xbolva00 updated this revision to Diff 172509.
https://reviews.llvm.org/D52835
Files:
include/clang/Basic/DiagnosticSemaKinds.td
lib/Sema/SemaChecking.cpp
test/Sema/ext_vector_casts.c
test/Sema/impcast-integer-float.c
Index: test/Sema/impcast-integer-float.c
===================================================================
--- test/Sema/impcast-integer-float.c
+++ test/Sema/impcast-integer-float.c
@@ -0,0 +1,25 @@
+// RUN: %clang_cc1 %s -verify -Wfloat-precision -fsyntax-only
+
+#define shift_plus_one(x) ((1ULL << x) + 1)
+
+void test(void) {
+ float a1 = (1ULL << 31) + 1; // expected-warning {{implicit conversion from 'unsigned long long' to 'float' changes value from 2147483649 to 2.1474836E+9}}
+ float a2 = 1ULL << 31;
+ float a3 = shift_plus_one(31); // expected-warning {{implicit conversion from 'unsigned long long' to 'float' changes value from 2147483649 to 2.1474836E+9}}
+ float a4 = (1ULL << 31) - 1; // expected-warning {{implicit conversion from 'unsigned long long' to 'float' changes value from 2147483647 to 2.1474836E+9}}
+
+ double b1 = (1ULL << 63) + 1; // expected-warning {{implicit conversion from 'unsigned long long' to 'double' changes value from 9223372036854775809 to 9.223372036854775E+18}}
+ double b2 = 1ULL << 63;
+ double b3 = shift_plus_one(63); // expected-warning {{implicit conversion from 'unsigned long long' to 'double' changes value from 9223372036854775809 to 9.223372036854775E+18}}
+ double b4 = (1ULL << 63) - 1; // expected-warning {{implicit conversion from 'unsigned long long' to 'double' changes value from 9223372036854775807 to 9.223372036854775E+18}}
+
+ long double c1 = ((__int128)1 << 127) + 1; // expected-warning {{implicit conversion from '__int128' to 'long double' changes value from -170141183460469231731687303715884105727 to -1.7014118346046923173E+38}}
+ long double c2 = (__int128)1 << 127;
+
+ _Float16 d1 = (1ULL << 15) + 1; // expected-warning {{implicit conversion from 'unsigned long long' to '_Float16' changes value from 32769 to 3.277E+4}}
+ _Float16 d2 = 1ULL << 15;
+ _Float16 d3 = shift_plus_one(15); // expected-warning {{implicit conversion from 'unsigned long long' to '_Float16' changes value from 32769 to 3.277E+4}}
+ _Float16 d4 = (1ULL << 15) - 1; // expected-warning {{implicit conversion from 'unsigned long long' to '_Float16' changes value from 32767 to 3.277E+4}}
+
+ float e = (__uint128_t)-1; // expected-warning {{implicit conversion from '__uint128_t' (aka 'unsigned __int128') to 'float' changes value from 340282366920938463463374607431768211455 to +Inf}}
+}
Index: test/Sema/ext_vector_casts.c
===================================================================
--- test/Sema/ext_vector_casts.c
+++ test/Sema/ext_vector_casts.c
@@ -118,7 +118,7 @@
vf = l + vf;
vf = 2.0 + vf;
vf = d + vf; // expected-warning {{implicit conversion loses floating-point precision}}
- vf = vf + 0xffffffff;
+ vf = vf + 0xffffffff; // expected-warning {{implicit conversion from 'unsigned int' to 'float2' (vector of 2 'float' values) changes value from 4294967295 to 4.2949673E+9}}
vf = vf + 2.1; // expected-warning {{implicit conversion loses floating-point precision}}
vd = l + vd;
Index: lib/Sema/SemaChecking.cpp
===================================================================
--- lib/Sema/SemaChecking.cpp
+++ lib/Sema/SemaChecking.cpp
@@ -105,6 +105,19 @@
Context.getTargetInfo());
}
+// FIXME: Force the precision of the source value down so we don't print
+// digits which are usually useless (we don't really care here if we
+// truncate a digit by accident in edge cases). Ideally, APFloat::toString
+// would automatically print the shortest representation, but it's a bit
+// tricky to implement.
+static void PrettyPrintFloat(const llvm::APFloat &floatValue,
+ const llvm::fltSemantics &floatSem,
+ SmallVectorImpl<char> &prettyFloatValue) {
+ unsigned precision = llvm::APFloat::semanticsPrecision(floatSem);
+ precision = llvm::divideCeil(precision * 59, 196);
+ floatValue.toString(prettyFloatValue, precision);
+}
+
/// Checks that a call expression's argument count is the desired number.
/// This is useful when doing custom type-checking. Returns true on error.
static bool checkArgCount(Sema &S, CallExpr *call, unsigned desiredArgCount) {
@@ -10467,15 +10480,8 @@
DiagID = diag::warn_impcast_float_to_integer;
}
- // FIXME: Force the precision of the source value down so we don't print
- // digits which are usually useless (we don't really care here if we
- // truncate a digit by accident in edge cases). Ideally, APFloat::toString
- // would automatically print the shortest representation, but it's a bit
- // tricky to implement.
SmallString<16> PrettySourceValue;
- unsigned precision = llvm::APFloat::semanticsPrecision(Value.getSemantics());
- precision = (precision * 59 + 195) / 196;
- Value.toString(PrettySourceValue, precision);
+ PrettyPrintFloat(Value, Value.getSemantics(), PrettySourceValue);
SmallString<16> PrettyTargetValue;
if (IsBool)
@@ -10908,6 +10914,32 @@
return;
}
+ if (Source->isIntegerType() && TargetBT && TargetBT->isFloatingType()) {
+ llvm::APSInt IntValue;
+ if (E->EvaluateAsInt(IntValue, S.Context, Expr::SE_AllowSideEffects)) {
+ if (S.SourceMgr.isInSystemMacro(CC))
+ return;
+ const llvm::fltSemantics &FloatSemantics =
+ S.Context.getFloatTypeSemantics(QualType(TargetBT, 0));
+ llvm::APFloat FloatValue(FloatSemantics);
+ if (FloatValue.convertFromAPInt(IntValue, Source->isSignedIntegerType(),
+ llvm::APFloat::rmNearestTiesToEven) !=
+ llvm::APFloat::opOK) {
+ SmallString<16> PrettyTargetValue;
+ SmallString<16> PrettySourceValue;
+ PrettyPrintFloat(FloatValue, FloatSemantics, PrettyTargetValue);
+ IntValue.toString(PrettySourceValue);
+
+ S.DiagRuntimeBehavior(
+ E->getExprLoc(), E,
+ S.PDiag(diag::warn_impcast_precision_float_to_integer)
+ << E->getType() << T << PrettySourceValue << PrettyTargetValue
+ << E->getSourceRange() << clang::SourceRange(CC));
+ return;
+ }
+ }
+ }
+
DiagnoseNullConversion(S, E, T, CC);
S.DiscardMisalignedMemberAddress(Target, E);
Index: include/clang/Basic/DiagnosticSemaKinds.td
===================================================================
--- include/clang/Basic/DiagnosticSemaKinds.td
+++ include/clang/Basic/DiagnosticSemaKinds.td
@@ -3226,6 +3226,10 @@
"implicit conversion turns floating-point number into integer: %0 to %1">,
InGroup<FloatConversion>, DefaultIgnore;
+def warn_impcast_precision_float_to_integer : Warning<
+ "implicit conversion from %0 to %1 changes value from %2 to %3">,
+ InGroup<DiagGroup<"float-precision">>;
+
def warn_impcast_float_to_integer : Warning<
"implicit conversion from %0 to %1 changes value from %2 to %3">,
InGroup<FloatOverflowConversion>, DefaultIgnore;
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