[PATCH 2/2] libdw: Search for the last matching address with dwarf_getsrc_die.

[Mark Wielaard <mjw at redhat dot com>]

In commit 7d9b5a dwfl_module_getsrc was changed so that it returns the last
line record <= addr, rather than returning immediately on a match. This
changes dwarf_getsrc_die to do the same. And it adds a new test that checks
this by comparing against the same results from eu-addr2line (which uses
dwfl_module_getsrc) using dwarf_addrdie and dwarf_getsrc_die instead.

Signed-off-by: Mark Wielaard <mjw@redhat.com>
---
 libdw/ChangeLog          |  6 ++++
 libdw/dwarf_getsrc_die.c | 46 ++++++++++++++-----------------
 tests/Makefile.am        | 10 +++++--
 tests/getsrc_die.c       | 72 ++++++++++++++++++++++++++++++++++++++++++++++++
 tests/run-getsrc-die.sh  | 51 ++++++++++++++++++++++++++++++++++
 5 files changed, 157 insertions(+), 28 deletions(-)
 create mode 100644 tests/getsrc_die.c
 create mode 100755 tests/run-getsrc-die.sh

diff --git a/libdw/ChangeLog b/libdw/ChangeLog
index 9dd2964..0e7e7a3 100644
--- a/libdw/ChangeLog
+++ b/libdw/ChangeLog
@@ -1,3 +1,9 @@
+2014-12-24  Mark Wielaard  <mjw@redhat.com>
+
+	* dwarf_getsrc_die.c (dwarf_getsrc_die): Return the last line record
+	smaller than or equal to addr, rather than returning immediately on
+	a match.
+
 2014-12-27  Mark Wielaard  <mjw@redhat.com>
 
 	* dwarf_siblingof.c (dwarf_siblingof): Check sibling attribute offset
diff --git a/libdw/dwarf_getsrc_die.c b/libdw/dwarf_getsrc_die.c
index 1914cdf..a95179f 100644
--- a/libdw/dwarf_getsrc_die.c
+++ b/libdw/dwarf_getsrc_die.c
@@ -1,5 +1,5 @@
 /* Find line information for address.
-   Copyright (C) 2004, 2005 Red Hat, Inc.
+   Copyright (C) 2004, 2005, 2014 Red Hat, Inc.
    This file is part of elfutils.
    Written by Ulrich Drepper <drepper@redhat.com>, 2004.
 
@@ -45,32 +45,28 @@ dwarf_getsrc_die (Dwarf_Die *cudie, Dwarf_Addr addr)
     return NULL;
 
   /* The lines are sorted by address, so we can use binary search.  */
-  size_t l = 0, u = nlines;
-  while (l < u)
-    {
-      size_t idx = (l + u) / 2;
-      if (addr < lines->info[idx].addr)
-	u = idx;
-      else if (addr > lines->info[idx].addr || lines->info[idx].end_sequence)
-	l = idx + 1;
-      else
-	return &lines->info[idx];
-    }
-
   if (nlines > 0)
-    assert (lines->info[nlines - 1].end_sequence);
-
-  /* If none were equal, the closest one below is what we want.  We
-     never want the last one, because it's the end-sequence marker
-     with an address at the high bound of the CU's code.  If the debug
-     information is faulty and no end-sequence marker is present, we
-     still ignore it.  */
-  if (u > 0 && u < nlines && addr > lines->info[u - 1].addr)
     {
-      while (lines->info[u - 1].end_sequence && u > 0)
-	--u;
-      if (u > 0)
-	return &lines->info[u - 1];
+      size_t l = 0, u = nlines - 1;
+      while (l < u)
+	{
+	  size_t idx = u - (u - l) / 2;
+	  Dwarf_Line *line = &lines->info[idx];
+	  if (addr < line->addr)
+	    u = idx - 1;
+	  else
+	    l = idx;
+	}
+
+      /* This is guaranteed for us by libdw read_srclines.  */
+      assert (lines->info[nlines - 1].end_sequence);
+
+      /* The last line which is less than or equal to addr is what we
+	 want, unless it is the end_sequence which is after the
+	 current line sequence.  */
+      Dwarf_Line *line = &lines->info[l];
+      if (! line->end_sequence && line->addr <= addr)
+	return &lines->info[l];
     }
 
   __libdw_seterrno (DWARF_E_ADDR_OUTOFRANGE);
diff --git a/tests/Makefile.am b/tests/Makefile.am
index 303f783..c364cc9 100644
--- a/tests/Makefile.am
+++ b/tests/Makefile.am
@@ -50,7 +50,8 @@ check_PROGRAMS = arextract arsymtest newfile saridx scnnames sectiondump \
 		  test-elf_cntl_gelf_getshdr dwflsyms dwfllines \
 		  dwfl-report-elf-align varlocs backtrace backtrace-child \
 		  backtrace-data backtrace-dwarf debuglink debugaltlink \
-		  buildid deleted deleted-lib.so aggregate_size vdsosyms
+		  buildid deleted deleted-lib.so aggregate_size vdsosyms \
+		  getsrc_die
 
 asm_TESTS = asm-tst1 asm-tst2 asm-tst3 asm-tst4 asm-tst5 \
 	    asm-tst6 asm-tst7 asm-tst8 asm-tst9
@@ -111,7 +112,8 @@ TESTS = run-arextract.sh run-arsymtest.sh newfile test-nlist \
 	run-backtrace-core-aarch64.sh \
 	run-backtrace-demangle.sh run-stack-d-test.sh run-stack-i-test.sh \
 	run-readelf-dwz-multi.sh run-allfcts-multi.sh run-deleted.sh \
-	run-linkmap-cut.sh run-aggregate-size.sh vdsosyms run-readelf-A.sh
+	run-linkmap-cut.sh run-aggregate-size.sh vdsosyms run-readelf-A.sh \
+	run-getsrc-die.sh
 
 if !BIARCH
 export ELFUTILS_DISABLE_BIARCH = 1
@@ -280,7 +282,8 @@ EXTRA_DIST = run-arextract.sh run-arsymtest.sh \
 	     linkmap-cut.bz2 linkmap-cut.core.bz2 \
 	     run-aggregate-size.sh testfile-sizes1.o.bz2 testfile-sizes2.o.bz2 \
 	     testfile-sizes3.o.bz2 \
-	     run-readelf-A.sh testfileppc32attrs.o.bz2
+	     run-readelf-A.sh testfileppc32attrs.o.bz2 \
+	     run-getsrc-die.sh
 
 if USE_VALGRIND
 valgrind_cmd='valgrind -q --error-exitcode=1 --run-libc-freeres=no'
@@ -420,6 +423,7 @@ deleted_lib_so_LDFLAGS = -shared -rdynamic
 deleted_lib_so_CFLAGS = -fPIC -fasynchronous-unwind-tables
 aggregate_size_LDADD = $(libdw) $(libelf)
 vdsosyms_LDADD = $(libdw) $(libelf)
+getsrc_die_LDADD = $(libdw) $(libelf)
 
 if GCOV
 check: check-am coverage
diff --git a/tests/getsrc_die.c b/tests/getsrc_die.c
new file mode 100644
index 0000000..055aede
--- /dev/null
+++ b/tests/getsrc_die.c
@@ -0,0 +1,72 @@
+/* Copyright (C) 2014 Red Hat, Inc.
+   This file is part of elfutils.
+
+   This file is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
+
+   elfutils 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 Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
+
+#ifdef HAVE_CONFIG_H
+# include <config.h>
+#endif
+
+#include <errno.h>
+#include <error.h>
+#include <fcntl.h>
+#include <inttypes.h>
+#include <libelf.h>
+#include ELFUTILS_HEADER(dw)
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+
+
+int
+main (int argc, char *argv[])
+{
+  /* file addr+ */
+  int fd = open (argv[1], O_RDONLY);
+  Dwarf *dbg = dwarf_begin (fd, DWARF_C_READ);
+  if  (dbg == NULL)
+    error (-1, 0, "dwarf_begin (%s): %s\n", argv[1], dwarf_errmsg (-1));
+
+  for (int i = 2; i < argc; i++)
+    {
+      Dwarf_Addr addr;
+      char *endptr;
+      Dwarf_Die cudie;
+      Dwarf_Line *line;
+
+      errno = 0;
+      addr = strtoull (argv[i], &endptr, 16);
+      if (errno != 0)
+	error (-1, errno, "Cannot parrse '%s'", argv[1]);
+
+      if (dwarf_addrdie (dbg, addr, &cudie) == NULL)
+	error (-1, 0, "dwarf_addrdie (%s): %s", argv[i], dwarf_errmsg (-1));
+
+      line = dwarf_getsrc_die (&cudie, addr);
+      if (line == NULL)
+	error (-1, 0, "dwarf_getsrc_die (%s): %s", argv[i], dwarf_errmsg (-1));
+
+      const char *f = dwarf_linesrc (line, NULL, NULL);
+      int l;
+      if (dwarf_lineno (line, &l) != 0)
+	l = 0;
+
+      printf ("%s:%d\n", f ?: "???", l);
+    }
+
+  dwarf_end (dbg);
+  close (fd);
+
+  return 0;
+}
diff --git a/tests/run-getsrc-die.sh b/tests/run-getsrc-die.sh
new file mode 100755
index 0000000..4da16e7
--- /dev/null
+++ b/tests/run-getsrc-die.sh
@@ -0,0 +1,51 @@
+#! /bin/sh
+# Copyright (C) 2014 Red Hat, Inc.
+# This file is part of elfutils.
+#
+# This file is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 3 of the License, or
+# (at your option) any later version.
+#
+# elfutils 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 Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+. $srcdir/test-subr.sh
+
+# See run-addr2line-test.sh run-addr2line-i-test.sh run-addr2line-i-lex-test.sh
+# Output/files/lines matched should equal what is done through addr2line
+# which uses dwfl_module_getsrc. This test uses dwarf_addrdie and
+# dwarf_getsrc_die
+testfiles testfile testfile-inlines testfile-lex-inlines
+
+testrun_compare ${abs_top_builddir}/tests/getsrc_die testfile 0x08048468 0x0804845c <<\EOF
+/home/drepper/gnu/new-bu/build/ttt/f.c:3
+/home/drepper/gnu/new-bu/build/ttt/b.c:4
+EOF
+
+testrun_compare ${abs_top_builddir}/tests/getsrc_die testfile-inlines 0x00000000000005a0 0x00000000000005a1 0x00000000000005b0 0x00000000000005b1 0x00000000000005c0 0x00000000000005d0 0x00000000000005e0 0x00000000000005e1 0x00000000000005f1 0x00000000000005f2 <<\EOF
+/tmp/x.cpp:5
+/tmp/x.cpp:6
+/tmp/x.cpp:10
+/tmp/x.cpp:11
+/tmp/x.cpp:5
+/tmp/x.cpp:10
+/tmp/x.cpp:5
+/tmp/x.cpp:10
+/tmp/x.cpp:10
+/tmp/x.cpp:5
+EOF
+
+testrun_compare ${abs_top_builddir}/tests/getsrc_die testfile-lex-inlines 0x0000000000000680 0x0000000000000681 0x0000000000000690 0x0000000000000691 <<\EOF
+/tmp/x.cpp:5
+/tmp/x.cpp:5
+/tmp/x.cpp:5
+/tmp/x.cpp:5
+EOF
+
+exit 0
-- 
2.1.0