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authorSriraman Tallam <tmsriram@google.com>2013-01-24 18:49:55 +0000
committerSriraman Tallam <tmsriram@google.com>2013-01-24 18:49:55 +0000
commitc6ac678db54ed727cb673a87beeb7a41bdf13182 (patch)
treeb2a220a0034d74e463386bb5efa8e1ac0a2fd697
parent45e6c716a91b609472e7b807347f9ed3a86c8113 (diff)
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Default text reordering fix with a flag to turn it off.
2013-01-24 Sriraman Tallam <tmsriram@google.com> * layout.cc (Layout::layout): Check for option text_reorder. (Layout::make_output_section): Ditto. * options.h (text_reorder): New option. * output.cc (Input_section_sort_compare): Remove special ordering of section names. (Output_section:: Input_section_sort_section_name_special_ordering_compare:: operator()): New function. (Output_section::sort_attached_input_sections): Use new sort function for .text. * output.h (Input_section_sort_section_name_special_ordering_compare): New struct. * testsuite/Makefile.am (text_section_grouping): Test option --no-text-reorder * testsuite/Makefile.in: Regenerate. * testsuite/text_section_grouping.sh: Check order of functions without default text reordering.
-rw-r--r--gold/ChangeLog20
-rw-r--r--gold/layout.cc6
-rw-r--r--gold/options.h5
-rw-r--r--gold/output.cc52
-rw-r--r--gold/output.h9
-rw-r--r--gold/testsuite/Makefile.am10
-rw-r--r--gold/testsuite/Makefile.in8
-rwxr-xr-xgold/testsuite/text_section_grouping.sh8
8 files changed, 99 insertions, 19 deletions
diff --git a/gold/ChangeLog b/gold/ChangeLog
index 8e70fdd..bcf8c06 100644
--- a/gold/ChangeLog
+++ b/gold/ChangeLog
@@ -1,3 +1,23 @@
+2013-01-24 Sriraman Tallam <tmsriram@google.com>
+
+ * layout.cc (Layout::layout): Check for option text_reorder.
+ (Layout::make_output_section): Ditto.
+ * options.h (text_reorder): New option.
+ * output.cc (Input_section_sort_compare): Remove special ordering
+ of section names.
+ (Output_section::
+ Input_section_sort_section_name_special_ordering_compare::
+ operator()): New function.
+ (Output_section::sort_attached_input_sections): Use new sort function
+ for .text.
+ * output.h (Input_section_sort_section_name_special_ordering_compare):
+ New struct.
+ * testsuite/Makefile.am (text_section_grouping): Test option
+ --no-text-reorder
+ * testsuite/Makefile.in: Regenerate.
+ * testsuite/text_section_grouping.sh: Check order of functions without
+ default text reordering.
+
2013-01-18 Mike Frysinger <vapier@gentoo.org>
* options.h (General_options): Change default to true for new_dtags.
diff --git a/gold/layout.cc b/gold/layout.cc
index 250782a..1eb2cc0 100644
--- a/gold/layout.cc
+++ b/gold/layout.cc
@@ -1149,7 +1149,8 @@ Layout::layout(Sized_relobj_file<size, big_endian>* object, unsigned int shndx,
// By default the GNU linker sorts some special text sections ahead
// of others. We are compatible.
- if (!this->script_options_->saw_sections_clause()
+ if (parameters->options().text_reorder()
+ && !this->script_options_->saw_sections_clause()
&& !this->is_section_ordering_specified()
&& !parameters->options().relocatable()
&& Layout::special_ordering_of_input_section(name) >= 0)
@@ -1646,7 +1647,8 @@ Layout::make_output_section(const char* name, elfcpp::Elf_Word type,
// sections before other .text sections. We are compatible. We
// need to know that this might happen before we attach any input
// sections.
- if (!this->script_options_->saw_sections_clause()
+ if (parameters->options().text_reorder()
+ && !this->script_options_->saw_sections_clause()
&& !this->is_section_ordering_specified()
&& !parameters->options().relocatable()
&& strcmp(name, ".text") == 0)
diff --git a/gold/options.h b/gold/options.h
index 9e65e8d..c138fa2 100644
--- a/gold/options.h
+++ b/gold/options.h
@@ -878,6 +878,11 @@ class General_options
DEFINE_dirlist(library_path, options::TWO_DASHES, 'L',
N_("Add directory to search path"), N_("DIR"));
+ DEFINE_bool(text_reorder, options::TWO_DASHES, '\0', true,
+ N_("Enable text section reordering for GCC section names "
+ "(default)"),
+ N_("Disable text section reordering for GCC section names"));
+
DEFINE_bool(nostdlib, options::ONE_DASH, '\0', false,
N_(" Only search directories specified on the command line."),
NULL);
diff --git a/gold/output.cc b/gold/output.cc
index 01126a3..22c0bf0 100644
--- a/gold/output.cc
+++ b/gold/output.cc
@@ -3389,19 +3389,6 @@ Output_section::Input_section_sort_compare::operator()(
return s1.index() < s2.index();
}
- // Some input section names have special ordering requirements.
- int o1 = Layout::special_ordering_of_input_section(s1.section_name().c_str());
- int o2 = Layout::special_ordering_of_input_section(s2.section_name().c_str());
- if (o1 != o2)
- {
- if (o1 < 0)
- return false;
- else if (o2 < 0)
- return true;
- else
- return o1 < o2;
- }
-
// A section with a priority follows a section without a priority.
bool s1_has_priority = s1.has_priority();
bool s2_has_priority = s2.has_priority();
@@ -3508,6 +3495,42 @@ Output_section::Input_section_sort_section_order_index_compare::operator()(
return s1_secn_index < s2_secn_index;
}
+// Return true if S1 should come before S2. This is the sort comparison
+// function for .text to sort sections with prefixes
+// .text.{unlikely,exit,startup,hot} before other sections.
+bool
+Output_section::Input_section_sort_section_name_special_ordering_compare
+ ::operator()(
+ const Output_section::Input_section_sort_entry& s1,
+ const Output_section::Input_section_sort_entry& s2) const
+{
+ // We sort all the sections with no names to the end.
+ if (!s1.section_has_name() || !s2.section_has_name())
+ {
+ if (s1.section_has_name())
+ return true;
+ if (s2.section_has_name())
+ return false;
+ return s1.index() < s2.index();
+ }
+
+ // Some input section names have special ordering requirements.
+ int o1 = Layout::special_ordering_of_input_section(s1.section_name().c_str());
+ int o2 = Layout::special_ordering_of_input_section(s2.section_name().c_str());
+ if (o1 != o2)
+ {
+ if (o1 < 0)
+ return false;
+ else if (o2 < 0)
+ return true;
+ else
+ return o1 < o2;
+ }
+
+ // Keep input order otherwise.
+ return s1.index() < s2.index();
+}
+
// This updates the section order index of input sections according to the
// the order specified in the mapping from Section id to order index.
@@ -3576,6 +3599,9 @@ Output_section::sort_attached_input_sections()
|| this->type() == elfcpp::SHT_FINI_ARRAY)
std::sort(sort_list.begin(), sort_list.end(),
Input_section_sort_init_fini_compare());
+ else if (strcmp(this->name(), ".text") == 0)
+ std::sort(sort_list.begin(), sort_list.end(),
+ Input_section_sort_section_name_special_ordering_compare());
else
std::sort(sort_list.begin(), sort_list.end(),
Input_section_sort_compare());
diff --git a/gold/output.h b/gold/output.h
index 8f3943b..7722237 100644
--- a/gold/output.h
+++ b/gold/output.h
@@ -4200,6 +4200,15 @@ class Output_section : public Output_data
const Input_section_sort_entry&) const;
};
+ // This is the sort comparison function for .text to sort sections with
+ // prefixes .text.{unlikely,exit,startup,hot} before other sections.
+ struct Input_section_sort_section_name_special_ordering_compare
+ {
+ bool
+ operator()(const Input_section_sort_entry&,
+ const Input_section_sort_entry&) const;
+ };
+
// Fill data. This is used to fill in data between input sections.
// It is also used for data statements (BYTE, WORD, etc.) in linker
// scripts. When we have to keep track of the input sections, we
diff --git a/gold/testsuite/Makefile.am b/gold/testsuite/Makefile.am
index fa1161f..499dba6 100644
--- a/gold/testsuite/Makefile.am
+++ b/gold/testsuite/Makefile.am
@@ -259,14 +259,18 @@ final_layout.stdout: final_layout
$(TEST_NM) -n --synthetic final_layout > final_layout.stdout
check_SCRIPTS += text_section_grouping.sh
-check_DATA += text_section_grouping.stdout
-MOSTLYCLEANFILES += text_section_grouping
+check_DATA += text_section_grouping.stdout text_section_no_grouping.stdout
+MOSTLYCLEANFILES += text_section_grouping text_section_no_grouping
text_section_grouping.o: text_section_grouping.cc
$(CXXCOMPILE) -O0 -c -ffunction-sections -g -o $@ $<
text_section_grouping: text_section_grouping.o gcctestdir/ld
$(CXXLINK) -Bgcctestdir/ text_section_grouping.o
+text_section_no_grouping: text_section_grouping.o gcctestdir/ld
+ $(CXXLINK) -Bgcctestdir/ -Wl,--no-text-reorder text_section_grouping.o
text_section_grouping.stdout: text_section_grouping
- $(TEST_NM) -n --synthetic text_section_grouping > text_section_grouping.stdout
+ $(TEST_NM) -n --synthetic text_section_grouping > text_section_grouping.stdout
+text_section_no_grouping.stdout: text_section_no_grouping
+ $(TEST_NM) -n --synthetic text_section_no_grouping > text_section_no_grouping.stdout
check_PROGRAMS += icf_virtual_function_folding_test
MOSTLYCLEANFILES += icf_virtual_function_folding_test icf_virtual_function_folding_test.map
diff --git a/gold/testsuite/Makefile.in b/gold/testsuite/Makefile.in
index 51bdb27..a8129f9 100644
--- a/gold/testsuite/Makefile.in
+++ b/gold/testsuite/Makefile.in
@@ -113,6 +113,7 @@ check_PROGRAMS = $(am__EXEEXT_1) $(am__EXEEXT_2) $(am__EXEEXT_3) \
@GCC_TRUE@@NATIVE_LINKER_TRUE@ icf_safe_so_test_2.stdout \
@GCC_TRUE@@NATIVE_LINKER_TRUE@ final_layout.stdout \
@GCC_TRUE@@NATIVE_LINKER_TRUE@ text_section_grouping.stdout \
+@GCC_TRUE@@NATIVE_LINKER_TRUE@ text_section_no_grouping.stdout \
@GCC_TRUE@@NATIVE_LINKER_TRUE@ icf_preemptible_functions_test.stdout \
@GCC_TRUE@@NATIVE_LINKER_TRUE@ icf_string_merge_test.stdout \
@GCC_TRUE@@NATIVE_LINKER_TRUE@ icf_sht_rel_addend_test.stdout \
@@ -128,6 +129,7 @@ check_PROGRAMS = $(am__EXEEXT_1) $(am__EXEEXT_2) $(am__EXEEXT_3) \
@GCC_TRUE@@NATIVE_LINKER_TRUE@ final_layout_sequence.txt \
@GCC_TRUE@@NATIVE_LINKER_TRUE@ final_layout_script.lds \
@GCC_TRUE@@NATIVE_LINKER_TRUE@ text_section_grouping \
+@GCC_TRUE@@NATIVE_LINKER_TRUE@ text_section_no_grouping \
@GCC_TRUE@@NATIVE_LINKER_TRUE@ icf_virtual_function_folding_test \
@GCC_TRUE@@NATIVE_LINKER_TRUE@ icf_virtual_function_folding_test.map \
@GCC_TRUE@@NATIVE_LINKER_TRUE@ icf_preemptible_functions_test \
@@ -4376,8 +4378,12 @@ uninstall-am:
@GCC_TRUE@@NATIVE_LINKER_TRUE@ $(CXXCOMPILE) -O0 -c -ffunction-sections -g -o $@ $<
@GCC_TRUE@@NATIVE_LINKER_TRUE@text_section_grouping: text_section_grouping.o gcctestdir/ld
@GCC_TRUE@@NATIVE_LINKER_TRUE@ $(CXXLINK) -Bgcctestdir/ text_section_grouping.o
+@GCC_TRUE@@NATIVE_LINKER_TRUE@text_section_no_grouping: text_section_grouping.o gcctestdir/ld
+@GCC_TRUE@@NATIVE_LINKER_TRUE@ $(CXXLINK) -Bgcctestdir/ -Wl,--no-text-reorder text_section_grouping.o
@GCC_TRUE@@NATIVE_LINKER_TRUE@text_section_grouping.stdout: text_section_grouping
-@GCC_TRUE@@NATIVE_LINKER_TRUE@ $(TEST_NM) -n --synthetic text_section_grouping > text_section_grouping.stdout
+@GCC_TRUE@@NATIVE_LINKER_TRUE@ $(TEST_NM) -n --synthetic text_section_grouping > text_section_grouping.stdout
+@GCC_TRUE@@NATIVE_LINKER_TRUE@text_section_no_grouping.stdout: text_section_no_grouping
+@GCC_TRUE@@NATIVE_LINKER_TRUE@ $(TEST_NM) -n --synthetic text_section_no_grouping > text_section_no_grouping.stdout
@GCC_TRUE@@NATIVE_LINKER_TRUE@icf_virtual_function_folding_test.o: icf_virtual_function_folding_test.cc
@GCC_TRUE@@NATIVE_LINKER_TRUE@ $(CXXCOMPILE) -O0 -c -ffunction-sections -fPIE -g -o $@ $<
@GCC_TRUE@@NATIVE_LINKER_TRUE@icf_virtual_function_folding_test: icf_virtual_function_folding_test.o gcctestdir/ld
diff --git a/gold/testsuite/text_section_grouping.sh b/gold/testsuite/text_section_grouping.sh
index a79836c..84ebe4c 100755
--- a/gold/testsuite/text_section_grouping.sh
+++ b/gold/testsuite/text_section_grouping.sh
@@ -26,6 +26,8 @@
# according to prefix. .text.unlikely, .text.startup and .text.hot should
# be grouped and placed together.
+# Also check if the functions do not get grouped with option --no-text-reorder.
+
set -e
check()
@@ -63,3 +65,9 @@ check text_section_grouping.stdout "unlikely_bar" "startup_bar"
check text_section_grouping.stdout "startup_bar" "hot_bar"
check text_section_grouping.stdout "unlikely_foo" "startup_bar"
check text_section_grouping.stdout "startup_foo" "hot_bar"
+
+check text_section_no_grouping.stdout "hot_foo" "startup_foo"
+check text_section_no_grouping.stdout "startup_foo" "unlikely_foo"
+check text_section_no_grouping.stdout "unlikely_foo" "hot_bar"
+check text_section_no_grouping.stdout "hot_bar" "startup_bar"
+check text_section_no_grouping.stdout "startup_bar" "unlikely_bar"