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[CLANG] Emit warning in finite math mode when INF and NAN are used. #99672

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Merged
merged 8 commits into from
Jul 25, 2024
Merged

[CLANG] Emit warning in finite math mode when INF and NAN are used. #99672

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452bc42
Fix issue https://github.com/llvm/llvm-project/issues/98018.
zahiraam Jul 19, 2024
523f73d
Addressed review comments.
zahiraam Jul 22, 2024
36094bf
Fix format.
zahiraam Jul 22, 2024
24b1d4c
Addressed review comments.
zahiraam Jul 24, 2024
057098f
Put back the FIXME.
zahiraam Jul 25, 2024
6c38f89
Put back the FIXME.
zahiraam Jul 25, 2024
93c7f57
Merge branch 'FixIssue98018' of https://github.com/zahiraam/llvm-proj…
zahiraam Jul 25, 2024
a7cb20f
Fix LIT test.
zahiraam Jul 25, 2024
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45 changes: 36 additions & 9 deletions clang/lib/Sema/SemaChecking.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -8198,20 +8198,47 @@ static bool IsStdFunction(const FunctionDecl *FDecl,
return true;
}

enum class MathCheck { NaN, Inf };
static bool IsInfOrNanFunction(StringRef calleeName, MathCheck Check) {
auto MatchesAny = [&](std::initializer_list<llvm::StringRef> names) {
return std::any_of(names.begin(), names.end(), [&](llvm::StringRef name) {
return calleeName == name;
});
};

switch (Check) {
case MathCheck::NaN:
return MatchesAny({"__builtin_nan", "__builtin_nanf", "__builtin_nanl",
"__builtin_nanf16", "__builtin_nanf128"});
case MathCheck::Inf:
return MatchesAny({"__builtin_inf", "__builtin_inff", "__builtin_infl",
"__builtin_inff16", "__builtin_inff128"});
default:
return false;
}
}

void Sema::CheckInfNaNFunction(const CallExpr *Call,
const FunctionDecl *FDecl) {
FPOptions FPO = Call->getFPFeaturesInEffect(getLangOpts());
if ((IsStdFunction(FDecl, "isnan") || IsStdFunction(FDecl, "isunordered") ||
(Call->getBuiltinCallee() == Builtin::BI__builtin_nanf)) &&
FPO.getNoHonorNaNs())
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()) {
Diag(Call->getBeginLoc(), diag::warn_fp_nan_inf_when_disabled)
<< 1 << 0 << Call->getSourceRange();
else if ((IsStdFunction(FDecl, "isinf") ||
(IsStdFunction(FDecl, "isfinite") ||
(FDecl->getIdentifier() && FDecl->getName() == "infinity"))) &&
FPO.getNoHonorInfs())
Diag(Call->getBeginLoc(), diag::warn_fp_nan_inf_when_disabled)
<< 0 << 0 << Call->getSourceRange();
} else {
bool IsInfOrIsFinite =
IsStdFunction(FDecl, "isinf") || IsStdFunction(FDecl, "isfinite");
bool IsInfinityOrIsSpecialInf =
HasIdentifier && ((FDecl->getName() == "infinity") ||
IsInfOrNanFunction(FDecl->getName(), MathCheck::Inf));
if ((IsInfOrIsFinite || IsInfinityOrIsSpecialInf) && FPO.getNoHonorInfs())
Diag(Call->getBeginLoc(), diag::warn_fp_nan_inf_when_disabled)
<< 0 << 0 << Call->getSourceRange();
}
}

void Sema::CheckAbsoluteValueFunction(const CallExpr *Call,
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5 changes: 3 additions & 2 deletions clang/test/Headers/float.c
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Original file line number Diff line number Diff line change
Expand Up @@ -223,8 +223,9 @@
#ifndef NAN
#error "Mandatory macro NAN is missing."
#endif
// FIXME: the NAN diagnostic should only be issued once, not twice.
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The fixme shouldn't be removed but updated to say the infinity and nan diagnostics should only be issued once, not twice.

_Static_assert(_Generic(INFINITY, float : 1, default : 0), ""); // finite-warning {{use of infinity via a macro is undefined behavior due to the currently enabled floating-point options}}
// FIXME: the NAN and INF diagnostics should only be issued once, not twice.
_Static_assert(_Generic(INFINITY, float : 1, default : 0), ""); // finite-warning {{use of infinity via a macro is undefined behavior due to the currently enabled floating-point options}} \
finite-warning {{use of infinity is undefined behavior due to the currently enabled floating-point options}}
_Static_assert(_Generic(NAN, float : 1, default : 0), ""); // finite-warning {{use of NaN is undefined behavior due to the currently enabled floating-point options}} \
finite-warning {{use of NaN via a macro is undefined behavior due to the currently enabled floating-point options}}

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28 changes: 20 additions & 8 deletions clang/test/Sema/warn-infinity-nan-disabled-lnx.cpp
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Expand Up @@ -87,11 +87,15 @@ class numeric_limits<double> {

int compareit(float a, float b) {
volatile int i, j, k, l, m, n, o, p;
// no-inf-no-nan-warning@+2 {{use of infinity via a macro is undefined behavior due to the currently enabled floating-point options}}
// no-inf-no-nan-warning@+4 {{use of infinity is undefined behavior due to the currently enabled floating-point options}}
// no-inf-no-nan-warning@+3 {{use of infinity via a macro is undefined behavior due to the currently enabled floating-point options}}
// no-inf-warning@+2 {{use of infinity is undefined behavior due to the currently enabled floating-point options}}
// no-inf-warning@+1 {{use of infinity via a macro is undefined behavior due to the currently enabled floating-point options}}
i = a == INFINITY;

// no-inf-no-nan-warning@+2 {{use of infinity via a macro is undefined behavior due to the currently enabled floating-point options}}
// no-inf-no-nan-warning@+4 {{use of infinity is undefined behavior due to the currently enabled floating-point options}}
// no-inf-no-nan-warning@+3 {{use of infinity via a macro is undefined behavior due to the currently enabled floating-point options}}
// no-inf-warning@+2 {{use of infinity is undefined behavior due to the currently enabled floating-point options}}
// no-inf-warning@+1 {{use of infinity via a macro is undefined behavior due to the currently enabled floating-point options}}
j = INFINITY == a;

Expand All @@ -107,11 +111,15 @@ int compareit(float a, float b) {
// no-nan-warning@+1 {{use of NaN via a macro is undefined behavior due to the currently enabled floating-point options}}
j = NAN == a;

// no-inf-no-nan-warning@+2 {{use of infinity via a macro is undefined behavior due to the currently enabled floating-point options}}
// no-inf-no-nan-warning@+4 {{use of infinity is undefined behavior due to the currently enabled floating-point options}}
// no-inf-no-nan-warning@+3 {{use of infinity via a macro is undefined behavior due to the currently enabled floating-point options}}
// no-inf-warning@+2 {{use of infinity is undefined behavior due to the currently enabled floating-point options}}
// no-inf-warning@+1 {{use of infinity via a macro is undefined behavior due to the currently enabled floating-point options}}
j = INFINITY <= a;

// no-inf-no-nan-warning@+2 {{use of infinity via a macro is undefined behavior due to the currently enabled floating-point options}}
// no-inf-no-nan-warning@+4 {{use of infinity is undefined behavior due to the currently enabled floating-point options}}
// no-inf-no-nan-warning@+3 {{use of infinity via a macro is undefined behavior due to the currently enabled floating-point options}}
// no-inf-warning@+2 {{use of infinity is undefined behavior due to the currently enabled floating-point options}}
// no-inf-warning@+1 {{use of infinity via a macro is undefined behavior due to the currently enabled floating-point options}}
j = INFINITY < a;

Expand Down Expand Up @@ -192,7 +200,9 @@ int compareit(float a, float b) {
// no-nan-warning@+1 {{use of NaN is undefined behavior due to the currently enabled floating-point options}}
j = isunorderedf(a, NAN);

// no-inf-no-nan-warning@+2 {{use of infinity via a macro is undefined behavior due to the currently enabled floating-point options}}
// no-inf-no-nan-warning@+4 {{use of infinity is undefined behavior due to the currently enabled floating-point options}}
// no-inf-no-nan-warning@+3 {{use of infinity via a macro is undefined behavior due to the currently enabled floating-point options}}
// no-inf-warning@+2 {{use of infinity is undefined behavior due to the currently enabled floating-point options}}
// no-inf-warning@+1 {{use of infinity via a macro is undefined behavior due to the currently enabled floating-point options}}
j = isunorderedf(a, INFINITY);

Expand All @@ -204,9 +214,11 @@ int compareit(float a, float b) {
// no-nan-warning@+1 {{use of NaN is undefined behavior due to the currently enabled floating-point options}}
i = std::isunordered(a, NAN);

// no-inf-no-nan-warning@+4 {{use of infinity via a macro is undefined behavior due to the currently enabled floating-point options}}
// no-inf-no-nan-warning@+3 {{use of NaN is undefined behavior due to the currently enabled floating-point options}}
// no-inf-warning@+2 {{use of infinity via a macro is undefined behavior due to the currently enabled floating-point options}}
// no-inf-no-nan-warning@+6 {{use of infinity is undefined behavior due to the currently enabled floating-point options}}
// no-inf-no-nan-warning@+5 {{use of infinity via a macro is undefined behavior due to the currently enabled floating-point options}}
// no-inf-no-nan-warning@+4 {{use of NaN is undefined behavior due to the currently enabled floating-point options}}
// no-inf-warning@+3 {{use of infinity via a macro is undefined behavior due to the currently enabled floating-point options}}
// no-inf-warning@+2 {{use of infinity is undefined behavior due to the currently enabled floating-point options}}
// no-nan-warning@+1 {{use of NaN is undefined behavior due to the currently enabled floating-point options}}
i = std::isunordered(a, INFINITY);

Expand Down
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