llvm dev - May 2012 - [LLVMdev] Fixed with hex numbers with raw_ostream

I've been using the nifty:
   DEBUG(errs() << "Here is the state of things:\n");
style of optional logging, but ran into an issue where I want to dump a table of
information.  The problem is getting the columns to line up, since the
raw_ostream methods write numbers as variable length.

I've worked up a patch that adds two new methods to raw_ostream:

 /// write_hex - Output \arg N as ten char hexadecimal string, including
 /// 0x prefix (e.g. 0x12345678 or 0x00000001).
 raw_ostream &write_hex32(uint32_t N);

 /// write_hex - Output \arg N as 18 char hexadecimal string, including
 /// 0x prefix (e.g. 0x0123456789abcdef or 0x0000000000000001).
 raw_ostream &write_hex64(uint64_t N);


Is there already some way to do this level of formatting with raw_ostream?


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-Nick

On May 18, 2012, at 11:50 AM, Nick Kledzik <kledzik at apple.com> wrote:
> I've been using the nifty:
>   DEBUG(errs() << "Here is the state of things:\n");
> style of optional logging, but ran into an issue where I want to dump a
table of information.  The problem is getting the columns to line up, since the
raw_ostream methods write numbers as variable length.
> 
> I've worked up a patch that adds two new methods to raw_ostream:
> 
> /// write_hex - Output \arg N as ten char hexadecimal string, including
> /// 0x prefix (e.g. 0x12345678 or 0x00000001).
> raw_ostream &write_hex32(uint32_t N);
> 
> /// write_hex - Output \arg N as 18 char hexadecimal string, including
> /// 0x prefix (e.g. 0x0123456789abcdef or 0x0000000000000001).
> raw_ostream &write_hex64(uint64_t N);
> 
> 
> Is there already some way to do this level of formatting with raw_ostream?
You can get the full awesomeness of printf with include/llvm/Support/Format.h:

OS << format("%016" PRIx64, N);

I don't know if there is a significant performance difference.

/jakob

On May 18, 2012, at 1:44 PM, Jakob Stoklund Olesen
wrote:
> On May 18, 2012, at 11:50 AM, Nick Kledzik <kledzik at apple.com>
wrote:
> 
>> I've been using the nifty:
>>  DEBUG(errs() << "Here is the state of things:\n");
>> style of optional logging, but ran into an issue where I want to dump a
table of information.  The problem is getting the columns to line up, since the
raw_ostream methods write numbers as variable length.
>> 
>> I've worked up a patch that adds two new methods to raw_ostream:
>> 
>> /// write_hex - Output \arg N as ten char hexadecimal string, including
>> /// 0x prefix (e.g. 0x12345678 or 0x00000001).
>> raw_ostream &write_hex32(uint32_t N);
>> 
>> /// write_hex - Output \arg N as 18 char hexadecimal string, including
>> /// 0x prefix (e.g. 0x0123456789abcdef or 0x0000000000000001).
>> raw_ostream &write_hex64(uint64_t N);
>> 
>> 
>> Is there already some way to do this level of formatting with
raw_ostream?
> 
> You can get the full awesomeness of printf with
include/llvm/Support/Format.h:
> 
> OS << format("%016" PRIx64, N);
Excellent!
> I don't know if there is a significant performance difference.
These are in DEBUG() statements, so I don't care about performance.  

I've switched over to using format().  Thanks!

-Nick