Lpc2000

FYI,

a co-worker found a bug in gcc parser (all gcc's I could get hands on):
Following bails out (but compiles correctly on all other compilers I could
get hands on):

int a = 0x3e+2;

gcc seems to take it as scientific notation.

Regards,

-- 
42Bastian Schick

It's interesting how I just came across this in a GCC compiler manual 
yesterday...
This is considered hexadecimal floating point by the compiler. Just put 
spaces around the "+" and it should work OK.

Jim

On 7/14/05, 42Bastian Schick <bastian42@...> wrote:
> 
> FYI,
> 
> a co-worker found a bug in gcc parser (all gcc's I could get hands on):
> Following bails out (but compiles correctly on all other compilers I could
> get hands on):
> 
> int a = 0x3e+2;
> 
> gcc seems to take it as scientific notation.
> 
> Regards,
> 
> --
> 42Bastian Schick
> 
>


[Non-text portions of this message have been removed]

Jim

> It's interesting how I just came across this in a GCC compiler manual
> yesterday...

I read the manual now, but still I think 0x3e+2 must be compiled and give
0x40.

> This is considered hexadecimal floating point by the compiler. Just put
> spaces around the "+" and it should work OK.

Yes. It is, but it meant touching code :(

-- 
42Bastian Schick

On Fri, Jul 15, 2005 at 07:59:06AM +0200, 42Bastian Schick wrote:
> I read the manual now, but still I think 0x3e+2 must be compiled and give
> 0x40.

I disagree with the GCC implementers on this, but nonetheless a strict
interpretation of the ANSI/ISO standard for C does mean that 0x3e+2 is
parsed as an invalid floating point number. My view is that a more intelligent
interpretation would be preferable, but that's not what GCC does.


-- 
Clyde Stubbs                     |            HI-TECH Software
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HI-TECH C: compiling the real world.

Clyde, 

> On Fri, Jul 15, 2005 at 07:59:06AM +0200, 42Bastian Schick wrote:
> > I read the manual now, but still I think 0x3e+2 must be 
> compiled and 
> > give 0x40.
> 
> I disagree with the GCC implementers on this, but nonetheless 
> a strict interpretation of the ANSI/ISO standard for C does 
> mean that 0x3e+2 is parsed as an invalid floating point 
> number. My view is that a more intelligent interpretation 
> would be preferable, but that's not what GCC does.

Even under C90, 0x3e+2 is a good preprocessing number but a bad C
floating point literal and *must* be reported as an error!

--
Paul Curtis, Rowley Associates Ltd  http://www.rowley.co.uk
CrossWorks for MSP430, ARM, AVR and now MAXQ processors