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Move definition of some prologue-related functions to a better location.

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gdb/ChangeLog:

	* symtab.c (in_prologue): Move definition to better spot.
	(skip_prologue_using_sal): Ditto.
This commit is contained in:
Doug Evans
2014-08-28 16:15:23 -07:00
parent aab2f20890
commit f1f58506e2
2 changed files with 192 additions and 187 deletions
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5
gdb/ChangeLog
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@@ -1,3 +1,8 @@
2014-08-28 Doug Evans <dje@google.com>
* symtab.c (in_prologue): Move definition to better spot.
(skip_prologue_using_sal): Ditto.
2014-08-28 Doug Evans <dje@google.com>
* symtab.c (find_function_start_sal): Move definition to better spot.

374
gdb/symtab.c
View File

@@ -3034,6 +3034,193 @@ skip_prologue_sal (struct symtab_and_line *sal)
}
}
/* Determine if PC is in the prologue of a function. The prologue is the area
between the first instruction of a function, and the first executable line.
Returns 1 if PC *might* be in prologue, 0 if definately *not* in prologue.
If non-zero, func_start is where we think the prologue starts, possibly
by previous examination of symbol table information. */
int
in_prologue (struct gdbarch *gdbarch, CORE_ADDR pc, CORE_ADDR func_start)
{
struct symtab_and_line sal;
CORE_ADDR func_addr, func_end;
/* We have several sources of information we can consult to figure
this out.
- Compilers usually emit line number info that marks the prologue
as its own "source line". So the ending address of that "line"
is the end of the prologue. If available, this is the most
reliable method.
- The minimal symbols and partial symbols, which can usually tell
us the starting and ending addresses of a function.
- If we know the function's start address, we can call the
architecture-defined gdbarch_skip_prologue function to analyze the
instruction stream and guess where the prologue ends.
- Our `func_start' argument; if non-zero, this is the caller's
best guess as to the function's entry point. At the time of
this writing, handle_inferior_event doesn't get this right, so
it should be our last resort. */
/* Consult the partial symbol table, to find which function
the PC is in. */
if (! find_pc_partial_function (pc, NULL, &func_addr, &func_end))
{
CORE_ADDR prologue_end;
/* We don't even have minsym information, so fall back to using
func_start, if given. */
if (! func_start)
return 1; /* We *might* be in a prologue. */
prologue_end = gdbarch_skip_prologue (gdbarch, func_start);
return func_start <= pc && pc < prologue_end;
}
/* If we have line number information for the function, that's
usually pretty reliable. */
sal = find_pc_line (func_addr, 0);
/* Now sal describes the source line at the function's entry point,
which (by convention) is the prologue. The end of that "line",
sal.end, is the end of the prologue.
Note that, for functions whose source code is all on a single
line, the line number information doesn't always end up this way.
So we must verify that our purported end-of-prologue address is
*within* the function, not at its start or end. */
if (sal.line == 0
|| sal.end <= func_addr
|| func_end <= sal.end)
{
/* We don't have any good line number info, so use the minsym
information, together with the architecture-specific prologue
scanning code. */
CORE_ADDR prologue_end = gdbarch_skip_prologue (gdbarch, func_addr);
return func_addr <= pc && pc < prologue_end;
}
/* We have line number info, and it looks good. */
return func_addr <= pc && pc < sal.end;
}
/* Given PC at the function's start address, attempt to find the
prologue end using SAL information. Return zero if the skip fails.
A non-optimized prologue traditionally has one SAL for the function
and a second for the function body. A single line function has
them both pointing at the same line.
An optimized prologue is similar but the prologue may contain
instructions (SALs) from the instruction body. Need to skip those
while not getting into the function body.
The functions end point and an increasing SAL line are used as
indicators of the prologue's endpoint.
This code is based on the function refine_prologue_limit
(found in ia64). */
CORE_ADDR
skip_prologue_using_sal (struct gdbarch *gdbarch, CORE_ADDR func_addr)
{
struct symtab_and_line prologue_sal;
CORE_ADDR start_pc;
CORE_ADDR end_pc;
const struct block *bl;
/* Get an initial range for the function. */
find_pc_partial_function (func_addr, NULL, &start_pc, &end_pc);
start_pc += gdbarch_deprecated_function_start_offset (gdbarch);
prologue_sal = find_pc_line (start_pc, 0);
if (prologue_sal.line != 0)
{
/* For languages other than assembly, treat two consecutive line
entries at the same address as a zero-instruction prologue.
The GNU assembler emits separate line notes for each instruction
in a multi-instruction macro, but compilers generally will not
do this. */
if (prologue_sal.symtab->language != language_asm)
{
struct linetable *linetable = LINETABLE (prologue_sal.symtab);
int idx = 0;
/* Skip any earlier lines, and any end-of-sequence marker
from a previous function. */
while (linetable->item[idx].pc != prologue_sal.pc
|| linetable->item[idx].line == 0)
idx++;
if (idx+1 < linetable->nitems
&& linetable->item[idx+1].line != 0
&& linetable->item[idx+1].pc == start_pc)
return start_pc;
}
/* If there is only one sal that covers the entire function,
then it is probably a single line function, like
"foo(){}". */
if (prologue_sal.end >= end_pc)
return 0;
while (prologue_sal.end < end_pc)
{
struct symtab_and_line sal;
sal = find_pc_line (prologue_sal.end, 0);
if (sal.line == 0)
break;
/* Assume that a consecutive SAL for the same (or larger)
line mark the prologue -> body transition. */
if (sal.line >= prologue_sal.line)
break;
/* Likewise if we are in a different symtab altogether
(e.g. within a file included via #include).  */
if (sal.symtab != prologue_sal.symtab)
break;
/* The line number is smaller. Check that it's from the
same function, not something inlined. If it's inlined,
then there is no point comparing the line numbers. */
bl = block_for_pc (prologue_sal.end);
while (bl)
{
if (block_inlined_p (bl))
break;
if (BLOCK_FUNCTION (bl))
{
bl = NULL;
break;
}
bl = BLOCK_SUPERBLOCK (bl);
}
if (bl != NULL)
break;
/* The case in which compiler's optimizer/scheduler has
moved instructions into the prologue. We look ahead in
the function looking for address ranges whose
corresponding line number is less the first one that we
found for the function. This is more conservative then
refine_prologue_limit which scans a large number of SALs
looking for any in the prologue. */
prologue_sal = sal;
}
}
if (prologue_sal.end < end_pc)
/* Return the end of this line, or zero if we could not find a
line. */
return prologue_sal.end;
else
/* Don't return END_PC, which is past the end of the function. */
return prologue_sal.pc;
}
/* If P is of the form "operator[ \t]+..." where `...' is
some legitimate operator text, return a pointer to the
beginning of the substring of the operator text.
@@ -4827,193 +5014,6 @@ make_source_files_completion_list (const char *text, const char *word)
return list;
}
/* Determine if PC is in the prologue of a function. The prologue is the area
between the first instruction of a function, and the first executable line.
Returns 1 if PC *might* be in prologue, 0 if definately *not* in prologue.
If non-zero, func_start is where we think the prologue starts, possibly
by previous examination of symbol table information. */
int
in_prologue (struct gdbarch *gdbarch, CORE_ADDR pc, CORE_ADDR func_start)
{
struct symtab_and_line sal;
CORE_ADDR func_addr, func_end;
/* We have several sources of information we can consult to figure
this out.
- Compilers usually emit line number info that marks the prologue
as its own "source line". So the ending address of that "line"
is the end of the prologue. If available, this is the most
reliable method.
- The minimal symbols and partial symbols, which can usually tell
us the starting and ending addresses of a function.
- If we know the function's start address, we can call the
architecture-defined gdbarch_skip_prologue function to analyze the
instruction stream and guess where the prologue ends.
- Our `func_start' argument; if non-zero, this is the caller's
best guess as to the function's entry point. At the time of
this writing, handle_inferior_event doesn't get this right, so
it should be our last resort. */
/* Consult the partial symbol table, to find which function
the PC is in. */
if (! find_pc_partial_function (pc, NULL, &func_addr, &func_end))
{
CORE_ADDR prologue_end;
/* We don't even have minsym information, so fall back to using
func_start, if given. */
if (! func_start)
return 1; /* We *might* be in a prologue. */
prologue_end = gdbarch_skip_prologue (gdbarch, func_start);
return func_start <= pc && pc < prologue_end;
}
/* If we have line number information for the function, that's
usually pretty reliable. */
sal = find_pc_line (func_addr, 0);
/* Now sal describes the source line at the function's entry point,
which (by convention) is the prologue. The end of that "line",
sal.end, is the end of the prologue.
Note that, for functions whose source code is all on a single
line, the line number information doesn't always end up this way.
So we must verify that our purported end-of-prologue address is
*within* the function, not at its start or end. */
if (sal.line == 0
|| sal.end <= func_addr
|| func_end <= sal.end)
{
/* We don't have any good line number info, so use the minsym
information, together with the architecture-specific prologue
scanning code. */
CORE_ADDR prologue_end = gdbarch_skip_prologue (gdbarch, func_addr);
return func_addr <= pc && pc < prologue_end;
}
/* We have line number info, and it looks good. */
return func_addr <= pc && pc < sal.end;
}
/* Given PC at the function's start address, attempt to find the
prologue end using SAL information. Return zero if the skip fails.
A non-optimized prologue traditionally has one SAL for the function
and a second for the function body. A single line function has
them both pointing at the same line.
An optimized prologue is similar but the prologue may contain
instructions (SALs) from the instruction body. Need to skip those
while not getting into the function body.
The functions end point and an increasing SAL line are used as
indicators of the prologue's endpoint.
This code is based on the function refine_prologue_limit
(found in ia64). */
CORE_ADDR
skip_prologue_using_sal (struct gdbarch *gdbarch, CORE_ADDR func_addr)
{
struct symtab_and_line prologue_sal;
CORE_ADDR start_pc;
CORE_ADDR end_pc;
const struct block *bl;
/* Get an initial range for the function. */
find_pc_partial_function (func_addr, NULL, &start_pc, &end_pc);
start_pc += gdbarch_deprecated_function_start_offset (gdbarch);
prologue_sal = find_pc_line (start_pc, 0);
if (prologue_sal.line != 0)
{
/* For languages other than assembly, treat two consecutive line
entries at the same address as a zero-instruction prologue.
The GNU assembler emits separate line notes for each instruction
in a multi-instruction macro, but compilers generally will not
do this. */
if (prologue_sal.symtab->language != language_asm)
{
struct linetable *linetable = LINETABLE (prologue_sal.symtab);
int idx = 0;
/* Skip any earlier lines, and any end-of-sequence marker
from a previous function. */
while (linetable->item[idx].pc != prologue_sal.pc
|| linetable->item[idx].line == 0)
idx++;
if (idx+1 < linetable->nitems
&& linetable->item[idx+1].line != 0
&& linetable->item[idx+1].pc == start_pc)
return start_pc;
}
/* If there is only one sal that covers the entire function,
then it is probably a single line function, like
"foo(){}". */
if (prologue_sal.end >= end_pc)
return 0;
while (prologue_sal.end < end_pc)
{
struct symtab_and_line sal;
sal = find_pc_line (prologue_sal.end, 0);
if (sal.line == 0)
break;
/* Assume that a consecutive SAL for the same (or larger)
line mark the prologue -> body transition. */
if (sal.line >= prologue_sal.line)
break;
/* Likewise if we are in a different symtab altogether
(e.g. within a file included via #include).  */
if (sal.symtab != prologue_sal.symtab)
break;
/* The line number is smaller. Check that it's from the
same function, not something inlined. If it's inlined,
then there is no point comparing the line numbers. */
bl = block_for_pc (prologue_sal.end);
while (bl)
{
if (block_inlined_p (bl))
break;
if (BLOCK_FUNCTION (bl))
{
bl = NULL;
break;
}
bl = BLOCK_SUPERBLOCK (bl);
}
if (bl != NULL)
break;
/* The case in which compiler's optimizer/scheduler has
moved instructions into the prologue. We look ahead in
the function looking for address ranges whose
corresponding line number is less the first one that we
found for the function. This is more conservative then
refine_prologue_limit which scans a large number of SALs
looking for any in the prologue. */
prologue_sal = sal;
}
}
if (prologue_sal.end < end_pc)
/* Return the end of this line, or zero if we could not find a
line. */
return prologue_sal.end;
else
/* Don't return END_PC, which is past the end of the function. */
return prologue_sal.pc;
}
/* Track MAIN */