[PATCH][GOLD] Add make_elf_object target hooks.
Doug Kwan (關振德)
dougkwan@google.com
Tue Aug 18 19:08:00 GMT 2009
Hi,
I have updated the patch.
-Doug
2009-08-18 Doug Kwan <dougkwan@google.com>
* dynobj.cc (Sized_dynobj::setup): Take a Target object instead of
an elcpp::Ehdr as parameter. Adjust call to set_target.
* dynobj.h (Sized_dynobj::setup): Take a Target object instead of
an elfcpp::Ehdr as parameter.
* object.cc (Object::set_target): Remove the version that looks up
a target and sets it.
(Sized_relobj::setup): Take a Target object instead of
an elfcpp::Ehdr as parameter. Adjust call to set_target.
(make_elf_sized_object): Find target and ask target to
make an ELF object.
* object.h: (Object::set_target): Remove the version that looks up
a target and sets it.
(Sized_relobj::setup): Take a Target object instead of
an elfcpp:Ehdr as parameter.
* target.cc: Include dynobj.h.
(Target::do_make_elf_object_implementation): New.
(Target::do_make_elf_object): New.
* target.h (Target::make_elf_object): New template declaration.
(Target::do_make_elf_object): New method declarations.
(Target::do_make_elf_object_implementation): New template declaration.
2009/8/18 Ian Lance Taylor <iant@google.com>:
> "Doug Kwan (關振德)" <dougkwan@google.com> writes:
>
>> 2009/8/18 Ian Lance Taylor <iant@google.com>:
>>
>>>> + obj->setup(ehdr);
>>>
>>> It no longer makes sense for Object::setup to take an ehdr parameter.
>>> It should take a target parameter, and avoid looking up the target
>>> again.
>>
>> Agree. I suppose all objects have targets and their targets do not
>> change. Should setup() be simply part of the constructor?
>
> I originally left it out because it can fail, and it's weird to have a
> constructor fail. I guess I'd prefer to keep it separate for now.
>
>
>>> Interesting problem. I wonder if there is anything we can do to make
>>> that easier to write.
>>
>> Unfortunately, virtual functions cannot be templated. That's why I
>> mentioned changing the paratmeter ehdr back to a raw unsigned char
>> pointer. If we do so, we only have one virtual function instead of
>> four. The downside of doing that is that callers must ensure that the
>> pointer points to something valid. Passing an
>> Elfcpp::Ehdr<size,big_endian> object enforces that automatically.
>
> Yeah, I guess the way you did it is fine.
>
> Ian
>
-------------- next part --------------
Index: gold/dynobj.cc
===================================================================
RCS file: /cvs/src/src/gold/dynobj.cc,v
retrieving revision 1.43
diff -u -p -r1.43 dynobj.cc
--- gold/dynobj.cc 13 Feb 2009 19:04:44 -0000 1.43
+++ gold/dynobj.cc 18 Aug 2009 18:50:10 -0000
@@ -83,13 +83,9 @@ Sized_dynobj<size, big_endian>::Sized_dy
template<int size, bool big_endian>
void
-Sized_dynobj<size, big_endian>::setup(
- const elfcpp::Ehdr<size, big_endian>& ehdr)
+Sized_dynobj<size, big_endian>::setup(Target *target)
{
- this->set_target(ehdr.get_e_machine(), size, big_endian,
- ehdr.get_e_ident()[elfcpp::EI_OSABI],
- ehdr.get_e_ident()[elfcpp::EI_ABIVERSION]);
-
+ this->set_target(target);
const unsigned int shnum = this->elf_file_.shnum();
this->set_shnum(shnum);
}
Index: gold/dynobj.h
===================================================================
RCS file: /cvs/src/src/gold/dynobj.h,v
retrieving revision 1.31
diff -u -p -r1.31 dynobj.h
--- gold/dynobj.h 10 Aug 2009 02:29:30 -0000 1.31
+++ gold/dynobj.h 18 Aug 2009 18:50:10 -0000
@@ -161,9 +161,9 @@ class Sized_dynobj : public Dynobj
Sized_dynobj(const std::string& name, Input_file* input_file, off_t offset,
const typename elfcpp::Ehdr<size, big_endian>&);
- // Set up the object file based on the ELF header.
+ // Set up the object file based on TARGET.
void
- setup(const typename elfcpp::Ehdr<size, big_endian>&);
+ setup(Target *target);
// Read the symbols.
void
Index: gold/object.cc
===================================================================
RCS file: /cvs/src/src/gold/object.cc,v
retrieving revision 1.97
diff -u -p -r1.97 object.cc
--- gold/object.cc 5 Aug 2009 20:51:56 -0000 1.97
+++ gold/object.cc 18 Aug 2009 18:50:11 -0000
@@ -132,19 +132,6 @@ Xindex::sym_xindex_to_shndx(Object* obje
// Class Object.
-// Set the target based on fields in the ELF file header.
-
-void
-Object::set_target(int machine, int size, bool big_endian, int osabi,
- int abiversion)
-{
- Target* target = select_target(machine, size, big_endian, osabi, abiversion);
- if (target == NULL)
- gold_fatal(_("%s: unsupported ELF machine number %d"),
- this->name().c_str(), machine);
- this->target_ = target;
-}
-
// Report an error for this object file. This is used by the
// elfcpp::Elf_file interface, and also called by the Object code
// itself.
@@ -353,12 +340,9 @@ Sized_relobj<size, big_endian>::~Sized_r
template<int size, bool big_endian>
void
-Sized_relobj<size, big_endian>::setup(
- const elfcpp::Ehdr<size, big_endian>& ehdr)
+Sized_relobj<size, big_endian>::setup(Target *target)
{
- this->set_target(ehdr.get_e_machine(), size, big_endian,
- ehdr.get_e_ident()[elfcpp::EI_OSABI],
- ehdr.get_e_ident()[elfcpp::EI_ABIVERSION]);
+ this->set_target(target);
const unsigned int shnum = this->elf_file_.shnum();
this->set_shnum(shnum);
@@ -2237,27 +2221,14 @@ Object*
make_elf_sized_object(const std::string& name, Input_file* input_file,
off_t offset, const elfcpp::Ehdr<size, big_endian>& ehdr)
{
- int et = ehdr.get_e_type();
- if (et == elfcpp::ET_REL)
- {
- Sized_relobj<size, big_endian>* obj =
- new Sized_relobj<size, big_endian>(name, input_file, offset, ehdr);
- obj->setup(ehdr);
- return obj;
- }
- else if (et == elfcpp::ET_DYN)
- {
- Sized_dynobj<size, big_endian>* obj =
- new Sized_dynobj<size, big_endian>(name, input_file, offset, ehdr);
- obj->setup(ehdr);
- return obj;
- }
- else
- {
- gold_error(_("%s: unsupported ELF file type %d"),
- name.c_str(), et);
- return NULL;
- }
+ Target* target = select_target(ehdr.get_e_machine(), size, big_endian,
+ ehdr.get_e_ident()[elfcpp::EI_OSABI],
+ ehdr.get_e_ident()[elfcpp::EI_ABIVERSION]);
+ if (target == NULL)
+ gold_fatal(_("%s: unsupported ELF machine number %d"),
+ name.c_str(), ehdr.get_e_machine());
+ return target->make_elf_object<size, big_endian>(name, input_file, offset,
+ ehdr);
}
} // End anonymous namespace.
Index: gold/object.h
===================================================================
RCS file: /cvs/src/src/gold/object.h,v
retrieving revision 1.77
diff -u -p -r1.77 object.h
--- gold/object.h 5 Aug 2009 20:51:56 -0000 1.77
+++ gold/object.h 18 Aug 2009 18:50:11 -0000
@@ -545,11 +545,6 @@ class Object
virtual void
do_get_global_symbol_counts(const Symbol_table*, size_t*, size_t*) const = 0;
- // Set the target.
- void
- set_target(int machine, int size, bool big_endian, int osabi,
- int abiversion);
-
// Set the number of sections.
void
set_shnum(int shnum)
@@ -1311,9 +1306,9 @@ class Sized_relobj : public Relobj
is_output_section_offset_invalid(unsigned int shndx) const
{ return this->get_output_section_offset(shndx) == invalid_address; }
- // Set up the object file based on the ELF header.
+ // Set up the object file based on TARGET.
void
- setup(const typename elfcpp::Ehdr<size, big_endian>&);
+ setup(Target *target);
// Return the number of symbols. This is only valid after
// Object::add_symbols has been called.
Index: gold/target.cc
===================================================================
RCS file: /cvs/src/src/gold/target.cc,v
retrieving revision 1.1
diff -u -p -r1.1 target.cc
--- gold/target.cc 5 Jun 2009 21:32:56 -0000 1.1
+++ gold/target.cc 18 Aug 2009 18:50:11 -0000
@@ -22,6 +22,7 @@
#include "gold.h"
#include "target.h"
+#include "dynobj.h"
namespace gold
{
@@ -55,4 +56,83 @@ Target::do_is_local_label_name (const ch
return false;
}
+// Implementations of methods Target::do_make_elf_object are almost identical
+// except for the address sizes and endianities. So we extract this
+// into a template.
+
+template<int size, bool big_endian>
+inline Object*
+Target::do_make_elf_object_implementation(
+ const std::string& name,
+ Input_file* input_file,
+ off_t offset,
+ const elfcpp::Ehdr<size, big_endian>& ehdr)
+{
+ int et = ehdr.get_e_type();
+ if (et == elfcpp::ET_REL)
+ {
+ Sized_relobj<size, big_endian>* obj =
+ new Sized_relobj<size, big_endian>(name, input_file, offset, ehdr);
+ obj->setup(this);
+ return obj;
+ }
+ else if (et == elfcpp::ET_DYN)
+ {
+ Sized_dynobj<size, big_endian>* obj =
+ new Sized_dynobj<size, big_endian>(name, input_file, offset, ehdr);
+ obj->setup(this);
+ return obj;
+ }
+ else
+ {
+ gold_error(_("%s: unsupported ELF file type %d"),
+ name.c_str(), et);
+ return NULL;
+ }
+}
+
+// Make an ELF object called NAME by reading INPUT_FILE at OFFSET. EHDR
+// is the ELF header of the object. There are four versions of this
+// for different address sizes and endianities.
+
+#ifdef HAVE_TARGET_32_LITTLE
+Object*
+Target::do_make_elf_object(const std::string& name, Input_file* input_file,
+ off_t offset, const elfcpp::Ehdr<32, false>& ehdr)
+{
+ return this->do_make_elf_object_implementation<32, false>(name, input_file,
+ offset, ehdr);
+}
+#endif
+
+#ifdef HAVE_TARGET_32_BIG
+Object*
+Target::do_make_elf_object(const std::string& name, Input_file* input_file,
+ off_t offset, const elfcpp::Ehdr<32, true>& ehdr)
+{
+ return this->do_make_elf_object_implementation<32, true>(name, input_file,
+ offset, ehdr);
+}
+#endif
+
+#ifdef HAVE_TARGET_64_LITTLE
+Object*
+Target::do_make_elf_object(const std::string& name, Input_file* input_file,
+ off_t offset, const elfcpp::Ehdr<64, false>& ehdr)
+{
+ return this->do_make_elf_object_implementation<64, false>(name, input_file,
+ offset, ehdr);
+}
+#endif
+
+#ifdef HAVE_TARGET_64_BIG
+Object*
+Target::do_make_elf_object(const std::string& name, Input_file* input_file,
+ off_t offset, const elfcpp::Ehdr<64, true>& ehdr)
+{
+ return this->do_make_elf_object_implementation<64, true>(name, input_file,
+ offset, ehdr);
+}
+#endif
+
} // End namespace gold.
Index: gold/target.h
===================================================================
RCS file: /cvs/src/src/gold/target.h,v
retrieving revision 1.34
diff -u -p -r1.34 target.h
--- gold/target.h 22 Jun 2009 06:51:53 -0000 1.34
+++ gold/target.h 18 Aug 2009 18:50:11 -0000
@@ -216,6 +216,13 @@ class Target
is_local_label_name(const char* name) const
{ return this->do_is_local_label_name(name); }
+ // Make an ELF object.
+ template<int size, bool big_endian>
+ Object*
+ make_elf_object(const std::string& name, Input_file* input_file,
+ off_t offset, const elfcpp::Ehdr<size, big_endian>& ehdr)
+ { return this->do_make_elf_object(name, input_file, offset, ehdr); }
+
protected:
// This struct holds the constant information for a child class. We
// use a struct to avoid the overhead of virtual function calls for
@@ -301,7 +308,46 @@ class Target
virtual bool
do_is_local_label_name(const char*) const;
+ // make_elf_object hooks. There are four versions of these for
+ // different address sizes and endianities.
+
+#ifdef HAVE_TARGET_32_LITTLE
+ // Virtual functions which may be overriden by the child class.
+ virtual Object*
+ do_make_elf_object(const std::string&, Input_file*, off_t,
+ const elfcpp::Ehdr<32, false>&);
+#endif
+
+#ifdef HAVE_TARGET_32_BIG
+ // Virtual functions which may be overriden by the child class.
+ virtual Object*
+ do_make_elf_object(const std::string&, Input_file*, off_t,
+ const elfcpp::Ehdr<32, true>&);
+#endif
+
+#ifdef HAVE_TARGET_64_LITTLE
+ // Virtual functions which may be overriden by the child class.
+ virtual Object*
+ do_make_elf_object(const std::string&, Input_file*, off_t,
+ const elfcpp::Ehdr<64, false>& ehdr);
+#endif
+
+#ifdef HAVE_TARGET_64_BIG
+ // Virtual functions which may be overriden by the child class.
+ virtual Object*
+ do_make_elf_object(const std::string& name, Input_file* input_file,
+ off_t offset, const elfcpp::Ehdr<64, true>& ehdr);
+#endif
+
private:
+ // The implementations of the four do_make_elf_object virtual functions are
+ // almost identical except for their sizes and endianity. We use a template.
+ // for their implementations.
+ template<int size, bool big_endian>
+ inline Object*
+ do_make_elf_object_implementation(const std::string&, Input_file*, off_t,
+ const elfcpp::Ehdr<size, big_endian>&);
+
Target(const Target&);
Target& operator=(const Target&);
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