* RFA: Fix tracepoints for LOC_COMPUTED - sort of
@ 2003-02-23 18:30 Daniel Jacobowitz
2003-02-24 21:56 ` Jim Blandy
0 siblings, 1 reply; 6+ messages in thread
From: Daniel Jacobowitz @ 2003-02-23 18:30 UTC (permalink / raw)
To: gdb-patches; +Cc: jimb
Like the description function, this is pretty minimal; I don't have time to
write a full evaluator right now, and I don't have access to a tracepoint
stub, so I suggest someone who does implement this properly. For now,
though, this handles the most likely types: DW_OP_reg and DW_OP_fbreg. It's
enough to fix the test failures; it's correct as far as it goes; and it
properly raises an error if it gets confused.
Is this OK? Should I file a PR about the need for a proper evaluator?
--
Daniel Jacobowitz
MontaVista Software Debian GNU/Linux Developer
2003-02-23 Daniel Jacobowitz <drow@mvista.com>
* Makefile.in (dwarf2loc.o): Update dependencies.
* ax-gdb.c (gen_var_ref): Handle LOC_COMPUTED and LOC_COMPUTED_ARG.
* dwarf2expr.c (read_uleb128, read_sleb128): Make non-static.
* dwarf2expr.h (read_uleb128, read_sleb128): Add prototypes.
* dwarf2loc.c: Include "ax.h" and "ax-gdb.h".
(locexpr_tracepoint_var_ref): New function.
(dwarf2_locexpr_funcs): Add locexpr_tracepoint_var_ref.
Index: Makefile.in
===================================================================
RCS file: /cvs/src/src/gdb/Makefile.in,v
retrieving revision 1.335
diff -u -p -r1.335 Makefile.in
--- Makefile.in 21 Feb 2003 15:24:17 -0000 1.335
+++ Makefile.in 23 Feb 2003 18:24:14 -0000
@@ -1639,7 +1639,7 @@ dwarf2expr.o: dwarf2expr.c $(defs_h) $(s
$(gdbcore_h) $(dwarf2expr_h)
dwarf2loc.o: dwarf2loc.c $(defs_h) $(ui_out_h) $(value_h) $(frame_h) \
$(gdbcore_h) $(target_h) $(inferior_h) $(dwarf2expr_h) \
- $(dwarf2loc_h) $(gdb_string_h)
+ $(dwarf2loc_h) $(ax_h) $(ax_gdb_h) $(gdb_string_h)
dwarf2read.o: dwarf2read.c $(defs_h) $(bfd_h) $(symtab_h) $(gdbtypes_h) \
$(symfile_h) $(objfiles_h) $(elf_dwarf2_h) $(buildsym_h) \
$(demangle_h) $(expression_h) $(filenames_h) $(macrotab_h) \
Index: ax-gdb.c
===================================================================
RCS file: /cvs/src/src/gdb/ax-gdb.c,v
retrieving revision 1.19
diff -u -p -r1.19 ax-gdb.c
--- ax-gdb.c 20 Feb 2003 17:17:23 -0000 1.19
+++ ax-gdb.c 23 Feb 2003 18:24:14 -0000
@@ -618,6 +618,11 @@ gen_var_ref (struct agent_expr *ax, stru
}
break;
+ case LOC_COMPUTED:
+ case LOC_COMPUTED_ARG:
+ (*SYMBOL_LOCATION_FUNCS (var)->tracepoint_var_ref) (var, ax, value);
+ break;
+
case LOC_OPTIMIZED_OUT:
error ("The variable `%s' has been optimized out.",
SYMBOL_PRINT_NAME (var));
Index: dwarf2expr.c
===================================================================
RCS file: /cvs/src/src/gdb/dwarf2expr.c,v
retrieving revision 1.1
diff -u -p -r1.1 dwarf2expr.c
--- dwarf2expr.c 21 Feb 2003 15:24:17 -0000 1.1
+++ dwarf2expr.c 23 Feb 2003 18:24:14 -0000
@@ -115,7 +115,7 @@ dwarf_expr_eval (struct dwarf_expr_conte
by R, and return the new value of BUF. Verify that it doesn't extend
past BUF_END. */
-static unsigned char *
+unsigned char *
read_uleb128 (unsigned char *buf, unsigned char *buf_end, ULONGEST * r)
{
unsigned shift = 0;
@@ -141,7 +141,7 @@ read_uleb128 (unsigned char *buf, unsign
by R, and return the new value of BUF. Verify that it doesn't extend
past BUF_END. */
-static unsigned char *
+unsigned char *
read_sleb128 (unsigned char *buf, unsigned char *buf_end, LONGEST * r)
{
unsigned shift = 0;
Index: dwarf2expr.h
===================================================================
RCS file: /cvs/src/src/gdb/dwarf2expr.h,v
retrieving revision 1.1
diff -u -p -r1.1 dwarf2expr.h
--- dwarf2expr.h 21 Feb 2003 15:24:17 -0000 1.1
+++ dwarf2expr.h 23 Feb 2003 18:24:14 -0000
@@ -94,4 +94,10 @@ void dwarf_expr_eval (struct dwarf_expr_
size_t len);
CORE_ADDR dwarf_expr_fetch (struct dwarf_expr_context *ctx, int n);
+
+unsigned char *read_uleb128 (unsigned char *buf, unsigned char *buf_end,
+ ULONGEST * r);
+unsigned char *read_sleb128 (unsigned char *buf, unsigned char *buf_end,
+ LONGEST * r);
+
#endif
Index: dwarf2loc.c
===================================================================
RCS file: /cvs/src/src/gdb/dwarf2loc.c,v
retrieving revision 1.1
diff -u -p -r1.1 dwarf2loc.c
--- dwarf2loc.c 21 Feb 2003 15:24:17 -0000 1.1
+++ dwarf2loc.c 23 Feb 2003 18:24:14 -0000
@@ -26,6 +26,8 @@
#include "gdbcore.h"
#include "target.h"
#include "inferior.h"
+#include "ax.h"
+#include "ax-gdb.h"
#include "elf/dwarf2.h"
#include "dwarf2expr.h"
@@ -277,11 +279,58 @@ locexpr_describe_location (struct symbol
return 1;
}
+void
+locexpr_tracepoint_var_ref (struct symbol * symbol, struct agent_expr * ax,
+ struct axs_value * value)
+{
+ /* FIXME: This one is also a bit minimal. */
+ struct dwarf2_locexpr_baton *dlbaton = SYMBOL_LOCATION_BATON (symbol);
+
+ if (dlbaton->size == 0)
+ error ("Optimized out.");
+
+ if (dlbaton->size == 1
+ && dlbaton->data[0] >= DW_OP_reg0
+ && dlbaton->data[0] <= DW_OP_reg31)
+ {
+ value->kind = axs_lvalue_register;
+ value->u.reg = dlbaton->data[0] - DW_OP_reg0;
+ }
+ else if (dlbaton->data[0] == DW_OP_regx)
+ {
+ ULONGEST reg;
+ read_uleb128 (dlbaton->data + 1, dlbaton->data + dlbaton->size,
+ ®);
+ value->kind = axs_lvalue_register;
+ value->u.reg = reg;
+ }
+ else if (dlbaton->data[0] == DW_OP_fbreg)
+ {
+ /* And this is worse than just minimal; we should honor the frame base
+ as above. */
+ int frame_reg;
+ LONGEST frame_offset;
+
+ TARGET_VIRTUAL_FRAME_POINTER (ax->scope, &frame_reg, &frame_offset);
+ ax_reg (ax, frame_reg);
+ ax_const_l (ax, frame_offset);
+ ax_simple (ax, aop_add);
+
+ read_sleb128 (dlbaton->data + 1, dlbaton->data + dlbaton->size,
+ &frame_offset);
+ ax_const_l (ax, frame_offset);
+ ax_simple (ax, aop_add);
+ value->kind = axs_lvalue_memory;
+ }
+ else
+ error ("Can't do it.");
+}
+
/* The set of location functions used with the DWARF-2 expression
evaluator. */
struct location_funcs dwarf2_locexpr_funcs = {
locexpr_read_variable,
locexpr_read_needs_frame,
locexpr_describe_location,
- NULL
+ locexpr_tracepoint_var_ref
};
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: RFA: Fix tracepoints for LOC_COMPUTED - sort of
2003-02-23 18:30 RFA: Fix tracepoints for LOC_COMPUTED - sort of Daniel Jacobowitz
@ 2003-02-24 21:56 ` Jim Blandy
2003-02-26 21:31 ` Daniel Jacobowitz
0 siblings, 1 reply; 6+ messages in thread
From: Jim Blandy @ 2003-02-24 21:56 UTC (permalink / raw)
To: Daniel Jacobowitz; +Cc: gdb-patches
Daniel Jacobowitz <drow@mvista.com> writes:
> Like the description function, this is pretty minimal; I don't have time to
> write a full evaluator right now, and I don't have access to a tracepoint
> stub, so I suggest someone who does implement this properly. For now,
> though, this handles the most likely types: DW_OP_reg and DW_OP_fbreg. It's
> enough to fix the test failures; it's correct as far as it goes; and it
> properly raises an error if it gets confused.
>
> Is this OK? Should I file a PR about the need for a proper
> evaluator?
Well, the problem is likely to sit around indefinitely:
1) I don't think anyone's using tracepoints at the moment.
2) Compiling Dwarf 2 bytecodes into ax bytecodes is, in general, not
a simple thing at all.
So its importance and difficulty both work against it. Would a
comment be better in this sort of situation? I don't know.
> Index: dwarf2expr.c
> ===================================================================
> RCS file: /cvs/src/src/gdb/dwarf2expr.c,v
> retrieving revision 1.1
> diff -u -p -r1.1 dwarf2expr.c
> --- dwarf2expr.c 21 Feb 2003 15:24:17 -0000 1.1
> +++ dwarf2expr.c 23 Feb 2003 18:24:14 -0000
> @@ -115,7 +115,7 @@ dwarf_expr_eval (struct dwarf_expr_conte
> by R, and return the new value of BUF. Verify that it doesn't extend
> past BUF_END. */
>
> -static unsigned char *
> +unsigned char *
> read_uleb128 (unsigned char *buf, unsigned char *buf_end, ULONGEST * r)
> {
> unsigned shift = 0;
> @@ -141,7 +141,7 @@ read_uleb128 (unsigned char *buf, unsign
> by R, and return the new value of BUF. Verify that it doesn't extend
> past BUF_END. */
>
> -static unsigned char *
> +unsigned char *
> read_sleb128 (unsigned char *buf, unsigned char *buf_end, LONGEST * r)
> {
> unsigned shift = 0;
> Index: dwarf2expr.h
> ===================================================================
> RCS file: /cvs/src/src/gdb/dwarf2expr.h,v
> retrieving revision 1.1
> diff -u -p -r1.1 dwarf2expr.h
> --- dwarf2expr.h 21 Feb 2003 15:24:17 -0000 1.1
> +++ dwarf2expr.h 23 Feb 2003 18:24:14 -0000
> @@ -94,4 +94,10 @@ void dwarf_expr_eval (struct dwarf_expr_
> size_t len);
> CORE_ADDR dwarf_expr_fetch (struct dwarf_expr_context *ctx, int n);
>
> +
> +unsigned char *read_uleb128 (unsigned char *buf, unsigned char *buf_end,
> + ULONGEST * r);
> +unsigned char *read_sleb128 (unsigned char *buf, unsigned char *buf_end,
> + LONGEST * r);
> +
> #endif
You know, dwarf2read.c's read_{un,}signed_leb128 don't actually need
their BFD argument for anything. The call to bfd_get_8 ignores it;
it's just a char fetch anyway. In the future, I wonder if we could
just use those everywhere.
> Index: dwarf2loc.c
> ===================================================================
> RCS file: /cvs/src/src/gdb/dwarf2loc.c,v
> retrieving revision 1.1
> diff -u -p -r1.1 dwarf2loc.c
> --- dwarf2loc.c 21 Feb 2003 15:24:17 -0000 1.1
> +++ dwarf2loc.c 23 Feb 2003 18:24:14 -0000
> @@ -26,6 +26,8 @@
> #include "gdbcore.h"
> #include "target.h"
> #include "inferior.h"
> +#include "ax.h"
> +#include "ax-gdb.h"
>
> #include "elf/dwarf2.h"
> #include "dwarf2expr.h"
> @@ -277,11 +279,58 @@ locexpr_describe_location (struct symbol
> return 1;
> }
>
> +void
> +locexpr_tracepoint_var_ref (struct symbol * symbol, struct agent_expr * ax,
> + struct axs_value * value)
> +{
> + /* FIXME: This one is also a bit minimal. */
> + struct dwarf2_locexpr_baton *dlbaton = SYMBOL_LOCATION_BATON (symbol);
> +
> + if (dlbaton->size == 0)
> + error ("Optimized out.");
The error message ought to be a complete sentence, and mention
SYMBOL_NAME.
> + if (dlbaton->size == 1
> + && dlbaton->data[0] >= DW_OP_reg0
> + && dlbaton->data[0] <= DW_OP_reg31)
> + {
> + value->kind = axs_lvalue_register;
> + value->u.reg = dlbaton->data[0] - DW_OP_reg0;
> + }
> + else if (dlbaton->data[0] == DW_OP_regx)
> + {
> + ULONGEST reg;
> + read_uleb128 (dlbaton->data + 1, dlbaton->data + dlbaton->size,
> + ®);
> + value->kind = axs_lvalue_register;
> + value->u.reg = reg;
> + }
> + else if (dlbaton->data[0] == DW_OP_fbreg)
> + {
> + /* And this is worse than just minimal; we should honor the frame base
> + as above. */
> + int frame_reg;
> + LONGEST frame_offset;
> +
> + TARGET_VIRTUAL_FRAME_POINTER (ax->scope, &frame_reg, &frame_offset);
> + ax_reg (ax, frame_reg);
> + ax_const_l (ax, frame_offset);
> + ax_simple (ax, aop_add);
> +
> + read_sleb128 (dlbaton->data + 1, dlbaton->data + dlbaton->size,
> + &frame_offset);
> + ax_const_l (ax, frame_offset);
> + ax_simple (ax, aop_add);
> + value->kind = axs_lvalue_memory;
> + }
> + else
> + error ("Can't do it.");
Gotta have a better error message, dude. It only takes a few
seconsd. Think of the poor user.
You should check that that's actually the end of the expression, too.
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: RFA: Fix tracepoints for LOC_COMPUTED - sort of
2003-02-24 21:56 ` Jim Blandy
@ 2003-02-26 21:31 ` Daniel Jacobowitz
2003-02-28 19:50 ` Jim Blandy
0 siblings, 1 reply; 6+ messages in thread
From: Daniel Jacobowitz @ 2003-02-26 21:31 UTC (permalink / raw)
To: Jim Blandy; +Cc: gdb-patches
On Mon, Feb 24, 2003 at 04:50:27PM -0500, Jim Blandy wrote:
>
> Daniel Jacobowitz <drow@mvista.com> writes:
> > Like the description function, this is pretty minimal; I don't have time to
> > write a full evaluator right now, and I don't have access to a tracepoint
> > stub, so I suggest someone who does implement this properly. For now,
> > though, this handles the most likely types: DW_OP_reg and DW_OP_fbreg. It's
> > enough to fix the test failures; it's correct as far as it goes; and it
> > properly raises an error if it gets confused.
> >
> > Is this OK? Should I file a PR about the need for a proper
> > evaluator?
>
> Well, the problem is likely to sit around indefinitely:
> 1) I don't think anyone's using tracepoints at the moment.
> 2) Compiling Dwarf 2 bytecodes into ax bytecodes is, in general, not
> a simple thing at all.
>
> So its importance and difficulty both work against it. Would a
> comment be better in this sort of situation? I don't know.
I went for a comment, because I'm a comment sort of person.
> You know, dwarf2read.c's read_{un,}signed_leb128 don't actually need
> their BFD argument for anything. The call to bfd_get_8 ignores it;
> it's just a char fetch anyway. In the future, I wonder if we could
> just use those everywhere.
Probably. There's a set in dwarf2cfi.c too; it would be nice to cut
them down.
> Gotta have a better error message, dude. It only takes a few
> seconsd. Think of the poor user.
> You should check that that's actually the end of the expression, too.
OK, even I am kind of ashamed of the error messages in the last
version... thanks for keeping me honest. How's this?
--
Daniel Jacobowitz
MontaVista Software Debian GNU/Linux Developer
2003-02-26 Daniel Jacobowitz <drow@mvista.com>
* Makefile.in (dwarf2loc.o): Update dependencies.
* ax-gdb.c (gen_var_ref): Handle LOC_COMPUTED and LOC_COMPUTED_ARG.
* dwarf2expr.c (read_uleb128, read_sleb128): Make non-static.
* dwarf2expr.h (read_uleb128, read_sleb128): Add prototypes.
* dwarf2loc.c: Include "ax.h" and "ax-gdb.h".
(locexpr_tracepoint_var_ref): New function.
(dwarf2_locexpr_funcs): Add locexpr_tracepoint_var_ref.
Index: Makefile.in
===================================================================
RCS file: /cvs/src/src/gdb/Makefile.in,v
retrieving revision 1.335
diff -u -p -r1.335 Makefile.in
--- Makefile.in 21 Feb 2003 15:24:17 -0000 1.335
+++ Makefile.in 26 Feb 2003 21:30:44 -0000
@@ -1639,7 +1639,7 @@ dwarf2expr.o: dwarf2expr.c $(defs_h) $(s
$(gdbcore_h) $(dwarf2expr_h)
dwarf2loc.o: dwarf2loc.c $(defs_h) $(ui_out_h) $(value_h) $(frame_h) \
$(gdbcore_h) $(target_h) $(inferior_h) $(dwarf2expr_h) \
- $(dwarf2loc_h) $(gdb_string_h)
+ $(dwarf2loc_h) $(ax_h) $(ax_gdb_h) $(gdb_string_h)
dwarf2read.o: dwarf2read.c $(defs_h) $(bfd_h) $(symtab_h) $(gdbtypes_h) \
$(symfile_h) $(objfiles_h) $(elf_dwarf2_h) $(buildsym_h) \
$(demangle_h) $(expression_h) $(filenames_h) $(macrotab_h) \
Index: ax-gdb.c
===================================================================
RCS file: /cvs/src/src/gdb/ax-gdb.c,v
retrieving revision 1.20
diff -u -p -r1.20 ax-gdb.c
--- ax-gdb.c 25 Feb 2003 21:36:16 -0000 1.20
+++ ax-gdb.c 26 Feb 2003 21:30:44 -0000
@@ -618,6 +618,11 @@ gen_var_ref (struct agent_expr *ax, stru
}
break;
+ case LOC_COMPUTED:
+ case LOC_COMPUTED_ARG:
+ (*SYMBOL_LOCATION_FUNCS (var)->tracepoint_var_ref) (var, ax, value);
+ break;
+
case LOC_OPTIMIZED_OUT:
error ("The variable `%s' has been optimized out.",
SYMBOL_PRINT_NAME (var));
Index: dwarf2expr.c
===================================================================
RCS file: /cvs/src/src/gdb/dwarf2expr.c,v
retrieving revision 1.1
diff -u -p -r1.1 dwarf2expr.c
--- dwarf2expr.c 21 Feb 2003 15:24:17 -0000 1.1
+++ dwarf2expr.c 26 Feb 2003 21:30:44 -0000
@@ -115,7 +115,7 @@ dwarf_expr_eval (struct dwarf_expr_conte
by R, and return the new value of BUF. Verify that it doesn't extend
past BUF_END. */
-static unsigned char *
+unsigned char *
read_uleb128 (unsigned char *buf, unsigned char *buf_end, ULONGEST * r)
{
unsigned shift = 0;
@@ -141,7 +141,7 @@ read_uleb128 (unsigned char *buf, unsign
by R, and return the new value of BUF. Verify that it doesn't extend
past BUF_END. */
-static unsigned char *
+unsigned char *
read_sleb128 (unsigned char *buf, unsigned char *buf_end, LONGEST * r)
{
unsigned shift = 0;
Index: dwarf2expr.h
===================================================================
RCS file: /cvs/src/src/gdb/dwarf2expr.h,v
retrieving revision 1.1
diff -u -p -r1.1 dwarf2expr.h
--- dwarf2expr.h 21 Feb 2003 15:24:17 -0000 1.1
+++ dwarf2expr.h 26 Feb 2003 21:30:44 -0000
@@ -94,4 +94,10 @@ void dwarf_expr_eval (struct dwarf_expr_
size_t len);
CORE_ADDR dwarf_expr_fetch (struct dwarf_expr_context *ctx, int n);
+
+unsigned char *read_uleb128 (unsigned char *buf, unsigned char *buf_end,
+ ULONGEST * r);
+unsigned char *read_sleb128 (unsigned char *buf, unsigned char *buf_end,
+ LONGEST * r);
+
#endif
Index: dwarf2loc.c
===================================================================
RCS file: /cvs/src/src/gdb/dwarf2loc.c,v
retrieving revision 1.1
diff -u -p -r1.1 dwarf2loc.c
--- dwarf2loc.c 21 Feb 2003 15:24:17 -0000 1.1
+++ dwarf2loc.c 26 Feb 2003 21:30:44 -0000
@@ -26,6 +26,8 @@
#include "gdbcore.h"
#include "target.h"
#include "inferior.h"
+#include "ax.h"
+#include "ax-gdb.h"
#include "elf/dwarf2.h"
#include "dwarf2expr.h"
@@ -277,11 +279,73 @@ locexpr_describe_location (struct symbol
return 1;
}
+
+/* Describe the location of SYMBOL as an agent value in VALUE, generating
+ any necessary bytecode in AX.
+
+ NOTE drow/2003-02-26: This function is extremely minimal, because
+ doing it correctly is extremely complicated and there is no
+ publicly available stub with tracepoint support for me to test
+ against. When there is one this function should be revisited. */
+
+void
+locexpr_tracepoint_var_ref (struct symbol * symbol, struct agent_expr * ax,
+ struct axs_value * value)
+{
+ struct dwarf2_locexpr_baton *dlbaton = SYMBOL_LOCATION_BATON (symbol);
+
+ if (dlbaton->size == 0)
+ error ("Symbol \"%s\" has been optimized out.",
+ SYMBOL_PRINT_NAME (symbol));
+
+ if (dlbaton->size == 1
+ && dlbaton->data[0] >= DW_OP_reg0
+ && dlbaton->data[0] <= DW_OP_reg31)
+ {
+ value->kind = axs_lvalue_register;
+ value->u.reg = dlbaton->data[0] - DW_OP_reg0;
+ }
+ else if (dlbaton->data[0] == DW_OP_regx)
+ {
+ ULONGEST reg;
+ read_uleb128 (dlbaton->data + 1, dlbaton->data + dlbaton->size,
+ ®);
+ value->kind = axs_lvalue_register;
+ value->u.reg = reg;
+ }
+ else if (dlbaton->data[0] == DW_OP_fbreg)
+ {
+ /* And this is worse than just minimal; we should honor the frame base
+ as above. */
+ int frame_reg;
+ LONGEST frame_offset;
+ char *buf_end;
+
+ buf_end = read_sleb128 (dlbaton->data + 1, dlbaton->data + dlbaton->size,
+ &frame_offset);
+ if (buf_end != dlbaton->data + dlbaton->size)
+ error ("Unexpected opcode after DW_OP_fbreg for symbol \"%s\".",
+ SYMBOL_PRINT_NAME (symbol));
+
+ TARGET_VIRTUAL_FRAME_POINTER (ax->scope, &frame_reg, &frame_offset);
+ ax_reg (ax, frame_reg);
+ ax_const_l (ax, frame_offset);
+ ax_simple (ax, aop_add);
+
+ ax_const_l (ax, frame_offset);
+ ax_simple (ax, aop_add);
+ value->kind = axs_lvalue_memory;
+ }
+ else
+ error ("Unsupported DWARF opcode in the location of \"%s\".",
+ SYMBOL_PRINT_NAME (symbol));
+}
+
/* The set of location functions used with the DWARF-2 expression
evaluator. */
struct location_funcs dwarf2_locexpr_funcs = {
locexpr_read_variable,
locexpr_read_needs_frame,
locexpr_describe_location,
- NULL
+ locexpr_tracepoint_var_ref
};
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: RFA: Fix tracepoints for LOC_COMPUTED - sort of
2003-02-26 21:31 ` Daniel Jacobowitz
@ 2003-02-28 19:50 ` Jim Blandy
2003-02-28 20:03 ` Daniel Jacobowitz
0 siblings, 1 reply; 6+ messages in thread
From: Jim Blandy @ 2003-02-28 19:50 UTC (permalink / raw)
To: Daniel Jacobowitz; +Cc: gdb-patches
Looks good to me!
Daniel Jacobowitz <drow@mvista.com> writes:
> On Mon, Feb 24, 2003 at 04:50:27PM -0500, Jim Blandy wrote:
> >
> > Daniel Jacobowitz <drow@mvista.com> writes:
> > > Like the description function, this is pretty minimal; I don't have time to
> > > write a full evaluator right now, and I don't have access to a tracepoint
> > > stub, so I suggest someone who does implement this properly. For now,
> > > though, this handles the most likely types: DW_OP_reg and DW_OP_fbreg. It's
> > > enough to fix the test failures; it's correct as far as it goes; and it
> > > properly raises an error if it gets confused.
> > >
> > > Is this OK? Should I file a PR about the need for a proper
> > > evaluator?
> >
> > Well, the problem is likely to sit around indefinitely:
> > 1) I don't think anyone's using tracepoints at the moment.
> > 2) Compiling Dwarf 2 bytecodes into ax bytecodes is, in general, not
> > a simple thing at all.
> >
> > So its importance and difficulty both work against it. Would a
> > comment be better in this sort of situation? I don't know.
>
> I went for a comment, because I'm a comment sort of person.
>
> > You know, dwarf2read.c's read_{un,}signed_leb128 don't actually need
> > their BFD argument for anything. The call to bfd_get_8 ignores it;
> > it's just a char fetch anyway. In the future, I wonder if we could
> > just use those everywhere.
>
> Probably. There's a set in dwarf2cfi.c too; it would be nice to cut
> them down.
>
> > Gotta have a better error message, dude. It only takes a few
> > seconsd. Think of the poor user.
>
> > You should check that that's actually the end of the expression, too.
>
> OK, even I am kind of ashamed of the error messages in the last
> version... thanks for keeping me honest. How's this?
>
> --
> Daniel Jacobowitz
> MontaVista Software Debian GNU/Linux Developer
>
> 2003-02-26 Daniel Jacobowitz <drow@mvista.com>
>
> * Makefile.in (dwarf2loc.o): Update dependencies.
> * ax-gdb.c (gen_var_ref): Handle LOC_COMPUTED and LOC_COMPUTED_ARG.
> * dwarf2expr.c (read_uleb128, read_sleb128): Make non-static.
> * dwarf2expr.h (read_uleb128, read_sleb128): Add prototypes.
> * dwarf2loc.c: Include "ax.h" and "ax-gdb.h".
> (locexpr_tracepoint_var_ref): New function.
> (dwarf2_locexpr_funcs): Add locexpr_tracepoint_var_ref.
>
> Index: Makefile.in
> ===================================================================
> RCS file: /cvs/src/src/gdb/Makefile.in,v
> retrieving revision 1.335
> diff -u -p -r1.335 Makefile.in
> --- Makefile.in 21 Feb 2003 15:24:17 -0000 1.335
> +++ Makefile.in 26 Feb 2003 21:30:44 -0000
> @@ -1639,7 +1639,7 @@ dwarf2expr.o: dwarf2expr.c $(defs_h) $(s
> $(gdbcore_h) $(dwarf2expr_h)
> dwarf2loc.o: dwarf2loc.c $(defs_h) $(ui_out_h) $(value_h) $(frame_h) \
> $(gdbcore_h) $(target_h) $(inferior_h) $(dwarf2expr_h) \
> - $(dwarf2loc_h) $(gdb_string_h)
> + $(dwarf2loc_h) $(ax_h) $(ax_gdb_h) $(gdb_string_h)
> dwarf2read.o: dwarf2read.c $(defs_h) $(bfd_h) $(symtab_h) $(gdbtypes_h) \
> $(symfile_h) $(objfiles_h) $(elf_dwarf2_h) $(buildsym_h) \
> $(demangle_h) $(expression_h) $(filenames_h) $(macrotab_h) \
> Index: ax-gdb.c
> ===================================================================
> RCS file: /cvs/src/src/gdb/ax-gdb.c,v
> retrieving revision 1.20
> diff -u -p -r1.20 ax-gdb.c
> --- ax-gdb.c 25 Feb 2003 21:36:16 -0000 1.20
> +++ ax-gdb.c 26 Feb 2003 21:30:44 -0000
> @@ -618,6 +618,11 @@ gen_var_ref (struct agent_expr *ax, stru
> }
> break;
>
> + case LOC_COMPUTED:
> + case LOC_COMPUTED_ARG:
> + (*SYMBOL_LOCATION_FUNCS (var)->tracepoint_var_ref) (var, ax, value);
> + break;
> +
> case LOC_OPTIMIZED_OUT:
> error ("The variable `%s' has been optimized out.",
> SYMBOL_PRINT_NAME (var));
> Index: dwarf2expr.c
> ===================================================================
> RCS file: /cvs/src/src/gdb/dwarf2expr.c,v
> retrieving revision 1.1
> diff -u -p -r1.1 dwarf2expr.c
> --- dwarf2expr.c 21 Feb 2003 15:24:17 -0000 1.1
> +++ dwarf2expr.c 26 Feb 2003 21:30:44 -0000
> @@ -115,7 +115,7 @@ dwarf_expr_eval (struct dwarf_expr_conte
> by R, and return the new value of BUF. Verify that it doesn't extend
> past BUF_END. */
>
> -static unsigned char *
> +unsigned char *
> read_uleb128 (unsigned char *buf, unsigned char *buf_end, ULONGEST * r)
> {
> unsigned shift = 0;
> @@ -141,7 +141,7 @@ read_uleb128 (unsigned char *buf, unsign
> by R, and return the new value of BUF. Verify that it doesn't extend
> past BUF_END. */
>
> -static unsigned char *
> +unsigned char *
> read_sleb128 (unsigned char *buf, unsigned char *buf_end, LONGEST * r)
> {
> unsigned shift = 0;
> Index: dwarf2expr.h
> ===================================================================
> RCS file: /cvs/src/src/gdb/dwarf2expr.h,v
> retrieving revision 1.1
> diff -u -p -r1.1 dwarf2expr.h
> --- dwarf2expr.h 21 Feb 2003 15:24:17 -0000 1.1
> +++ dwarf2expr.h 26 Feb 2003 21:30:44 -0000
> @@ -94,4 +94,10 @@ void dwarf_expr_eval (struct dwarf_expr_
> size_t len);
> CORE_ADDR dwarf_expr_fetch (struct dwarf_expr_context *ctx, int n);
>
> +
> +unsigned char *read_uleb128 (unsigned char *buf, unsigned char *buf_end,
> + ULONGEST * r);
> +unsigned char *read_sleb128 (unsigned char *buf, unsigned char *buf_end,
> + LONGEST * r);
> +
> #endif
> Index: dwarf2loc.c
> ===================================================================
> RCS file: /cvs/src/src/gdb/dwarf2loc.c,v
> retrieving revision 1.1
> diff -u -p -r1.1 dwarf2loc.c
> --- dwarf2loc.c 21 Feb 2003 15:24:17 -0000 1.1
> +++ dwarf2loc.c 26 Feb 2003 21:30:44 -0000
> @@ -26,6 +26,8 @@
> #include "gdbcore.h"
> #include "target.h"
> #include "inferior.h"
> +#include "ax.h"
> +#include "ax-gdb.h"
>
> #include "elf/dwarf2.h"
> #include "dwarf2expr.h"
> @@ -277,11 +279,73 @@ locexpr_describe_location (struct symbol
> return 1;
> }
>
> +
> +/* Describe the location of SYMBOL as an agent value in VALUE, generating
> + any necessary bytecode in AX.
> +
> + NOTE drow/2003-02-26: This function is extremely minimal, because
> + doing it correctly is extremely complicated and there is no
> + publicly available stub with tracepoint support for me to test
> + against. When there is one this function should be revisited. */
> +
> +void
> +locexpr_tracepoint_var_ref (struct symbol * symbol, struct agent_expr * ax,
> + struct axs_value * value)
> +{
> + struct dwarf2_locexpr_baton *dlbaton = SYMBOL_LOCATION_BATON (symbol);
> +
> + if (dlbaton->size == 0)
> + error ("Symbol \"%s\" has been optimized out.",
> + SYMBOL_PRINT_NAME (symbol));
> +
> + if (dlbaton->size == 1
> + && dlbaton->data[0] >= DW_OP_reg0
> + && dlbaton->data[0] <= DW_OP_reg31)
> + {
> + value->kind = axs_lvalue_register;
> + value->u.reg = dlbaton->data[0] - DW_OP_reg0;
> + }
> + else if (dlbaton->data[0] == DW_OP_regx)
> + {
> + ULONGEST reg;
> + read_uleb128 (dlbaton->data + 1, dlbaton->data + dlbaton->size,
> + ®);
> + value->kind = axs_lvalue_register;
> + value->u.reg = reg;
> + }
> + else if (dlbaton->data[0] == DW_OP_fbreg)
> + {
> + /* And this is worse than just minimal; we should honor the frame base
> + as above. */
> + int frame_reg;
> + LONGEST frame_offset;
> + char *buf_end;
> +
> + buf_end = read_sleb128 (dlbaton->data + 1, dlbaton->data + dlbaton->size,
> + &frame_offset);
> + if (buf_end != dlbaton->data + dlbaton->size)
> + error ("Unexpected opcode after DW_OP_fbreg for symbol \"%s\".",
> + SYMBOL_PRINT_NAME (symbol));
> +
> + TARGET_VIRTUAL_FRAME_POINTER (ax->scope, &frame_reg, &frame_offset);
> + ax_reg (ax, frame_reg);
> + ax_const_l (ax, frame_offset);
> + ax_simple (ax, aop_add);
> +
> + ax_const_l (ax, frame_offset);
> + ax_simple (ax, aop_add);
> + value->kind = axs_lvalue_memory;
> + }
> + else
> + error ("Unsupported DWARF opcode in the location of \"%s\".",
> + SYMBOL_PRINT_NAME (symbol));
> +}
> +
> /* The set of location functions used with the DWARF-2 expression
> evaluator. */
> struct location_funcs dwarf2_locexpr_funcs = {
> locexpr_read_variable,
> locexpr_read_needs_frame,
> locexpr_describe_location,
> - NULL
> + locexpr_tracepoint_var_ref
> };
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: RFA: Fix tracepoints for LOC_COMPUTED - sort of
2003-02-28 19:50 ` Jim Blandy
@ 2003-02-28 20:03 ` Daniel Jacobowitz
0 siblings, 0 replies; 6+ messages in thread
From: Daniel Jacobowitz @ 2003-02-28 20:03 UTC (permalink / raw)
To: gdb-patches
Thanks, checked in (with a warning I accidentally introduced fixed).
On Fri, Feb 28, 2003 at 02:45:29PM -0500, Jim Blandy wrote:
>
> Looks good to me!
>
> Daniel Jacobowitz <drow@mvista.com> writes:
>
> > On Mon, Feb 24, 2003 at 04:50:27PM -0500, Jim Blandy wrote:
> > >
> > > Daniel Jacobowitz <drow@mvista.com> writes:
> > > > Like the description function, this is pretty minimal; I don't have time to
> > > > write a full evaluator right now, and I don't have access to a tracepoint
> > > > stub, so I suggest someone who does implement this properly. For now,
> > > > though, this handles the most likely types: DW_OP_reg and DW_OP_fbreg. It's
> > > > enough to fix the test failures; it's correct as far as it goes; and it
> > > > properly raises an error if it gets confused.
> > > >
> > > > Is this OK? Should I file a PR about the need for a proper
> > > > evaluator?
> > >
> > > Well, the problem is likely to sit around indefinitely:
> > > 1) I don't think anyone's using tracepoints at the moment.
> > > 2) Compiling Dwarf 2 bytecodes into ax bytecodes is, in general, not
> > > a simple thing at all.
> > >
> > > So its importance and difficulty both work against it. Would a
> > > comment be better in this sort of situation? I don't know.
> >
> > I went for a comment, because I'm a comment sort of person.
> >
> > > You know, dwarf2read.c's read_{un,}signed_leb128 don't actually need
> > > their BFD argument for anything. The call to bfd_get_8 ignores it;
> > > it's just a char fetch anyway. In the future, I wonder if we could
> > > just use those everywhere.
> >
> > Probably. There's a set in dwarf2cfi.c too; it would be nice to cut
> > them down.
> >
> > > Gotta have a better error message, dude. It only takes a few
> > > seconsd. Think of the poor user.
> >
> > > You should check that that's actually the end of the expression, too.
> >
> > OK, even I am kind of ashamed of the error messages in the last
> > version... thanks for keeping me honest. How's this?
> >
> > --
> > Daniel Jacobowitz
> > MontaVista Software Debian GNU/Linux Developer
> >
> > 2003-02-26 Daniel Jacobowitz <drow@mvista.com>
> >
> > * Makefile.in (dwarf2loc.o): Update dependencies.
> > * ax-gdb.c (gen_var_ref): Handle LOC_COMPUTED and LOC_COMPUTED_ARG.
> > * dwarf2expr.c (read_uleb128, read_sleb128): Make non-static.
> > * dwarf2expr.h (read_uleb128, read_sleb128): Add prototypes.
> > * dwarf2loc.c: Include "ax.h" and "ax-gdb.h".
> > (locexpr_tracepoint_var_ref): New function.
> > (dwarf2_locexpr_funcs): Add locexpr_tracepoint_var_ref.
> >
> > Index: Makefile.in
> > ===================================================================
> > RCS file: /cvs/src/src/gdb/Makefile.in,v
> > retrieving revision 1.335
> > diff -u -p -r1.335 Makefile.in
> > --- Makefile.in 21 Feb 2003 15:24:17 -0000 1.335
> > +++ Makefile.in 26 Feb 2003 21:30:44 -0000
> > @@ -1639,7 +1639,7 @@ dwarf2expr.o: dwarf2expr.c $(defs_h) $(s
> > $(gdbcore_h) $(dwarf2expr_h)
> > dwarf2loc.o: dwarf2loc.c $(defs_h) $(ui_out_h) $(value_h) $(frame_h) \
> > $(gdbcore_h) $(target_h) $(inferior_h) $(dwarf2expr_h) \
> > - $(dwarf2loc_h) $(gdb_string_h)
> > + $(dwarf2loc_h) $(ax_h) $(ax_gdb_h) $(gdb_string_h)
> > dwarf2read.o: dwarf2read.c $(defs_h) $(bfd_h) $(symtab_h) $(gdbtypes_h) \
> > $(symfile_h) $(objfiles_h) $(elf_dwarf2_h) $(buildsym_h) \
> > $(demangle_h) $(expression_h) $(filenames_h) $(macrotab_h) \
> > Index: ax-gdb.c
> > ===================================================================
> > RCS file: /cvs/src/src/gdb/ax-gdb.c,v
> > retrieving revision 1.20
> > diff -u -p -r1.20 ax-gdb.c
> > --- ax-gdb.c 25 Feb 2003 21:36:16 -0000 1.20
> > +++ ax-gdb.c 26 Feb 2003 21:30:44 -0000
> > @@ -618,6 +618,11 @@ gen_var_ref (struct agent_expr *ax, stru
> > }
> > break;
> >
> > + case LOC_COMPUTED:
> > + case LOC_COMPUTED_ARG:
> > + (*SYMBOL_LOCATION_FUNCS (var)->tracepoint_var_ref) (var, ax, value);
> > + break;
> > +
> > case LOC_OPTIMIZED_OUT:
> > error ("The variable `%s' has been optimized out.",
> > SYMBOL_PRINT_NAME (var));
> > Index: dwarf2expr.c
> > ===================================================================
> > RCS file: /cvs/src/src/gdb/dwarf2expr.c,v
> > retrieving revision 1.1
> > diff -u -p -r1.1 dwarf2expr.c
> > --- dwarf2expr.c 21 Feb 2003 15:24:17 -0000 1.1
> > +++ dwarf2expr.c 26 Feb 2003 21:30:44 -0000
> > @@ -115,7 +115,7 @@ dwarf_expr_eval (struct dwarf_expr_conte
> > by R, and return the new value of BUF. Verify that it doesn't extend
> > past BUF_END. */
> >
> > -static unsigned char *
> > +unsigned char *
> > read_uleb128 (unsigned char *buf, unsigned char *buf_end, ULONGEST * r)
> > {
> > unsigned shift = 0;
> > @@ -141,7 +141,7 @@ read_uleb128 (unsigned char *buf, unsign
> > by R, and return the new value of BUF. Verify that it doesn't extend
> > past BUF_END. */
> >
> > -static unsigned char *
> > +unsigned char *
> > read_sleb128 (unsigned char *buf, unsigned char *buf_end, LONGEST * r)
> > {
> > unsigned shift = 0;
> > Index: dwarf2expr.h
> > ===================================================================
> > RCS file: /cvs/src/src/gdb/dwarf2expr.h,v
> > retrieving revision 1.1
> > diff -u -p -r1.1 dwarf2expr.h
> > --- dwarf2expr.h 21 Feb 2003 15:24:17 -0000 1.1
> > +++ dwarf2expr.h 26 Feb 2003 21:30:44 -0000
> > @@ -94,4 +94,10 @@ void dwarf_expr_eval (struct dwarf_expr_
> > size_t len);
> > CORE_ADDR dwarf_expr_fetch (struct dwarf_expr_context *ctx, int n);
> >
> > +
> > +unsigned char *read_uleb128 (unsigned char *buf, unsigned char *buf_end,
> > + ULONGEST * r);
> > +unsigned char *read_sleb128 (unsigned char *buf, unsigned char *buf_end,
> > + LONGEST * r);
> > +
> > #endif
> > Index: dwarf2loc.c
> > ===================================================================
> > RCS file: /cvs/src/src/gdb/dwarf2loc.c,v
> > retrieving revision 1.1
> > diff -u -p -r1.1 dwarf2loc.c
> > --- dwarf2loc.c 21 Feb 2003 15:24:17 -0000 1.1
> > +++ dwarf2loc.c 26 Feb 2003 21:30:44 -0000
> > @@ -26,6 +26,8 @@
> > #include "gdbcore.h"
> > #include "target.h"
> > #include "inferior.h"
> > +#include "ax.h"
> > +#include "ax-gdb.h"
> >
> > #include "elf/dwarf2.h"
> > #include "dwarf2expr.h"
> > @@ -277,11 +279,73 @@ locexpr_describe_location (struct symbol
> > return 1;
> > }
> >
> > +
> > +/* Describe the location of SYMBOL as an agent value in VALUE, generating
> > + any necessary bytecode in AX.
> > +
> > + NOTE drow/2003-02-26: This function is extremely minimal, because
> > + doing it correctly is extremely complicated and there is no
> > + publicly available stub with tracepoint support for me to test
> > + against. When there is one this function should be revisited. */
> > +
> > +void
> > +locexpr_tracepoint_var_ref (struct symbol * symbol, struct agent_expr * ax,
> > + struct axs_value * value)
> > +{
> > + struct dwarf2_locexpr_baton *dlbaton = SYMBOL_LOCATION_BATON (symbol);
> > +
> > + if (dlbaton->size == 0)
> > + error ("Symbol \"%s\" has been optimized out.",
> > + SYMBOL_PRINT_NAME (symbol));
> > +
> > + if (dlbaton->size == 1
> > + && dlbaton->data[0] >= DW_OP_reg0
> > + && dlbaton->data[0] <= DW_OP_reg31)
> > + {
> > + value->kind = axs_lvalue_register;
> > + value->u.reg = dlbaton->data[0] - DW_OP_reg0;
> > + }
> > + else if (dlbaton->data[0] == DW_OP_regx)
> > + {
> > + ULONGEST reg;
> > + read_uleb128 (dlbaton->data + 1, dlbaton->data + dlbaton->size,
> > + ®);
> > + value->kind = axs_lvalue_register;
> > + value->u.reg = reg;
> > + }
> > + else if (dlbaton->data[0] == DW_OP_fbreg)
> > + {
> > + /* And this is worse than just minimal; we should honor the frame base
> > + as above. */
> > + int frame_reg;
> > + LONGEST frame_offset;
> > + char *buf_end;
> > +
> > + buf_end = read_sleb128 (dlbaton->data + 1, dlbaton->data + dlbaton->size,
> > + &frame_offset);
> > + if (buf_end != dlbaton->data + dlbaton->size)
> > + error ("Unexpected opcode after DW_OP_fbreg for symbol \"%s\".",
> > + SYMBOL_PRINT_NAME (symbol));
> > +
> > + TARGET_VIRTUAL_FRAME_POINTER (ax->scope, &frame_reg, &frame_offset);
> > + ax_reg (ax, frame_reg);
> > + ax_const_l (ax, frame_offset);
> > + ax_simple (ax, aop_add);
> > +
> > + ax_const_l (ax, frame_offset);
> > + ax_simple (ax, aop_add);
> > + value->kind = axs_lvalue_memory;
> > + }
> > + else
> > + error ("Unsupported DWARF opcode in the location of \"%s\".",
> > + SYMBOL_PRINT_NAME (symbol));
> > +}
> > +
> > /* The set of location functions used with the DWARF-2 expression
> > evaluator. */
> > struct location_funcs dwarf2_locexpr_funcs = {
> > locexpr_read_variable,
> > locexpr_read_needs_frame,
> > locexpr_describe_location,
> > - NULL
> > + locexpr_tracepoint_var_ref
> > };
>
--
Daniel Jacobowitz
MontaVista Software Debian GNU/Linux Developer
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: RFA: Fix tracepoints for LOC_COMPUTED - sort of
@ 2003-02-23 20:07 Michael Elizabeth Chastain
0 siblings, 0 replies; 6+ messages in thread
From: Michael Elizabeth Chastain @ 2003-02-23 20:07 UTC (permalink / raw)
To: drow, gdb-patches; +Cc: jimb
I tested this with native i686-pc-linux-gnu, gcc v2 and v3,
dwarf-2 and stabs+. It works for me. It fixes this problem:
FAIL: gdb.trace/packetlen.exp: setup collect actions
... with no regressions.
Lightly proofread, nothing wrong that I can see.
Recommended for approval.
Michael C
===
2003-02-23 Daniel Jacobowitz <drow@mvista.com>
* Makefile.in (dwarf2loc.o): Update dependencies.
* ax-gdb.c (gen_var_ref): Handle LOC_COMPUTED and LOC_COMPUTED_ARG.
* dwarf2expr.c (read_uleb128, read_sleb128): Make non-static.
* dwarf2expr.h (read_uleb128, read_sleb128): Add prototypes.
* dwarf2loc.c: Include "ax.h" and "ax-gdb.h".
(locexpr_tracepoint_var_ref): New function.
(dwarf2_locexpr_funcs): Add locexpr_tracepoint_var_ref.
^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2003-02-28 20:03 UTC | newest]
Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
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2003-02-23 18:30 RFA: Fix tracepoints for LOC_COMPUTED - sort of Daniel Jacobowitz
2003-02-24 21:56 ` Jim Blandy
2003-02-26 21:31 ` Daniel Jacobowitz
2003-02-28 19:50 ` Jim Blandy
2003-02-28 20:03 ` Daniel Jacobowitz
2003-02-23 20:07 Michael Elizabeth Chastain
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