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FYI: handle DW_OP_call_frame_cfa in AX compiler (Was: [unavailable values part 1, 16/17] don't merge almost but not quite adjacent memory ranges to collect)
Here is a patch to implement compilation of DW_OP_call_frame_cfa to
agent expressions.
Let me know what you think.
It at least let collection.exp run here. I'll do a full regression test
against gdbserver sometime soon.
Tom
2011-02-16 Tom Tromey <tromey@redhat.com>
* dwarf2loc.c (compile_dwarf_to_ax) <DW_OP_call_frame_cfa>: Use
dwarf2_compile_cfa_to_ax.
* dwarf2-frame.h (dwarf2_compile_ftype): New typedef.
(dwarf2_compile_cfa_to_ax): Declare.
* dwarf2-frame.c: Include ax.h.
(execute_cfa_program): Remove 'this_frame' argument; 'gdbarch' and
'pc'.
(dwarf2_compile_cfa_to_ax): New function.
(dwarf2_frame_cache): Update.
diff --git a/gdb/dwarf2-frame.c b/gdb/dwarf2-frame.c
index 48f47af..014da44 100644
--- a/gdb/dwarf2-frame.c
+++ b/gdb/dwarf2-frame.c
@@ -38,6 +38,7 @@
#include "complaints.h"
#include "dwarf2-frame.h"
+#include "ax.h"
struct comp_unit;
@@ -428,13 +429,11 @@ Not implemented: computing unwound register using explicit value operator"));
static void
execute_cfa_program (struct dwarf2_fde *fde, const gdb_byte *insn_ptr,
- const gdb_byte *insn_end, struct frame_info *this_frame,
- struct dwarf2_frame_state *fs)
+ const gdb_byte *insn_end, struct gdbarch *gdbarch,
+ CORE_ADDR pc, struct dwarf2_frame_state *fs)
{
int eh_frame_p = fde->eh_frame_p;
- CORE_ADDR pc = get_frame_pc (this_frame);
int bytes_read;
- struct gdbarch *gdbarch = get_frame_arch (this_frame);
enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
while (insn_ptr < insn_end && fs->pc <= pc)
@@ -902,6 +901,85 @@ dwarf2_frame_find_quirks (struct dwarf2_frame_state *fs,
}
+void
+dwarf2_compile_cfa_to_ax (struct agent_expr *expr, struct axs_value *loc,
+ struct gdbarch *gdbarch,
+ CORE_ADDR pc,
+ dwarf2_compile_ftype compile,
+ struct dwarf2_per_cu_data *data)
+{
+ const int num_regs = gdbarch_num_regs (gdbarch)
+ + gdbarch_num_pseudo_regs (gdbarch);
+ struct dwarf2_fde *fde;
+ CORE_ADDR text_offset, cfa;
+ struct dwarf2_frame_state fs;
+ int addr_size;
+
+ memset (&fs, 0, sizeof (struct dwarf2_frame_state));
+
+ fs.pc = pc;
+
+ /* Find the correct FDE. */
+ fde = dwarf2_frame_find_fde (&fs.pc, &text_offset);
+ if (fde == NULL)
+ error (_("Could not compute CFA; needed to translate this expression"));
+
+ /* Extract any interesting information from the CIE. */
+ fs.data_align = fde->cie->data_alignment_factor;
+ fs.code_align = fde->cie->code_alignment_factor;
+ fs.retaddr_column = fde->cie->return_address_register;
+ addr_size = fde->cie->addr_size;
+
+ /* Check for "quirks" - known bugs in producers. */
+ dwarf2_frame_find_quirks (&fs, fde);
+
+ /* First decode all the insns in the CIE. */
+ execute_cfa_program (fde, fde->cie->initial_instructions,
+ fde->cie->end, gdbarch, pc, &fs);
+
+ /* Save the initialized register set. */
+ fs.initial = fs.regs;
+ fs.initial.reg = dwarf2_frame_state_copy_regs (&fs.regs);
+
+ /* Then decode the insns in the FDE up to our target PC. */
+ execute_cfa_program (fde, fde->instructions, fde->end, gdbarch, pc, &fs);
+
+ /* Calculate the CFA. */
+ switch (fs.regs.cfa_how)
+ {
+ case CFA_REG_OFFSET:
+ {
+ int regnum = gdbarch_dwarf2_reg_to_regnum (gdbarch, fs.regs.cfa_reg);
+
+ if (regnum == -1)
+ error (_("Unable to access DWARF register number %d"),
+ (int) fs.regs.cfa_reg); /* FIXME */
+ ax_reg (expr, regnum);
+
+ if (fs.regs.cfa_offset != 0)
+ {
+ if (fs.armcc_cfa_offsets_reversed)
+ ax_const_l (expr, - fs.regs.cfa_offset);
+ else
+ ax_const_l (expr, fs.regs.cfa_offset);
+ ax_simple (expr, aop_add);
+ }
+ }
+ break;
+
+ case CFA_EXP:
+ ax_const_l (expr, text_offset);
+ (*compile) (expr, loc, gdbarch, addr_size,
+ fs.regs.cfa_exp, fs.regs.cfa_exp + fs.regs.cfa_exp_len,
+ data);
+ break;
+
+ default:
+ internal_error (__FILE__, __LINE__, _("Unknown CFA rule."));
+ }
+}
+
+
struct dwarf2_frame_cache
{
/* DWARF Call Frame Address. */
@@ -979,14 +1057,15 @@ dwarf2_frame_cache (struct frame_info *this_frame, void **this_cache)
/* First decode all the insns in the CIE. */
execute_cfa_program (fde, fde->cie->initial_instructions,
- fde->cie->end, this_frame, fs);
+ fde->cie->end, gdbarch, get_frame_pc (this_frame), fs);
/* Save the initialized register set. */
fs->initial = fs->regs;
fs->initial.reg = dwarf2_frame_state_copy_regs (&fs->regs);
/* Then decode the insns in the FDE up to our target PC. */
- execute_cfa_program (fde, fde->instructions, fde->end, this_frame, fs);
+ execute_cfa_program (fde, fde->instructions, fde->end, gdbarch,
+ get_frame_pc (this_frame), fs);
/* Calculate the CFA. */
switch (fs->regs.cfa_how)
diff --git a/gdb/dwarf2-frame.h b/gdb/dwarf2-frame.h
index bf7134d..e8a3e85 100644
--- a/gdb/dwarf2-frame.h
+++ b/gdb/dwarf2-frame.h
@@ -26,6 +26,9 @@
struct gdbarch;
struct objfile;
struct frame_info;
+struct dwarf2_per_cu_data;
+struct agent_expr;
+struct axs_value;
/* Register rule. */
@@ -118,4 +121,26 @@ extern const struct frame_base *
CORE_ADDR dwarf2_frame_cfa (struct frame_info *this_frame);
+/* Type of the compilation function for dwarf2_compile_cfa_to_ax. */
+
+typedef void (*dwarf2_compile_ftype) (struct agent_expr *expr,
+ struct axs_value *loc,
+ struct gdbarch *arch,
+ unsigned int addr_size,
+ const gdb_byte *op_ptr,
+ const gdb_byte *op_end,
+ struct dwarf2_per_cu_data *data);
+
+/* Update the agent expression EXPR with code to compute the CFA for a
+ frame at PC. GDBARCH is the frame architecture. The COMPILE
+ function can be used to compile a location expression into EXPR.
+ DATA is passed to COMPILE if needed. */
+
+extern void dwarf2_compile_cfa_to_ax (struct agent_expr *expr,
+ struct axs_value *loc,
+ struct gdbarch *gdbarch,
+ CORE_ADDR pc,
+ dwarf2_compile_ftype compile,
+ struct dwarf2_per_cu_data *data);
+
#endif /* dwarf2-frame.h */
diff --git a/gdb/dwarf2loc.c b/gdb/dwarf2loc.c
index ac786e4..8840a81 100644
--- a/gdb/dwarf2loc.c
+++ b/gdb/dwarf2loc.c
@@ -1926,7 +1926,9 @@ compile_dwarf_to_ax (struct agent_expr *expr, struct axs_value *loc,
break;
case DW_OP_call_frame_cfa:
- unimplemented (op);
+ dwarf2_compile_cfa_to_ax (expr, loc, arch, expr->scope,
+ compile_dwarf_to_ax, per_cu);
+ loc->kind = axs_lvalue_memory;
break;
case DW_OP_GNU_push_tls_address: