Enable control flow pruning of float overflow warnings.
Like other conversion warnings, allow float overflow warnings to be disabled
in known dead paths of template instantiation. This often occurs when a
template template type is a numeric type and the template will check the
range of the numeric type before performing the conversion.
llvm-svn: 332310
diff --git a/clang/lib/Sema/SemaChecking.cpp b/clang/lib/Sema/SemaChecking.cpp
index 74ecf5f..f8ab8a6 100644
--- a/clang/lib/Sema/SemaChecking.cpp
+++ b/clang/lib/Sema/SemaChecking.cpp
@@ -9673,7 +9673,8 @@
return DiagnoseImpCast(
S, E, T, CContext,
IsLiteral ? diag::warn_impcast_literal_float_to_integer_out_of_range
- : diag::warn_impcast_float_to_integer_out_of_range);
+ : diag::warn_impcast_float_to_integer_out_of_range,
+ PruneWarnings);
unsigned DiagID = 0;
if (IsLiteral) {
diff --git a/clang/test/SemaCXX/warn-float-conversion.cpp b/clang/test/SemaCXX/warn-float-conversion.cpp
index 2e89acb..a3d1786 100644
--- a/clang/test/SemaCXX/warn-float-conversion.cpp
+++ b/clang/test/SemaCXX/warn-float-conversion.cpp
@@ -89,4 +89,38 @@
char e = 1.0 / 0.0; // expected-warning{{implicit conversion of out of range value from 'double' to 'char' is undefined}}
}
+
+
+template <typename T>
+class Check {
+ public:
+ static constexpr bool Safe();
+};
+
+template<>
+constexpr bool Check<char>::Safe() { return false; }
+
+template<>
+constexpr bool Check<float>::Safe() { return true; }
+
+template <typename T>
+T run1(T t) {
+ const float ret = 800;
+ return ret; // expected-warning {{implicit conversion of out of range value from 'const float' to 'char' is undefined}}
+}
+
+template <typename T>
+T run2(T t) {
+ const float ret = 800;
+ if (Check<T>::Safe())
+ return ret;
+ else
+ return t;
+}
+
+void test() {
+ float a = run1(a) + run2(a);
+ char b = run1(b) + run2(b); // expected-note {{in instantiation of function template specialization 'run1<char>' requested here}}
+}
+
#endif // OVERFLOW