Tue Nov 17 11:17:06 1992 Ian Lance Taylor (ian@cygnus.com)

 	* tm-rs6000.h (BELIEVE_PCC_PROMOTION): Define, since AIX cc gets
	it right.
	(aix_framedata): added nosavedpc field.
	(SAVED_PC_AFTER_CALL): Don't try to optimize; just call
	read_register.
	(FRAMELESS_FUNCTION_INVOCATION): Pass second argument of 0.
	(FRAME_SAVED_PC): If PC not saved, use SAVED_PC_AFTER_CALL.
	* rs6000-tdep.c (skip_prologue): Handle gcc generated stfd
	instructions as function_frame_info does.  Expand special case of
	st r31,-4(r1) to be st r31,NUM(r1), since gcc can generate offsets
	other than -4.
	(pop_frame): Add 4 rather than sizeof (int) to avoid host
	dependence.
	(function_frame_info): Set frameless if the function has no frame,
	and set nosavedpc if the PC was not saved.  Handle gcc generated
	stfd 31,-4(31); st 31, -12(31) correctly.
	(frameless_function_invocation): New second argument pcsaved; if 0
	return whether the function has a frame, if 1 return whether the
	function saved PC.
	(frame_initial_stack_address): Correct typo: cache registers for
	callee_fi, not for fi, (avoids reading garbage memory locations).

3 files changed, 88 insertions, 29 deletions

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 58d5758..a999142 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,5 +1,34 @@
+Tue Nov 17 11:17:06 1992  Ian Lance Taylor  (ian@cygnus.com)
+
+ 	* tm-rs6000.h (BELIEVE_PCC_PROMOTION): Define, since AIX cc gets
+	it right.
+	(aix_framedata): added nosavedpc field.
+	(SAVED_PC_AFTER_CALL): Don't try to optimize; just call
+	read_register.
+	(FRAMELESS_FUNCTION_INVOCATION): Pass second argument of 0.
+	(FRAME_SAVED_PC): If PC not saved, use SAVED_PC_AFTER_CALL.
+	* rs6000-tdep.c (skip_prologue): Handle gcc generated stfd
+	instructions as function_frame_info does.  Expand special case of
+	st r31,-4(r1) to be st r31,NUM(r1), since gcc can generate offsets
+	other than -4.
+	(pop_frame): Add 4 rather than sizeof (int) to avoid host
+	dependence.
+	(function_frame_info): Set frameless if the function has no frame,
+	and set nosavedpc if the PC was not saved.  Handle gcc generated
+	stfd 31,-4(31); st 31, -12(31) correctly.
+	(frameless_function_invocation): New second argument pcsaved; if 0
+	return whether the function has a frame, if 1 return whether the
+	function saved PC.
+	(frame_initial_stack_address): Correct typo: cache registers for
+	callee_fi, not for fi, (avoids reading garbage memory locations).
+
 Mon Nov 16 15:58:07 1992  Stu Grossman  (grossman at cygnus.com)
 
+	* infrun.c (wait_for_inferior (just before step_over_function
+	label)):  Change test for stepping into subroutine to check for the
+	presence of line number info.  This makes stuff compiled with -g1
+	cause GDB to not lose control when stepping.
+
 	* symtab.c (find_pc_line):  Improve code per gnu's suggestions.
 	Improve comments as well.
 
diff --git a/gdb/rs6000-tdep.c b/gdb/rs6000-tdep.c
index 80deb81..14c88a4 100644
--- a/gdb/rs6000-tdep.c
+++ b/gdb/rs6000-tdep.c
@@ -210,6 +210,11 @@ CORE_ADDR pc;
       return pc - 4;			/* don't skip over this branch */
   }
 
+  if ((op & 0xfc1f0000) == 0xd8010000) { /* stfd Rx,NUM(r1) */
+    pc += 4;				 /* store floating register double */
+    op = read_memory_integer (pc, 4);
+  }
+
   if ((op & 0xfc1f0000) == 0xbc010000) { /* stm Rx, NUM(r1) */
     pc += 4;
     op = read_memory_integer (pc, 4);
@@ -217,7 +222,7 @@ CORE_ADDR pc;
 
   while (((tmp = op >> 16) == 0x9001) || /* st   r0, NUM(r1) */
 	 (tmp == 0x9421) ||		/* stu  r1, NUM(r1) */
-	 (op == 0x93e1fffc)) 		/* st   r31,-4(r1) */
+	 (tmp == 0x93e1)) 		/* st   r31,NUM(r1) */
   {
     pc += 4;
     op = read_memory_integer (pc, 4);
@@ -476,7 +481,7 @@ pop_frame ()
   if (fdata.saved_gpr != -1)
     for (ii=fdata.saved_gpr; ii <= 31; ++ii) {
       read_memory (addr, &registers [REGISTER_BYTE (ii)], 4);
-      addr += sizeof (int);
+      addr += 4;
     }
 
   if (fdata.saved_fpr != -1)
@@ -533,7 +538,8 @@ fix_call_dummy(dummyname, pc, fun, nargs, type)
 
 /* return information about a function frame.
    in struct aix_frameinfo fdata:
-    - frameless is TRUE, if function does not save %pc value in its frame.
+    - frameless is TRUE, if function does not have a frame.
+    - nosavedpc is TRUE, if function does not save %pc value in its frame.
     - offset is the number of bytes used in the frame to save registers.
     - saved_gpr is the number of the first saved gpr.
     - saved_fpr is the number of the first saved fpr.
@@ -550,20 +556,22 @@ function_frame_info (pc, fdata)
 
   fdata->offset = 0;
   fdata->saved_gpr = fdata->saved_fpr = fdata->alloca_reg = -1;
+  fdata->frameless = 1;
 
   op  = read_memory_integer (pc, 4);
   if (op == 0x7c0802a6) {		/* mflr r0 */
     pc += 4;
     op = read_memory_integer (pc, 4);
+    fdata->nosavedpc = 0;
     fdata->frameless = 0;
   }
-  else				/* else, this is a frameless invocation */
-    fdata->frameless = 1;
-
+  else				/* else, pc is not saved */
+    fdata->nosavedpc = 1;
 
   if ((op & 0xfc00003e) == 0x7c000026) { /* mfcr Rx */
     pc += 4;
     op = read_memory_integer (pc, 4);
+    fdata->frameless = 0;
   }
 
   if ((op & 0xfc000000) == 0x48000000) { /* bl foo, to save fprs??? */
@@ -577,11 +585,13 @@ function_frame_info (pc, fdata)
     if (op == 0x4def7b82 ||		/* crorc 15, 15, 15 */
 	op == 0x0)
       return;				/* prologue is over */
+    fdata->frameless = 0;
   }
 
   if ((op & 0xfc1f0000) == 0xd8010000) { /* stfd Rx,NUM(r1) */
     pc += 4;				 /* store floating register double */
     op = read_memory_integer (pc, 4);
+    fdata->frameless = 0;
   }
 
   if ((op & 0xfc1f0000) == 0xbc010000) { /* stm Rx, NUM(r1) */
@@ -589,7 +599,7 @@ function_frame_info (pc, fdata)
     fdata->saved_gpr = (op >> 21) & 0x1f;
     tmp2 = op & 0xffff;
     if (tmp2 > 0x7fff)
-      tmp2 = 0xffff0000 | tmp2;
+      tmp2 = (~0 &~ 0xffff) | tmp2;
 
     if (tmp2 < 0) {
       tmp2 = tmp2 * -1;
@@ -602,29 +612,43 @@ function_frame_info (pc, fdata)
     fdata->offset = tmp2;
     pc += 4;
     op = read_memory_integer (pc, 4);
+    fdata->frameless = 0;
   }
 
   while (((tmp = op >> 16) == 0x9001) ||	/* st   r0, NUM(r1) */
 	 (tmp == 0x9421) ||			/* stu  r1, NUM(r1) */
-	 (op == 0x93e1fffc)) 			/* st   r31,-4(r1) */
+	 (tmp == 0x93e1))			/* st r31, NUM(r1) */
   {
+    int tmp2;
+
     /* gcc takes a short cut and uses this instruction to save r31 only. */
 
-    if (op == 0x93e1fffc) {
+    if (tmp == 0x93e1) {
       if (fdata->offset)
 /*        fatal ("Unrecognized prolog."); */
         printf ("Unrecognized prolog!\n");
 
       fdata->saved_gpr = 31;
-      fdata->offset = 4;
+      tmp2 = op & 0xffff;
+      if (tmp2 > 0x7fff) {
+	tmp2 = - ((~0 &~ 0xffff) | tmp2);
+	fdata->saved_fpr = (tmp2 - ((32 - 31) * 4)) / 8;
+	if ( fdata->saved_fpr > 0)
+	  fdata->saved_fpr = 32 - fdata->saved_fpr;
+	else
+	  fdata->saved_fpr = -1;
+      }
+      fdata->offset = tmp2;
     }
     pc += 4;
     op = read_memory_integer (pc, 4);
+    fdata->frameless = 0;
   }
 
   while ((tmp = (op >> 22)) == 0x20f) {	/* l	r31, ... or */
     pc += 4;				/* l	r30, ...    */
     op = read_memory_integer (pc, 4);
+    fdata->frameless = 0;
   }
 
   /* store parameters into stack */
@@ -636,10 +660,13 @@ function_frame_info (pc, fdata)
     {
       pc += 4;					/* store fpr double */
       op = read_memory_integer (pc, 4);
+      fdata->frameless = 0;
     }
 
-  if (op == 0x603f0000)				/* oril r31, r1, 0x0 */
+  if (op == 0x603f0000) {			/* oril r31, r1, 0x0 */
     fdata->alloca_reg = 31;
+    fdata->frameless = 0;
+  }
 }
 
 
@@ -906,11 +933,14 @@ CORE_ADDR pc;
 
 
 /* Determines whether the function FI has a frame on the stack or not.
-   Called from the FRAMELESS_FUNCTION_INVOCATION macro in tm.h.  */
+   Called from the FRAMELESS_FUNCTION_INVOCATION macro in tm.h with a
+   second argument of 0, and from the FRAME_SAVED_PC macro with a
+   second argument of 1.  */
 
 int
-frameless_function_invocation (fi)
+frameless_function_invocation (fi, pcsaved)
 struct frame_info *fi;
+int pcsaved;
 {
   CORE_ADDR func_start;
   struct aix_framedata fdata;
@@ -924,7 +954,7 @@ struct frame_info *fi;
     return 0;
 
   function_frame_info (func_start, &fdata);
-  return fdata.frameless;
+  return pcsaved ? fdata.nosavedpc : fdata.frameless;
 }
 
 
@@ -1026,7 +1056,7 @@ frame_initial_stack_address (fi)
   for (callee_fi = fi->next; callee_fi; callee_fi = callee_fi->next) {
 
     if (!callee_fi->cache_fsr)
-      frame_get_cache_fsr (fi, NULL);
+      frame_get_cache_fsr (callee_fi, NULL);
 
     /* this is the address in which alloca register is saved. */
 
diff --git a/gdb/tm-rs6000.h b/gdb/tm-rs6000.h
index 1b0ffde..5dff65c 100644
--- a/gdb/tm-rs6000.h
+++ b/gdb/tm-rs6000.h
@@ -36,6 +36,9 @@ extern int	symtab_relocated;
 
 #define	PC_LOAD_SEGMENT(PC)	pc_load_segment_name(PC)
 
+/* AIX cc seems to get this right.  */
+
+#define BELIEVE_PCC_PROMOTION 1
 
 /* Conversion between a register number in stab string to actual register num. */
 
@@ -82,6 +85,7 @@ struct aix_framedata {
   int	saved_fpr;			/* smallest # of saved fpr */
   int	alloca_reg;			/* alloca register number (frame ptr) */
   char	frameless;			/* true if frameless functions. */
+  char	nosavedpc;			/* true if pc not saved. */
 };
 
 void 
@@ -174,13 +178,7 @@ extern int loadinfotextindex;
    the new frame is not set up until the new function executes
    some instructions.  */
 
-#define	SAVED_PC_AFTER_CALL(frame)	\
-	(register_valid [LR_REGNUM] ? 	\
-	  (*(int*)&registers[REGISTER_BYTE (LR_REGNUM)]) :	\
-	  read_register (LR_REGNUM))
-
-/*#define SAVED_PC_AFTER_CALL(frame)	saved_pc_after_call(frame) */
-
+#define	SAVED_PC_AFTER_CALL(frame) read_register (LR_REGNUM)
 
 /* Address of end of stack space.  */
 
@@ -423,7 +421,7 @@ extern unsigned int rs6000_struct_return_address;
    does not, FRAMELESS is set to 1, else 0.  */
 
 #define FRAMELESS_FUNCTION_INVOCATION(FI, FRAMELESS) \
-	FRAMELESS = frameless_function_invocation (FI)
+	FRAMELESS = frameless_function_invocation (FI, 0)
 
 /* Functions calling alloca() change the value of the stack pointer. We
    need to use initial stack pointer (which is saved in r31 by gcc) in 
@@ -436,17 +434,19 @@ extern unsigned int rs6000_struct_return_address;
 	CORE_ADDR initial_sp;			/* initial stack pointer. */ \
 	struct frame_saved_regs *cache_fsr;	/* saved registers	  */
 
-/* Frameless function invocation in IBM RS/6000 is half-done. It perfectly
-   sets up a new frame, e.g. a new frame (in fact stack) pointer, etc, but it 
-   doesn't save the %pc. In the following, even though it is considered a 
-   frameless invocation, we still need to walk one frame up. */
+/* Frameless function invocation in IBM RS/6000 is sometimes
+   half-done. It perfectly sets up a new frame, e.g. a new frame (in
+   fact stack) pointer, etc, but it doesn't save the %pc.  We call
+   frameless_function_invocation to tell us how to get the %pc.  */
 
 #define	INIT_EXTRA_FRAME_INFO(fromleaf, fi)	\
 	fi->initial_sp = 0;		\
 	fi->cache_fsr = 0;
 
-#define FRAME_SAVED_PC(FRAME)		\
-	read_memory_integer (read_memory_integer ((FRAME)->frame, 4)+8, 4)
+#define FRAME_SAVED_PC(FRAME)					\
+	(frameless_function_invocation (FRAME, 1)		\
+	 ? SAVED_PC_AFTER_CALL (FRAME)				\
+	 : read_memory_integer (read_memory_integer ((FRAME)->frame, 4)+8, 4))
 
 #define FRAME_ARGS_ADDRESS(FI)	\
   (((struct frame_info*)(FI))->initial_sp ?		\