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authorPedro Alves <palves@redhat.com>2017-03-26 17:24:07 +0100
committerPedro Alves <palves@redhat.com>2017-03-29 02:35:42 +0100
commit473b3a4fc9ca24e96849e952f9bae3cd710471d8 (patch)
tree691e1f7de8282f2caef9447a7b72a71089222c00
parent33cd0d93623813b5e9bc0ed6a065df9a0d9c2012 (diff)
downloadbinutils-gdb-users/palves/cxx-dwarf2read.tar.gz
dwarf2read.c: C++fy lnp_state_machineusers/palves/cxx-dwarf2read
While I was looking at the file, I noticed that this struct could be nicely converted to a class. As I was progressing, I ended up moving all state machine actual internal state manipulation to methods of lnp_state_machine, essentially decoupling DWARF parsing from state tracking. I also noticed that the lnp_reader_state doesn't really serve any good use, so that's eliminated in the process. gdb/ChangeLog: yyyy-mm-dd Pedro Alves <palves@redhat.com> * dwarf2read.c (lnp_state_machine): Now a class. Initialize all data fields, make them private and add "m_" prefixes. (lnp_state_machine::lnp_state_machine): New ctor. (record_line, check_line_address, handle_set_discriminator) (handle_set_address, handle_advance_pc, handle_special_opcode) (handle_advance_line, handle_set_file, handle_negate_stmt) (handle_const_add_pc, handle_fixed_advance_pc, handle_copy) (end_sequence, advance_line): New methods. (m_gdbarch, m_record_lines_p): New fields. (lnp_reader_state): Delete. (dwarf_record_line): Rename to ... (lnp_state_machine::record_line): ... adjust. (init_lnp_state_machine): Delete. (lnp_state_machine::lnp_state_machine): New. (check_line_address): Rename to ... (lnp_state_machine::check_line_address): This. (dwarf_decode_lines_1): Remove reference to "reader_state". Adjust lnp_state_machine having a non-default ctor. Use bool. State machine internal state manipulation moved to lnp_state_machine methods.
-rw-r--r--gdb/dwarf2read.c442
1 files changed, 244 insertions, 198 deletions
diff --git a/gdb/dwarf2read.c b/gdb/dwarf2read.c
index 392ebd424eb..51217baca4d 100644
--- a/gdb/dwarf2read.c
+++ b/gdb/dwarf2read.c
@@ -18051,62 +18051,203 @@ psymtab_include_file_name (const struct line_header *lh, int file_index,
/* State machine to track the state of the line number program. */
-struct lnp_state_machine
+class lnp_state_machine
{
+public:
+ /* Initialize a machine state for the start of a line number
+ program. */
+ lnp_state_machine (gdbarch *arch, line_header *lh, bool record_lines_p);
+
file_entry *current_file ()
{
/* lh->file_names is 0-based, but the file name numbers in the
statement program are 1-based. */
- return the_line_header->file_name_at (to_underlying (file) - 1);
+ return m_line_header->file_name_at (to_underlying (m_file) - 1);
+ }
+
+ /* Record the line in the state machine. END_SEQUENCE is true if
+ we're processing the end of a sequence. */
+ void record_line (bool end_sequence);
+
+ /* Check address and if invalid nop-out the rest of the lines in this
+ sequence. */
+ void check_line_address (struct dwarf2_cu *cu,
+ const gdb_byte *line_ptr,
+ CORE_ADDR lowpc, CORE_ADDR address);
+
+ void handle_set_discriminator (unsigned int discriminator)
+ {
+ m_discriminator = discriminator;
+ m_line_has_non_zero_discriminator |= discriminator != 0;
+ }
+
+ /* Handle DW_LNE_set_address. */
+ void handle_set_address (CORE_ADDR baseaddr, CORE_ADDR address)
+ {
+ m_op_index = 0;
+ address += baseaddr;
+ m_address = gdbarch_adjust_dwarf2_line (m_gdbarch, address, false);
+ }
+
+ /* Handle DW_LNS_advance_pc. */
+ void handle_advance_pc (CORE_ADDR adjust);
+
+ /* Handle a special opcode. */
+ void handle_special_opcode (unsigned char op_code);
+
+ /* Handle DW_LNS_advance_line. */
+ void handle_advance_line (int line_delta)
+ {
+ advance_line (line_delta);
+ }
+
+ /* Handle DW_LNS_set_file. */
+ void handle_set_file (file_name_index file);
+
+ /* Handle DW_LNS_negate_stmt. */
+ void handle_negate_stmt ()
+ {
+ m_is_stmt = !m_is_stmt;
+ }
+
+ /* Handle DW_LNS_const_add_pc. */
+ void handle_const_add_pc ();
+
+ /* Handle DW_LNS_fixed_advance_pc. */
+ void handle_fixed_advance_pc (CORE_ADDR addr_adj)
+ {
+ m_address += gdbarch_adjust_dwarf2_line (m_gdbarch, addr_adj, true);
+ m_op_index = 0;
+ }
+
+ /* Handle DW_LNS_copy. */
+ void handle_copy ()
+ {
+ record_line (false);
+ m_discriminator = 0;
+ }
+
+ /* Handle DW_LNE_end_sequence. */
+ void handle_end_sequence ()
+ {
+ m_record_line_callback = ::record_line;
+ }
+
+private:
+ /* Advance the line by LINE_DELTA. */
+ void advance_line (int line_delta)
+ {
+ m_line += line_delta;
+
+ if (line_delta != 0)
+ m_line_has_non_zero_discriminator = m_discriminator != 0;
}
+ gdbarch *m_gdbarch;
+
+ /* True if we're recording lines.
+ Otherwise we're building partial symtabs and are just interested in
+ finding include files mentioned by the line number program. */
+ bool m_record_lines_p;
+
/* The line number header. */
- line_header *the_line_header;
+ line_header *m_line_header;
- /* These are part of the standard DWARF line number state machine. */
+ /* These are part of the standard DWARF line number state machine,
+ and initialized according to the DWARF spec. */
- unsigned char op_index;
+ unsigned char m_op_index = 0;
/* The line table index (1-based) of the current file. */
- file_name_index file;
- unsigned int line;
- CORE_ADDR address;
- int is_stmt;
- unsigned int discriminator;
+ file_name_index m_file = (file_name_index) 1;
+ unsigned int m_line = 1;
+
+ /* These are initialized in the constructor. */
+
+ CORE_ADDR m_address;
+ bool m_is_stmt;
+ unsigned int m_discriminator;
/* Additional bits of state we need to track. */
/* The last file that we called dwarf2_start_subfile for.
This is only used for TLLs. */
- unsigned int last_file;
+ unsigned int m_last_file = 0;
/* The last file a line number was recorded for. */
- struct subfile *last_subfile;
+ struct subfile *m_last_subfile = NULL;
/* The function to call to record a line. */
- record_line_ftype *record_line;
+ record_line_ftype *m_record_line_callback = NULL;
/* The last line number that was recorded, used to coalesce
consecutive entries for the same line. This can happen, for
example, when discriminators are present. PR 17276. */
- unsigned int last_line;
- int line_has_non_zero_discriminator;
+ unsigned int m_last_line = 0;
+ bool m_line_has_non_zero_discriminator = false;
};
-/* There's a lot of static state to pass to dwarf_record_line.
- This keeps it all together. */
+void
+lnp_state_machine::handle_advance_pc (CORE_ADDR adjust)
+{
+ CORE_ADDR addr_adj = (((m_op_index + adjust)
+ / m_line_header->maximum_ops_per_instruction)
+ * m_line_header->minimum_instruction_length);
+ m_address += gdbarch_adjust_dwarf2_line (m_gdbarch, addr_adj, true);
+ m_op_index = ((m_op_index + adjust)
+ % m_line_header->maximum_ops_per_instruction);
+}
-typedef struct
+void
+lnp_state_machine::handle_special_opcode (unsigned char op_code)
{
- /* The gdbarch. */
- struct gdbarch *gdbarch;
+ unsigned char adj_opcode = op_code - m_line_header->opcode_base;
+ CORE_ADDR addr_adj = (((m_op_index
+ + (adj_opcode / m_line_header->line_range))
+ / m_line_header->maximum_ops_per_instruction)
+ * m_line_header->minimum_instruction_length);
+ m_address += gdbarch_adjust_dwarf2_line (m_gdbarch, addr_adj, true);
+ m_op_index = ((m_op_index + (adj_opcode / m_line_header->line_range))
+ % m_line_header->maximum_ops_per_instruction);
- /* The line number header. */
- struct line_header *line_header;
+ int line_delta = (m_line_header->line_base
+ + (adj_opcode % m_line_header->line_range));
+ advance_line (line_delta);
+ record_line (false);
+ m_discriminator = 0;
+}
- /* Non-zero if we're recording lines.
- Otherwise we're building partial symtabs and are just interested in
- finding include files mentioned by the line number program. */
- int record_lines_p;
-} lnp_reader_state;
+void
+lnp_state_machine::handle_set_file (file_name_index file)
+{
+ m_file = file;
+
+ const file_entry *fe = current_file ();
+ if (fe == NULL)
+ dwarf2_debug_line_missing_file_complaint ();
+ else if (m_record_lines_p)
+ {
+ const char *dir = fe->include_dir (m_line_header);
+
+ m_last_subfile = current_subfile;
+ m_line_has_non_zero_discriminator = m_discriminator != 0;
+ dwarf2_start_subfile (fe->name, dir);
+ }
+}
+
+void
+lnp_state_machine::handle_const_add_pc ()
+{
+ CORE_ADDR adjust
+ = (255 - m_line_header->opcode_base) / m_line_header->line_range;
+
+ CORE_ADDR addr_adj
+ = (((m_op_index + adjust)
+ / m_line_header->maximum_ops_per_instruction)
+ * m_line_header->minimum_instruction_length);
+
+ m_address += gdbarch_adjust_dwarf2_line (m_gdbarch, addr_adj, true);
+ m_op_index = ((m_op_index + adjust)
+ % m_line_header->maximum_ops_per_instruction);
+}
/* Ignore this record_line request. */
@@ -18207,104 +18348,76 @@ dwarf_finish_line (struct gdbarch *gdbarch, struct subfile *subfile,
dwarf_record_line_1 (gdbarch, subfile, 0, address, p_record_line);
}
-/* Record the line in STATE.
- END_SEQUENCE is non-zero if we're processing the end of a sequence. */
-
-static void
-dwarf_record_line (lnp_reader_state *reader, lnp_state_machine *state,
- int end_sequence)
+void
+lnp_state_machine::record_line (bool end_sequence)
{
- const struct line_header *lh = reader->line_header;
- unsigned int line, discriminator;
- int is_stmt;
-
- line = state->line;
- is_stmt = state->is_stmt;
- discriminator = state->discriminator;
-
if (dwarf_line_debug)
{
fprintf_unfiltered (gdb_stdlog,
"Processing actual line %u: file %u,"
" address %s, is_stmt %u, discrim %u\n",
- line, to_underlying (state->file),
- paddress (reader->gdbarch, state->address),
- is_stmt, discriminator);
+ m_line, to_underlying (m_file),
+ paddress (m_gdbarch, m_address),
+ m_is_stmt, m_discriminator);
}
- file_entry *fe = state->current_file ();
+ file_entry *fe = current_file ();
if (fe == NULL)
dwarf2_debug_line_missing_file_complaint ();
/* For now we ignore lines not starting on an instruction boundary.
But not when processing end_sequence for compatibility with the
previous version of the code. */
- else if (state->op_index == 0 || end_sequence)
+ else if (m_op_index == 0 || end_sequence)
{
fe->included_p = 1;
- if (reader->record_lines_p && is_stmt)
+ if (m_record_lines_p && m_is_stmt)
{
- if (state->last_subfile != current_subfile || end_sequence)
+ if (m_last_subfile != current_subfile || end_sequence)
{
- dwarf_finish_line (reader->gdbarch, state->last_subfile,
- state->address, state->record_line);
+ dwarf_finish_line (m_gdbarch, m_last_subfile,
+ m_address, m_record_line_callback);
}
if (!end_sequence)
{
- if (dwarf_record_line_p (line, state->last_line,
- state->line_has_non_zero_discriminator,
- state->last_subfile))
+ if (dwarf_record_line_p (m_line, m_last_line,
+ m_line_has_non_zero_discriminator,
+ m_last_subfile))
{
- dwarf_record_line_1 (reader->gdbarch, current_subfile,
- line, state->address,
- state->record_line);
+ dwarf_record_line_1 (m_gdbarch, current_subfile,
+ m_line, m_address,
+ m_record_line_callback);
}
- state->last_subfile = current_subfile;
- state->last_line = line;
+ m_last_subfile = current_subfile;
+ m_last_line = m_line;
}
}
}
}
-/* Initialize STATE for the start of a line number program. */
-
-static void
-init_lnp_state_machine (lnp_state_machine *state,
- const lnp_reader_state *reader)
+lnp_state_machine::lnp_state_machine (gdbarch *arch, line_header *lh,
+ bool record_lines_p)
{
- memset (state, 0, sizeof (*state));
+ m_gdbarch = arch;
+ m_record_lines_p = record_lines_p;
+ m_line_header = lh;
- /* Just starting, there is no "last file". */
- state->last_file = 0;
- state->last_subfile = NULL;
+ m_record_line_callback = ::record_line;
- state->record_line = record_line;
-
- state->last_line = 0;
- state->line_has_non_zero_discriminator = 0;
-
- /* Initialize these according to the DWARF spec. */
- state->op_index = 0;
- state->file = (file_name_index) 1;
- state->line = 1;
/* Call `gdbarch_adjust_dwarf2_line' on the initial 0 address as if there
was a line entry for it so that the backend has a chance to adjust it
and also record it in case it needs it. This is currently used by MIPS
code, cf. `mips_adjust_dwarf2_line'. */
- state->address = gdbarch_adjust_dwarf2_line (reader->gdbarch, 0, 0);
- state->is_stmt = reader->line_header->default_is_stmt;
- state->discriminator = 0;
- state->the_line_header = reader->line_header;
+ m_address = gdbarch_adjust_dwarf2_line (arch, 0, 0);
+ m_is_stmt = lh->default_is_stmt;
+ m_discriminator = 0;
}
-/* Check address and if invalid nop-out the rest of the lines in this
- sequence. */
-
-static void
-check_line_address (struct dwarf2_cu *cu, lnp_state_machine *state,
- const gdb_byte *line_ptr,
- CORE_ADDR lowpc, CORE_ADDR address)
+void
+lnp_state_machine::check_line_address (struct dwarf2_cu *cu,
+ const gdb_byte *line_ptr,
+ CORE_ADDR lowpc, CORE_ADDR address)
{
/* If address < lowpc then it's not a usable value, it's outside the
pc range of the CU. However, we restrict the test to only address
@@ -18322,9 +18435,9 @@ check_line_address (struct dwarf2_cu *cu, lnp_state_machine *state,
complaint (&symfile_complaints,
_(".debug_line address at offset 0x%lx is 0 [in module %s]"),
line_offset, objfile_name (objfile));
- state->record_line = noop_record_line;
- /* Note: sm.record_line is left as noop_record_line
- until we see DW_LNE_end_sequence. */
+ m_record_line_callback = noop_record_line;
+ /* Note: record_line_callback is left as noop_record_line until
+ we see DW_LNE_end_sequence. */
}
}
@@ -18345,30 +18458,23 @@ dwarf_decode_lines_1 (struct line_header *lh, struct dwarf2_cu *cu,
struct objfile *objfile = cu->objfile;
bfd *abfd = objfile->obfd;
struct gdbarch *gdbarch = get_objfile_arch (objfile);
- /* Non-zero if we're recording line info (as opposed to building partial
- symtabs). */
- int record_lines_p = !decode_for_pst_p;
- /* A collection of things we need to pass to dwarf_record_line. */
- lnp_reader_state reader_state;
+ /* True if we're recording line info (as opposed to building partial
+ symtabs and just interested in finding include files mentioned by
+ the line number program). */
+ bool record_lines_p = !decode_for_pst_p;
baseaddr = ANOFFSET (objfile->section_offsets, SECT_OFF_TEXT (objfile));
line_ptr = lh->statement_program_start;
line_end = lh->statement_program_end;
- reader_state.gdbarch = gdbarch;
- reader_state.line_header = lh;
- reader_state.record_lines_p = record_lines_p;
-
/* Read the statement sequences until there's nothing left. */
while (line_ptr < line_end)
{
- /* The DWARF line number program state machine. */
- lnp_state_machine state_machine;
- int end_sequence = 0;
-
- /* Reset the state machine at the start of each sequence. */
- init_lnp_state_machine (&state_machine, &reader_state);
+ /* The DWARF line number program state machine. Reset the state
+ machine at the start of each sequence. */
+ lnp_state_machine state_machine (gdbarch, lh, record_lines_p);
+ bool end_sequence = false;
if (record_lines_p)
{
@@ -18389,28 +18495,7 @@ dwarf_decode_lines_1 (struct line_header *lh, struct dwarf2_cu *cu,
if (op_code >= lh->opcode_base)
{
/* Special opcode. */
- unsigned char adj_opcode;
- CORE_ADDR addr_adj;
- int line_delta;
-
- adj_opcode = op_code - lh->opcode_base;
- addr_adj = (((state_machine.op_index
- + (adj_opcode / lh->line_range))
- / lh->maximum_ops_per_instruction)
- * lh->minimum_instruction_length);
- state_machine.address
- += gdbarch_adjust_dwarf2_line (gdbarch, addr_adj, 1);
- state_machine.op_index = ((state_machine.op_index
- + (adj_opcode / lh->line_range))
- % lh->maximum_ops_per_instruction);
- line_delta = lh->line_base + (adj_opcode % lh->line_range);
- state_machine.line += line_delta;
- if (line_delta != 0)
- state_machine.line_has_non_zero_discriminator
- = state_machine.discriminator != 0;
-
- dwarf_record_line (&reader_state, &state_machine, 0);
- state_machine.discriminator = 0;
+ state_machine.handle_special_opcode (op_code);
}
else switch (op_code)
{
@@ -18424,21 +18509,18 @@ dwarf_decode_lines_1 (struct line_header *lh, struct dwarf2_cu *cu,
switch (extended_op)
{
case DW_LNE_end_sequence:
- state_machine.record_line = record_line;
- end_sequence = 1;
+ state_machine.handle_end_sequence ();
+ end_sequence = true;
break;
case DW_LNE_set_address:
{
CORE_ADDR address
= read_address (abfd, line_ptr, cu, &bytes_read);
-
line_ptr += bytes_read;
- check_line_address (cu, &state_machine, line_ptr,
- lowpc, address);
- state_machine.op_index = 0;
- address += baseaddr;
- state_machine.address
- = gdbarch_adjust_dwarf2_line (gdbarch, address, 0);
+
+ state_machine.check_line_address (cu, line_ptr,
+ lowpc, address);
+ state_machine.handle_set_address (baseaddr, address);
}
break;
case DW_LNE_define_file:
@@ -18463,16 +18545,19 @@ dwarf_decode_lines_1 (struct line_header *lh, struct dwarf2_cu *cu,
}
break;
case DW_LNE_set_discriminator:
- /* The discriminator is not interesting to the debugger;
- just ignore it. We still need to check its value though:
- if there are consecutive entries for the same
- (non-prologue) line we want to coalesce them.
- PR 17276. */
- state_machine.discriminator
- = read_unsigned_leb128 (abfd, line_ptr, &bytes_read);
- state_machine.line_has_non_zero_discriminator
- |= state_machine.discriminator != 0;
- line_ptr += bytes_read;
+ {
+ /* The discriminator is not interesting to the
+ debugger; just ignore it. We still need to
+ check its value though:
+ if there are consecutive entries for the same
+ (non-prologue) line we want to coalesce them.
+ PR 17276. */
+ unsigned int discr
+ = read_unsigned_leb128 (abfd, line_ptr, &bytes_read);
+ line_ptr += bytes_read;
+
+ state_machine.handle_set_discriminator (discr);
+ }
break;
default:
complaint (&symfile_complaints,
@@ -18490,59 +18575,34 @@ dwarf_decode_lines_1 (struct line_header *lh, struct dwarf2_cu *cu,
}
break;
case DW_LNS_copy:
- dwarf_record_line (&reader_state, &state_machine, 0);
- state_machine.discriminator = 0;
+ state_machine.handle_copy ();
break;
case DW_LNS_advance_pc:
{
CORE_ADDR adjust
= read_unsigned_leb128 (abfd, line_ptr, &bytes_read);
- CORE_ADDR addr_adj;
-
- addr_adj = (((state_machine.op_index + adjust)
- / lh->maximum_ops_per_instruction)
- * lh->minimum_instruction_length);
- state_machine.address
- += gdbarch_adjust_dwarf2_line (gdbarch, addr_adj, 1);
- state_machine.op_index = ((state_machine.op_index + adjust)
- % lh->maximum_ops_per_instruction);
line_ptr += bytes_read;
+
+ state_machine.handle_advance_pc (adjust);
}
break;
case DW_LNS_advance_line:
{
int line_delta
= read_signed_leb128 (abfd, line_ptr, &bytes_read);
-
- state_machine.line += line_delta;
- if (line_delta != 0)
- state_machine.line_has_non_zero_discriminator
- = state_machine.discriminator != 0;
line_ptr += bytes_read;
+
+ state_machine.handle_advance_line (line_delta);
}
break;
case DW_LNS_set_file:
{
- state_machine.file
+ file_name_index file
= (file_name_index) read_unsigned_leb128 (abfd, line_ptr,
&bytes_read);
line_ptr += bytes_read;
- const file_entry *fe = state_machine.current_file ();
- if (fe == NULL)
- dwarf2_debug_line_missing_file_complaint ();
- else
- {
- if (record_lines_p)
- {
- const char *dir = fe->include_dir (lh);
-
- state_machine.last_subfile = current_subfile;
- state_machine.line_has_non_zero_discriminator
- = state_machine.discriminator != 0;
- dwarf2_start_subfile (fe->name, dir);
- }
- }
+ state_machine.handle_set_file (file);
}
break;
case DW_LNS_set_column:
@@ -18550,7 +18610,7 @@ dwarf_decode_lines_1 (struct line_header *lh, struct dwarf2_cu *cu,
line_ptr += bytes_read;
break;
case DW_LNS_negate_stmt:
- state_machine.is_stmt = (!state_machine.is_stmt);
+ state_machine.handle_negate_stmt ();
break;
case DW_LNS_set_basic_block:
break;
@@ -18560,28 +18620,14 @@ dwarf_decode_lines_1 (struct line_header *lh, struct dwarf2_cu *cu,
instruction length since special opcode 255 would have
scaled the increment. */
case DW_LNS_const_add_pc:
- {
- CORE_ADDR adjust = (255 - lh->opcode_base) / lh->line_range;
- CORE_ADDR addr_adj;
-
- addr_adj = (((state_machine.op_index + adjust)
- / lh->maximum_ops_per_instruction)
- * lh->minimum_instruction_length);
- state_machine.address
- += gdbarch_adjust_dwarf2_line (gdbarch, addr_adj, 1);
- state_machine.op_index = ((state_machine.op_index + adjust)
- % lh->maximum_ops_per_instruction);
- }
+ state_machine.handle_const_add_pc ();
break;
case DW_LNS_fixed_advance_pc:
{
- CORE_ADDR addr_adj;
-
- addr_adj = read_2_bytes (abfd, line_ptr);
- state_machine.address
- += gdbarch_adjust_dwarf2_line (gdbarch, addr_adj, 1);
- state_machine.op_index = 0;
+ CORE_ADDR addr_adj = read_2_bytes (abfd, line_ptr);
line_ptr += 2;
+
+ state_machine.handle_fixed_advance_pc (addr_adj);
}
break;
default:
@@ -18603,7 +18649,7 @@ dwarf_decode_lines_1 (struct line_header *lh, struct dwarf2_cu *cu,
/* We got a DW_LNE_end_sequence (or we ran off the end of the buffer,
in which case we still finish recording the last line). */
- dwarf_record_line (&reader_state, &state_machine, 1);
+ state_machine.record_line (true);
}
}