yonghong-song created this revision.
yonghong-song added a reviewer: ast.
Herald added subscribers: cfe-commits, arphaman.
Herald added a project: clang.
Commit c15aa241f821
<https://reviews.llvm.org/rGc15aa241f8213334f6980b7981cee1f28f81112a>
("[CLANG][BPF] change __builtin_preserve_access_index()
signature") changed the builtin function signature to
PointerT __builtin_preserve_access_index(PointerT ptr)
with a pointer type as the argument/return type, where argument and
return types must be the same.
There is really no reason for this constraint. The builtin just
presented a code region so that IR builtins
__builtin_{array, struct, union}_preserve_access_index
can be applied.
This patch removed the pointer type restriction to permit any
argument type as long as it is permitted by the compiler.
Repository:
rG LLVM Github Monorepo
https://reviews.llvm.org/D67883
Files:
clang/docs/LanguageExtensions.rst
clang/include/clang/Basic/DiagnosticSemaKinds.td
clang/lib/Sema/SemaChecking.cpp
clang/test/CodeGen/builtin-preserve-access-index-nonptr.c
clang/test/Sema/builtin-preserve-access-index.c
Index: clang/test/Sema/builtin-preserve-access-index.c
===================================================================
--- clang/test/Sema/builtin-preserve-access-index.c
+++ clang/test/Sema/builtin-preserve-access-index.c
@@ -4,8 +4,8 @@
return __builtin_preserve_access_index(&arg[1], 1); // expected-error {{too many arguments to function call, expected 1, have 2}}
}
-const void *invalid2(const int *arg) {
- return __builtin_preserve_access_index(1); // expected-error {{__builtin_preserve_access_index argument must a pointer type instead of 'int'}}
+int valid2(void) {
+ return __builtin_preserve_access_index(1);
}
void *invalid3(const int *arg) {
@@ -29,3 +29,11 @@
int valid7(struct s *arg) {
return *__builtin_preserve_access_index(&arg->b);
}
+
+int valid8(struct s *arg) {
+ return __builtin_preserve_access_index(arg->a + arg->b);
+}
+
+int valid9(struct s *arg) {
+ return __builtin_preserve_access_index(({arg->a = 2; arg->b = 3; }));
+}
Index: clang/test/CodeGen/builtin-preserve-access-index-nonptr.c
===================================================================
--- /dev/null
+++ clang/test/CodeGen/builtin-preserve-access-index-nonptr.c
@@ -0,0 +1,18 @@
+// RUN: %clang -target x86_64 -emit-llvm -S -g %s -o - | FileCheck %s
+
+#define _(x) (__builtin_preserve_access_index(x))
+
+struct s1 {
+ char a;
+ int b[4];
+};
+
+int unit1(struct s1 *arg) {
+ return _(arg->b[2]);
+}
+// CHECK: define dso_local i32 @unit1
+// CHECK: call [4 x i32]* @llvm.preserve.struct.access.index.p0a4i32.p0s_struct.s1s(%struct.s1* %{{[0-9a-z]+}}, i32 1, i32 1), !dbg !{{[0-9]+}}, !llvm.preserve.access.index ![[STRUCT_S1:[0-9]+]]
+// CHECK: call i32* @llvm.preserve.array.access.index.p0i32.p0a4i32([4 x i32]* %{{[0-9a-z]+}}, i32 1, i32 2), !dbg !{{[0-9]+}}, !llvm.preserve.access.index ![[ARRAY:[0-9]+]]
+//
+// CHECK: ![[ARRAY]] = !DICompositeType(tag: DW_TAG_array_type
+// CHECK: ![[STRUCT_S1]] = distinct !DICompositeType(tag: DW_TAG_structure_type, name: "s1"
Index: clang/lib/Sema/SemaChecking.cpp
===================================================================
--- clang/lib/Sema/SemaChecking.cpp
+++ clang/lib/Sema/SemaChecking.cpp
@@ -191,22 +191,12 @@
return false;
}
-/// Check the number of arguments and arg type, and set the result type to
+/// Check the number of arguments and set the result type to
/// the argument type.
static bool SemaBuiltinPreserveAI(Sema &S, CallExpr *TheCall) {
if (checkArgCount(S, TheCall, 1))
return true;
- // The argument type must be a pointer
- ExprResult Arg = TheCall->getArg(0);
- QualType Ty = Arg.get()->getType();
- if (!Ty->isPointerType()) {
- S.Diag(Arg.get()->getBeginLoc(),
- diag::err_builtin_preserve_access_index_invalid_arg)
- << Ty << Arg.get()->getSourceRange();
- return true;
- }
-
TheCall->setType(TheCall->getArg(0)->getType());
return false;
}
Index: clang/include/clang/Basic/DiagnosticSemaKinds.td
===================================================================
--- clang/include/clang/Basic/DiagnosticSemaKinds.td
+++ clang/include/clang/Basic/DiagnosticSemaKinds.td
@@ -9916,7 +9916,4 @@
"__builtin_bit_cast %select{source|destination}0 type must be trivially copyable">;
def err_bit_cast_type_size_mismatch : Error<
"__builtin_bit_cast source size does not equal destination size (%0 vs %1)">;
-
-def err_builtin_preserve_access_index_invalid_arg : Error<
- "__builtin_preserve_access_index argument must a pointer type instead of %0">;
} // end of sema component.
Index: clang/docs/LanguageExtensions.rst
===================================================================
--- clang/docs/LanguageExtensions.rst
+++ clang/docs/LanguageExtensions.rst
@@ -2354,13 +2354,13 @@
under bpf compile-once run-everywhere framework. Debuginfo (typically
with ``-g``) is needed, otherwise, the compiler will exit with an error.
The return type for the intrinsic is the same as the type of the
-argument, and must be a pointer type.
+argument.
**Syntax**:
.. code-block:: c
- PointerT __builtin_preserve_access_index(PointerT ptr)
+ type __builtin_preserve_access_index(type arg)
**Example of Use**:
@@ -2375,7 +2375,8 @@
} c[4];
};
struct t *v = ...;
- const void *pb =__builtin_preserve_access_index(&v->c[3].b);
+ int *pb =__builtin_preserve_access_index(&v->c[3].b);
+ __builtin_preserve_access_index(v->j);
Multiprecision Arithmetic Builtins
----------------------------------
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