[clang] [clang] The ms-extension __noop should return zero in a constexpr context. (PR #106849)
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Sat Aug 31 17:14:04 PDT 2024
https://github.com/c8ef updated https://github.com/llvm/llvm-project/pull/106849
>From 6ce4604725d36afaea17cf533d422a978c4389ff Mon Sep 17 00:00:00 2001
From: c8ef <c8ef at outlook.com>
Date: Fri, 30 Aug 2024 15:34:34 +0000
Subject: [PATCH 1/5] fix cast
---
clang/lib/AST/ExprConstant.cpp | 2 +-
clang/test/AST/atomic-expr.c | 10 ++++++++++
2 files changed, 11 insertions(+), 1 deletion(-)
create mode 100644 clang/test/AST/atomic-expr.c
diff --git a/clang/lib/AST/ExprConstant.cpp b/clang/lib/AST/ExprConstant.cpp
index e8a4d1d3c74102..0571771e2a7e7d 100644
--- a/clang/lib/AST/ExprConstant.cpp
+++ b/clang/lib/AST/ExprConstant.cpp
@@ -14458,7 +14458,6 @@ bool IntExprEvaluator::VisitCastExpr(const CastExpr *E) {
case CK_IntegralComplexToFloatingComplex:
case CK_BuiltinFnToFnPtr:
case CK_ZeroToOCLOpaqueType:
- case CK_NonAtomicToAtomic:
case CK_AddressSpaceConversion:
case CK_IntToOCLSampler:
case CK_FloatingToFixedPoint:
@@ -14482,6 +14481,7 @@ bool IntExprEvaluator::VisitCastExpr(const CastExpr *E) {
case CK_UserDefinedConversion:
case CK_LValueToRValue:
case CK_AtomicToNonAtomic:
+ case CK_NonAtomicToAtomic:
case CK_NoOp:
case CK_LValueToRValueBitCast:
case CK_HLSLArrayRValue:
diff --git a/clang/test/AST/atomic-expr.c b/clang/test/AST/atomic-expr.c
new file mode 100644
index 00000000000000..0826a6491e8a6a
--- /dev/null
+++ b/clang/test/AST/atomic-expr.c
@@ -0,0 +1,10 @@
+// RUN: %clang_cc1 -fsyntax-only %s -verify
+// expected-no-diagnostics
+
+typedef _Atomic char atomic_char;
+
+atomic_char counter;
+
+char load_plus_one() {
+ return ({ counter; }) + 1;
+}
\ No newline at end of file
>From f0957df83597a2c43a8510a83619ef67c918c7d6 Mon Sep 17 00:00:00 2001
From: c8ef <c8ef at outlook.com>
Date: Sat, 31 Aug 2024 21:19:46 +0800
Subject: [PATCH 2/5] __noop should return 0
---
clang/lib/AST/ExprConstant.cpp | 4 ++--
clang/test/SemaCXX/builtins.cpp | 1 +
2 files changed, 3 insertions(+), 2 deletions(-)
diff --git a/clang/lib/AST/ExprConstant.cpp b/clang/lib/AST/ExprConstant.cpp
index 0571771e2a7e7d..69d2707aed9171 100644
--- a/clang/lib/AST/ExprConstant.cpp
+++ b/clang/lib/AST/ExprConstant.cpp
@@ -12720,8 +12720,8 @@ bool IntExprEvaluator::VisitBuiltinCallExpr(const CallExpr *E,
}
case Builtin::BI__noop:
- // __noop always evaluates successfully
- return true;
+ // __noop always evaluates successfully
+ return false;
case Builtin::BI__builtin_is_constant_evaluated: {
const auto *Callee = Info.CurrentCall->getCallee();
diff --git a/clang/test/SemaCXX/builtins.cpp b/clang/test/SemaCXX/builtins.cpp
index c6fbb8b514d671..78344c45092a79 100644
--- a/clang/test/SemaCXX/builtins.cpp
+++ b/clang/test/SemaCXX/builtins.cpp
@@ -178,4 +178,5 @@ static void __builtin_cpu_init(); // expected-error {{static declaration of '__b
#ifdef _MSC_VER
constexpr int x = []{ __noop; return 0; }(); // expected-no-diagnostics
+static_assert([] { return __noop; }() == 0);
#endif
>From a53cbbb4f3aaf65d0ebb49602f76d7f648e80410 Mon Sep 17 00:00:00 2001
From: c8ef <c8ef at outlook.com>
Date: Sat, 31 Aug 2024 21:22:47 +0800
Subject: [PATCH 3/5] Revert "fix cast"
This reverts commit 6ce4604725d36afaea17cf533d422a978c4389ff.
---
clang/lib/AST/ExprConstant.cpp | 2 +-
clang/test/AST/atomic-expr.c | 10 ----------
2 files changed, 1 insertion(+), 11 deletions(-)
delete mode 100644 clang/test/AST/atomic-expr.c
diff --git a/clang/lib/AST/ExprConstant.cpp b/clang/lib/AST/ExprConstant.cpp
index 69d2707aed9171..57040043f74193 100644
--- a/clang/lib/AST/ExprConstant.cpp
+++ b/clang/lib/AST/ExprConstant.cpp
@@ -14458,6 +14458,7 @@ bool IntExprEvaluator::VisitCastExpr(const CastExpr *E) {
case CK_IntegralComplexToFloatingComplex:
case CK_BuiltinFnToFnPtr:
case CK_ZeroToOCLOpaqueType:
+ case CK_NonAtomicToAtomic:
case CK_AddressSpaceConversion:
case CK_IntToOCLSampler:
case CK_FloatingToFixedPoint:
@@ -14481,7 +14482,6 @@ bool IntExprEvaluator::VisitCastExpr(const CastExpr *E) {
case CK_UserDefinedConversion:
case CK_LValueToRValue:
case CK_AtomicToNonAtomic:
- case CK_NonAtomicToAtomic:
case CK_NoOp:
case CK_LValueToRValueBitCast:
case CK_HLSLArrayRValue:
diff --git a/clang/test/AST/atomic-expr.c b/clang/test/AST/atomic-expr.c
deleted file mode 100644
index 0826a6491e8a6a..00000000000000
--- a/clang/test/AST/atomic-expr.c
+++ /dev/null
@@ -1,10 +0,0 @@
-// RUN: %clang_cc1 -fsyntax-only %s -verify
-// expected-no-diagnostics
-
-typedef _Atomic char atomic_char;
-
-atomic_char counter;
-
-char load_plus_one() {
- return ({ counter; }) + 1;
-}
\ No newline at end of file
>From a3727d3ab517a78b85792378b473f3d531e8532c Mon Sep 17 00:00:00 2001
From: c8ef <c8ef at outlook.com>
Date: Sat, 31 Aug 2024 22:11:24 +0800
Subject: [PATCH 4/5] __noop should return 0
---
clang/lib/AST/ExprConstant.cpp | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/clang/lib/AST/ExprConstant.cpp b/clang/lib/AST/ExprConstant.cpp
index 57040043f74193..55b51c2d25f7f6 100644
--- a/clang/lib/AST/ExprConstant.cpp
+++ b/clang/lib/AST/ExprConstant.cpp
@@ -12721,7 +12721,7 @@ bool IntExprEvaluator::VisitBuiltinCallExpr(const CallExpr *E,
case Builtin::BI__noop:
// __noop always evaluates successfully
- return false;
+ return ZeroInitialization(E);
case Builtin::BI__builtin_is_constant_evaluated: {
const auto *Callee = Info.CurrentCall->getCallee();
>From cc6f2087a4d4f3e556d6411cf839648571571b18 Mon Sep 17 00:00:00 2001
From: c8ef <c8ef at outlook.com>
Date: Sun, 1 Sep 2024 08:13:47 +0800
Subject: [PATCH 5/5] add more test
---
clang/test/SemaCXX/builtins.cpp | 17 ++++++++++++++++-
1 file changed, 16 insertions(+), 1 deletion(-)
diff --git a/clang/test/SemaCXX/builtins.cpp b/clang/test/SemaCXX/builtins.cpp
index 78344c45092a79..f47ed3a1f7ebfc 100644
--- a/clang/test/SemaCXX/builtins.cpp
+++ b/clang/test/SemaCXX/builtins.cpp
@@ -177,6 +177,21 @@ static void __builtin_cpu_init(); // expected-error {{static declaration of '__b
#endif
#ifdef _MSC_VER
-constexpr int x = []{ __noop; return 0; }(); // expected-no-diagnostics
+constexpr int x = [] {
+ __noop;
+ return 0;
+}(); // expected-no-diagnostics
static_assert([] { return __noop; }() == 0);
+static_assert([] { return __noop(4); }() == 0);
+extern int not_accessed;
+void not_called();
+static_assert([] { return __noop(not_accessed *= 6); }() == 0);
+static_assert([] { return __noop(not_called()); }() == 0);
+static_assert([] { return __noop(throw ""); }() == 0);
+static_assert([] { return __noop(throw "", throw ""); }() == 0);
+static_assert([] {
+ int a = 5;
+ __noop(++a);
+ return a;
+}() == 5);
#endif
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