[clang-tidy] fix wrong float to float conversion check when floating point type is not standard type #122637
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@llvm/pr-subscribers-clang-tools-extra Author: Congcong Cai (HerrCai0907) Changescompare type kind is the wrong way to compare floating point type compatibility. Full diff: https://github.com/llvm/llvm-project/pull/122637.diff 3 Files Affected:
diff --git a/clang-tools-extra/clang-tidy/bugprone/NarrowingConversionsCheck.cpp b/clang-tools-extra/clang-tidy/bugprone/NarrowingConversionsCheck.cpp
index 408390ebc70b64..bafcd402ca8510 100644
--- a/clang-tools-extra/clang-tidy/bugprone/NarrowingConversionsCheck.cpp
+++ b/clang-tools-extra/clang-tidy/bugprone/NarrowingConversionsCheck.cpp
@@ -513,7 +513,9 @@ void NarrowingConversionsCheck::handleFloatingCast(const ASTContext &Context,
return;
}
const BuiltinType *FromType = getBuiltinType(Rhs);
- if (ToType->getKind() < FromType->getKind())
+ if (!llvm::APFloatBase::isRepresentableBy(
+ Context.getFloatTypeSemantics(FromType->desugar()),
+ Context.getFloatTypeSemantics(ToType->desugar())))
diagNarrowType(SourceLoc, Lhs, Rhs);
}
}
diff --git a/clang-tools-extra/docs/ReleaseNotes.rst b/clang-tools-extra/docs/ReleaseNotes.rst
index 835a0269a2733c..f709902cfd45e7 100644
--- a/clang-tools-extra/docs/ReleaseNotes.rst
+++ b/clang-tools-extra/docs/ReleaseNotes.rst
@@ -206,6 +206,11 @@ Changes in existing checks
<clang-tidy/checks/bugprone/forwarding-reference-overload>` check by fixing
a crash when determining if an ``enable_if[_t]`` was found.
+- Improve :doc:`bugprone-narrowing-conversions
+ <clang-tidy/checks/bugprone/narrowing-conversions>` to avoid incorrect check
+ results when floating point type is not ``float``, ``double`` and
+ ``long double``.
+
- Improved :doc:`bugprone-optional-value-conversion
<clang-tidy/checks/bugprone/optional-value-conversion>` to support detecting
conversion directly by ``std::make_unique`` and ``std::make_shared``.
diff --git a/clang-tools-extra/test/clang-tidy/checkers/bugprone/narrowing-conversions-narrowingfloatingpoint-option.cpp b/clang-tools-extra/test/clang-tidy/checkers/bugprone/narrowing-conversions-narrowingfloatingpoint-option.cpp
index 9ded2f0923f4e6..180b789e45bb37 100644
--- a/clang-tools-extra/test/clang-tidy/checkers/bugprone/narrowing-conversions-narrowingfloatingpoint-option.cpp
+++ b/clang-tools-extra/test/clang-tidy/checkers/bugprone/narrowing-conversions-narrowingfloatingpoint-option.cpp
@@ -36,6 +36,15 @@ void narrow_double_to_float_not_ok(double d) {
f = narrow_double_to_float_return();
}
+float narrow_float16_to_float_return(_Float16 f) {
+ return f;
+}
+
+_Float16 narrow_float_to_float16_return(float f) {
+ return f;
+ // CHECK-MESSAGES: :[[@LINE-1]]:10: warning: narrowing conversion from 'float' to '_Float16' [bugprone-narrowing-conversions]
+}
+
void narrow_fp_constants() {
float f;
f = 0.5; // [dcl.init.list] 7.2 : in-range fp constant to narrower float is not a narrowing.
|
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@llvm/pr-subscribers-clang-tidy Author: Congcong Cai (HerrCai0907) Changescompare type kind is the wrong way to compare floating point type compatibility. Full diff: https://github.com/llvm/llvm-project/pull/122637.diff 3 Files Affected:
diff --git a/clang-tools-extra/clang-tidy/bugprone/NarrowingConversionsCheck.cpp b/clang-tools-extra/clang-tidy/bugprone/NarrowingConversionsCheck.cpp
index 408390ebc70b64..bafcd402ca8510 100644
--- a/clang-tools-extra/clang-tidy/bugprone/NarrowingConversionsCheck.cpp
+++ b/clang-tools-extra/clang-tidy/bugprone/NarrowingConversionsCheck.cpp
@@ -513,7 +513,9 @@ void NarrowingConversionsCheck::handleFloatingCast(const ASTContext &Context,
return;
}
const BuiltinType *FromType = getBuiltinType(Rhs);
- if (ToType->getKind() < FromType->getKind())
+ if (!llvm::APFloatBase::isRepresentableBy(
+ Context.getFloatTypeSemantics(FromType->desugar()),
+ Context.getFloatTypeSemantics(ToType->desugar())))
diagNarrowType(SourceLoc, Lhs, Rhs);
}
}
diff --git a/clang-tools-extra/docs/ReleaseNotes.rst b/clang-tools-extra/docs/ReleaseNotes.rst
index 835a0269a2733c..f709902cfd45e7 100644
--- a/clang-tools-extra/docs/ReleaseNotes.rst
+++ b/clang-tools-extra/docs/ReleaseNotes.rst
@@ -206,6 +206,11 @@ Changes in existing checks
<clang-tidy/checks/bugprone/forwarding-reference-overload>` check by fixing
a crash when determining if an ``enable_if[_t]`` was found.
+- Improve :doc:`bugprone-narrowing-conversions
+ <clang-tidy/checks/bugprone/narrowing-conversions>` to avoid incorrect check
+ results when floating point type is not ``float``, ``double`` and
+ ``long double``.
+
- Improved :doc:`bugprone-optional-value-conversion
<clang-tidy/checks/bugprone/optional-value-conversion>` to support detecting
conversion directly by ``std::make_unique`` and ``std::make_shared``.
diff --git a/clang-tools-extra/test/clang-tidy/checkers/bugprone/narrowing-conversions-narrowingfloatingpoint-option.cpp b/clang-tools-extra/test/clang-tidy/checkers/bugprone/narrowing-conversions-narrowingfloatingpoint-option.cpp
index 9ded2f0923f4e6..180b789e45bb37 100644
--- a/clang-tools-extra/test/clang-tidy/checkers/bugprone/narrowing-conversions-narrowingfloatingpoint-option.cpp
+++ b/clang-tools-extra/test/clang-tidy/checkers/bugprone/narrowing-conversions-narrowingfloatingpoint-option.cpp
@@ -36,6 +36,15 @@ void narrow_double_to_float_not_ok(double d) {
f = narrow_double_to_float_return();
}
+float narrow_float16_to_float_return(_Float16 f) {
+ return f;
+}
+
+_Float16 narrow_float_to_float16_return(float f) {
+ return f;
+ // CHECK-MESSAGES: :[[@LINE-1]]:10: warning: narrowing conversion from 'float' to '_Float16' [bugprone-narrowing-conversions]
+}
+
void narrow_fp_constants() {
float f;
f = 0.5; // [dcl.init.list] 7.2 : in-range fp constant to narrower float is not a narrowing.
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January 13, 2025 22:12
…point type is not standard type compare type kind is the wrong way to compare floating point type compatibility. more generic compatibility check is needed.
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compare type kind is the wrong way to compare floating point type compatibility.
more generic compatibility check is needed.