Commit Graph

12 Commits

Author SHA1 Message Date
Erich Keane a4c48c68c5 Fix float->int conversion warnings when near barriers.
As Eli brought up here: https://reviews.llvm.org/D46535
I'd previously messed up this fix by missing conversions
that are just slightly outside the range.  This patch fixes
this by no longer ignoring the return value of 
convertToInteger.  Additionally, one of the error messages
wasn't very sensical (mentioning out of range value, when it 
really was not), so it was cleaned up as well.

llvm-svn: 331812
2018-05-08 21:26:21 +00:00
Erich Keane 7130a93934 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
2018-05-07 20:52:56 +00:00
Richard Trieu 891f0f176c Revert the bool portion of r267054
Remove the floating point to bool conversion warnings.  Some of these
conversions will be caught by -Wliteral-conversion and -Wfloat-conversion

llvm-svn: 267234
2016-04-22 22:14:32 +00:00
Richard Trieu be234c30ad Split interesting warnings off from -Wfloat-conversion
Restructure the implict floating point to integer conversions so that
interesting sub-groups are under different flags.  Breakdown of warnings:

No warning:
Exact conversions from floating point to integer:
int x = 10.0;
int x = 1e10;

-Wliteral-conversion - Floating point literal to integer with rounding:
int x = 5.5;
int x = -3.4;

-Wfloat-conversion - All conversions not covered by the above two:
int x = GetFloat();
int x = 5.5 + 3.5;

-Wfloat-zero-conversion - The expression converted has a non-zero floating
point value that gets converted to a zero integer value, excluded the cases
falling under -Wliteral-conversion.  Subset of -Wfloat-conversion.
int x = 1.0 / 2.0;

-Wfloat-overflow-conversion - The floating point value is outside the range
of the integer type, exluding cases from -Wliteral conversion.  Subset of
-Wfloat-conversion.
char x = 500;
char x = -1000;

-Wfloat-bool-conversion - Any conversion of a floating point type to bool.
Subset of -Wfloat-conversion.
if (GetFloat()) {}
bool x = 5.0;

-Wfloat-bool-constant-conversion - Conversion of a compile time evaluatable
floating point value to bool.  Subset of -Wfloat-bool-conversion.
bool x = 1.0;
bool x = 4.0 / 20.0;

Also add EvaluateAsFloat to Sema, which is similar to EvaluateAsInt, but for
floating point values.

llvm-svn: 267054
2016-04-21 21:04:55 +00:00
Aaron Ballman dbc441eb34 When performing an implicit from float to bool, the floating point value must be *exactly* zero in order for the conversion to result in 0. This does not involve a conversion through an integer value, and so truncation of the value is not performed.
This patch address PR25876.

llvm-svn: 256643
2015-12-30 14:26:07 +00:00
David Blaikie 7555b6a4e5 Improve some of the conversion warnings to fire on conversion to bool.
Moves the bool bail-out down a little in SemaChecking - so now
-Wnull-conversion and -Wliteral-conversion can fire when the target type is
bool.

Also improve the wording/details in the -Wliteral-conversion warning to match
the -Wconstant-conversion.

llvm-svn: 156826
2012-05-15 16:56:36 +00:00
Matt Beaumont-Gay c622163b0f Only warn in -Wliteral-conversion if the conversion loses information
llvm-svn: 141955
2011-10-14 15:36:25 +00:00
Richard Trieu 1db746afbf Move string literal to bool conversion into its own warning flag -Wstring-conversion.
llvm-svn: 140574
2011-09-26 22:38:21 +00:00
Richard Trieu 021baa373f Add a new warning to -Wliteral-conversion to catch cases where a string literal
is cast to a boolean.  An exception has been made for string literals in
logical expressions to allow the common case of use in assert statements.

bool x;
x = "hi";  // Warn here
void foo(bool x);
foo("hi");  // Warn here
assert(0 && "error");
assert("error);  // Warn here

llvm-svn: 140405
2011-09-23 20:10:00 +00:00
Matt Beaumont-Gay 042ce8e9d8 Extend -Wliteral-conversion to catch "int i = -1.234"
llvm-svn: 139326
2011-09-08 22:30:47 +00:00
Chandler Carruth 016ef400c4 Enhance the diagnostic for literal float -> int conversions to suggest
rewriting the literal when the value is integral. It is not uncommon to
see code written as:

  const int kBigNumber = 42e5;

Without any real awareness that this is no longer an ICE. The note helps
automate and ease the process of fixing code that violates the warning.

llvm-svn: 129243
2011-04-10 08:36:24 +00:00
Chandler Carruth 22c7a79a1d Implement a sub-group of -Wconversion: -Wliteral-conversion. This
specifically targets literals which are implicitly converted, a those
are more often unintended and trivial to fix. This can be especially
helpful for diagnosing what makes 'const int x = 1e6' not an ICE.

Original patch authored by Jim Meehan with contributions from other
Googlers and a few cleanups from myself.

llvm-svn: 125745
2011-02-17 11:05:49 +00:00