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authorDoug Kwan <dougkwan@google.com>2010-01-22 06:06:46 +0000
committerDoug Kwan <dougkwan@google.com>2010-01-22 06:06:46 +0000
commitaf2cdeae83b5b69c6ad5fe598e9c511b58abf8bd (patch)
tree0b39a42c1ef47197a2eff05cb4969fe01e454c6f /gold
parent993d07c1d5bfa809e42b3412dcf395ea6f93ebce (diff)
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2010-01-21 Doug Kwan <dougkwan@google.com>
elfcpp/ChangeLog: * arm.h (EXIDX_CANTUNWIND): New enum. gold/ChangeLog: * arm.cc (Arm_exidx_cantunwind, Arm_exidx_merged_section): New classes. (Arm_exidx_section_offset_map): New type.
Diffstat (limited to 'gold')
-rw-r--r--gold/ChangeLog6
-rw-r--r--gold/arm.cc266
2 files changed, 272 insertions, 0 deletions
diff --git a/gold/ChangeLog b/gold/ChangeLog
index 3d2b181..6cb3d92 100644
--- a/gold/ChangeLog
+++ b/gold/ChangeLog
@@ -1,5 +1,11 @@
2010-01-21 Doug Kwan <dougkwan@google.com>
+ * arm.cc (Arm_exidx_cantunwind, Arm_exidx_merged_section): New
+ classes.
+ (Arm_exidx_section_offset_map): New type.
+
+2010-01-21 Doug Kwan <dougkwan@google.com>
+
* arm.cc (Arm_exidx_input_section): New class.
(Arm_relobj::exidx_input_section_by_link,
Arm_relobj::exidx_input_section_by_shndx,
diff --git a/gold/arm.cc b/gold/arm.cc
index b7d369c..1e2b8e6 100644
--- a/gold/arm.cc
+++ b/gold/arm.cc
@@ -64,6 +64,10 @@ class Stub_table;
template<bool big_endian>
class Arm_input_section;
+class Arm_exidx_cantunwind;
+
+class Arm_exidx_merged_section;
+
template<bool big_endian>
class Arm_output_section;
@@ -1027,6 +1031,97 @@ class Stub_table : public Output_data
uint64_t prev_addralign_;
};
+// Arm_exidx_cantunwind class. This represents an EXIDX_CANTUNWIND entry
+// we add to the end of an EXIDX input section that goes into the output.
+
+class Arm_exidx_cantunwind : public Output_section_data
+{
+ public:
+ Arm_exidx_cantunwind(Relobj* relobj, unsigned int shndx)
+ : Output_section_data(8, 4, true), relobj_(relobj), shndx_(shndx)
+ { }
+
+ // Return the object containing the section pointed by this.
+ Relobj*
+ relobj() const
+ { return this->relobj_; }
+
+ // Return the section index of the section pointed by this.
+ unsigned int
+ shndx() const
+ { return this->shndx_; }
+
+ protected:
+ void
+ do_write(Output_file* of)
+ {
+ if (parameters->target().is_big_endian())
+ this->do_fixed_endian_write<true>(of);
+ else
+ this->do_fixed_endian_write<false>(of);
+ }
+
+ private:
+ // Implement do_write for a given endianity.
+ template<bool big_endian>
+ void inline
+ do_fixed_endian_write(Output_file*);
+
+ // The object containing the section pointed by this.
+ Relobj* relobj_;
+ // The section index of the section pointed by this.
+ unsigned int shndx_;
+};
+
+// During EXIDX coverage fix-up, we compact an EXIDX section. The
+// Offset map is used to map input section offset within the EXIDX section
+// to the output offset from the start of this EXIDX section.
+
+typedef std::map<section_offset_type, section_offset_type>
+ Arm_exidx_section_offset_map;
+
+// Arm_exidx_merged_section class. This represents an EXIDX input section
+// with some of its entries merged.
+
+class Arm_exidx_merged_section : public Output_relaxed_input_section
+{
+ public:
+ // Constructor for Arm_exidx_merged_section.
+ // EXIDX_INPUT_SECTION points to the unmodified EXIDX input section.
+ // SECTION_OFFSET_MAP points to a section offset map describing how
+ // parts of the input section are mapped to output. DELETED_BYTES is
+ // the number of bytes deleted from the EXIDX input section.
+ Arm_exidx_merged_section(
+ const Arm_exidx_input_section& exidx_input_section,
+ const Arm_exidx_section_offset_map& section_offset_map,
+ uint32_t deleted_bytes);
+
+ // Return the original EXIDX input section.
+ const Arm_exidx_input_section&
+ exidx_input_section() const
+ { return this->exidx_input_section_; }
+
+ // Return the section offset map.
+ const Arm_exidx_section_offset_map&
+ section_offset_map() const
+ { return this->section_offset_map_; }
+
+ protected:
+ // Write merged section into file OF.
+ void
+ do_write(Output_file* of);
+
+ bool
+ do_output_offset(const Relobj*, unsigned int, section_offset_type,
+ section_offset_type*) const;
+
+ private:
+ // Original EXIDX input section.
+ const Arm_exidx_input_section& exidx_input_section_;
+ // Section offset map.
+ const Arm_exidx_section_offset_map& section_offset_map_;
+};
+
// A class to wrap an ordinary input section containing executable code.
template<bool big_endian>
@@ -4329,6 +4424,177 @@ Arm_input_section<big_endian>::do_reset_address_and_file_offset()
this->set_current_data_size(off);
}
+// Arm_exidx_cantunwind methods.
+
+// Write this to Output file OF for a fixed endianity.
+
+template<bool big_endian>
+void
+Arm_exidx_cantunwind::do_fixed_endian_write(Output_file* of)
+{
+ off_t offset = this->offset();
+ const section_size_type oview_size = 8;
+ unsigned char* const oview = of->get_output_view(offset, oview_size);
+
+ typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
+ Valtype* wv = reinterpret_cast<Valtype*>(oview);
+
+ Output_section* os = this->relobj_->output_section(this->shndx_);
+ gold_assert(os != NULL);
+
+ Arm_relobj<big_endian>* arm_relobj =
+ Arm_relobj<big_endian>::as_arm_relobj(this->relobj_);
+ Arm_address output_offset =
+ arm_relobj->get_output_section_offset(this->shndx_);
+ Arm_address section_start;
+ if(output_offset != Arm_relobj<big_endian>::invalid_address)
+ section_start = os->address() + output_offset;
+ else
+ {
+ // Currently this only happens for a relaxed section.
+ const Output_relaxed_input_section* poris =
+ os->find_relaxed_input_section(this->relobj_, this->shndx_);
+ gold_assert(poris != NULL);
+ section_start = poris->address();
+ }
+
+ // We always append this to the end of an EXIDX section.
+ Arm_address output_address =
+ section_start + this->relobj_->section_size(this->shndx_);
+
+ // Write out the entry. The first word either points to the beginning
+ // or after the end of a text section. The second word is the special
+ // EXIDX_CANTUNWIND value.
+ elfcpp::Swap<32, big_endian>::writeval(wv, output_address);
+ elfcpp::Swap<32, big_endian>::writeval(wv + 1, elfcpp::EXIDX_CANTUNWIND);
+
+ of->write_output_view(this->offset(), oview_size, oview);
+}
+
+// Arm_exidx_merged_section methods.
+
+// Constructor for Arm_exidx_merged_section.
+// EXIDX_INPUT_SECTION points to the unmodified EXIDX input section.
+// SECTION_OFFSET_MAP points to a section offset map describing how
+// parts of the input section are mapped to output. DELETED_BYTES is
+// the number of bytes deleted from the EXIDX input section.
+
+Arm_exidx_merged_section::Arm_exidx_merged_section(
+ const Arm_exidx_input_section& exidx_input_section,
+ const Arm_exidx_section_offset_map& section_offset_map,
+ uint32_t deleted_bytes)
+ : Output_relaxed_input_section(exidx_input_section.relobj(),
+ exidx_input_section.shndx(),
+ exidx_input_section.addralign()),
+ exidx_input_section_(exidx_input_section),
+ section_offset_map_(section_offset_map)
+{
+ // Fix size here so that we do not need to implement set_final_data_size.
+ this->set_data_size(exidx_input_section.size() - deleted_bytes);
+ this->fix_data_size();
+}
+
+// Given an input OBJECT, an input section index SHNDX within that
+// object, and an OFFSET relative to the start of that input
+// section, return whether or not the corresponding offset within
+// the output section is known. If this function returns true, it
+// sets *POUTPUT to the output offset. The value -1 indicates that
+// this input offset is being discarded.
+
+bool
+Arm_exidx_merged_section::do_output_offset(
+ const Relobj* relobj,
+ unsigned int shndx,
+ section_offset_type offset,
+ section_offset_type* poutput) const
+{
+ // We only handle offsets for the original EXIDX input section.
+ if (relobj != this->exidx_input_section_.relobj()
+ || shndx != this->exidx_input_section_.shndx())
+ return false;
+
+ if (offset < 0 || offset >= this->exidx_input_section_.size())
+ // Input offset is out of valid range.
+ *poutput = -1;
+ else
+ {
+ // We need to look up the section offset map to determine the output
+ // offset. Find the reference point in map that is first offset
+ // bigger than or equal to this offset.
+ Arm_exidx_section_offset_map::const_iterator p =
+ this->section_offset_map_.lower_bound(offset);
+
+ // The section offset maps are build such that this should not happen if
+ // input offset is in the valid range.
+ gold_assert(p != this->section_offset_map_.end());
+
+ // We need to check if this is dropped.
+ section_offset_type ref = p->first;
+ section_offset_type mapped_ref = p->second;
+
+ if (mapped_ref != Arm_exidx_input_section::invalid_offset)
+ // Offset is present in output.
+ *poutput = mapped_ref + (offset - ref);
+ else
+ // Offset is discarded owing to EXIDX entry merging.
+ *poutput = -1;
+ }
+
+ return true;
+}
+
+// Write this to output file OF.
+
+void
+Arm_exidx_merged_section::do_write(Output_file* of)
+{
+ // If we retain or discard the whole EXIDX input section, we would
+ // not be here.
+ gold_assert(this->data_size() != this->exidx_input_section_.size()
+ && this->data_size() != 0);
+
+ off_t offset = this->offset();
+ const section_size_type oview_size = this->data_size();
+ unsigned char* const oview = of->get_output_view(offset, oview_size);
+
+ Output_section* os = this->relobj()->output_section(this->shndx());
+ gold_assert(os != NULL);
+
+ // Get contents of EXIDX input section.
+ section_size_type section_size;
+ const unsigned char* section_contents =
+ this->relobj()->section_contents(this->shndx(), &section_size, false);
+ gold_assert(section_size == this->exidx_input_section_.size());
+
+ // Go over spans of input offsets and write only those that are not
+ // discarded.
+ section_offset_type in_start = 0;
+ section_offset_type out_start = 0;
+ for(Arm_exidx_section_offset_map::const_iterator p =
+ this->section_offset_map_.begin();
+ p != this->section_offset_map_.end();
+ ++p)
+ {
+ section_offset_type in_end = p->first;
+ gold_assert(in_end >= in_start);
+ section_offset_type out_end = p->second;
+ size_t in_chunk_size = convert_types<size_t>(in_end - in_start + 1);
+ if (out_end != -1)
+ {
+ size_t out_chunk_size =
+ convert_types<size_t>(out_end - out_start + 1);
+ gold_assert(out_chunk_size == in_chunk_size);
+ memcpy(oview + out_start, section_contents + in_start,
+ out_chunk_size);
+ out_start += out_chunk_size;
+ }
+ in_start += in_chunk_size;
+ }
+
+ gold_assert(convert_to_section_size_type(out_start) == oview_size);
+ of->write_output_view(this->offset(), oview_size, oview);
+}
+
// Arm_output_section methods.
// Create a stub group for input sections from BEGIN to END. OWNER