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darwin.c (machopic_classify_ident): Handle "stale" section- encoded name problem to avoid generating illegal stubs.

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* darwin.c (machopic_classify_ident): Handle "stale" section-
	encoded name problem to avoid generating illegal stubs.
	(func_name_maybe_scoped): Remove, not needed for gcc3.
	(machopic_indirect_call_target): Don't use it.
	(darwin_encode_section_info): Call only one of update_stubs()
	or update_non_lazy_ptrs() as DECL cannot be both.
	(machopic_output_possible_stub_label): New.
	* darwin.h (ASM_DECLARE_FUNCTION_NAME): Use it.
	* darwin-protos.h (machopic_output_possible_stub_label): Declare.

From-SVN: r48238
This commit is contained in:
Turly O'Connor 2001-12-21 10:44:50 +00:00
parent a00b07c5e5
commit b7fb9feb71
3 changed files with 65 additions and 75 deletions
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2
gcc/config/darwin-protos.h
View File

@ -64,6 +64,8 @@ extern void darwin_encode_section_info PARAMS ((tree));
extern void machopic_finish PARAMS ((FILE *));
extern void machopic_output_possible_stub_label PARAMS ((FILE *, const char*));
extern void darwin_exception_section PARAMS ((void));
extern void darwin_eh_frame_section PARAMS ((void));

135
gcc/config/darwin.c
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@ -118,6 +118,22 @@ machopic_classify_ident (ident)
else if (name[1] == 'T')
return MACHOPIC_DEFINED_FUNCTION;
/* It is possible that someone is holding a "stale" name, which has
since been defined. See if there is a "defined" name (i.e,
different from NAME only in having a '!D_' or a '!T_' instead of
a '!d_' or '!t_' prefix) in the identifier hash tables. If so, say
that this identifier is defined. */
else if (name[1] == 'd' || name[1] == 't')
{
char *new_name;
new_name = (char *)alloca (strlen (name) + 1);
strcpy (new_name, name);
new_name[1] = (name[1] == 'd') ? 'D' : 'T';
if (maybe_get_identifier (new_name) != NULL)
return (name[1] == 'd') ? MACHOPIC_DEFINED_DATA
: MACHOPIC_DEFINED_FUNCTION;
}
for (temp = machopic_defined_list; temp != NULL_TREE; temp = TREE_CHAIN (temp))
{
if (ident == TREE_VALUE (temp))
@ -527,78 +543,6 @@ machopic_indirect_data_reference (orig, reg)
return ptr_ref;
}
/* For MACHOPIC_INDIRECT_CALL_TARGET below, we need to beware of:
extern "C" { int f(); }
struct X { int f(); int g(); };
int X::f() { ::f(); }
int X::g() { ::f(); f();}
This is hairy. Both calls to "::f()" need to be indirect (i.e., to
appropriate symbol stubs), but since MACHOPIC_NAME_DEFINED_P calls
GET_IDENTIFIER which treats "f" as "X::f", and "X::f" is indeed (being)
defined somewhere in "X"'s inheritance hierarchy, MACHOPIC_NAME_DEFINED_P
returns TRUE when called with "f", which means that
MACHOPIC_INDIRECT_CALL_TARGET uses an "internal" call instead of an
indirect one as it should.
Our quick-n-dirty solution to this is to call the following
FUNC_NAME_MAYBE_SCOPED routine which (only for C++) checks whether
FNAME -- the name of the function which we're calling -- is NOT a
mangled C++ name, AND if the current function being compiled is a
method, and if so, use an "external" or "indirect" call.
Note that this function will be called ONLY when MACHOPIC_INDIRECT_TARGET_P
has already indicated that the target is NOT indirect.
This conservative solution will sometimes make indirect calls where
it might have been possible to make direct ones.
FUNC_NAME_MAYBE_SCOPED returns 1 to indicate a "C" name (not scoped),
which in turns means we should create a stub for an indirect call.
*/
static int is_cplusplus = -1;
static int
func_name_maybe_scoped (fname)
const char *fname;
{
if (is_cplusplus < 0)
is_cplusplus = (strcmp (lang_hooks.name, "GNU C++") == 0);
if (is_cplusplus)
{
/* If we have a method, then check whether the function we're trying to
call is a "C" function. If so, we should use an indirect call.
It turns out to be hard to tell whether "we have a method", since
static member functions have a TREE_CODE of FUNCTION_TYPE, as do
namespace-level non-member functions. So here, we always look for
an extern-"C"-like name, and make stubs for them no matter the
calling context. This is temporary, and leaves nagging suspicion
that improvements should be possible here. (I.e., I suspect that
it can still sometimes make stubs where it needn't.) */
/* if (1 || TREE_CODE (TREE_TYPE (current_function_decl)) == METHOD_TYPE) */
{
/* If fname is of the form "f__1X" or "f__Fv", it's C++. */
while (*fname == '_') ++fname; /* skip leading underscores */
while (*fname != 0)
{
if (fname[0] == '_' && fname[1] == '_'
&& (fname[2] == 'F' || ISDIGIT (fname[2])))
return 0;
++fname;
}
/* Not a C++ mangled name: must be "C", in which case play safe. */
return 1;
}
}
return 0;
}
/* Transform TARGET (a MEM), which is a function call target, to the
corresponding symbol_stub if necessary. Return a new MEM. */
@ -614,7 +558,11 @@ machopic_indirect_call_target (target)
enum machine_mode mode = GET_MODE (XEXP (target, 0));
const char *name = XSTR (XEXP (target, 0), 0);
if (!machopic_name_defined_p (name) || func_name_maybe_scoped (name))
/* If the name is already defined, we need do nothing. */
if (name[0] == '!' && name[1] == 'T')
return target;
if (!machopic_name_defined_p (name))
{
const char *stub_name = machopic_stub_name (name);
@ -894,6 +842,10 @@ machopic_finish (asm_out_file)
if (! TREE_USED (temp))
continue;
/* If the symbol is actually defined, we don't need a stub. */
if (sym_name[0] == '!' && sym_name[1] == 'T')
continue;
STRIP_NAME_ENCODING (sym_name, sym_name);
sym = alloca (strlen (sym_name) + 2);
@ -1056,8 +1008,10 @@ darwin_encode_section_info (decl)
}
/* The non-lazy pointer list may have captured references to the
old encoded name, change them. */
update_non_lazy_ptrs (XSTR (sym_ref, 0));
update_stubs (XSTR (sym_ref, 0));
if (TREE_CODE (decl) == VAR_DECL)
update_non_lazy_ptrs (XSTR (sym_ref, 0));
else
update_stubs (XSTR (sym_ref, 0));
}
/* Scan the list of non-lazy pointers and update any recorded names whose
@ -1090,6 +1044,37 @@ update_non_lazy_ptrs (name)
}
}
/* Function NAME is being defined, and its label has just been output.
If there's already a reference to a stub for this function, we can
just emit the stub label now and we don't bother emitting the stub later. */
void
machopic_output_possible_stub_label (file, name)
FILE *file;
const char *name;
{
tree temp;
/* Ensure we're looking at a section-encoded name. */
if (name[0] != '!' || (name[1] != 't' && name[1] != 'T'))
return;
for (temp = machopic_stubs;
temp != NULL_TREE;
temp = TREE_CHAIN (temp))
{
const char *sym_name;
sym_name = IDENTIFIER_POINTER (TREE_VALUE (temp));
if (sym_name[0] == '!' && sym_name[1] == 'T'
&& ! strcmp (name+2, sym_name+2))
{
ASM_OUTPUT_LABEL (file, IDENTIFIER_POINTER (TREE_PURPOSE (temp)));
break;
}
}
}
/* Scan the list of stubs and update any recorded names whose
stripped name matches the argument. */

3
gcc/config/darwin.h
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@ -232,6 +232,9 @@ do { text_section (); \
|| DECL_INITIAL (DECL)) \
ENCODE_SECTION_INFO (DECL); \
ASM_OUTPUT_LABEL (FILE, xname); \
/* Avoid generating stubs for functions we've just defined by \
outputting any required stub name label now. */ \
machopic_output_possible_stub_label (FILE, xname); \
} while (0)
/* Wrap new method names in quotes so the assembler doesn't gag.