Re: `print' does not print

[Ralf Fassel <ralfixx@gmx.de>]

* Eli Zaretskii
| This gets stranger and stranger...

Indeed :-/

| How about disassembly of printchar?  Does it show the call to fwrite
| in both cases?

You mean the assembler code output as of gcc -S ... print.c?  Yes, it
does show a call to fwrite, although in different syntax for gcc and
cc (which doesn't surprise me).

------------------------------
gcc
    .L22:
    .LM36:

	    lw	$2,noninteractive
	    beq	$2,$0,.L25
    .LM37:

	    addu	$2,$fp,24
	    move	$4,$2
	    li	$5,1			# 0x1
	    lw	$6,32($fp)
	    lw	$7,.LC0
	    la	$25,fwrite
	    jal	$31,$25
    .LM38:

	    li	$2,1			# 0x1
	    sw	$2,noninteractive_need_newline
    .LM39:
------------------------------
cc:
    .BB25.printchar:	# 0x2c8
	    .loc	1 333 4
     # 332  	{
     # 333  	  fwrite (str, 1, len, stdout);
	    addiu $4,$sp,0                	#  str
	    addiu $5,$0,1                 	#  
	    lw $6,4($sp)                  	#  len
	    lw $7,%got_disp(__iob)($gp)   	#  __iob
	    addiu $7,$7,16                	#  
	    lw $25,%call16(fwrite)($gp)   	#  fwrite
	    jalr $25                      	#  fwrite
	    nop                           	#  
    .BB26.printchar:	# 0x2e8
	    .loc	1 334 4
     # 334  	  noninteractive_need_newline = 1;
	    addiu $8,$0,1                 	#  
-------------------------

| What happens if you replace `fwrite' with `fflush' followed by
| `write'?  Does that change anything?

Errr, yes, it does.  If I apply the following diff:
*** print.c~	Wed Aug  1 10:27:38 2001
--- print.c	Fri Mar 22 18:35:49 2002
***************
*** 330,336 ****
  	}
        else if (noninteractive)
  	{
! 	  fwrite (str, 1, len, stdout);
  	  noninteractive_need_newline = 1;
  	}
        else
--- 330,339 ----
  	}
        else if (noninteractive)
  	{
! 		fflush(stdout);
! 		write (1, str, len);
! 
! 		/* fwrite (str, 1, len, stdout); */
  	  noninteractive_need_newline = 1;
  	}
        else

I get
    ./emacs -batch -no-site-file -l foo

    "21.2.1"

I.e. it `works'.

If I put at the start of main:
  write(1,"write\n",6);
  fwrite("frwite\n", 7,1,stdout);
I see the `write', but not the fwrite when I compile with gcc.  I see
both when I compile with cc.
    
| Another idea is to put a breakpoint inside fwrite, and see if it's
| called at all.

While gdb accepts the break command, it does not stop in fwrite in
both cases (gcc and cc).  However, cc-compiled prints, gcc-compiled
does not.

cc:
    (gdb) br fwrite
    Breakpoint 4 at 0xfa52f48: file engine.c, line 592.
    (gdb) c

    "21.2.1"

    Program exited normally.

gcc:
    (gdb) br fwrite
    Breakpoint 4 at 0xfa52f48: file engine.c, line 592.
    (gdb) c

    Program exited normally.
    
I don't know whether it makes much sense to dig deeper here.  While
I'm as curious what is the problem here, maybe I just go and fetch the
CVS version and see what happens there.

R'

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