====== textflag ======

A flag for the "ld" linker, with special link-time information about a function.

===== textflag 7 =====

Extracted from a comment in ''pkg/runtime/proc.c'':

''
 * Newproc and deferproc need to be textflag 7
 * (no possible stack split when nearing overflow)
''

See [[split stacks]].

===== Usage =====

In "cc" C, add a ''pragma'' directive before the function definition -- example:

<code c>
#pragma textflag 7
void
somefunction(int x, int y)
{
    //...
}
</code>

In "asm" assembly, put the number ''7'' in function's entry point definition line -- example:

<code asm>
TEXT runtime·tstart(SB),7,$0
</code>

Note: These C and assembly syntaxes are supported only by the C compilers and assemblers shipped with Go (i.e. the modified [[http://doc.cat-v.org/plan_9/4th_edition/papers/compiler|Plan 9 ones]]). Stock ''Gcc'' does not have the ability to set these flags (but maybe a ''Gcc'' with ''gccgo'' integrated in it can?)