[GOLD] Reduce size of class Symbol
Alan Modra
amodra@gmail.com
Mon Aug 28 11:36:00 GMT 2017
On Sun, Aug 27, 2017 at 10:15:44PM -0700, Cary Coutant wrote:
> Still seems fragile to me -- you don't get any static checking that
> the conditions are met. I prefer to split the union into two.
OK, here's that patch.
* symtab.h (Symbol): Split u_ into u1_ and u2_. Move plt_offset_
before got_offsets_. Adjust accessors to suit.
* symtab.cc (Symbol::init_fields): Adjust for union change.
(Symbol::init_base_output_data): Likewise.
(Symbol::init_base_output_segment): Likewise.
(Symbol::allocate_base_common): Likewise.
(Symbol::output_section): Likewise.
(Symbol::set_output_section): Likewise.
(Symbol::set_output_segment): Likewise.
* resolve.cc (Symbol::override_base): Likewise.
(Symbol::override_base_with_special): Likewise.
diff --git a/gold/resolve.cc b/gold/resolve.cc
index 7c22606..042d032 100644
--- a/gold/resolve.cc
+++ b/gold/resolve.cc
@@ -92,9 +92,9 @@ Symbol::override_base(const elfcpp::Sym<size, big_endian>& sym,
Object* object, const char* version)
{
gold_assert(this->source_ == FROM_OBJECT);
- this->u_.from_object.object = object;
+ this->u1_.object = object;
this->override_version(version);
- this->u_.from_object.shndx = st_shndx;
+ this->u2_.shndx = st_shndx;
this->is_ordinary_shndx_ = is_ordinary;
// Don't override st_type from plugin placeholder symbols.
if (object->pluginobj() == NULL)
@@ -952,13 +952,10 @@ Symbol::override_base_with_special(const Symbol* from)
switch (from->source_)
{
case FROM_OBJECT:
- this->u_.from_object = from->u_.from_object;
- break;
case IN_OUTPUT_DATA:
- this->u_.in_output_data = from->u_.in_output_data;
- break;
case IN_OUTPUT_SEGMENT:
- this->u_.in_output_segment = from->u_.in_output_segment;
+ this->u1_ = from->u1_;
+ this->u2_ = from->u2_;
break;
case IS_CONSTANT:
case IS_UNDEFINED:
diff --git a/gold/symtab.cc b/gold/symtab.cc
index 7e0a3f8..1555de6 100644
--- a/gold/symtab.cc
+++ b/gold/symtab.cc
@@ -47,8 +47,8 @@ namespace gold
// Class Symbol.
-// Initialize fields in Symbol. This initializes everything except u_
-// and source_.
+// Initialize fields in Symbol. This initializes everything except
+// u1_, u2_ and source_.
void
Symbol::init_fields(const char* name, const char* version,
@@ -120,8 +120,8 @@ Symbol::init_base_object(const char* name, const char* version, Object* object,
{
this->init_fields(name, version, sym.get_st_type(), sym.get_st_bind(),
sym.get_st_visibility(), sym.get_st_nonvis());
- this->u_.from_object.object = object;
- this->u_.from_object.shndx = st_shndx;
+ this->u1_.object = object;
+ this->u2_.shndx = st_shndx;
this->is_ordinary_shndx_ = is_ordinary;
this->source_ = FROM_OBJECT;
this->in_reg_ = !object->is_dynamic();
@@ -140,8 +140,8 @@ Symbol::init_base_output_data(const char* name, const char* version,
bool is_predefined)
{
this->init_fields(name, version, type, binding, visibility, nonvis);
- this->u_.in_output_data.output_data = od;
- this->u_.in_output_data.offset_is_from_end = offset_is_from_end;
+ this->u1_.output_data = od;
+ this->u2_.offset_is_from_end = offset_is_from_end;
this->source_ = IN_OUTPUT_DATA;
this->in_reg_ = true;
this->in_real_elf_ = true;
@@ -160,8 +160,8 @@ Symbol::init_base_output_segment(const char* name, const char* version,
bool is_predefined)
{
this->init_fields(name, version, type, binding, visibility, nonvis);
- this->u_.in_output_segment.output_segment = os;
- this->u_.in_output_segment.offset_base = offset_base;
+ this->u1_.output_segment = os;
+ this->u2_.offset_base = offset_base;
this->source_ = IN_OUTPUT_SEGMENT;
this->in_reg_ = true;
this->in_real_elf_ = true;
@@ -206,8 +206,8 @@ Symbol::allocate_base_common(Output_data* od)
{
gold_assert(this->is_common());
this->source_ = IN_OUTPUT_DATA;
- this->u_.in_output_data.output_data = od;
- this->u_.in_output_data.offset_is_from_end = false;
+ this->u1_.output_data = od;
+ this->u2_.offset_is_from_end = false;
}
// Initialize the fields in Sized_symbol for SYM in OBJECT.
@@ -488,19 +488,19 @@ Symbol::output_section() const
{
case FROM_OBJECT:
{
- unsigned int shndx = this->u_.from_object.shndx;
+ unsigned int shndx = this->u2_.shndx;
if (shndx != elfcpp::SHN_UNDEF && this->is_ordinary_shndx_)
{
- gold_assert(!this->u_.from_object.object->is_dynamic());
- gold_assert(this->u_.from_object.object->pluginobj() == NULL);
- Relobj* relobj = static_cast<Relobj*>(this->u_.from_object.object);
+ gold_assert(!this->u1_.object->is_dynamic());
+ gold_assert(this->u1_.object->pluginobj() == NULL);
+ Relobj* relobj = static_cast<Relobj*>(this->u1_.object);
return relobj->output_section(shndx);
}
return NULL;
}
case IN_OUTPUT_DATA:
- return this->u_.in_output_data.output_data->output_section();
+ return this->u1_.output_data->output_section();
case IN_OUTPUT_SEGMENT:
case IS_CONSTANT:
@@ -527,8 +527,8 @@ Symbol::set_output_section(Output_section* os)
break;
case IS_CONSTANT:
this->source_ = IN_OUTPUT_DATA;
- this->u_.in_output_data.output_data = os;
- this->u_.in_output_data.offset_is_from_end = false;
+ this->u1_.output_data = os;
+ this->u2_.offset_is_from_end = false;
break;
case IN_OUTPUT_SEGMENT:
case IS_UNDEFINED:
@@ -546,8 +546,8 @@ Symbol::set_output_segment(Output_segment* os, Segment_offset_base base)
{
gold_assert(this->is_predefined_);
this->source_ = IN_OUTPUT_SEGMENT;
- this->u_.in_output_segment.output_segment = os;
- this->u_.in_output_segment.offset_base = base;
+ this->u1_.output_segment = os;
+ this->u2_.offset_base = base;
}
// Set the symbol to undefined. This is used for pre-defined
diff --git a/gold/symtab.h b/gold/symtab.h
index c371731..88d6c27 100644
--- a/gold/symtab.h
+++ b/gold/symtab.h
@@ -159,7 +159,7 @@ class Symbol
object() const
{
gold_assert(this->source_ == FROM_OBJECT);
- return this->u_.from_object.object;
+ return this->u1_.object;
}
// Return the index of the section in the input relocatable or
@@ -169,7 +169,7 @@ class Symbol
{
gold_assert(this->source_ == FROM_OBJECT);
*is_ordinary = this->is_ordinary_shndx_;
- return this->u_.from_object.shndx;
+ return this->u2_.shndx;
}
// Return the output data section with which this symbol is
@@ -179,7 +179,7 @@ class Symbol
output_data() const
{
gold_assert(this->source_ == IN_OUTPUT_DATA);
- return this->u_.in_output_data.output_data;
+ return this->u1_.output_data;
}
// If this symbol was defined with respect to an output data
@@ -188,7 +188,7 @@ class Symbol
offset_is_from_end() const
{
gold_assert(this->source_ == IN_OUTPUT_DATA);
- return this->u_.in_output_data.offset_is_from_end;
+ return this->u2_.offset_is_from_end;
}
// Return the output segment with which this symbol is associated,
@@ -198,7 +198,7 @@ class Symbol
output_segment() const
{
gold_assert(this->source_ == IN_OUTPUT_SEGMENT);
- return this->u_.in_output_segment.output_segment;
+ return this->u1_.output_segment;
}
// If this symbol was defined with respect to an output segment,
@@ -207,7 +207,7 @@ class Symbol
offset_base() const
{
gold_assert(this->source_ == IN_OUTPUT_SEGMENT);
- return this->u_.in_output_segment.offset_base;
+ return this->u2_.offset_base;
}
// Return the symbol binding.
@@ -973,38 +973,38 @@ class Symbol
union
{
- // This struct is used if SOURCE_ == FROM_OBJECT.
- struct
- {
- // Object in which symbol is defined, or in which it was first
- // seen.
- Object* object;
- // Section number in object_ in which symbol is defined.
- unsigned int shndx;
- } from_object;
-
- // This struct is used if SOURCE_ == IN_OUTPUT_DATA.
- struct
- {
- // Output_data in which symbol is defined. Before
- // Layout::finalize the symbol's value is an offset within the
- // Output_data.
- Output_data* output_data;
- // True if the offset is from the end, false if the offset is
- // from the beginning.
- bool offset_is_from_end;
- } in_output_data;
-
- // This struct is used if SOURCE_ == IN_OUTPUT_SEGMENT.
- struct
- {
- // Output_segment in which the symbol is defined. Before
- // Layout::finalize the symbol's value is an offset.
- Output_segment* output_segment;
- // The base to use for the offset before Layout::finalize.
- Segment_offset_base offset_base;
- } in_output_segment;
- } u_;
+ // This is used if SOURCE_ == FROM_OBJECT.
+ // Object in which symbol is defined, or in which it was first
+ // seen.
+ Object* object;
+
+ // This is used if SOURCE_ == IN_OUTPUT_DATA.
+ // Output_data in which symbol is defined. Before
+ // Layout::finalize the symbol's value is an offset within the
+ // Output_data.
+ Output_data* output_data;
+
+ // This is used if SOURCE_ == IN_OUTPUT_SEGMENT.
+ // Output_segment in which the symbol is defined. Before
+ // Layout::finalize the symbol's value is an offset.
+ Output_segment* output_segment;
+ } u1_;
+
+ union
+ {
+ // This is used if SOURCE_ == FROM_OBJECT.
+ // Section number in object in which symbol is defined.
+ unsigned int shndx;
+
+ // This is used if SOURCE_ == IN_OUTPUT_DATA.
+ // True if the offset is from the end, false if the offset is
+ // from the beginning.
+ bool offset_is_from_end;
+
+ // This is used if SOURCE_ == IN_OUTPUT_SEGMENT.
+ // The base to use for the offset before Layout::finalize.
+ Segment_offset_base offset_base;
+ } u2_;
// The index of this symbol in the output file. If the symbol is
// not going into the output file, this value is -1U. This field
@@ -1018,16 +1018,16 @@ class Symbol
// non-zero value during Layout::finalize.
unsigned int dynsym_index_;
- // The GOT section entries for this symbol. A symbol may have more
- // than one GOT offset (e.g., when mixing modules compiled with two
- // different TLS models), but will usually have at most one.
- Got_offset_list got_offsets_;
-
// If this symbol has an entry in the PLT section, then this is the
// offset from the start of the PLT section. This is -1U if there
// is no PLT entry.
unsigned int plt_offset_;
+ // The GOT section entries for this symbol. A symbol may have more
+ // than one GOT offset (e.g., when mixing modules compiled with two
+ // different TLS models), but will usually have at most one.
+ Got_offset_list got_offsets_;
+
// Symbol type (bits 0 to 3).
elfcpp::STT type_ : 4;
// Symbol binding (bits 4 to 7).
@@ -1069,7 +1069,7 @@ class Symbol
// True if this symbol was forced to local visibility by a version
// script (bit 28).
bool is_forced_local_ : 1;
- // True if the field u_.from_object.shndx is an ordinary section
+ // True if the field u2_.shndx is an ordinary section
// index, not one of the special codes from SHN_LORESERVE to
// SHN_HIRESERVE (bit 29).
bool is_ordinary_shndx_ : 1;
--
Alan Modra
Australia Development Lab, IBM
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