RE: [RFA-new version][gdbserver] x86 agent expression bytecode compiler (speed up conditional tracepoints)

["Pierre Muller" <pierre.muller@ics-cnrs.unistra.fr>]

 This patch fixes compilation on gcc16.

May I commit this?


Pierre


gdbserver/ChangeLog entry:

2010-06-20  Ian Lance Taylor  <iant@google.com>
	    Pierre Muller  <muller@ics.u-strasbg.fr>

	* linux-x86-low.c (always_true): Delete function.
	(EMIT_ASM, EMIT_ASM32): Use `do ... while (0)' to avoid
	code been optimzed out.


Index: src/gdb/gdbserver/linux-x86-low.c
===================================================================
RCS file: /cvs/src/src/gdb/gdbserver/linux-x86-low.c,v
retrieving revision 1.19
diff -u -p -r1.19 linux-x86-low.c
--- src/gdb/gdbserver/linux-x86-low.c     15 Jun 2010 10:44:48 -0000
1.19
+++ src/gdb/gdbserver/linux-x86-low.c     20 Jun 2010 06:25:07 -0000
@@ -1484,14 +1484,6 @@ add_insns (unsigned char *start, int len
   current_insn_ptr = buildaddr;
 }
 
-/* A function used to trick optimizers.  */
-
-int
-always_true (void)
-{
-  return 1;
-}
-
 /* Our general strategy for emitting code is to avoid specifying raw
    bytes whenever possible, and instead copy a block of inline asm
    that is embedded in the function.  This is a little messy, because
@@ -1499,26 +1491,20 @@ always_true (void)
    code, plus suppress various warnings.  */
 
 #define EMIT_ASM(NAME,INSNS)						\
-  { extern unsigned char start_ ## NAME, end_ ## NAME;			\
+  do  { extern unsigned char start_ ## NAME, end_ ## NAME;		\
     add_insns (&start_ ## NAME, &end_ ## NAME - &start_ ## NAME);	\
-    if (always_true ())						\
-      goto skipover ## NAME;						\
     __asm__ ("start_" #NAME ":\n\t" INSNS "\n\tend_" #NAME ":\n\t");	\
-    skipover ## NAME:							\
-    ; }
+    ; } while (0)
 
 
 #ifdef __x86_64__
 
 #define EMIT_ASM32(NAME,INSNS)						\
-  { extern unsigned char start_ ## NAME, end_ ## NAME;			\
+  do { extern unsigned char start_ ## NAME, end_ ## NAME;		\
     add_insns (&start_ ## NAME, &end_ ## NAME - &start_ ## NAME);	\
-    if (always_true ())						\
-      goto skipover ## NAME;						\
     __asm__ (".code32\n\tstart_" #NAME ":\n\t" INSNS "\n\tend_" #NAME ":\n"
\
 	     "\t.code64\n\t");						\
-    skipover ## NAME:							\
-    ; }
+    ; } while (0)
 
 #else