On 2005-04-27 15:26:39 +0200, Gabriel Dos Reis wrote: > Vincent Lefevre <[EMAIL PROTECTED]> writes: > > | On 2005-04-27 03:37:15 -0700, Zack Weinberg wrote: > | > Vincent Lefevre <[EMAIL PROTECTED]> writes: > | > > However it is correct to store any integer to an unsigned variable, > | > > even if the original value cannot be represented. > | > > | > If that operation occurs at runtime it has a well-defined result. > | > | And gcc 4 doesn't output a diagnostic in this case? > > Why shall it?
No reason. I was just asking for a confirmation (I don't have gcc 4 here yet). > In my version of the C standard, 6.6 contains *at least* these two > constraints > Semantics > > [#5] An expression that evaluates to a constant is required > in several contexts. If a floating expression is evaluated > in the translation environment, the arithmetic precision and > range shall be at least as great as if the expression were > being evaluated in the execution environment. > > [#6] An integer constant expression96) shall have integer > type and shall only have operands that are integer > constants, enumeration constants, character constants, > sizeof expressions whose results are integer constants, and > floating constants that are the immediate operands of casts. > Cast operators in an integer constant expression shall only > convert arithmetic types to integer types, except as part of > an operand to the sizeof operator. > > Clearly, 6.6/6 rules out AAA from being an integer constant. It rules out AAA from being an integer constant expression. -- Vincent Lefèvre <[EMAIL PROTECTED]> - Web: <http://www.vinc17.org/> 100% accessible validated (X)HTML - Blog: <http://www.vinc17.org/blog/> Work: CR INRIA - computer arithmetic / SPACES project at LORIA
