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Re: C++ PATCH: Disallow floating-point literals in integral-constantexpressions


Ranjit Mathew wrote:
Mark Mitchell wrote:

The standard says that floating-point literals are only allowed in
integral constant expressions if they are immediately cast to an
integral or enumeration type.  When I implemented checks for integral
constant-expressions, I failed to check this case.  Remedied with the
attached patch.

The standard library fell afound of this rule in std_limits.h; that's
now fixed too.

Tested on x86_64-unknown-linux-gnu, applied on the mainline.


This seems to break libjava on i686-pc-linux-gnu:

./java/util/Hashtable.h:53: error: floating-point literal cannot appear in a con
stant-expression

The relevant line from
$BUILD_DIR/i686-pc-linux-gnu/libjava/java/util/Hashtable.h is:

static const jfloat DEFAULT_LOAD_FACTOR = 0x1.800000p-1f;

Ugh. That's invalid C++.


However, we can't have a broken Java compiler.

I'll take a quick look at fixing gjavah, and, failing that, disable the new error temporarily.

--
Mark Mitchell
CodeSourcery, LLC
mark@codesourcery.com
(916) 791-8304


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