[clang] [Clang] Add support for [[msvc::noinline]] attribute. (PR #91720)

Xu Zhang via cfe-commits cfe-commits at lists.llvm.org
Fri May 10 02:46:55 PDT 2024


https://github.com/simonzgx updated https://github.com/llvm/llvm-project/pull/91720

>From d0cde98f5e933c6f88703a55986f6cc508721fdc Mon Sep 17 00:00:00 2001
From: Xu Zhang <simonzgx at gmail.com>
Date: Fri, 10 May 2024 01:24:24 +0800
Subject: [PATCH 1/2] [Clang] Add support for [[msvc::noinline]] attribute.
 (#90941)

---
 clang/include/clang/Basic/Attr.td       | 5 ++++-
 clang/include/clang/Basic/AttrDocs.td   | 2 ++
 clang/test/CodeGen/attr-ms-noinline.cpp | 0
 clang/test/Sema/attr-ms-noinline.cpp    | 0
 4 files changed, 6 insertions(+), 1 deletion(-)
 create mode 100644 clang/test/CodeGen/attr-ms-noinline.cpp
 create mode 100644 clang/test/Sema/attr-ms-noinline.cpp

diff --git a/clang/include/clang/Basic/Attr.td b/clang/include/clang/Basic/Attr.td
index 0225598cbbe8a..2c7a238f61764 100644
--- a/clang/include/clang/Basic/Attr.td
+++ b/clang/include/clang/Basic/Attr.td
@@ -1997,9 +1997,12 @@ def Convergent : InheritableAttr {
 def NoInline : DeclOrStmtAttr {
   let Spellings = [CustomKeyword<"__noinline__">, GCC<"noinline">,
                    CXX11<"clang", "noinline">, C23<"clang", "noinline">,
+                   CXX11<"msvc", "noinline">, C23<"msvc", "noinline">,
                    Declspec<"noinline">];
   let Accessors = [Accessor<"isClangNoInline", [CXX11<"clang", "noinline">,
-                                                C23<"clang", "noinline">]>];
+                                                C23<"clang", "noinline">,
+                                                CXX11<"msvc", "noinline">,
+                                                C23<"msvc", "noinline">]>];
   let Documentation = [NoInlineDocs];
   let Subjects = SubjectList<[Function, Stmt], WarnDiag,
                              "functions and statements">;
diff --git a/clang/include/clang/Basic/AttrDocs.td b/clang/include/clang/Basic/AttrDocs.td
index 8e6faabfae647..0ef636f716be5 100644
--- a/clang/include/clang/Basic/AttrDocs.td
+++ b/clang/include/clang/Basic/AttrDocs.td
@@ -597,6 +597,8 @@ spellings of the attribute are not supported on statements. If a statement is
 marked ``[[clang::noinline]]`` and contains calls, those calls inside the
 statement will not be inlined by the compiler.
 
+``[[msvc::noinline]]`` 
+
 ``__noinline__`` can be used as a keyword in CUDA/HIP languages. This is to
 avoid diagnostics due to usage of ``__attribute__((__noinline__))``
 with ``__noinline__`` defined as a macro as ``__attribute__((noinline))``.
diff --git a/clang/test/CodeGen/attr-ms-noinline.cpp b/clang/test/CodeGen/attr-ms-noinline.cpp
new file mode 100644
index 0000000000000..e69de29bb2d1d
diff --git a/clang/test/Sema/attr-ms-noinline.cpp b/clang/test/Sema/attr-ms-noinline.cpp
new file mode 100644
index 0000000000000..e69de29bb2d1d

>From e17ba55102457f2d37bdea9adb49b47edddad115 Mon Sep 17 00:00:00 2001
From: Xu Zhang <simonzgx at gmail.com>
Date: Fri, 10 May 2024 17:46:40 +0800
Subject: [PATCH 2/2] add unit test

---
 clang/include/clang/Basic/AttrDocs.td   |  2 -
 clang/test/CodeGen/attr-ms-noinline.cpp | 53 ++++++++++++++++++++
 clang/test/Sema/attr-ms-noinline.cpp    | 66 +++++++++++++++++++++++++
 3 files changed, 119 insertions(+), 2 deletions(-)

diff --git a/clang/include/clang/Basic/AttrDocs.td b/clang/include/clang/Basic/AttrDocs.td
index 0ef636f716be5..8e6faabfae647 100644
--- a/clang/include/clang/Basic/AttrDocs.td
+++ b/clang/include/clang/Basic/AttrDocs.td
@@ -597,8 +597,6 @@ spellings of the attribute are not supported on statements. If a statement is
 marked ``[[clang::noinline]]`` and contains calls, those calls inside the
 statement will not be inlined by the compiler.
 
-``[[msvc::noinline]]`` 
-
 ``__noinline__`` can be used as a keyword in CUDA/HIP languages. This is to
 avoid diagnostics due to usage of ``__attribute__((__noinline__))``
 with ``__noinline__`` defined as a macro as ``__attribute__((noinline))``.
diff --git a/clang/test/CodeGen/attr-ms-noinline.cpp b/clang/test/CodeGen/attr-ms-noinline.cpp
index e69de29bb2d1d..99b0a05af715d 100644
--- a/clang/test/CodeGen/attr-ms-noinline.cpp
+++ b/clang/test/CodeGen/attr-ms-noinline.cpp
@@ -0,0 +1,53 @@
+// RUN: %clang_cc1 -emit-llvm %s -triple x86_64-unknown-linux-gnu -o - | FileCheck %s
+
+bool bar();
+void f(bool, bool);
+void g(bool);
+
+static int baz(int x) {
+    return x * 10;
+}
+
+[[msvc::noinline]] bool noi() { }
+
+void foo(int i) {
+  [[msvc::noinline]] bar();
+// CHECK: call noundef zeroext i1 @_Z3barv() #[[NOINLINEATTR:[0-9]+]]
+  [[msvc::noinline]] i = baz(i);
+// CHECK: call noundef i32 @_ZL3bazi({{.*}}) #[[NOINLINEATTR]]
+  [[msvc::noinline]] (i = 4, bar());
+// CHECK: call noundef zeroext i1 @_Z3barv() #[[NOINLINEATTR]]
+  [[msvc::noinline]] (void)(bar());
+// CHECK: call noundef zeroext i1 @_Z3barv() #[[NOINLINEATTR]]
+  [[msvc::noinline]] f(bar(), bar());
+// CHECK: call noundef zeroext i1 @_Z3barv() #[[NOINLINEATTR]]
+// CHECK: call noundef zeroext i1 @_Z3barv() #[[NOINLINEATTR]]
+// CHECK: call void @_Z1fbb({{.*}}) #[[NOINLINEATTR]]
+  [[msvc::noinline]] [] { bar(); bar(); }(); // noinline only applies to the anonymous function call
+// CHECK: call void @"_ZZ3fooiENK3$_0clEv"(ptr {{[^,]*}} %ref.tmp) #[[NOINLINEATTR]]
+  [[msvc::noinline]] for (bar(); bar(); bar()) {}
+// CHECK: call noundef zeroext i1 @_Z3barv() #[[NOINLINEATTR]]
+// CHECK: call noundef zeroext i1 @_Z3barv() #[[NOINLINEATTR]]
+// CHECK: call noundef zeroext i1 @_Z3barv() #[[NOINLINEATTR]]
+  bar();
+// CHECK: call noundef zeroext i1 @_Z3barv()
+  [[msvc::noinline]] noi();
+// CHECK: call noundef zeroext i1 @_Z3noiv()
+  noi();
+// CHECK: call noundef zeroext i1 @_Z3noiv()
+}
+
+struct S {
+  friend bool operator==(const S &LHS, const S &RHS);
+};
+
+void func(const S &s1, const S &s2) {
+  [[msvc::noinline]]g(s1 == s2);
+// CHECK: call noundef zeroext i1 @_ZeqRK1SS1_({{.*}}) #[[NOINLINEATTR]]
+// CHECK: call void @_Z1gb({{.*}}) #[[NOINLINEATTR]]
+  bool b;
+  [[msvc::noinline]] b = s1 == s2;
+// CHECK: call noundef zeroext i1 @_ZeqRK1SS1_({{.*}}) #[[NOINLINEATTR]]
+}
+
+// CHECK: attributes #[[NOINLINEATTR]] = { noinline }
diff --git a/clang/test/Sema/attr-ms-noinline.cpp b/clang/test/Sema/attr-ms-noinline.cpp
index e69de29bb2d1d..080939396565c 100644
--- a/clang/test/Sema/attr-ms-noinline.cpp
+++ b/clang/test/Sema/attr-ms-noinline.cpp
@@ -0,0 +1,66 @@
+// RUN: %clang_cc1 -verify -fsyntax-only %s -Wno-c++17-extensions
+
+int bar();
+
+void foo() {
+  [[msvc::noinline]] bar();
+  [[msvc::noinline(0)]] bar(); // expected-error {{'noinline' attribute takes no arguments}}
+  int x;
+  [[msvc::noinline]] x = 0; // expected-warning {{'noinline' attribute is ignored because there exists no call expression inside the statement}}
+  [[msvc::noinline]] { asm("nop"); } // expected-warning {{'noinline' attribute is ignored because there exists no call expression inside the statement}}
+  [[msvc::noinline]] label: x = 1; // expected-warning {{'noinline' attribute only applies to functions and statements}}
+
+
+  [[msvc::noinline]] always_inline_fn(); // expected-warning {{statement attribute 'noinline' has higher precedence than function attribute 'always_inline'}}
+  [[msvc::noinline]] flatten_fn(); // expected-warning {{statement attribute 'noinline' has higher precedence than function attribute 'flatten'}}
+  [[msvc::noinline]] noinline_fn();
+}
+
+[[msvc::noinline]] static int i = bar(); // expected-warning {{'noinline' attribute only applies to functions and statements}}
+
+// This used to crash the compiler.
+template<int D>
+int foo(int x) {
+  [[msvc::noinline]] return foo<D-1>(x + 1);
+}
+
+template<int D>
+[[clang::always_inline]]
+int dependent(int x){ return x + D;} // #DEP
+[[clang::always_inline]]
+int non_dependent(int x){return x;} // #NO_DEP
+
+template<int D> [[clang::always_inline]]
+int baz(int x) { // #BAZ
+  // expected-warning at +2{{statement attribute 'noinline' has higher precedence than function attribute 'always_inline'}}
+  // expected-note@#NO_DEP{{conflicting attribute is here}}
+  [[msvc::noinline]] non_dependent(x);
+  if constexpr (D>0) {
+    // expected-warning at +6{{statement attribute 'noinline' has higher precedence than function attribute 'always_inline'}}
+    // expected-note@#NO_DEP{{conflicting attribute is here}}
+    // expected-warning at +4 3{{statement attribute 'noinline' has higher precedence than function attribute 'always_inline'}}
+    // expected-note@#BAZ 3{{conflicting attribute is here}}
+    // expected-note@#BAZ_INST 3{{in instantiation}}
+    // expected-note at +1 3{{in instantiation}}
+    [[msvc::noinline]] return non_dependent(x), baz<D-1>(x + 1);
+  }
+  return x;
+}
+
+// We can't suppress if there is a variadic involved.
+template<int ... D>
+int variadic_baz(int x) {
+  // Diagnoses NO_DEP 2x, once during phase 1, the second during instantiation.
+  // Dianoses DEP 3x, once per variadic expansion.
+  // expected-warning at +5 2{{statement attribute 'noinline' has higher precedence than function attribute 'always_inline'}}
+  // expected-note@#NO_DEP 2{{conflicting attribute is here}}
+  // expected-warning at +3 3{{statement attribute 'noinline' has higher precedence than function attribute 'always_inline'}}
+  // expected-note@#DEP 3{{conflicting attribute is here}}
+  // expected-note@#VARIADIC_INST{{in instantiation}}
+  [[msvc::noinline]] return non_dependent(x) + (dependent<D>(x) + ...);
+}
+
+void use() {
+  baz<3>(0); // #BAZ_INST
+  variadic_baz<0, 1, 2>(0); // #VARIADIC_INST
+}



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