determining function name in runtime

[shyam]

Hi all

is there any way the determine which function currently is executing in
a process ?

For example we can find the file name using __FILE__
and line number using __LINE__ macros

simillarly is there any macro which gives the function name

thanks shyam

[Jordan Abel]

On 2006-03-02, Lew Pitcher <Le*********@td securities.com> wrote:

Ico wrote:

Lew Pitcher <Le*********@td securities.com> wrote:

Note: Unlike __FILE__ and __LINE__, __func__ is not a macro, but a
predefined identifier of local (to the function) scope.

Is there a reason why __func__ is not a macro ?

My copy of the draft C99 standard doesn't give a reason.

That's because that's not the right place to look
http://www.open-std.org/jtc1/sc22/wg...onaleV5.10.pdf

lines 29-31 on page 50 [PDF page 57] read as follows:

A new feature of C99: C99 introduces predefined identifiers, which have
block scope (as distinct 30 from predefined macros which have file
scope), and one such predefined identifier, __func__, which allows the
function name to be used at execution time.

That seems to be saying that the reason is because a macro has file
scope, and thus couldn't have a different value on different lines
unless undefined and redefined by the user.

Note, however, that string literal concatenation takes place in phase 6,
whereas semantic analysis [which is when { } becomes a block scope, etc]
is phase 7.

[Ben Bacarisse]

On Thu, 02 Mar 2006 21:48:10 +0000, Jordan Abel wrote:

No, but i have a suggestion:

#if __STDC_VERSION_ _ < 199901l
#define WHERE_FMT __FILE__ ":%d"
#define WHERE_ARGS __LINE__
#else
#define WHERE_FMT __FILE__ ":%s:%d"
Micro correction: swap %s and %d (or __LINE__ and __func__ below)
#define WHERE_ARGS __LINE__,__func __
#endif

fprintf(stderr, "Line printed to stderr at "WHERE_FMT"\n", WHERE_ARGS);

--
Ben.

[Keith Thompson]

Jordan Abel <ra*******@gmai l.com> writes:

On 2006-03-02, Lew Pitcher <Le*********@td securities.com> wrote:

Ico wrote:

Lew Pitcher <Le*********@td securities.com> wrote:

Note: Unlike __FILE__ and __LINE__, __func__ is not a macro, but a
predefined identifier of local (to the function) scope.
Is there a reason why __func__ is not a macro ?

My copy of the draft C99 standard doesn't give a reason.

That's because that's not the right place to look
http://www.open-std.org/jtc1/sc22/wg...onaleV5.10.pdf

lines 29-31 on page 50 [PDF page 57] read as follows:

A new feature of C99: C99 introduces predefined identifiers, which have
block scope (as distinct 30 from predefined macros which have file
scope), and one such predefined identifier, __func__, which allows the
function name to be used at execution time.

That seems to be saying that the reason is because a macro has file
scope, and thus couldn't have a different value on different lines
unless undefined and redefined by the user.

__LINE__ has a different value on different lines, and the
preprocessor has no problem handling that.

__func__ isn't a macro because making it one would have required the
preprocessor (more precisely, translation phase 4) to understand more
of the language grammar than is currently required.

--
Keith Thompson (The_Other_Keit h) ks***@mib.org <http://www.ghoti.net/~kst>
San Diego Supercomputer Center <*> <http://users.sdsc.edu/~kst>
We must do something. This is something. Therefore, we must do this.