[CodeGen][counted_by] Support use of the comma operator

[bwendling]

Writing something like this:

__builtin_dynamic_object_size((0, p->array), 0)

is equivalent to writing this:

__builtin_dynamic_object_size(p->array, 0)

though the former will give a warning about the first value being unused.

[llvmbot]

@llvm/pr-subscribers-clang

@llvm/pr-subscribers-clang-codegen

Author: Bill Wendling (bwendling)

Changes

Writing something like this:

__builtin_dynamic_object_size((0, p->array), 0)

is equivalent to writing this:

__builtin_dynamic_object_size(p->array, 0)

though the former will give a warning about the first value being unused.

---

Full diff: https://github.com/llvm/llvm-project/pull/151776.diff

2 Files Affected:

• (modified) clang/lib/CodeGen/CGBuiltin.cpp (+3)
• (modified) clang/test/CodeGen/attr-counted-by.c (+36)

diff --git a/clang/lib/CodeGen/CGBuiltin.cpp b/clang/lib/CodeGen/CGBuiltin.cpp
index e1f7ea08837c5..a648bde5f7544 100644
--- a/clang/lib/CodeGen/CGBuiltin.cpp
+++ b/clang/lib/CodeGen/CGBuiltin.cpp
@@ -973,6 +973,9 @@ class StructFieldAccess
     AddrOfSeen = false;
     return Visit(E->getSubExpr());
   }
+  const Expr *VisitBinaryOperator(const clang::BinaryOperator *Op) {
+    return Op->isCommaOp() ? Visit(Op->getRHS()) : nullptr;
+  }
 };
 
 } // end anonymous namespace
diff --git a/clang/test/CodeGen/attr-counted-by.c b/clang/test/CodeGen/attr-counted-by.c
index 101949af208e1..9fb50c6ef0fff 100644
--- a/clang/test/CodeGen/attr-counted-by.c
+++ b/clang/test/CodeGen/attr-counted-by.c
@@ -2445,3 +2445,39 @@ struct {
 size_t test36() {
   return __builtin_dynamic_object_size(&x.dev_addr[4], 1);
 }
+
+// SANITIZE-WITH-ATTR-LABEL: define dso_local range(i64 -8589934592, 8589934589) i64 @test37(
+// SANITIZE-WITH-ATTR-SAME: ptr noundef [[PTR:%.*]]) local_unnamed_addr #[[ATTR0]] {
+// SANITIZE-WITH-ATTR-NEXT:  entry:
+// SANITIZE-WITH-ATTR-NEXT:    [[COUNTED_BY_GEP:%.*]] = getelementptr inbounds nuw i8, ptr [[PTR]], i64 8
+// SANITIZE-WITH-ATTR-NEXT:    [[COUNTED_BY_LOAD:%.*]] = load i32, ptr [[COUNTED_BY_GEP]], align 4
+// SANITIZE-WITH-ATTR-NEXT:    [[COUNT:%.*]] = sext i32 [[COUNTED_BY_LOAD]] to i64
+// SANITIZE-WITH-ATTR-NEXT:    [[FLEXIBLE_ARRAY_MEMBER_SIZE:%.*]] = shl nsw i64 [[COUNT]], 2
+// SANITIZE-WITH-ATTR-NEXT:    [[TMP0:%.*]] = icmp sgt i32 [[COUNTED_BY_LOAD]], -1
+// SANITIZE-WITH-ATTR-NEXT:    [[TMP1:%.*]] = select i1 [[TMP0]], i64 [[FLEXIBLE_ARRAY_MEMBER_SIZE]], i64 0
+// SANITIZE-WITH-ATTR-NEXT:    ret i64 [[TMP1]]
+//
+// NO-SANITIZE-WITH-ATTR-LABEL: define dso_local range(i64 -8589934592, 8589934589) i64 @test37(
+// NO-SANITIZE-WITH-ATTR-SAME: ptr noundef readonly captures(none) [[PTR:%.*]]) local_unnamed_addr #[[ATTR2]] {
+// NO-SANITIZE-WITH-ATTR-NEXT:  entry:
+// NO-SANITIZE-WITH-ATTR-NEXT:    [[COUNTED_BY_GEP:%.*]] = getelementptr inbounds nuw i8, ptr [[PTR]], i64 8
+// NO-SANITIZE-WITH-ATTR-NEXT:    [[COUNTED_BY_LOAD:%.*]] = load i32, ptr [[COUNTED_BY_GEP]], align 4
+// NO-SANITIZE-WITH-ATTR-NEXT:    [[COUNT:%.*]] = sext i32 [[COUNTED_BY_LOAD]] to i64
+// NO-SANITIZE-WITH-ATTR-NEXT:    [[FLEXIBLE_ARRAY_MEMBER_SIZE:%.*]] = shl nsw i64 [[COUNT]], 2
+// NO-SANITIZE-WITH-ATTR-NEXT:    [[TMP0:%.*]] = icmp sgt i32 [[COUNTED_BY_LOAD]], -1
+// NO-SANITIZE-WITH-ATTR-NEXT:    [[TMP1:%.*]] = select i1 [[TMP0]], i64 [[FLEXIBLE_ARRAY_MEMBER_SIZE]], i64 0
+// NO-SANITIZE-WITH-ATTR-NEXT:    ret i64 [[TMP1]]
+//
+// SANITIZE-WITHOUT-ATTR-LABEL: define dso_local i64 @test37(
+// SANITIZE-WITHOUT-ATTR-SAME: ptr noundef [[PTR:%.*]]) local_unnamed_addr #[[ATTR0]] {
+// SANITIZE-WITHOUT-ATTR-NEXT:  entry:
+// SANITIZE-WITHOUT-ATTR-NEXT:    ret i64 -1
+//
+// NO-SANITIZE-WITHOUT-ATTR-LABEL: define dso_local i64 @test37(
+// NO-SANITIZE-WITHOUT-ATTR-SAME: ptr noundef readnone [[PTR:%.*]]) local_unnamed_addr #[[ATTR1]] {
+// NO-SANITIZE-WITHOUT-ATTR-NEXT:  entry:
+// NO-SANITIZE-WITHOUT-ATTR-NEXT:    ret i64 -1
+//
+size_t test37(struct annotated *ptr) {
+  return __builtin_dynamic_object_size((1, 2, (4, 5, (7, 8, 9, (10, ptr->array)))), 1);
+}

[kees]

That is a deeply unholy test case. I love it. ;)