[clang] [Clang] Fix warning for non std functions with name `infinity` (PR #123417)
Amr Hesham via cfe-commits
cfe-commits at lists.llvm.org
Sat Jan 18 11:53:48 PST 2025
https://github.com/AmrDeveloper updated https://github.com/llvm/llvm-project/pull/123417
>From 51dd53feb7a35d4fac648dd165fb5b99f73c6c24 Mon Sep 17 00:00:00 2001
From: AmrDeveloper <amr96 at programmer.net>
Date: Fri, 17 Jan 2025 23:32:48 +0100
Subject: [PATCH 1/4] [Clang] Fix invalid use of infinity warning
---
clang/lib/Sema/SemaChecking.cpp | 22 +++++++++-
.../Sema/warn-infinity-nan-disabled-lnx.cpp | 42 ++++++++++++++++--
.../Sema/warn-infinity-nan-disabled-win.cpp | 43 +++++++++++++++++--
3 files changed, 98 insertions(+), 9 deletions(-)
diff --git a/clang/lib/Sema/SemaChecking.cpp b/clang/lib/Sema/SemaChecking.cpp
index 881907ac311a30..3d2b2e1e96d2dd 100644
--- a/clang/lib/Sema/SemaChecking.cpp
+++ b/clang/lib/Sema/SemaChecking.cpp
@@ -8454,6 +8454,26 @@ static bool IsInfOrNanFunction(StringRef calleeName, MathCheck Check) {
llvm_unreachable("unknown MathCheck");
}
+static bool IsInfinityFunction(const FunctionDecl *FDecl) {
+ if (FDecl->getName() != "infinity") {
+ return false;
+ }
+
+ if (const CXXMethodDecl *MDecl = dyn_cast<CXXMethodDecl>(FDecl)) {
+ const CXXRecordDecl *RDecl = MDecl->getParent();
+ if (RDecl->getName() != "numeric_limits") {
+ return false;
+ }
+
+ if (const NamespaceDecl *NSDecl =
+ dyn_cast<NamespaceDecl>(RDecl->getDeclContext())) {
+ return NSDecl->isStdNamespace();
+ }
+ }
+
+ return false;
+}
+
void Sema::CheckInfNaNFunction(const CallExpr *Call,
const FunctionDecl *FDecl) {
FPOptions FPO = Call->getFPFeaturesInEffect(getLangOpts());
@@ -8469,7 +8489,7 @@ void Sema::CheckInfNaNFunction(const CallExpr *Call,
bool IsInfOrIsFinite =
IsStdFunction(FDecl, "isinf") || IsStdFunction(FDecl, "isfinite");
bool IsInfinityOrIsSpecialInf =
- HasIdentifier && ((FDecl->getName() == "infinity") ||
+ HasIdentifier && (IsInfinityFunction(FDecl) ||
IsInfOrNanFunction(FDecl->getName(), MathCheck::Inf));
if ((IsInfOrIsFinite || IsInfinityOrIsSpecialInf) && FPO.getNoHonorInfs())
Diag(Call->getBeginLoc(), diag::warn_fp_nan_inf_when_disabled)
diff --git a/clang/test/Sema/warn-infinity-nan-disabled-lnx.cpp b/clang/test/Sema/warn-infinity-nan-disabled-lnx.cpp
index 357c9e5b641073..4f46b777c88742 100644
--- a/clang/test/Sema/warn-infinity-nan-disabled-lnx.cpp
+++ b/clang/test/Sema/warn-infinity-nan-disabled-lnx.cpp
@@ -45,24 +45,48 @@ namespace std __attribute__((__visibility__("default"))) {
isnan(double __x);
bool
isnan(long double __x);
-bool
+ bool
isfinite(float __x);
bool
isfinite(double __x);
bool
isfinte(long double __x);
- bool
+ bool
isunordered(float __x, float __y);
bool
isunordered(double __x, double __y);
bool
isunordered(long double __x, long double __y);
+
+template <class _Ty>
+class numeric_limits {
+public:
+ [[nodiscard]] static constexpr _Ty infinity() noexcept {
+ return _Ty();
+ }
+};
} // namespace )
}
#define NAN (__builtin_nanf(""))
#define INFINITY (__builtin_inff())
+template <>
+class std::numeric_limits<float> {
+public:
+ [[nodiscard]] static constexpr float infinity() noexcept {
+ return __builtin_huge_val();
+ }
+};
+
+template <>
+class std::numeric_limits<double> {
+public:
+ [[nodiscard]] static constexpr double infinity() noexcept {
+ return __builtin_huge_val();
+ }
+};
+
template <class _Ty>
class numeric_limits {
public:
@@ -78,6 +102,7 @@ class numeric_limits<float> {
return __builtin_huge_val();
}
};
+
template <>
class numeric_limits<double> {
public:
@@ -86,6 +111,8 @@ class numeric_limits<double> {
}
};
+double infinity() { return 0; }
+
int compareit(float a, float b) {
volatile int i, j, k, l, m, n, o, p;
// no-inf-no-nan-warning at +4 {{use of infinity is undefined behavior due to the currently enabled floating-point options}}
@@ -225,11 +252,18 @@ int compareit(float a, float b) {
// no-inf-no-nan-warning at +2 {{use of infinity is undefined behavior due to the currently enabled floating-point options}}
// no-inf-warning at +1 {{use of infinity is undefined behavior due to the currently enabled floating-point options}}
- double y = i * numeric_limits<double>::infinity();
+ double y = i * std::numeric_limits<double>::infinity();
+
+ y = i * numeric_limits<double>::infinity(); // expected-no-diagnostics
// no-inf-no-nan-warning at +2 {{use of infinity is undefined behavior due to the currently enabled floating-point options}}
// no-inf-warning at +1 {{use of infinity is undefined behavior due to the currently enabled floating-point options}}
- j = numeric_limits<float>::infinity();
+ j = std::numeric_limits<float>::infinity();
+
+ j = numeric_limits<float>::infinity(); // expected-no-diagnostics
+
+ y = infinity(); // expected-no-diagnostics
+
return 0;
}
diff --git a/clang/test/Sema/warn-infinity-nan-disabled-win.cpp b/clang/test/Sema/warn-infinity-nan-disabled-win.cpp
index ee4eb33a16e449..655024f5909b33 100644
--- a/clang/test/Sema/warn-infinity-nan-disabled-win.cpp
+++ b/clang/test/Sema/warn-infinity-nan-disabled-win.cpp
@@ -48,24 +48,49 @@ namespace std __attribute__((__visibility__("default"))) {
isnan(double __x);
bool
isnan(long double __x);
-bool
+ bool
isfinite(float __x);
bool
isfinite(double __x);
bool
isfinte(long double __x);
- bool
+ bool
isunordered(float __x, float __y);
bool
isunordered(double __x, double __y);
bool
isunordered(long double __x, long double __y);
+
+template <class _Ty>
+class numeric_limits {
+public:
+ [[nodiscard]] static constexpr _Ty infinity() noexcept {
+ return _Ty();
+ }
+};
+
} // namespace )
}
#define INFINITY ((float)(1e+300 * 1e+300))
#define NAN (-(float)(INFINITY * 0.0F))
+template <>
+class std::numeric_limits<float> {
+public:
+ [[nodiscard]] static constexpr float infinity() noexcept {
+ return __builtin_huge_val();
+ }
+};
+
+template <>
+class std::numeric_limits<double> {
+public:
+ [[nodiscard]] static constexpr double infinity() noexcept {
+ return __builtin_huge_val();
+ }
+};
+
template <class _Ty>
class numeric_limits {
public:
@@ -81,6 +106,7 @@ class numeric_limits<float> {
return __builtin_huge_val();
}
};
+
template <>
class numeric_limits<double> {
public:
@@ -89,6 +115,8 @@ class numeric_limits<double> {
}
};
+double infinity() { return 0; }
+
int compareit(float a, float b) {
volatile int i, j, k, l, m, n, o, p;
// no-inf-no-nan-warning at +2 {{use of infinity via a macro is undefined behavior due to the currently enabled floating-point options}}
@@ -216,11 +244,18 @@ int compareit(float a, float b) {
// no-inf-no-nan-warning at +2 {{use of infinity is undefined behavior due to the currently enabled floating-point options}}
// no-inf-warning at +1 {{use of infinity is undefined behavior due to the currently enabled floating-point options}}
- double y = i * numeric_limits<double>::infinity();
+ double y = i * std::numeric_limits<double>::infinity();
+
+ y = i * numeric_limits<double>::infinity(); // expected-no-diagnostics
// no-inf-no-nan-warning at +2 {{use of infinity is undefined behavior due to the currently enabled floating-point options}}
// no-inf-warning at +1 {{use of infinity is undefined behavior due to the currently enabled floating-point options}}
- j = numeric_limits<float>::infinity();
+ j = std::numeric_limits<float>::infinity();
+
+ j = numeric_limits<float>::infinity(); // expected-no-diagnostics
+
+ y = infinity(); // expected-no-diagnostics
+
return 0;
}
>From 0023e155b41dad2b6c571162db64c64be9d3596c Mon Sep 17 00:00:00 2001
From: AmrDeveloper <amr96 at programmer.net>
Date: Sat, 18 Jan 2025 18:44:05 +0100
Subject: [PATCH 2/4] Optimize CheckInfNaNFunction function
---
clang/lib/Sema/SemaChecking.cpp | 31 ++++++++++++++++---------------
1 file changed, 16 insertions(+), 15 deletions(-)
diff --git a/clang/lib/Sema/SemaChecking.cpp b/clang/lib/Sema/SemaChecking.cpp
index 3d2b2e1e96d2dd..d0cdfdad723f3b 100644
--- a/clang/lib/Sema/SemaChecking.cpp
+++ b/clang/lib/Sema/SemaChecking.cpp
@@ -8476,24 +8476,25 @@ static bool IsInfinityFunction(const FunctionDecl *FDecl) {
void Sema::CheckInfNaNFunction(const CallExpr *Call,
const FunctionDecl *FDecl) {
+ if (!FDecl->getIdentifier()) {
+ return;
+ }
+
FPOptions FPO = Call->getFPFeaturesInEffect(getLangOpts());
- bool HasIdentifier = FDecl->getIdentifier() != nullptr;
- bool IsNaNOrIsUnordered =
- IsStdFunction(FDecl, "isnan") || IsStdFunction(FDecl, "isunordered");
- bool IsSpecialNaN =
- HasIdentifier && IsInfOrNanFunction(FDecl->getName(), MathCheck::NaN);
- if ((IsNaNOrIsUnordered || IsSpecialNaN) && FPO.getNoHonorNaNs()) {
+ if (FPO.getNoHonorNaNs() &&
+ (IsStdFunction(FDecl, "isnan") || IsStdFunction(FDecl, "isunordered") ||
+ IsInfOrNanFunction(FDecl->getName(), MathCheck::NaN))) {
Diag(Call->getBeginLoc(), diag::warn_fp_nan_inf_when_disabled)
<< 1 << 0 << Call->getSourceRange();
- } else {
- bool IsInfOrIsFinite =
- IsStdFunction(FDecl, "isinf") || IsStdFunction(FDecl, "isfinite");
- bool IsInfinityOrIsSpecialInf =
- HasIdentifier && (IsInfinityFunction(FDecl) ||
- IsInfOrNanFunction(FDecl->getName(), MathCheck::Inf));
- if ((IsInfOrIsFinite || IsInfinityOrIsSpecialInf) && FPO.getNoHonorInfs())
- Diag(Call->getBeginLoc(), diag::warn_fp_nan_inf_when_disabled)
- << 0 << 0 << Call->getSourceRange();
+ return;
+ }
+
+ if (FPO.getNoHonorInfs() &&
+ (IsStdFunction(FDecl, "isinf") || IsStdFunction(FDecl, "isfinite") ||
+ IsInfinityFunction(FDecl) ||
+ IsInfOrNanFunction(FDecl->getName(), MathCheck::Inf))) {
+ Diag(Call->getBeginLoc(), diag::warn_fp_nan_inf_when_disabled)
+ << 0 << 0 << Call->getSourceRange();
}
}
>From 0bb6cf1b06d88de0b91ebf394d525497d03fc407 Mon Sep 17 00:00:00 2001
From: AmrDeveloper <amr96 at programmer.net>
Date: Sat, 18 Jan 2025 20:45:55 +0100
Subject: [PATCH 3/4] Add changelog entry
---
clang/docs/ReleaseNotes.rst | 2 ++
1 file changed, 2 insertions(+)
diff --git a/clang/docs/ReleaseNotes.rst b/clang/docs/ReleaseNotes.rst
index aa1c02d04f7caa..2c5cf71bfbe045 100644
--- a/clang/docs/ReleaseNotes.rst
+++ b/clang/docs/ReleaseNotes.rst
@@ -791,6 +791,8 @@ Improvements to Clang's diagnostics
}
- Diagnose invalid declarators in the declaration of constructors and destructors (#GH121706).
+- Fix false positives warning for non-std functions with name `infinity` (#123231).
+
Improvements to Clang's time-trace
----------------------------------
>From 6b72d636d8a3d445e2c755e995e9273e0645ba97 Mon Sep 17 00:00:00 2001
From: AmrDeveloper <amr96 at programmer.net>
Date: Sat, 18 Jan 2025 20:53:31 +0100
Subject: [PATCH 4/4] Address code review nits
---
clang/lib/Sema/SemaChecking.cpp | 12 ++++--------
1 file changed, 4 insertions(+), 8 deletions(-)
diff --git a/clang/lib/Sema/SemaChecking.cpp b/clang/lib/Sema/SemaChecking.cpp
index d0cdfdad723f3b..c41164a2f1af1c 100644
--- a/clang/lib/Sema/SemaChecking.cpp
+++ b/clang/lib/Sema/SemaChecking.cpp
@@ -8455,20 +8455,17 @@ static bool IsInfOrNanFunction(StringRef calleeName, MathCheck Check) {
}
static bool IsInfinityFunction(const FunctionDecl *FDecl) {
- if (FDecl->getName() != "infinity") {
+ if (FDecl->getName() != "infinity")
return false;
- }
if (const CXXMethodDecl *MDecl = dyn_cast<CXXMethodDecl>(FDecl)) {
const CXXRecordDecl *RDecl = MDecl->getParent();
- if (RDecl->getName() != "numeric_limits") {
+ if (RDecl->getName() != "numeric_limits")
return false;
- }
if (const NamespaceDecl *NSDecl =
- dyn_cast<NamespaceDecl>(RDecl->getDeclContext())) {
+ dyn_cast<NamespaceDecl>(RDecl->getDeclContext()))
return NSDecl->isStdNamespace();
- }
}
return false;
@@ -8476,9 +8473,8 @@ static bool IsInfinityFunction(const FunctionDecl *FDecl) {
void Sema::CheckInfNaNFunction(const CallExpr *Call,
const FunctionDecl *FDecl) {
- if (!FDecl->getIdentifier()) {
+ if (!FDecl->getIdentifier())
return;
- }
FPOptions FPO = Call->getFPFeaturesInEffect(getLangOpts());
if (FPO.getNoHonorNaNs() &&
More information about the cfe-commits
mailing list