[PATCH v3 02/12] btrace: Enable auxiliary instructions in record instruction-history.

[Felix Willgerodt <felix.willgerodt@intel.com>]

Print the auxiliary data when a btrace_insn of type BTRACE_INSN_AUX
is encountered in the instruction-history.  Printing is active by default,
it can be silenced with the /a modifier.

This patch is in preparation for the new ptwrite feature, which is based on
auxiliary instructions.

gdb/ChangeLog:
2021-06-14  Felix Willgerodt  <felix.willgerodt@intel.com>

	* record-btrace.c (btrace_insn_history): Handle BTRACE_INSN_AUX.
	* record.c (get_insn_history_modifiers): Add /a modifier.
	* disasm.h (gdb_disassembly_flag): Add DISASSEMBLY_OMIT_AUX_INSN.

gdb/doc/ChangeLog:
2021-06-14  Felix Willgerodt  <felix.willgerodt@intel.com>

	* gdb.texinfo (record instruction history): Document /a modifier.
---
 gdb/disasm.h        |  1 +
 gdb/doc/gdb.texinfo |  3 +++
 gdb/record-btrace.c | 13 +++++++++++++
 gdb/record.c        |  5 +++++
 4 files changed, 22 insertions(+)

diff --git a/gdb/disasm.h b/gdb/disasm.h
index eb82bc3cd01..4db5bd943eb 100644
--- a/gdb/disasm.h
+++ b/gdb/disasm.h
@@ -31,6 +31,7 @@ enum gdb_disassembly_flag
     DISASSEMBLY_OMIT_PC = (0x1 << 4),
     DISASSEMBLY_SOURCE = (0x1 << 5),
     DISASSEMBLY_SPECULATIVE = (0x1 << 6),
+    DISASSEMBLY_OMIT_AUX_INSN = (0x1 << 7),
   };
 DEF_ENUM_FLAGS_TYPE (enum gdb_disassembly_flag, gdb_disassembly_flags);
 
diff --git a/gdb/doc/gdb.texinfo b/gdb/doc/gdb.texinfo
index ff4f41941d3..8f49a91347f 100644
--- a/gdb/doc/gdb.texinfo
+++ b/gdb/doc/gdb.texinfo
@@ -7883,6 +7883,9 @@ To better align the printed instructions when the trace contains
 instructions from more than one function, the function name may be
 omitted by specifying the @code{/f} modifier.
 
+Printing auxiliary information is enabled by default and can be
+omitted with the @code{/a} modifier.
+
 Speculatively executed instructions are prefixed with @samp{?}.  This
 feature is not available for all recording formats.
 
diff --git a/gdb/record-btrace.c b/gdb/record-btrace.c
index 00affb85d22..96c1b69cb0f 100644
--- a/gdb/record-btrace.c
+++ b/gdb/record-btrace.c
@@ -821,6 +821,19 @@ btrace_insn_history (struct ui_out *uiout,
 	  btrace_ui_out_decode_error (uiout, btrace_insn_get_error (&it),
 				      conf->format);
 	}
+      else if (insn->iclass == BTRACE_INSN_AUX)
+	{
+	  if ((flags & DISASSEMBLY_OMIT_AUX_INSN) != 0)
+	    continue;
+
+	  uiout->field_fmt ("insn-number", "%u", btrace_insn_number (&it));
+	  uiout->text ("\t");
+	  uiout->spaces (3);
+	  uiout->text ("[");
+	  uiout->field_fmt ("aux-data", "%s",
+			    it.btinfo->aux_data[insn->aux_data_index].c_str ());
+	  uiout->text ("]\n");
+	}
       else
 	{
 	  struct disasm_insn dinsn;
diff --git a/gdb/record.c b/gdb/record.c
index 6968c30d930..084c8a12c16 100644
--- a/gdb/record.c
+++ b/gdb/record.c
@@ -486,6 +486,9 @@ get_insn_history_modifiers (const char **arg)
 
 	  switch (*args)
 	    {
+	    case 'a':
+	      modifiers |= DISASSEMBLY_OMIT_AUX_INSN;
+	      break;
 	    case 'm':
 	    case 's':
 	      modifiers |= DISASSEMBLY_SOURCE;
@@ -854,6 +857,8 @@ With a /m or /s modifier, source lines are included (if available).\n\
 With a /r modifier, raw instructions in hex are included.\n\
 With a /f modifier, function names are omitted.\n\
 With a /p modifier, current position markers are omitted.\n\
+With a /a modifier, omits output of auxiliary data, which is enabled \
+by default.\n\
 With no argument, disassembles ten more instructions after the previous \
 disassembly.\n\
 \"record instruction-history -\" disassembles ten instructions before a \
-- 
2.25.4

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