Support alternate debug info sections

ABGBZ#17193
	* include/abg-dwarf-reader.h (class read_context)
	(typedef read_context_sptr, create_read_context)
	(has_alt_debug_info): Declare these.
	(read_corpus_from_elf): Declare new overload.
	* src/abg-dwarf-reader.cc (find_alt_debug_info)
	(is_die_attribute_resolved_through_gnu_ref_alt)
	(build_primary_die_parent_relations_under)
	(build_alternate_die_parent_relations_under):
	Define new static functions.
	(read_context::{alt_dwarf_,
	alt_debug_info_path_, alternate_die_decl_map_,
	alternate_die_parent_map_}): New data members.
	(read_context::{alt_dwarf, alt_debug_info_path,
	alternate_die_decl_map, associate_die_to_decl_primary,
	associate_die_to_decl_alternate, associate_die_to_decl,
	lookup_decl_from_die_offset_primary,
	lookup_decl_from_die_offset_alternate,
	lookup_decl_from_die_offset, alternate_die_parent_map}): New
	member functions.
	(read_context::load_debug_info): Painfully Get a handle on the
	alternate debug info section too.  We shouldn't have to do all
	this work; we could use the new dwarf_getalt() function from
	libdw, but we cannot as we want to support supports that predate
	that api.  When a version of elfutils gets released with that api
	though, we should conditionally use that instead.
	(build_ir_node_from_die, get_parent_die, get_scope_for_die)
	(build_namespace_decl_and_add_to_ir)
	(build_class_type_and_add_to_ir, build_qualified_type)
	(build_pointer_type_def, build_reference_type, build_typedef_type)
	(build_var_decl, build_function_decl): Take a new parameter that
	tells if the input DIE is from alternate debug info.  Adjust their
	code accordingly.
	(die_die_attribute): Take a new output parameter that tells if the
	resolved DIE is from alternate debug info.  Also take a new
	parameter that tells if the input DIE is from alternate debug info
	sections.
	(build_die_parent_relations_under): Take the DIE -> parent map to
	act upon.  Also, add a new overload that takes a flag saying if
	the DIE is from alternate debug info or not, and act upon that.
	(build_die_parent_maps): Renamed build_die_parent_map into this
	and make it build DIE -> parent DIE relationship for the alternate
	debug info file as well.
	(find_last_import_unit_point_before_die, ): Adjust to use the
	information about if the relevant DIEs are in alternate debug info
	or not.
	(build_translation_unit_and_add_to_ir): Clear the alternate DIE ->
	decl map, that is per TU just as the primary DIE -> decl map.
	Adjust to use the information about if the relevant DIEs are in
	alternate debug info or not.
	(read_debug_info_into_corpus): Build the two DIE -> DIE parent
	maps (one for the primary debug info and one for the alternate
	debug info).
	(create_read_context, has_alt_debug_info): Define new public entry
	points.
	(read_corpus_from_elf): New entry point overload that takes a
	read_context.
	* tools/bidw.cc (options::{check_alt_debug_info_path,
	show_base_name_alt_debug_info_path}): New data members.
	(display_usage): Update for the two new options
	--check-alternate-debug-info and
	check-alternate-debug-info-base-name.
	(parse_command_line): Parse the two options above.
	(main) Handle the two new options above.
	* tests/Makefile.am: Build the new runtestaltdwarf test.  Add the
	new data/test-alt-dwarf-file/* files to the build system.
	* tests/test-alt-dwarf-file.cc: New test driver.
	* tests/data/test-alt-dwarf-file/test0-common.cc: New test input
	files.
	* tests/data/test-alt-dwarf-file/libtest0-common.so: Likewise.
	* tests/data/test-alt-dwarf-file/test0.cc: Likewise.
	* tests/data/test-alt-dwarf-file/libtest0.so: Likewise.
	* tests/data/test-alt-dwarf-file/test0.h: Likewise.
	* tests/data/test-alt-dwarf-file/test0-common-dwz.debug: Likewise.
	* tests/data/test-alt-dwarf-file/test0-debug-dir/.build-id/16/7088580c513b439c9ed95fe6a8b29496495f26.debug:
	Likewise.
	* tests/data/test-alt-dwarf-file/test0-debug-dir/test0-common-dwz.debug:
	Likewise.
	* tests/data/test-read-dwarf/test1.abi: Adjust. bidw doesn't emit
	an abstract constructor/destructor anymore. It emits just the
	functions matching the cdtor symbols found in the binary.
	* tests/data/test-read-dwarf/test2.so.abi: Likewise.

Signed-off-by: Dodji Seketeli <dodji@redhat.com>

include/abg-dwarf-reader.h

@@ -52,10 +52,23 @@ enum status
   STATUS_NO_SYMBOLS_FOUND,
 };
 
+class read_context;
+
+/// A convenience typedef for a smart pointer to a
+/// dwarf_reader::read_context.
+typedef shared_ptr<read_context> read_context_sptr;
+
+read_context_sptr
+create_read_context(const std::string&	elf_path,
+		    char**		debug_info_root_path);
+
+status
+read_corpus_from_elf(read_context&	ctxt,
+		     corpus_sptr&	resulting_corp);
 status
 read_corpus_from_elf(const std::string& elf_path,
-		     char** debug_info_root_path,
-		     corpus_sptr& resulting_corp);
+		     char**		debug_info_root_path,
+		     corpus_sptr&	resulting_corp);
 
 bool
 lookup_symbol_from_elf(const string&		elf_path,
@@ -68,6 +81,17 @@ lookup_public_function_symbol_from_elf(const string&		path,
 				       const string&		symname,
 				       vector<elf_symbol>&	func_syms);
 
+status
+has_alt_debug_info(read_context&	elf_path,
+		   bool&		has_alt_di,
+		   string&		alt_debug_info_path);
+
+status
+has_alt_debug_info(const string&	elf_path,
+		   char**		debug_info_root_path,
+		   bool&		has_alt_di,
+		   string&		alt_debug_info_path);
+
 }// end namespace dwarf_reader
 
 }// end namespace abigail

tests/Makefile.am

@@ -7,6 +7,7 @@ runtestreadwrite		\
 runtestwritereadarchive		\
 runtestreaddwarf		\
 runtestlookupsyms		\
+runtestaltdwarf			\
 runtestcorediff			\
 runtestbidiff			\
 runtestdiffdwarf		\
@@ -41,6 +42,9 @@ runtestreaddwarf_LDADD=libtestutils.la $(top_builddir)/src/libabigail.la
 runtestlookupsyms_SOURCES=test-lookup-syms.cc
 runtestlookupsyms_LDADD=libtestutils.la $(top_builddir)/src/libabigail.la
 
+runtestaltdwarf_SOURCES=test-alt-dwarf-file.cc
+runtestaltdwarf_LDADD=libtestutils.la $(top_builddir)/src/libabigail.la
+
 runtestcorediff_SOURCES=test-core-diff.cc
 runtestcorediff_LDADD=libtestutils.la $(top_builddir)/src/libabigail.la
 
@@ -277,7 +281,16 @@ data/test-lookup-syms/test1.version-script	\
 data/test-lookup-syms/test1.so			\
 data/test-lookup-syms/test1-1-report.txt	\
 data/test-lookup-syms/test1-2-report.txt	\
-data/test-lookup-syms/test1-3-report.txt
+data/test-lookup-syms/test1-3-report.txt	\
+\
+data/test-alt-dwarf-file/test0.cc		\
+data/test-alt-dwarf-file/libtest0.so		\
+data/test-alt-dwarf-file/test0-common.cc	\
+data/test-alt-dwarf-file/libtest0-common.so	\
+data/test-alt-dwarf-file/test0-report.txt	\
+data/test-alt-dwarf-file/test0-debug-dir/test0-common-dwz.debug \
+data/test-alt-dwarf-file/test0-debug-dir/.build-id/16/7088580c513b439c9ed95fe6a8b29496495f26.debug
+
 
 clean-local: clean-local-check
 .PHONY: clean-local-check

tests/data/test-alt-dwarf-file/test0-common.cc

@@ -0,0 +1,17 @@
+// To compile this type:
+//
+// g++ -shared -g -Wall -o libtest0-common.so test0-common.cc
+
+#include "test0.h"
+
+S::S()
+  :m0(0), m1(0), m2(0)
+{}
+
+int
+S::get_m0() const
+{return m0;}
+
+char
+S::get_m1() const
+{return m1;}

tests/data/test-alt-dwarf-file/test0-debug-dir/.build-id/16/7088580c513b439c9ed95fe6a8b29496495f26.debug

@@ -0,0 +1 @@
+/home/dodji/git/libabigail/fixes/tests/data/test-alt-dwarf-file/test0-common-dwz.debug

tests/data/test-alt-dwarf-file/test0-debug-dir/test0-common-dwz.debug

@@ -0,0 +1 @@
+../test0-common-dwz.debug

tests/data/test-alt-dwarf-file/test0-report.txt

@@ -0,0 +1 @@
+found the alternate debug info file 'test0-common-dwz.debug'

tests/data/test-alt-dwarf-file/test0.cc

@@ -0,0 +1,36 @@
+// To compile this, type:
+// g++ -shared -fPIC -g -Wall -L. -ltest0-common -o libtest0.so test0.cc
+//
+// Once the libtest0-common.so as been generated as well (from the
+// test0-common.cc file), please geneate the common debug info file
+// using the 'dwz' tool by doing:
+//
+// dwz -m test0-common-dwz.debug -r libtest0-common.so libtest0.so.
+//
+// Then, create a build-id subdirectory my doing:
+//
+// mkdir -p test0-debug-dir/.build-id/<first-two-chars-of-ascii-repr-of-build-id-of-test0-common-dwz.debug>
+// Then ln -s `pwd`/test0-common-dwz.debug `pwd`/test0-debug-dir/.build-id/<build-id-of-test0-common-dwz.debug>.debug
+
+#include "test0.h"
+
+S global_s;
+
+unsigned
+S::get_m2() const
+{return m2;}
+
+void
+foo(S& s)
+{
+  S a = s;
+  char c = a.get_m1();
+  int i = c + a.get_m0();
+  i += (int) a.get_m2();
+}
+
+S*
+bar()
+{
+  return &global_s;
+}

tests/data/test-alt-dwarf-file/test0.h

@@ -0,0 +1,17 @@
+struct S
+{
+  int m0;
+  char m1;
+  unsigned m2;
+
+  S();
+
+  int
+  get_m0() const;
+
+  char
+  get_m1() const;
+
+  unsigned
+  get_m2() const;
+};

tests/data/test-read-dwarf/test1.abi

@@ -65,24 +65,6 @@
       <data-member access='public' layout-offset-in-bits='96'>
         <var-decl name='m1' type-id='type-id-9' visibility='default' filepath='/home/dodji/git/libabigail/dwarf/tests/data/test-read-dwarf/test1.cc' line='19' column='1'/>
       </data-member>
-      <member-function access='public' constructor='yes'>
-        <function-decl name='s0' filepath='/home/dodji/git/libabigail/dwarf/tests/data/test-read-dwarf/test1.cc' line='21' column='1' visibility='default' binding='global' size-in-bits='64' alignment-in-bits='64'>
-          <parameter type-id='type-id-11' is-artificial='yes'/>
-          <parameter type-id='type-id-8' is-artificial='yes'/>
-        </function-decl>
-      </member-function>
-      <member-function access='public' destructor='yes'>
-        <function-decl name='~s0' filepath='/home/dodji/git/libabigail/dwarf/tests/data/test-read-dwarf/test1.cc' line='27' column='1' visibility='default' binding='global' size-in-bits='64' alignment-in-bits='64'>
-          <parameter type-id='type-id-11' is-artificial='yes'/>
-          <parameter type-id='type-id-8' is-artificial='yes'/>
-        </function-decl>
-      </member-function>
-      <member-function access='public'>
-        <function-decl name='mem_fun' mangled-name='_ZN2s07mem_funEv' filepath='/home/dodji/git/libabigail/dwarf/tests/data/test-read-dwarf/test1.cc' line='36' column='1' visibility='default' binding='global' size-in-bits='64' alignment-in-bits='64' elf-symbol-id='_ZN2s07mem_funEv'>
-          <parameter type-id='type-id-11' is-artificial='yes'/>
-          <return type-id='type-id-7'/>
-        </function-decl>
-      </member-function>
       <member-function access='public' constructor='yes'>
         <function-decl name='s0' mangled-name='_ZN2s0C1Ev' filepath='/home/dodji/git/libabigail/dwarf/tests/data/test-read-dwarf/test1.cc' line='21' column='1' visibility='default' binding='global' size-in-bits='64' alignment-in-bits='64' elf-symbol-id='_ZN2s0C1Ev'>
           <parameter type-id='type-id-11' is-artificial='yes'/>
@@ -95,6 +77,12 @@
           <parameter type-id='type-id-8' is-artificial='yes'/>
         </function-decl>
       </member-function>
+      <member-function access='public'>
+        <function-decl name='mem_fun' mangled-name='_ZN2s07mem_funEv' filepath='/home/dodji/git/libabigail/dwarf/tests/data/test-read-dwarf/test1.cc' line='36' column='1' visibility='default' binding='global' size-in-bits='64' alignment-in-bits='64' elf-symbol-id='_ZN2s07mem_funEv'>
+          <parameter type-id='type-id-11' is-artificial='yes'/>
+          <return type-id='type-id-7'/>
+        </function-decl>
+      </member-function>
     </class-decl>
     <type-decl name='int' size-in-bits='32' alignment-in-bits='32' id='type-id-8'/>
     <type-decl name='unsigned char' size-in-bits='8' alignment-in-bits='8' id='type-id-10'/>

tests/data/test-read-dwarf/test2.so.abi

@@ -17,11 +17,6 @@
       <data-member access='public' layout-offset-in-bits='32'>
         <var-decl name='member1' type-id='type-id-3' visibility='default' filepath='/home/dodji/git/libabigail/dwarf/tests/data/test-read-dwarf/test2.h' line='7' column='1'/>
       </data-member>
-      <member-function access='public' constructor='yes'>
-        <function-decl name='first_type' filepath='/home/dodji/git/libabigail/dwarf/tests/data/test-read-dwarf/test2.h' line='9' column='1' visibility='default' binding='global' size-in-bits='64' alignment-in-bits='64'>
-          <parameter type-id='type-id-4' is-artificial='yes'/>
-        </function-decl>
-      </member-function>
       <member-function access='public' constructor='yes'>
         <function-decl name='first_type' mangled-name='_ZN10first_typeC1Ev' filepath='/home/dodji/git/libabigail/dwarf/tests/data/test-read-dwarf/test2.h' line='9' column='1' visibility='default' binding='global' size-in-bits='64' alignment-in-bits='64' elf-symbol-id='_ZN10first_typeC1Ev'>
           <parameter type-id='type-id-4' is-artificial='yes'/>
@@ -47,11 +42,6 @@
       <data-member access='public' layout-offset-in-bits='32'>
         <var-decl name='member1' type-id='type-id-9' visibility='default' filepath='/home/dodji/git/libabigail/dwarf/tests/data/test-read-dwarf/test2.h' line='15' column='1'/>
       </data-member>
-      <member-function access='public' constructor='yes'>
-        <function-decl name='second_type' filepath='/home/dodji/git/libabigail/dwarf/tests/data/test-read-dwarf/test2.h' line='17' column='1' visibility='default' binding='global' size-in-bits='64' alignment-in-bits='64'>
-          <parameter type-id='type-id-10' is-artificial='yes'/>
-        </function-decl>
-      </member-function>
       <member-function access='public' constructor='yes'>
         <function-decl name='second_type' mangled-name='_ZN11second_typeC1Ev' filepath='/home/dodji/git/libabigail/dwarf/tests/data/test-read-dwarf/test2.h' line='17' column='1' visibility='default' binding='global' size-in-bits='64' alignment-in-bits='64' elf-symbol-id='_ZN11second_typeC1Ev'>
           <parameter type-id='type-id-10' is-artificial='yes'/>

tests/test-alt-dwarf-file.cc

@@ -0,0 +1,115 @@
+// -*- Mode: C++ -*-
+//
+// Copyright (C) 2013-2014 Red Hat, Inc.
+//
+// This file is part of the GNU Application Binary Interface Generic
+// Analysis and Instrumentation Library (libabigail).  This library is
+// free software; you can redistribute it and/or modify it under the
+// terms of the GNU Lesser General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option) any
+// later version.
+
+// This library is distributed in the hope that it will be useful, but
+// WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+// General Lesser Public License for more details.
+
+// You should have received a copy of the GNU Lesser General Public
+// License along with this program; see the file COPYING-LGPLV3.  If
+// not, see <http://www.gnu.org/licenses/>.
+
+// Author: Dodji Seketeli
+
+/// @file
+///
+/// This program tests that libabigail can handle alternate debug info
+/// files as specified by http://www.dwarfstd.org/ShowIssue.php?issue=120604.1.
+
+#include <iostream>
+#include <cstdlib>
+#include "abg-tools-utils.h"
+#include "test-utils.h"
+
+using std::cerr;
+using std::string;
+
+struct InOutSpec
+{
+  const char* in_elf_path;
+  const char* debug_info_dir_path;
+  const char* bidw_options;
+  const char* in_report_path;
+  const char* out_report_path;
+};
+
+
+InOutSpec in_out_specs[] =
+{
+  {
+    "data/test-alt-dwarf-file/libtest0.so",
+    "data/test-alt-dwarf-file/test0-debug-dir",
+    "--check-alternate-debug-info-base-name",
+    "data/test-alt-dwarf-file/test0-report.txt",
+    "output/test-alt-dwarf-file/test0-report.txt"
+  },
+  {
+    "data/test-alt-dwarf-file/libtest0-common.so",
+    "data/test-alt-dwarf-file/test0-debug-dir",
+    "--check-alternate-debug-info-base-name",
+    "data/test-alt-dwarf-file/test0-report.txt",
+    "output/test-alt-dwarf-file/test0-report.txt"
+  },
+
+  // This should always be the last entry
+  {NULL, NULL, NULL, NULL, NULL}
+};
+
+int
+main()
+{
+  using abigail::tests::get_src_dir;
+  using abigail::tests::get_build_dir;
+  using abigail::tools::ensure_parent_dir_created;
+
+  bool is_ok = true;
+  string in_elf_path, ref_report_path, out_report_path, debug_info_dir;
+  string bidw, bidw_options;
+
+  bidw = get_build_dir() + "/tools/bidw";
+  for (InOutSpec* s = in_out_specs; s->in_elf_path; ++s)
+    {
+      bidw_options = s->bidw_options;
+      in_elf_path = get_src_dir() + "/tests/" + s->in_elf_path;
+      debug_info_dir = get_src_dir() + "/tests/" + s->debug_info_dir_path;
+      ref_report_path = get_src_dir() + "/tests/" + s->in_report_path;
+      out_report_path = get_build_dir() + "/tests/" + s->out_report_path;
+      if (!ensure_parent_dir_created(out_report_path))
+	{
+	  cerr << "could not create parent directory for "
+	       << out_report_path;
+	  is_ok = false;
+	  continue;
+	}
+
+      string cmd = bidw + " --debug-info-dir " + debug_info_dir
+	+ " " + bidw_options + " " + in_elf_path + " > " + out_report_path;
+
+      bool bidw_ok = true;
+      if (system(cmd.c_str()))
+	bidw_ok = false;
+
+      if (bidw_ok)
+	{
+	  cmd = "diff -u " + ref_report_path + " " + out_report_path;
+	  if (system(cmd.c_str()))
+	    is_ok &=false;
+	}
+      else
+	{
+	  cerr << "command failed: " << cmd << "\n";
+	  is_ok &= false;
+	}
+    }
+
+  return !is_ok;
+}

tools/bidw.cc

@@ -52,8 +52,12 @@ struct options
   string		in_file_path;
   string		out_file_path;
   shared_ptr<char>	di_root_path;
+  bool			check_alt_debug_info_path;
+  bool			show_base_name_alt_debug_info_path;
 
   options()
+    : check_alt_debug_info_path(false),
+      show_base_name_alt_debug_info_path(false)
   {}
 };
 
@@ -64,7 +68,12 @@ display_usage(const string& prog_name, ostream& out)
       << " where options can be: \n"
       << "  --help display this message\n"
       << "  --debug-info-dir <dir-path> look for debug info under 'dir-path'\n"
-      << "  --out-file <file-path> write the output to 'file-path'\n";
+      << "  --out-file <file-path> write the output to 'file-path'\n"
+      << "  --check-alternate-debug-info <elf-path> check alternate debug info "
+		"of <elf-path>\n"
+      << "  --check-alternate-debug-info-base-name <elf-path> check alternate "
+    "debug info of <elf-path>, and show its base name\n"
+    ;
 }
 
 static bool
@@ -103,6 +112,19 @@ parse_command_line(int argc, char* argv[], options& opts)
 	  opts.out_file_path = argv[i + 1];
 	  ++i;
 	}
+      else if (!strcmp(argv[i], "--check-alternate-debug-info")
+	       || !strcmp(argv[i], "--check-alternate-debug-info-base-name"))
+	{
+	  if (argc <= i + 1
+	      || argv[i + 1][0] == '-'
+	      || !opts.in_file_path.empty())
+	    return false;
+	  if (!strcmp(argv[i], "--check-alternate-debug-info-base-name"))
+	    opts.show_base_name_alt_debug_info_path = true;
+	  opts.check_alt_debug_info_path = true;
+	  opts.in_file_path = argv[i + 1];
+	  ++i;
+	}
       else if (!strcmp(argv[i], "--help"))
 	return false;
       else
@@ -139,13 +161,47 @@ main(int argc, char* argv[])
   using abigail::corpus;
   using abigail::corpus_sptr;
   using abigail::translation_units;
+  using abigail::dwarf_reader::read_context_sptr;
+  using abigail::dwarf_reader::read_context;
   using abigail::dwarf_reader::read_corpus_from_elf;
+  using abigail::dwarf_reader::create_read_context;
   using namespace abigail;
 
   char* p = opts.di_root_path.get();
   corpus_sptr corp;
-  dwarf_reader::status s = read_corpus_from_elf(opts.in_file_path, &p, corp);
+  read_context_sptr c = create_read_context(opts.in_file_path, &p);
+  read_context& ctxt = *c;
 
+  if (opts.check_alt_debug_info_path)
+    {
+      bool has_alt_di = false;
+      string alt_di_path;
+      abigail::dwarf_reader::status status =
+	abigail::dwarf_reader::has_alt_debug_info(ctxt,
+						  has_alt_di, alt_di_path);
+      if (status == abigail::dwarf_reader::STATUS_OK)
+	{
+	  if (alt_di_path.empty())
+	    ;
+	  else
+	    {
+	      if (opts.show_base_name_alt_debug_info_path)
+		tools::base_name(alt_di_path, alt_di_path);
+
+	      cout << "found the alternate debug info file '"
+		   << alt_di_path
+		   << "'\n";
+	    }
+	  return 0;
+	}
+      else
+	{
+	  cerr << "could not find alternate debug info file\n";
+	  return 1;
+	}
+    }
+
+  dwarf_reader::status s = read_corpus_from_elf(ctxt, corp);
   if (!corp)
     {
       if (s == dwarf_reader::STATUS_DEBUG_INFO_NOT_FOUND)
@@ -174,8 +230,8 @@ main(int argc, char* argv[])
 
       return 1;
     }
-
-  abigail::xml_writer::write_corpus_to_native_xml(corp, 0, cout);
+  else
+    abigail::xml_writer::write_corpus_to_native_xml(corp, 0, cout);
 
   return 0;
 }