[llvm-commits] [llvm-gcc-4.0] r42287 - in /llvm-gcc-4.0/trunk/gcc: c-common.h llvm-backend.cpp objc/objc-act.c stub-objc.c
Fariborz Jahanian
fjahanian at apple.com
Tue Sep 25 14:44:06 PDT 2007
On Sep 25, 2007, at 2:29 PM, Chris Lattner wrote:
> On Sep 24, 2007, at 7:51 PM, Bill Wendling wrote:
>> URL: http://llvm.org/viewvc/llvm-project?rev=42287&view=rev
>> Log:
>> During the processing of Objective-C "protocols", the objc frontend
>> creates two
>> decls for the protocol. One for the metadata and another for when
>> it's
>> referenced. However, protocols are "internal global", so when we do
>> a lookup
>> for the reference, it doesn't find the first decl because it's not
>> "external".
>> This will perform a second lookup for objective C protocols if we
>> don't find
>> it among the "external globals".
>
> Hi Bill,
>
> This is a good short-term solution Bill, but I don't think it is
> what we want to keep.
>
> Specifically, your new function adds a fairly expensive call to
> strstr to the global variable emission path for all languages.
>
> It would be better to merge the vardecls in objc-act.c where it
> creates them. I see this code:
>
> /* Build decl = initializer; for each protocol referenced in
> @protocol(MyProtole) expression. */
>
> static void
> build_protocollist_translation_table (void)
> {
> tree chain;
> static char string[BUFSIZE];
>
> for (chain = protocollist_ref_chain; chain; chain = TREE_CHAIN
> (chain))
> {
> tree expr = TREE_VALUE (chain);
> tree decl = TREE_PURPOSE (chain);
> gcc_assert (TREE_CODE (expr) == PROTOCOL_INTERFACE_TYPE);
> /* APPLE LOCAL begin radar 4695109 */
> sprintf (string, "_OBJC_PROTOCOL_$_%s",
> IDENTIFIER_POINTER (PROTOCOL_NAME (expr)));
> expr = start_var_decl (objc_v2_protocol_template, string);
> /* APPLE LOCAL end radar 4695109 */
> expr = convert (objc_protocol_type, build_fold_addr_expr (expr));
> finish_var_decl (decl, expr);
> }
> }
>
> and this:
>
> static void
> build_v2_protocol_reference (tree p)
> {
> tree decl;
> const char *proto_name;
>
> /* static struct protocol_t _OBJC_PROTOCOL_$<mumble>; */
>
> proto_name = synth_id_with_class_suffix ("_OBJC_PROTOCOL_$", p);
> decl = start_var_decl (objc_v2_protocol_template, proto_name);
> PROTOCOL_V2_FORWARD_DECL (p) = decl;
> }
>
> I'm not sure which happens first, but this is creating two DECL
> nodes with the same name. Can you please investigate using
> lookup_name to only
build_v2_protocol_reference happens first, which is caused by
@protocol expression in user code. The other one is related to meta-
data generaiton which comes at the very end.
- fariborz
> create the new var_decl node if it doesn't already exist?
>
> It might just be a matter of changing the code to looks like this:
>
> proto_name = synth_id_with_class_suffix ("_OBJC_PROTOCOL_$", p);
> if ((decl = lookup_name(proto_name)) == 0)
> decl = start_var_decl (objc_v2_protocol_template, proto_name);
> PROTOCOL_V2_FORWARD_DECL (p) = decl;
>
> Or something.
>
> -Chris
>
>
>
>> Modified:
>> llvm-gcc-4.0/trunk/gcc/c-common.h
>> llvm-gcc-4.0/trunk/gcc/llvm-backend.cpp
>> llvm-gcc-4.0/trunk/gcc/objc/objc-act.c
>> llvm-gcc-4.0/trunk/gcc/stub-objc.c
>>
>> Modified: llvm-gcc-4.0/trunk/gcc/c-common.h
>> URL: http://llvm.org/viewvc/llvm-project/llvm-gcc-4.0/trunk/gcc/c-common.h?rev=42287&r1=42286&r2=42287&view=diff
>>
>> =
>> =
>> =
>> =
>> =
>> =
>> =
>> =
>> =
>> =====================================================================
>> --- llvm-gcc-4.0/trunk/gcc/c-common.h (original)
>> +++ llvm-gcc-4.0/trunk/gcc/c-common.h Mon Sep 24 21:51:18 2007
>> @@ -1139,6 +1139,12 @@
>> extern void objc_remove_weak_read (tree*);
>> /* APPLE LOCAL end radar 4426814 */
>>
>> +/* APPLE LOCAL begin - LLVM radar 5476262 */
>> +#ifdef ENABLE_LLVM
>> +extern bool objc_is_protocol_reference (const char *name);
>> +#endif
>> +/* APPLE LOCAL end - LLVM radar 5476262 */
>> +
>> /* APPLE LOCAL begin C* language */
>> extern void objc_set_method_opt (int);
>> void objc_finish_foreach_loop (location_t, tree, tree, tree, tree);
>>
>> Modified: llvm-gcc-4.0/trunk/gcc/llvm-backend.cpp
>> URL: http://llvm.org/viewvc/llvm-project/llvm-gcc-4.0/trunk/gcc/llvm-backend.cpp?rev=42287&r1=42286&r2=42287&view=diff
>>
>> =
>> =
>> =
>> =
>> =
>> =
>> =
>> =
>> =
>> =====================================================================
>> --- llvm-gcc-4.0/trunk/gcc/llvm-backend.cpp (original)
>> +++ llvm-gcc-4.0/trunk/gcc/llvm-backend.cpp Mon Sep 24 21:51:18 2007
>> @@ -66,6 +66,7 @@
>> #include "function.h"
>> #include "tree-inline.h"
>> #include "langhooks.h"
>> +#include "c-common.h"
>> }
>>
>> // Non-zero if bytecode from PCH is successfully read.
>> @@ -1060,6 +1061,14 @@
>> // If the global has a name, prevent multiple vars with the
>> same name from
>> // being created.
>> GlobalVariable *GVE = TheModule->getGlobalVariable(Name);
>> +
>> + // And Objective-C "@protocol" will create a decl for the
>> + // protocol metadata and then when the protocol is
>> + // referenced. However, protocols have file-scope, so they
>> + // aren't found in the GlobalVariable list unless we look at
>> + // non-extern globals as well.
>> + if (!GVE && c_dialect_objc() &&
>> objc_is_protocol_reference(Name))
>> + GVE = TheModule->getGlobalVariable(Name, true);
>>
>> if (GVE == 0) {
>> GV = new GlobalVariable(Ty, false,
>> GlobalValue::ExternalLinkage,0,
>>
>> Modified: llvm-gcc-4.0/trunk/gcc/objc/objc-act.c
>> URL: http://llvm.org/viewvc/llvm-project/llvm-gcc-4.0/trunk/gcc/objc/objc-act.c?rev=42287&r1=42286&r2=42287&view=diff
>>
>> =
>> =
>> =
>> =
>> =
>> =
>> =
>> =
>> =
>> =====================================================================
>> --- llvm-gcc-4.0/trunk/gcc/objc/objc-act.c (original)
>> +++ llvm-gcc-4.0/trunk/gcc/objc/objc-act.c Mon Sep 24 21:51:18 2007
>> @@ -11669,6 +11669,19 @@
>> }
>> }
>>
>> +/* APPLE LOCAL begin - LLVM radar 5476262 */
>> +#ifdef ENABLE_LLVM
>> +/* This routine returns true if the name is the same as a protocol
>> + reference name. */
>> +
>> +bool
>> +objc_is_protocol_reference (const char *name)
>> +{
>> + return flag_objc_abi == 2 && strstr (name, "_OBJC_PROTOCOL_$_") !
>> = 0;
>> +}
>> +#endif
>> +/* APPLE LOCAL end - LLVM radar 5476262 */
>> +
>> /* This routine builds the protocol_reference_chain for each
>> protocol name used
>> @protocol(MyProtocol) expression. IDENT is current protocol
>> name. */
>>
>>
>> Modified: llvm-gcc-4.0/trunk/gcc/stub-objc.c
>> URL: http://llvm.org/viewvc/llvm-project/llvm-gcc-4.0/trunk/gcc/stub-objc.c?rev=42287&r1=42286&r2=42287&view=diff
>>
>> =
>> =
>> =
>> =
>> =
>> =
>> =
>> =
>> =
>> =====================================================================
>> --- llvm-gcc-4.0/trunk/gcc/stub-objc.c (original)
>> +++ llvm-gcc-4.0/trunk/gcc/stub-objc.c Mon Sep 24 21:51:18 2007
>> @@ -548,3 +548,13 @@
>> return false;
>> }
>> /* APPLE LOCAL end radar 4985544 */
>> +
>> +/* APPLE LOCAL begin - LLVM radar 5476262 */
>> +#ifdef ENABLE_LLVM
>> +bool
>> +objc_is_protocol_reference (const char * ARG_UNUSED(name))
>> +{
>> + return false;
>> +}
>> +#endif
>> +/* APPLE LOCAL end - LLVM radar 5476262 */
>>
>>
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>
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