Correct warning on Float->Integer conversions.
As identified and briefly discussed here:
https://bugs.llvm.org/show_bug.cgi?id=37305
Converting a floating point number to an integer type when
the integral part is out of the range of the integer type is
undefined behavior in C. Additionally, CodeGen emits an undef
in this situation.
HOWEVER, we've been giving a warning that says that the value is
changed. This patch corrects the warning to list that it is actually
undefined behavior.
Differential Revision: https://reviews.llvm.org/D46535
llvm-svn: 331673
diff --git a/clang/test/SemaCXX/coroutines.cpp b/clang/test/SemaCXX/coroutines.cpp
index 2c979f5..0d0588d 100644
--- a/clang/test/SemaCXX/coroutines.cpp
+++ b/clang/test/SemaCXX/coroutines.cpp
@@ -157,7 +157,7 @@
void yield() {
co_yield 0;
co_yield {"foo", 1, 2};
- co_yield {1e100}; // expected-error {{cannot be narrowed}} expected-note {{explicit cast}} expected-warning {{changes value}} expected-warning {{braces around scalar}}
+ co_yield {1e100}; // expected-error {{cannot be narrowed}} expected-note {{explicit cast}} expected-warning {{implicit conversion}} expected-warning {{braces around scalar}}
co_yield {"foo", __LONG_LONG_MAX__}; // expected-error {{cannot be narrowed}} expected-note {{explicit cast}} expected-warning {{changes value}}
co_yield {"foo"};
co_yield "foo"; // expected-error {{no matching}}
diff --git a/clang/test/SemaCXX/warn-float-conversion.cpp b/clang/test/SemaCXX/warn-float-conversion.cpp
index fc22189..cf1ead0 100644
--- a/clang/test/SemaCXX/warn-float-conversion.cpp
+++ b/clang/test/SemaCXX/warn-float-conversion.cpp
@@ -81,9 +81,9 @@
char b = -500.0; // caught by -Wliteral-conversion
const float LargeNumber = 1024;
- char c = LargeNumber; // expected-warning{{implicit conversion of out of range value from 'const float' to 'char' changes value from 1024 to 127}}
- char d = 400.0 + 400.0; // expected-warning{{implicit conversion of out of range value from 'double' to 'char' changes value from 800 to 127}}
+ char c = LargeNumber; // expected-warning{{implicit conversion of out of range value from 'const float' to 'char' is undefined}}
+ char d = 400.0 + 400.0; // expected-warning{{implicit conversion of out of range value from 'double' to 'char' is undefined}}
- char e = 1.0 / 0.0; // expected-warning{{implicit conversion of out of range value from 'double' to 'char' changes value from +Inf to 127}}
+ char e = 1.0 / 0.0; // expected-warning{{implicit conversion of out of range value from 'double' to 'char' is undefined}}
}
#endif // OVERFLOW
diff --git a/clang/test/SemaCXX/warn-literal-conversion.cpp b/clang/test/SemaCXX/warn-literal-conversion.cpp
index 875aa1d..7efcf90 100644
--- a/clang/test/SemaCXX/warn-literal-conversion.cpp
+++ b/clang/test/SemaCXX/warn-literal-conversion.cpp
@@ -48,4 +48,11 @@
// values.
bool b3 = 0.0f;
bool b4 = 0.0;
+
+ // These all warn because they overflow the target type.
+ short s = 32768.0; // expected-warning{{implicit conversion of out of range value from 'double' to 'short' is undefined}}
+ unsigned short us = 65536.0; // expected-warning{{implicit conversion of out of range value from 'double' to 'unsigned short' is undefined}}
+
+ short s2 = -32769.0; // expected-warning{{implicit conversion of out of range value from 'double' to 'short' is undefined}}
+ unsigned short us2 = -65537.0; // expected-warning{{implicit conversion of out of range value from 'double' to 'unsigned short' is undefined}}
}