANITIZE-WITHOUT-ATTR-NEXT: [[ARRAYIDX:%.*]] = getelementptr inbounds [[STRUCT_ANNOTATED:%.*]], ptr [[P]], i64 0, i32 2, i64 [[IDXPROM]]
+// NO-SANITIZE-WITHOUT-ATTR-NEXT: store i32 [[VAL]], ptr [[ARRAYIDX]], align 4, !tbaa [[TBAA2:![0-9]+]]
+// NO-SANITIZE-WITHOUT-ATTR-NEXT: ret void
+//
+void test1(struct annotated *p, int index, int val) {
+ p->array[index] = val;
+}
+
+// SANITIZE-WITH-ATTR-LABEL: define dso_local void @test2(
+// SANITIZE-WITH-ATTR-SAME: ptr noundef [[P:%.*]], i64 noundef [[INDEX:%.*]]) local_unnamed_addr #[[ATTR0]] {
+// SANITIZE-WITH-ATTR-NEXT: entry:
+// SANITIZE-WITH-ATTR-NEXT: [[COUNT:%.*]] = getelementptr inbounds [[STRUCT_ANNOTATED:%.*]], ptr [[P]], i64 0, i32 1
+// SANITIZE-WITH-ATTR-NEXT: [[TMP0:%.*]] = load i32, ptr [[COUNT]], align 8, !tbaa [[TBAA2]]
+// SANITIZE-WITH-ATTR-NEXT: [[TMP1:%.*]] = zext i32 [[TMP0]] to i64, !nosanitize !6
+// SANITIZE-WITH-ATTR-NEXT: [[TMP2:%.*]] = icmp ugt i64 [[TMP1]], [[INDEX]], !nosanitize !6
+// SANITIZE-WITH-ATTR-NEXT: br i1 [[TMP2]], label [[CONT12:%.*]], label [[HANDLER_OUT_OF_BOUNDS:%.*]], !prof [[PROF7]], !nosanitize !6
+// SANITIZE-WITH-ATTR: handler.out_of_bounds:
+// SANITIZE-WITH-ATTR-NEXT: tail call void @__ubsan_handle_out_of_bounds_abort(ptr nonnull @[[GLOB4:[0-9]+]], i64 [[INDEX]]) #[[ATTR2]], !nosanitize !6
+// SANITIZE-WITH-ATTR-NEXT: unreachable, !nosanitize !6
+// SANITIZE-WITH-ATTR: cont12:
+// SANITIZE-WITH-ATTR-NEXT: [[ARRAYIDX:%.*]] = getelementptr inbounds [[STRUCT_ANNOTATED]], ptr [[P]], i64 0, i32 2, i64 [[INDEX]]
+// SANITIZE-WITH-ATTR-NEXT: [[TMP3:%.*]] = shl i32 [[TMP0]], 2
+// SANITIZE-WITH-ATTR-NEXT: store i32 [[TMP3]], ptr [[ARRAYIDX]], align 4, !tbaa [[TBAA2]]
+// SANITIZE-WITH-ATTR-NEXT: ret void
+//
+// NO-SANITIZE-WITH-ATTR-LABEL: define dso_local void @test2(
+// NO-SANITIZE-WITH-ATTR-SAME: ptr nocapture noundef [[P:%.*]], i64 noundef [[INDEX:%.*]]) local_unnamed_addr #[[ATTR1:[0-9]+]] {
+// NO-SANITIZE-WITH-ATTR-NEXT: entry:
+// NO-SANITIZE-WITH-ATTR-NEXT: [[COUNT:%.*]] = getelementptr inbounds [[STRUCT_ANNOTATED:%.*]], ptr [[P]], i64 0, i32 1
+// NO-SANITIZE-WITH-ATTR-NEXT: [[TMP0:%.*]] = load i32, ptr [[COUNT]], align 8, !tbaa [[TBAA2]]
+// NO-SANITIZE-WITH-ATTR-NEXT: [[TMP1:%.*]] = shl i32 [[TMP0]], 2
+// NO-SANITIZE-WITH-ATTR-NEXT: [[ARRAYIDX:%.*]] = getelementptr inbounds [[STRUCT_ANNOTATED]], ptr [[P]], i64 0, i32 2, i64 [[INDEX]]
+// NO-SANITIZE-WITH-ATTR-NEXT: store i32 [[TMP1]], ptr [[ARRAYIDX]], align 4, !tbaa [[TBAA2]]
+// NO-SANITIZE-WITH-ATTR-NEXT: ret void
+//
+// SANITIZE-WITHOUT-ATTR-LABEL: define dso_local void @test2(
+// SANITIZE-WITHOUT-ATTR-SAME: ptr noundef [[P:%.*]], i64 noundef [[INDEX:%.*]]) local_unnamed_addr #[[ATTR0]] {
+// SANITIZE-WITHOUT-ATTR-NEXT: entry:
+// SANITIZE-WITHOUT-ATTR-NEXT: [[ARRAYIDX:%.*]] = getelementptr inbounds [[STRUCT_ANNOTATED:%.*]], ptr [[P]], i64 0, i32 2, i64 [[INDEX]]
+// SANITIZE-WITHOUT-ATTR-NEXT: store i32 -1, ptr [[ARRAYIDX]], align 4, !tbaa [[TBAA2]]
+// SANITIZE-WITHOUT-ATTR-NEXT: ret void
+//
+// NO-SANITIZE-WITHOUT-ATTR-LABEL: define dso_local void @test2(
+// NO-SANITIZE-WITHOUT-ATTR-SAME: ptr noundef [[P:%.*]], i64 noundef [[INDEX:%.*]]) local_unnamed_addr #[[ATTR1:[0-9]+]] {
+// NO-SANITIZE-WITHOUT-ATTR-NEXT: entry:
+// NO-SANITIZE-WITHOUT-ATTR-NEXT: [[ARRAYIDX:%.*]] = getelementptr inbounds [[STRUCT_ANNOTATED:%.*]], ptr [[P]], i64 0, i32 2, i64 [[INDEX]]
+// NO-SANITIZE-WITHOUT-ATTR-NEXT: store i32 -1, ptr [[ARRAYIDX]], align 4, !tbaa [[TBAA2]]
+// NO-SANITIZE-WITHOUT-ATTR-NEXT: ret void
+//
+void test2(struct annotated *p, size_t index) {
+ p->array[index] = __builtin_dynamic_object_size(p->array, 1);
+}
+
+// SANITIZE-WITH-ATTR-LABEL: define dso_local void @test3(
+// SANITIZE-WITH-ATTR-SAME: ptr noundef [[P:%.*]], i64 noundef [[INDEX:%.*]]) local_unnamed_addr #[[ATTR0]] {
+// SANITIZE-WITH-ATTR-NEXT: entry:
+// SANITIZE-WITH-ATTR-NEXT: [[COUNT:%.*]] = getelementptr inbounds [[STRUCT_ANNOTATED:%.*]], ptr [[P]], i64 0, i32 1
+// SANITIZE-WITH-ATTR-NEXT: [[TMP0:%.*]] = load i32, ptr [[COUNT]], align 8, !tbaa [[TBAA2]]
+// SANITIZE-WITH-ATTR-NEXT: [[TMP1:%.*]] = zext i32 [[TMP0]] to i64, !nosanitize !6
+// SANITIZE-WITH-ATTR-NEXT: [[TMP2:%.*]] = icmp ugt i64 [[TMP1]], [[INDEX]], !nosanitize !6
+// SANITIZE-WITH-ATTR-NEXT: br i1 [[TMP2]], label [[CONT12:%.*]], label [[HANDLER_OUT_OF_BOUNDS:%.*]], !prof [[PROF7]], !nosanitize !6
+// SANITIZE-WITH-ATTR: handler.out_of_bounds:
+// SANITIZE-WITH-ATTR-NEXT: tail call void @__ubsan_handle_out_of_bounds_abort(ptr nonnull @[[GLOB5:[0-9]+]], i64 [[INDEX]]) #[[ATTR2]], !nosanitize !6
+// SANITIZE-WITH-ATTR-NEXT: unreachable, !nosanitize !6
+// SANITIZE-WITH-ATTR: cont12:
+// SANITIZE-WITH-ATTR-NEXT: [[ARRAYIDX:%.*]] = getelementptr inbounds [[STRUCT_ANNOTATED]], ptr [[P]], i64 0, i32 2, i64 [[INDEX]]
+// SANITIZE-WITH-ATTR-NEXT: [[TMP3:%.*]] = shl i32 [[TMP0]], 2
+// SANITIZE-WITH-ATTR-NEXT: [[CONV:%.*]] = add i32 [[TMP3]], 16
+// SANITIZE-WITH-ATTR-NEXT: store i32 [[CONV]], ptr [[ARRAYIDX]], align 4, !tbaa [[TBAA2]]
+// SANITIZE-WITH-ATTR-NEXT: ret void
+//
+// NO-SANITIZE-WITH-ATTR-LABEL: define dso_local void @test3(
+// NO-SANITIZE-WITH-ATTR-SAME: ptr nocapture noundef [[P:%.*]], i64 noundef [[INDEX:%.*]]) local_unnamed_addr #[[ATTR1]] {
+// NO-SANITIZE-WITH-ATTR-NEXT: entry:
+// NO-SANITIZE-WITH-ATTR-NEXT: [[COUNT:%.*]] = getelementptr inbounds [[STRUCT_ANNOTATED:%.*]], ptr [[P]], i64 0, i32 1
+// NO-SANITIZE-WITH-ATTR-NEXT: [[TMP0:%.*]] = load i32, ptr [[COUNT]], align 8, !tbaa [[TBAA2]]
+// NO-SANITIZE-WITH-ATTR-NEXT: [[TMP1:%.*]] = shl i32 [[TMP0]], 2
+// NO-SANITIZE-WITH-ATTR-NEXT: [[CONV:%.*]] = add i32 [[TMP1]], 16
+// NO-SANITIZE-WITH-ATTR-NEXT: [[ARRAYIDX:%.*]] = getelementptr inbounds [[STRUCT_ANNOTATED]], ptr [[P]], i64 0, i32 2, i64 [[INDEX]]
+// NO-SANITIZE-WITH-ATTR-NEXT: store i32 [[CONV]], ptr [[ARRAYIDX]], align 4, !tbaa [[TBAA2]]
+// NO-SANITIZE-WITH-ATTR-NEXT: ret void
+//
+// SANITIZE-WITHOUT-ATTR-LABEL: define dso_local void @test3(
+// SANITIZE-WITHOUT-ATTR-SAME: ptr noundef [[P:%.*]], i64 noundef [[INDEX:%.*]]) local_unnamed_addr #[[ATTR0]] {
+// SANITIZE-WITHOUT-ATTR-NEXT: entry:
+// SANITIZE-WITHOUT-ATTR-NEXT: [[ARRAYIDX:%.*]] = getelementptr inbounds [[STRUCT_ANNOTATED:%.*]], ptr [[P]], i64 0, i32 2, i64 [[INDEX]]
+// SANITIZE-WITHOUT-ATTR-NEXT: store i32 -1, ptr [[ARRAYIDX]], align 4, !tbaa [[TBAA2]]
+// SANITIZE-WITHOUT-ATTR-NEXT: ret void
+//
+// NO-SANITIZE-WITHOUT-ATTR-LABEL: define dso_local void @test3(
+// NO-SANITIZE-WITHOUT-ATTR-SAME: ptr noundef [[P:%.*]], i64 noundef [[INDEX:%.*]]) local_unnamed_addr #[[ATTR1]] {
+// NO-SANITIZE-WITHOUT-ATTR-NEXT: entry:
+// NO-SANITIZE-WITHOUT-ATTR-NEXT: [[ARRAYIDX:%.*]] = getelementptr inbounds [[STRUCT_ANNOTATED:%.*]], ptr [[P]], i64 0, i32 2, i64 [[INDEX]]
+// NO-SANITIZE-WITHOUT-ATTR-NEXT: store i32 -1, ptr [[ARRAYIDX]], align 4, !tbaa [[TBAA2]]
+// NO-SANITIZE-WITHOUT-ATTR-NEXT: ret void
+//
+void test3(struct annotated *p, size_t index) {
+ // This test differs from 'test2' by checking bdos on the whole array and not
+ // just the FAM.
+ p->array[index] = __builtin_dynamic_object_size(p, 1);
+}
+
+struct annotated_with_anon_struct {
+ unsigned long flags;
+ struct {
+ unsigned char count;
+ int array[] __counted_by(count);
+ };
+};
+
+// SANITIZE-WITH-ATTR-LABEL: define dso_local void @test4(
+// SANITIZE-WITH-ATTR-SAME: ptr noundef [[P:%.*]], i32 noundef [[INDEX:%.*]]) local_unnamed_addr #[[ATTR0]] {
+// SANITIZE-WITH-ATTR-NEXT: entry:
+// SANITIZE-WITH-ATTR-NEXT: [[TMP0:%.*]] = getelementptr inbounds [[STRUCT_ANNOTATED_WITH_ANON_STRUCT:%.*]], ptr [[P]], i64 0, i32 1
+// SANITIZE-WITH-ATTR-NEXT: [[TMP1:%.*]] = load i8, ptr [[TMP0]], align 8, !tbaa [[TBAA8:![0-9]+]]
+// SANITIZE-WITH-ATTR-NEXT: [[TMP2:%.*]] = sext i32 [[INDEX]] to i64, !nosanitize !6
+// SANITIZE-WITH-ATTR-NEXT: [[TMP3:%.*]] = zext i8 [[TMP1]] to i64, !nosanitize !6
+// SANITIZE-WITH-ATTR-NEXT: [[TMP4:%.*]] = icmp ult i64 [[TMP2]], [[TMP3]], !nosanitize !6
+// SANITIZE-WITH-ATTR-NEXT: br i1 [[TMP4]], label [[CONT18:%.*]], label [[HANDLER_OUT_OF_BOUNDS:%.*]], !prof [[PROF7]], !nosanitize !6
+// SANITIZE-WITH-ATTR: handler.out_of_bounds:
+// SANITIZE-WITH-ATTR-NEXT: [[TMP5:%.*]] = zext i32 [[INDEX]] to i64, !nosanitize !6
+// SANITIZE-WITH-ATTR-NEXT: tail call void @__ubsan_handle_out_of_bounds_abort(ptr nonnull @[[GLOB6:[0-9]+]], i64 [[TMP5]]) #[[ATTR2]], !nosanitize !6
+// SANITIZE-WITH-ATTR-NEXT: unreachable, !nosanitize !6
+// SANITIZE-WITH-ATTR: cont18:
+// SANITIZE-WITH-ATTR-NEXT: [[ARRAY:%.*]] = getelementptr inbounds i8, ptr [[P]], i64 12
+// SANITIZE-WITH-ATTR-NEXT: [[ARRAYIDX:%.*]] = getelementptr inbounds [0 x i32], ptr [[ARRAY]], i64 0, i64 [[TMP2]]
+// SANITIZE-WITH-ATTR-NEXT: [[TMP6:%.*]] = shl i8 [[TMP1]], 2
+// SANITIZE-WITH-ATTR-NEXT: [[CONV:%.*]] = zext i8 [[TMP6]] to i32
+// SANITIZE-WITH-ATTR-NEXT: store i32 [[CONV]], ptr [[ARRAYIDX]], align 4, !tbaa [[TBAA2]]
+// SANITIZE-WITH-ATTR-NEXT: ret void
+//
+// NO-SANITIZE-WITH-ATTR-LABEL: define dso_local void @test4(
+// NO-SANITIZE-WITH-ATTR-SAME: ptr nocapture noundef [[P:%.*]], i32 noundef [[INDEX:%.*]]) local_unnamed_addr #[[ATTR1]] {
+// NO-SANITIZE-WITH-ATTR-NEXT: entry:
+// NO-SANITIZE-WITH-ATTR-NEXT: [[TMP0:%.*]] = getelementptr inbounds [[STRUCT_ANNOTATED_WITH_ANON_STRUCT:%.*]], ptr [[P]], i64 0, i32 1
+// NO-SANITIZE-WITH-ATTR-NEXT: [[TMP1:%.*]] = load i8, ptr [[TMP0]], align 8, !tbaa [[TBAA6:![0-9]+]]
+// NO-SANITIZE-WITH-ATTR-NEXT: [[TMP2:%.*]] = shl i8 [[TMP1]], 2
+// NO-SANITIZE-WITH-ATTR-NEXT: [[CONV:%.*]] = zext i8 [[TMP2]] to i32
+// NO-SANITIZE-WITH-ATTR-NEXT: [[ARRAY:%.*]] = getelementptr inbounds i8, ptr [[P]], i64 12
+// NO-SANITIZE-WITH-ATTR-NEXT: [[IDXPROM:%.*]] = sext i32 [[INDEX]] to i64
+// NO-SANITIZE-WITH-ATTR-NEXT: [[ARRAYIDX:%.*]] = getelementptr inbounds [0 x i32], ptr [[ARRAY]], i64 0, i64 [[IDXPROM]]
+// NO-SANITIZE-WITH-ATTR-NEXT: store i32 [[CONV]], ptr [[ARRAYIDX]], align 4, !tbaa [[TBAA2]]
+// NO-SANITIZE-WITH-ATTR-NEXT: ret void
+//
+// SANITIZE-WITHOUT-ATTR-LABEL: define dso_local void @test4(
+// SANITIZE-WITHOUT-ATTR-SAME: ptr noundef [[P:%.*]], i32 noundef [[INDEX:%.*]]) local_unnamed_addr #[[ATTR0]] {
+// SANITIZE-WITHOUT-ATTR-NEXT: entry:
+// SANITIZE-WITHOUT-ATTR-NEXT: [[ARRAY:%.*]] = getelementptr inbounds i8, ptr [[P]], i64 12
+// SANITIZE-WITHOUT-ATTR-NEXT: [[IDXPROM:%.*]] = sext i32 [[INDEX]] to i64
+// SANITIZE-WITHOUT-ATTR-NEXT: [[ARRAYIDX:%.*]] = getelementptr inbounds [0 x i32], ptr [[ARRAY]], i64 0, i64 [[IDXPROM]]
+// SANITIZE-WITHOUT-ATTR-NEXT: store i32 -1, ptr [[ARRAYIDX]], align 4, !tbaa [[TBAA2]]
+// SANITIZE-WITHOUT-ATTR-NEXT: ret void
+//
+// NO-SANITIZE-WITHOUT-ATTR-LABEL: define dso_local void @test4(
+// NO-SANITIZE-WITHOUT-ATTR-SAME: ptr noundef [[P:%.*]], i32 noundef [[INDEX:%.*]]) local_unnamed_addr #[[ATTR1]] {
+// NO-SANITIZE-WITHOUT-ATTR-NEXT: entry:
+// NO-SANITIZE-WITHOUT-ATTR-NEXT: [[ARRAY:%.*]] = getelementptr inbounds i8, ptr [[P]], i64 12
+// NO-SANITIZE-WITHOUT-ATTR-NEXT: [[IDXPROM:%.*]] = sext i32 [[INDEX]] to i64
+// NO-SANITIZE-WITHOUT-ATTR-NEXT: [[ARRAYIDX:%.*]] = getelementptr inbounds [0 x i32], ptr [[ARRAY]], i64 0, i64 [[IDXPROM]]
+// NO-SANITIZE-WITHOUT-ATTR-NEXT: store i32 -1, ptr [[ARRAYIDX]], align 4, !tbaa [[TBAA2]]
+// NO-SANITIZE-WITHOUT-ATTR-NEXT: ret void
+//
+void test4(struct annotated_with_anon_struct *p, int index) {
+ p->array[index] = __builtin_dynamic_object_size(p->array, 1);
+}
Index: clang/lib/Sema/SemaDeclAttr.cpp
===================================================================
--- clang/lib/Sema/SemaDeclAttr.cpp
+++ clang/lib/Sema/SemaDeclAttr.cpp
@@ -8336,6 +8336,20 @@
D->addAttr(ZeroCallUsedRegsAttr::Create(S.Context, Kind, AL));
}
+static void handleCountedByAttr(Sema &S, Decl *D, const ParsedAttr &AL) {
+ if (!AL.isArgIdent(0)) {
+ S.Diag(AL.getLoc(), diag::err_attribute_argument_type)
+ << AL << AANT_ArgumentIdentifier;
+ return;
+ }
+
+ IdentifierLoc *IL = AL.getArgAsIdent(0);
+ CountedByAttr *CBA =
+ ::new (S.Context) CountedByAttr(S.Context, AL, IL->Ident);
+ CBA->setCountedByFieldLoc(IL->Loc);
+ D->addAttr(CBA);
+}
+
static void handleFunctionReturnThunksAttr(Sema &S, Decl *D,
const ParsedAttr &AL) {
StringRef KindStr;
@@ -9282,6 +9296,10 @@
handleAvailableOnlyInDefaultEvalMethod(S, D, AL);
break;
+ case ParsedAttr::AT_CountedBy:
+ handleCountedByAttr(S, D, AL);
+ break;
+
// Microsoft attributes:
case ParsedAttr::AT_LayoutVersion:
handleLayoutVersion(S, D, AL);
Index: clang/lib/Sema/SemaDecl.cpp
===================================================================
--- clang/lib/Sema/SemaDecl.cpp
+++ clang/lib/Sema/SemaDecl.cpp
@@ -17991,6 +17991,83 @@
"Broken injected-class-name");
}
+template <typename Functor>
+static const FieldDecl *FindFieldIf(const RecordDecl *RD, Functor &Pred) {
+ for (const Decl *D : RD->decls()) {
+ if (const auto *FD = dyn_cast<FieldDecl>(D); FD && Pred(FD))
+ return FD;
+
+ if (const auto *SubRD = dyn_cast<RecordDecl>(D))
+ if (const FieldDecl *FD = FindFieldIf(SubRD, Pred))
+ return FD;
+ }
+
+ return nullptr;
+}
+
+static void CheckCountedByAttr(Scope *Scope, Sema &S, const FieldDecl *FD) {
+ ASTContext &Ctx = S.getASTContext();
+ const RecordDecl *RD = FD->getParent();
+ const auto *CBA = FD->getAttr<CountedByAttr>();
+
+ auto Pred = [&](const Decl *D) {
+ if (const auto *Field = dyn_cast<FieldDecl>(D))
+ return Field->getName() == CBA->getCountedByField()->getName();
+ return false;
+ };
+ const FieldDecl *Field = FindFieldIf(RD, Pred);
+
+ LangOptions::StrictFlexArraysLevelKind StrictFlexArraysLevel =
+ Ctx.getLangOpts().getStrictFlexArraysLevel();
+
+ if (!Field) {
+ // The "counted_by" field needs to exist within the struct.
+ DeclarationNameInfo NameInfo(CBA->getCountedByField(),
+ CBA->getCountedByFieldLoc().getBegin());
+ LookupResult Result(S, NameInfo, Sema::LookupOrdinaryName);
+
+ S.LookupName(Result, Scope);
+ if (Result.getResultKind() == LookupResult::Found) {
+ SourceRange SR = CBA->getCountedByFieldLoc();
+ S.Diag(SR.getBegin(),
+ diag::err_flexible_array_counted_by_attr_field_not_found_in_struct)
+ << CBA->getCountedByField() << SR;
+
+ SR = Result.getAsSingle<NamedDecl>()->getSourceRange();
+ S.Diag(SR.getBegin(), diag::note_var_declared_here)
+ << Result.getAsSingle<NamedDecl>() << SR;
+ } else {
+ SourceRange SR = CBA->getCountedByFieldLoc();
+ S.Diag(SR.getBegin(),
+ diag::err_flexible_array_counted_by_attr_field_not_found)
+ << CBA->getCountedByField() << SR;
+ }
+ } else if (!Decl::isFlexibleArrayMemberLike(Ctx, FD, FD->getType(),
+ StrictFlexArraysLevel, true)) {
+ SourceRange SR = FD->getLocation();
+ S.Diag(SR.getBegin(),
+ diag::err_counted_by_attr_not_on_flexible_array_member)
+ << SR;
+ } else if (Field->hasAttr<CountedByAttr>()) {
+ // The "counted_by" field can't point to the flexible array member.
+ SourceRange SR = CBA->getCountedByFieldLoc();
+ S.Diag(SR.getBegin(),
+ diag::err_flexible_array_counted_by_attr_refers_to_self)
+ << CBA->getCountedByField() << SR;
+ } else if (!Field->getType()->isIntegerType() ||
+ Field->getType()->isBooleanType()) {
+ // The "counted_by" field must have an integer type.
+ SourceRange SR = Field->getLocation();
+ S.Diag(SR.getBegin(),
+ diag::err_flexible_array_counted_by_attr_field_not_integer)
+ << Field << SR;
+
+ SR = CBA->getCountedByFieldLoc();
+ S.Diag(SR.getBegin(), diag::note_flexible_array_counted_by_attr_field)
+ << CBA->getCountedByField() << SR;
+ }
+}
+
void Sema::ActOnTagFinishDefinition(Scope *S, Decl *TagD,
SourceRange BraceRange) {
AdjustDeclIfTemplate(TagD);
@@ -18048,6 +18125,18 @@
[](const FieldDecl *FD) { return FD->isBitField(); }))
Diag(BraceRange.getBegin(), diag::warn_pragma_align_not_xl_compatible);
}
+
+ // Check the "counted_by" attribute to ensure that the count field exists in
+ // the struct.
+ if (const auto *RD = dyn_cast<RecordDecl>(Tag)) {
+ auto Pred = [](const Decl *D) {
+ if (const auto *FD = dyn_cast<FieldDecl>(D))
+ return FD->hasAttr<CountedByAttr>();
+ return false;
+ };
+ if (const FieldDecl *FD = FindFieldIf(RD, Pred))
+ CheckCountedByAttr(S, *this, FD);
+ }
}
void Sema::ActOnObjCContainerFinishDefinition() {
Index: clang/lib/CodeGen/CodeGenFunction.h
===================================================================
--- clang/lib/CodeGen/CodeGenFunction.h
+++ clang/lib/CodeGen/CodeGenFunction.h
@@ -3022,6 +3022,12 @@
void EmitBoundsCheck(const Expr *E, const Expr *Base, llvm::Value *Index,
QualType IndexType, bool Accessed);
+ /// Find the FieldDecl specified in a FAM's "counted_by" attribute. Returns
+ /// \p nullptr if either the attribute or the field doesn't exist.
+ FieldDecl *FindCountedByField(
+ const Expr *Base,
+ LangOptions::StrictFlexArraysLevelKind StrictFlexArraysLevel);
+
llvm::Value *EmitScalarPrePostIncDec(const UnaryOperator *E, LValue LV,
bool isInc, bool isPre);
ComplexPairTy EmitComplexPrePostIncDec(const UnaryOperator *E, LValue LV,
Index: clang/lib/CodeGen/CGExpr.cpp
===================================================================
--- clang/lib/CodeGen/CGExpr.cpp
+++ clang/lib/CodeGen/CGExpr.cpp
@@ -30,6 +30,7 @@
#include "clang/Basic/CodeGenOptions.h"
#include "clang/Basic/SourceManager.h"
#include "llvm/ADT/Hashing.h"
+#include "llvm/ADT/STLExtras.h"
#include "llvm/ADT/StringExtras.h"
#include "llvm/IR/DataLayout.h"
#include "llvm/IR/Intrinsics.h"
@@ -925,16 +926,31 @@
if (CE->getCastKind() == CK_ArrayToPointerDecay &&
!CE->getSubExpr()->isFlexibleArrayMemberLike(CGF.getContext(),
StrictFlexArraysLevel)) {
+ CodeGenFunction::SanitizerScope SanScope(&CGF);
+
IndexedType = CE->getSubExpr()->getType();
const ArrayType *AT = IndexedType->castAsArrayTypeUnsafe();
if (const auto *CAT = dyn_cast<ConstantArrayType>(AT))
return CGF.Builder.getInt(CAT->getSize());
- else if (const auto *VAT = dyn_cast<VariableArrayType>(AT))
+
+ if (const auto *VAT = dyn_cast<VariableArrayType>(AT))
return CGF.getVLASize(VAT).NumElts;
// Ignore pass_object_size here. It's not applicable on decayed pointers.
}
+
+ if (FieldDecl *FD = CGF.FindCountedByField(Base, StrictFlexArraysLevel)) {
+ const auto *ME = dyn_cast<MemberExpr>(CE->getSubExpr());
+ IndexedType = Base->getType();
+ return CGF
+ .EmitAnyExprToTemp(MemberExpr::CreateImplicit(
+ CGF.getContext(), const_cast<Expr *>(ME->getBase()),
+ ME->isArrow(), FD, FD->getType(), VK_LValue, OK_Ordinary))
+ .getScalarVal();
+ }
}
+ CodeGenFunction::SanitizerScope SanScope(&CGF);
+
QualType EltTy{Base->getType()->getPointeeOrArrayElementType(), 0};
if (llvm::Value *POS = CGF.LoadPassedObjectSize(Base, EltTy)) {
IndexedType = Base->getType();
@@ -944,13 +960,53 @@
return nullptr;
}
+FieldDecl *CodeGenFunction::FindCountedByField(
+ const Expr *Base,
+ LangOptions::StrictFlexArraysLevelKind StrictFlexArraysLevel) {
+ const ValueDecl *VD = nullptr;
+
+ Base = Base->IgnoreParenImpCasts();
+
+ if (const auto *ME = dyn_cast<MemberExpr>(Base)) {
+ VD = dyn_cast<ValueDecl>(ME->getMemberDecl());
+ } else if (const auto *DRE = dyn_cast<DeclRefExpr>(Base)) {
+ // Pointing to the full structure.
+ VD = dyn_cast<ValueDecl>(DRE->getDecl());
+
+ QualType Ty = VD->getType();
+ if (Ty->isPointerType())
+ Ty = Ty->getPointeeType();
+
+ if (const auto *RD = Ty->getAsRecordDecl())
+ VD = RD->getLastField();
+ } else if (const auto *CE = dyn_cast<CastExpr>(Base)) {
+ if (const auto *ME = dyn_cast<MemberExpr>(CE->getSubExpr()))
+ VD = dyn_cast<ValueDecl>(ME->getMemberDecl());
+ }
+
+ const auto *FD = dyn_cast_if_present<FieldDecl>(VD);
+ if (!FD || !FD->getParent() ||
+ !Decl::isFlexibleArrayMemberLike(getContext(), FD, FD->getType(),
+ StrictFlexArraysLevel, true))
+ return nullptr;
+
+ const auto *CBA = FD->getAttr<CountedByAttr>();
+ if (!CBA)
+ return nullptr;
+
+ StringRef FieldName = CBA->getCountedByField()->getName();
+ auto It =
+ llvm::find_if(FD->getParent()->fields(), [&](const FieldDecl *Field) {
+ return FieldName == Field->getName();
+ });
+ return It != FD->getParent()->field_end() ? *It : nullptr;
+}
+
void CodeGenFunction::EmitBoundsCheck(const Expr *E, const Expr *Base,
llvm::Value *Index, QualType IndexType,
bool Accessed) {
assert(SanOpts.has(SanitizerKind::ArrayBounds) &&
"should not be called unless adding bounds checks");
- SanitizerScope SanScope(this);
-
const LangOptions::StrictFlexArraysLevelKind StrictFlexArraysLevel =
getLangOpts().getStrictFlexArraysLevel();
@@ -960,6 +1016,8 @@
if (!Bound)
return;
+ SanitizerScope SanScope(this);
+
bool IndexSigned = IndexType->isSignedIntegerOrEnumerationType();
llvm::Value *IndexVal = Builder.CreateIntCast(Index, SizeTy, IndexSigned);
llvm::Value *BoundVal = Builder.CreateIntCast(Bound, SizeTy, false);
Index: clang/lib/CodeGen/CGBuiltin.cpp
===================================================================
--- clang/lib/CodeGen/CGBuiltin.cpp
+++ clang/lib/CodeGen/CGBuiltin.cpp
@@ -853,6 +853,57 @@
}
}
+ if (IsDynamic) {
+ LangOptions::StrictFlexArraysLevelKind StrictFlexArraysLevel =
+ getLangOpts().getStrictFlexArraysLevel();
+ const Expr *Base = E->IgnoreParenImpCasts();
+
+ if (FieldDecl *FD = FindCountedByField(Base, StrictFlexArraysLevel)) {
+ const auto *ME = dyn_cast<MemberExpr>(Base);
+ llvm::Value *ObjectSize = nullptr;
+
+ if (!ME) {
+ const auto *DRE = dyn_cast<DeclRefExpr>(Base);
+ ValueDecl *VD = nullptr;
+
+ ObjectSize = ConstantInt::get(
+ ResType,
+ getContext().getTypeSize(DRE->getType()->getPointeeType()) / 8,
+ true);
+
+ if (auto *RD = DRE->getType()->getPointeeType()->getAsRecordDecl())
+ VD = RD->getLastField();
+
+ Expr *ICE = ImplicitCastExpr::Create(
+ getContext(), DRE->getType(), CK_LValueToRValue,
+ const_cast<Expr *>(cast<Expr>(DRE)), nullptr, VK_PRValue,
+ FPOptionsOverride());
+ ME = MemberExpr::CreateImplicit(getContext(), ICE, true, VD,
+ VD->getType(), VK_LValue, OK_Ordinary);
+ }
+
+ // At this point, we know that \p ME is a flexible array member.
+ const auto *ArrayTy = getContext().getAsArrayType(ME->getType());
+ unsigned Size = getContext().getTypeSize(ArrayTy->getElementType());
+
+ llvm::Value *CountField =
+ EmitAnyExprToTemp(MemberExpr::CreateImplicit(
+ getContext(), const_cast<Expr *>(ME->getBase()),
+ ME->isArrow(), FD, FD->getType(), VK_LValue,
+ OK_Ordinary))
+ .getScalarVal();
+
+ llvm::Value *Mul = Builder.CreateMul(
+ CountField, llvm::ConstantInt::get(CountField->getType(), Size / 8));
+ Mul = Builder.CreateZExtOrTrunc(Mul, ResType);
+
+ if (ObjectSize)
+ return Builder.CreateAdd(ObjectSize, Mul);
+
+ return Mul;
+ }
+ }
+
// LLVM can't handle Type=3 appropriately, and __builtin_object_size shouldn't
// evaluate E for side-effects. In either case, we shouldn't lower to
// @llvm.objectsize.
Index: clang/lib/AST/Expr.cpp
===================================================================
--- clang/lib/AST/Expr.cpp
+++ clang/lib/AST/Expr.cpp
@@ -205,85 +205,22 @@
}
bool Expr::isFlexibleArrayMemberLike(
- ASTContext &Context,
+ ASTContext &Ctx,
LangOptions::StrictFlexArraysLevelKind StrictFlexArraysLevel,
bool IgnoreTemplateOrMacroSubstitution) const {
-
- // For compatibility with existing code, we treat arrays of length 0 or
- // 1 as flexible array members.
- const auto *CAT = Context.getAsConstantArrayType(getType());
- if (CAT) {
- llvm::APInt Size = CAT->getSize();
-
- using FAMKind = LangOptions::StrictFlexArraysLevelKind;
-
- if (StrictFlexArraysLevel == FAMKind::IncompleteOnly)
- return false;
-
- // GCC extension, only allowed to represent a FAM.
- if (Size == 0)
- return true;
-
- if (StrictFlexArraysLevel == FAMKind::ZeroOrIncomplete && Size.uge(1))
- return false;
-
- if (StrictFlexArraysLevel == FAMKind::OneZeroOrIncomplete && Size.uge(2))
- return false;
- } else if (!Context.getAsIncompleteArrayType(getType()))
- return false;
-
const Expr *E = IgnoreParens();
+ const Decl *D = nullptr;
- const NamedDecl *ND = nullptr;
- if (const auto *DRE = dyn_cast<DeclRefExpr>(E))
- ND = DRE->getDecl();
- else if (const auto *ME = dyn_cast<MemberExpr>(E))
- ND = ME->getMemberDecl();
+ if (const auto *ME = dyn_cast<MemberExpr>(E))
+ D = ME->getMemberDecl();
+ else if (const auto *DRE = dyn_cast<DeclRefExpr>(E))
+ D = DRE->getDecl();
else if (const auto *IRE = dyn_cast<ObjCIvarRefExpr>(E))
- return IRE->getDecl()->getNextIvar() == nullptr;
+ D = IRE->getDecl();
- if (!ND)
- return false;
-
- // A flexible array member must be the last member in the class.
- // FIXME: If the base type of the member expr is not FD->getParent(),
- // this should not be treated as a flexible array member access.
- if (const auto *FD = dyn_cast<FieldDecl>(ND)) {
- // GCC treats an array memeber of a union as an FAM if the size is one or
- // zero.
- if (CAT) {
- llvm::APInt Size = CAT->getSize();
- if (FD->getParent()->isUnion() && (Size.isZero() || Size.isOne()))
- return true;
- }
-
- // Don't consider sizes resulting from macro expansions or template argument
- // substitution to form C89 tail-padded arrays.
- if (IgnoreTemplateOrMacroSubstitution) {
- TypeSourceInfo *TInfo = FD->getTypeSourceInfo();
- while (TInfo) {
- TypeLoc TL = TInfo->getTypeLoc();
- // Look through typedefs.
- if (TypedefTypeLoc TTL = TL.getAsAdjusted<TypedefTypeLoc>()) {
- const TypedefNameDecl *TDL = TTL.getTypedefNameDecl();
- TInfo = TDL->getTypeSourceInfo();
- continue;
- }
- if (ConstantArrayTypeLoc CTL = TL.getAs<ConstantArrayTypeLoc>()) {
- const Expr *SizeExpr = dyn_cast<IntegerLiteral>(CTL.getSizeExpr());
- if (!SizeExpr || SizeExpr->getExprLoc().isMacroID())
- return false;
- }
- break;
- }
- }
-
- RecordDecl::field_iterator FI(
- DeclContext::decl_iterator(const_cast<FieldDecl *>(FD)));
- return ++FI == FD->getParent()->field_end();
- }
-
- return false;
+ return Decl::isFlexibleArrayMemberLike(Ctx, D, E->getType(),
+ StrictFlexArraysLevel,
+ IgnoreTemplateOrMacroSubstitution);
}
const ValueDecl *
Index: clang/lib/AST/DeclBase.cpp
===================================================================
--- clang/lib/AST/DeclBase.cpp
+++ clang/lib/AST/DeclBase.cpp
@@ -29,7 +29,6 @@
#include "clang/AST/Type.h"
#include "clang/Basic/IdentifierTable.h"
#include "clang/Basic/LLVM.h"
-#include "clang/Basic/LangOptions.h"
#include "clang/Basic/Module.h"
#include "clang/Basic/ObjCRuntime.h"
#include "clang/Basic/PartialDiagnostic.h"
@@ -411,6 +410,81 @@
return DC && DC->isFileContext();
}
+bool Decl::isFlexibleArrayMemberLike(
+ ASTContext &Ctx, const Decl *D, QualType Ty,
+ LangOptions::StrictFlexArraysLevelKind StrictFlexArraysLevel,
+ bool IgnoreTemplateOrMacroSubstitution) {
+ // For compatibility with existing code, we treat arrays of length 0 or
+ // 1 as flexible array members.
+ const auto *CAT = Ctx.getAsConstantArrayType(Ty);
+ if (CAT) {
+ using FAMKind = LangOptions::StrictFlexArraysLevelKind;
+
+ llvm::APInt Size = CAT->getSize();
+ FAMKind StrictFlexArraysLevel =
+ Ctx.getLangOpts().getStrictFlexArraysLevel();
+
+ if (StrictFlexArraysLevel == FAMKind::IncompleteOnly)
+ return false;
+
+ // GCC extension, only allowed to represent a FAM.
+ if (Size.isZero())
+ return true;
+
+ if (StrictFlexArraysLevel == FAMKind::ZeroOrIncomplete && Size.uge(1))
+ return false;
+
+ if (StrictFlexArraysLevel == FAMKind::OneZeroOrIncomplete && Size.uge(2))
+ return false;
+ } else if (!Ctx.getAsIncompleteArrayType(Ty)) {
+ return false;
+ }
+
+ if (const auto *OID = dyn_cast_if_present<ObjCIvarDecl>(D))
+ return OID->getNextIvar() == nullptr;
+
+ const auto *FD = dyn_cast_if_present<FieldDecl>(D);
+ if (!FD)
+ return false;
+
+ if (CAT) {
+ // GCC treats an array memeber of a union as an FAM if the size is one or
+ // zero.
+ llvm::APInt Size = CAT->getSize();
+ if (FD->getParent()->isUnion() && (Size.isZero() || Size.isOne()))
+ return true;
+ }
+
+ // Don't consider sizes resulting from macro expansions or template argument
+ // substitution to form C89 tail-padded arrays.
+ if (IgnoreTemplateOrMacroSubstitution) {
+ TypeSourceInfo *TInfo = FD->getTypeSourceInfo();
+ while (TInfo) {
+ TypeLoc TL = TInfo->getTypeLoc();
+
+ // Look through typedefs.
+ if (TypedefTypeLoc TTL = TL.getAsAdjusted<TypedefTypeLoc>()) {
+ const TypedefNameDecl *TDL = TTL.getTypedefNameDecl();
+ TInfo = TDL->getTypeSourceInfo();
+ continue;
+ }
+
+ if (auto CTL = TL.getAs<ConstantArrayTypeLoc>()) {
+ const Expr *SizeExpr = dyn_cast<IntegerLiteral>(CTL.getSizeExpr());
+ if (!SizeExpr || SizeExpr->getExprLoc().isMacroID())
+ return false;
+ }
+
+ break;
+ }
+ }
+
+ // Test that the field is the last in the structure.
+ RecordDecl::field_iterator FI(
+ DeclContext::decl_iterator(const_cast<FieldDecl *>(FD)));
+ return ++FI == FD->getParent()->field_end();
+}
+
TranslationUnitDecl *Decl::getTranslationUnitDecl() {
if (auto *TUD = dyn_cast<TranslationUnitDecl>(this))
return TUD;
Index: clang/lib/AST/ASTImporter.cpp
===================================================================
--- clang/lib/AST/ASTImporter.cpp
+++ clang/lib/AST/ASTImporter.cpp
@@ -8975,6 +8975,10 @@
public:
AttrImporter(ASTImporter &I) : Importer(I), NImporter(I) {}
+ // Useful for accessing the imported attribute.
+ template <typename T> T *castAttrAs() { return cast<T>(ToAttr); }
+ template <typename T> const T *castAttrAs() const { return cast<T>(ToAttr); }
+
// Create an "importer" for an attribute parameter.
// Result of the 'value()' of that object is to be passed to the function
// 'importAttr', in the order that is expected by the attribute class.
@@ -9181,6 +9185,15 @@
From->args_size());
break;
}
+ case attr::CountedBy: {
+ AI.cloneAttr(FromAttr);
+ const auto *CBA = cast<CountedByAttr>(FromAttr);
+ Expected<SourceRange> SR = Import(CBA->getCountedByFieldLoc()).get();
+ if (!SR)
+ return SR.takeError();
+ AI.castAttrAs<CountedByAttr>()->setCountedByFieldLoc(SR.get());
+ break;
+ }
default: {
// The default branch works for attributes that have no arguments to import.
Index: clang/include/clang/Basic/DiagnosticSemaKinds.td
===================================================================
--- clang/include/clang/Basic/DiagnosticSemaKinds.td
+++ clang/include/clang/Basic/DiagnosticSemaKinds.td
@@ -6379,6 +6379,19 @@
"field %0 can overwrite instance variable %1 with variable sized type %2"
" in superclass %3">, InGroup<ObjCFlexibleArray>;
+def err_counted_by_attr_not_on_flexible_array_member : Error<
+ "'counted_by' only applies to flexible array members">;
+def err_flexible_array_counted_by_attr_field_not_found : Error<
+ "field %0 in 'counted_by' not found">;
+def err_flexible_array_counted_by_attr_field_not_found_in_struct : Error<
+ "field %0 in 'counted_by' is not found in struct">;
+def err_flexible_array_counted_by_attr_refers_to_self : Error<
+ "field %0 in 'counted_by' cannot refer to the flexible array">;
+def err_flexible_array_counted_by_attr_field_not_integer : Error<
+ "field %0 in 'counted_by' is not a non-boolean integer type">;
+def note_flexible_array_counted_by_attr_field : Note<
+ "field %0 declared here">;
+
let CategoryName = "ARC Semantic Issue" in {
// ARC-mode diagnostics.
Index: clang/include/clang/Basic/AttrDocs.td
===================================================================
--- clang/include/clang/Basic/AttrDocs.td
+++ clang/include/clang/Basic/AttrDocs.td
@@ -7271,3 +7271,69 @@
attribute, they default to the value ``65535``.
}];
}
+
+def CountedByDocs : Documentation {
+ let Category = DocCatField;
+ let Content = [{
+Clang supports the ``counted_by`` attribute on the flexible array member of a
+structure in C. The argument for the attribute is the name of a field member in
+the same structure holding the count of elements in the flexible array. This
+information can be used to improve the results of the array bound sanitizer and
+the ``__builtin_dynamic_object_size`` builtin.
+
+For example, the following code:
+
+.. code-block:: c
+
+ struct bar;
+
+ struct foo {
+ size_t count;
+ char other;
+ struct bar *array[] __attribute__((counted_by(count)));
+ };
+
+specifies that the flexible array member ``array`` has the number of elements
+allocated for it stored in ``count``. This establishes a relationship between
+``array`` and ``count``. Specifically, ``p->array`` must have at least
+``p->count`` number of elements available. It's the user's responsibility to
+ensure that this relationship is maintained through changes to the structure.
+
+In the following example, the allocated array erroneously has fewer elements
+than what's specified by ``p->count``. This would result in an out-of-bounds
+access not being detected.
+
+.. code-block:: c
+
+ #define SIZE_INCR 42
+
+ struct foo *p;
+
+ void foo_alloc(size_t count) {
+ p = malloc(MAX(sizeof(struct foo),
+ offsetof(struct foo, array[0]) + count * sizeof(struct bar *)));
+ p->count = count + SIZE_INCR;
+ }
+
+The next example updates ``p->count``, breaking the relationship requirement
+that ``p->array`` must have at least ``p->count`` number of elements available:
+
+.. code-block:: c
+
+ #define SIZE_INCR 42
+
+ struct foo *p;
+
+ void foo_alloc(size_t count) {
+ p = malloc(MAX(sizeof(struct foo),
+ offsetof(struct foo, array[0]) + count * sizeof(struct bar *)));
+ p->count = count;
+ }
+
+ void use_foo(int index) {
+ p->count += SIZE_INCR + 1; /* 'count' is now larger than the number of elements of 'array'. */
+ p->array[index] = 0; /* the sanitizer can't properly check if this is an out-of-bounds access. */
+ }
+
+ }];
+}
Index: clang/include/clang/Basic/Attr.td
===================================================================
--- clang/include/clang/Basic/Attr.td
+++ clang/include/clang/Basic/Attr.td
@@ -4234,3 +4234,21 @@
let Subjects = SubjectList<[TypedefName], ErrorDiag>;
let Documentation = [Undocumented];
}
+
+def CountedBy : InheritableAttr {
+ let Spellings = [Clang<"counted_by">];
+ let Subjects = SubjectList<[Field]>;
+ let Args = [IdentifierArgument<"CountedByField">];
+ let Documentation = [CountedByDocs];
+ let LangOpts = [COnly];
+ // FIXME: This is ugly. Let using a DeclArgument would be nice, but a Decl
+ // isn't yet available due to the fact that we're still parsing the
+ // structure. Maybe that code could be changed sometime in the future.
+ code AdditionalMembers = [{
+ private:
+ SourceRange CountedByFieldLoc;
+ public:
+ SourceRange getCountedByFieldLoc() const { return CountedByFieldLoc; }
+ void setCountedByFieldLoc(SourceRange Loc) { CountedByFieldLoc = Loc; }
+ }];
+}
Index: clang/include/clang/AST/DeclBase.h
===================================================================
--- clang/include/clang/AST/DeclBase.h
+++ clang/include/clang/AST/DeclBase.h
@@ -18,6 +18,7 @@
#include "clang/AST/DeclarationName.h"
#include "clang/Basic/IdentifierTable.h"
#include "clang/Basic/LLVM.h"
+#include "clang/Basic/LangOptions.h"
#include "clang/Basic/SourceLocation.h"
#include "clang/Basic/Specifiers.h"
#include "llvm/ADT/ArrayRef.h"
@@ -477,6 +478,15 @@
// Return true if this is a FileContext Decl.
bool isFileContextDecl() const;
+ /// Whether it resembles a flexible array member. This is a static member
+ /// because we want to be able to call it with a nullptr. That allows us to
+ /// perform non-Decl specific checks based on the object's type and strict
+ /// flex array level.
+ static bool isFlexibleArrayMemberLike(
+ ASTContext &Context, const Decl *D, QualType Ty,
+ LangOptions::StrictFlexArraysLevelKind StrictFlexArraysLevel,
+ bool IgnoreTemplateOrMacroSubstitution);
+
ASTContext &getASTContext() const LLVM_READONLY;
/// Helper to get the language options from the ASTContext.
Index: clang/include/clang/AST/Decl.h
===================================================================
--- clang/include/clang/AST/Decl.h
+++ clang/include/clang/AST/Decl.h
@@ -4272,6 +4272,16 @@
return field_begin() == field_end();
}
+ FieldDecl *getLastField() {
+ FieldDecl *FD = nullptr;
+ for (FieldDecl *Field : fields())
+ FD = Field;
+ return FD;
+ }
+ const FieldDecl *getLastField() const {
+ return const_cast<RecordDecl *>(this)->getLastField();
+ }
+
/// Note that the definition of this type is now complete.
virtual void completeDefinition();
Index: clang/docs/ReleaseNotes.rst
===================================================================
--- clang/docs/ReleaseNotes.rst
+++ clang/docs/ReleaseNotes.rst
@@ -127,6 +127,11 @@
- ``structs``, ``unions``, and ``arrays`` that are const may now be used as
constant expressions. This change is more consistent with the behavior of
GCC.
+- Clang now supports the C-only attribute ``counted_by``. When applied to a
+ struct's flexible array member, it points to the struct field that holds the
+ number of elements in the flexible array member. This information can improve
+ the results of the array bound sanitizer and the
+ ``__builtin_dynamic_object_size`` builtin.
C23 Feature Support
^^^^^^^^^^^^^^^^^^^
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