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authorDoug Evans <dje@google.com>2014-08-28 16:15:23 -0700
committerDoug Evans <dje@google.com>2014-08-28 16:15:23 -0700
commitf1f58506e2b52740916fa233d3b223733e3847cf (patch)
tree13ac5e96d0aeeb554adfcccdf718d3482c7aa450 /gdb/symtab.c
parentaab2f20890b9252f88a157611df14e79902e02b6 (diff)
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Move definition of some prologue-related functions to a better location.
gdb/ChangeLog: * symtab.c (in_prologue): Move definition to better spot. (skip_prologue_using_sal): Ditto.
Diffstat (limited to 'gdb/symtab.c')
-rw-r--r--gdb/symtab.c374
1 files changed, 187 insertions, 187 deletions
diff --git a/gdb/symtab.c b/gdb/symtab.c
index c505f97..c530d50 100644
--- a/gdb/symtab.c
+++ b/gdb/symtab.c
@@ -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 */