[PATCH] libdw: Search skeleton DIE for split compile unit DIE attributes.

[Mark Wielaard <mark at klomp dot org>]

dwarf_attr_integrate and dwarf_hasattr_integrate should also search
for attributes from the skeleton DIE in case the given DIE is a split
compile unit DIE. Split compile unit DIEs inherit various attributes
from their skeleton unit DIE in DWARF5.

Signed-off-by: Mark Wielaard <mark@klomp.org>
---
 libdw/ChangeLog                  |   7 ++
 libdw/dwarf_attr_integrate.c     |  15 ++++-
 libdw/dwarf_hasattr_integrate.c  |  16 ++++-
 libdw/libdwP.h                   |   2 +-
 tests/ChangeLog                  |   9 +++
 tests/Makefile.am                |  11 ++--
 tests/attr-integrate-skel.c      | 109 +++++++++++++++++++++++++++++++
 tests/run-attr-integrate-skel.sh |  52 +++++++++++++++
 8 files changed, 214 insertions(+), 7 deletions(-)
 create mode 100644 tests/attr-integrate-skel.c
 create mode 100755 tests/run-attr-integrate-skel.sh

diff --git a/libdw/ChangeLog b/libdw/ChangeLog
index a87a7092..c22811ec 100644
--- a/libdw/ChangeLog
+++ b/libdw/ChangeLog
@@ -1,3 +1,10 @@
+2018-05-17  Mark Wielaard  <mark@klomp.org>
+
+	* dwarf_attr_integrate.c (dwarf_attr_integrate): Handle split_compile
+	unit DIE, search skeleton_compile unit DIE.
+	* dwarf_hasattr_integrate.c (dwarf_hasattr_integrate): Likewise.
+	* libdwP.h (is_cudie): Check cu is not NULL.
+
 2018-05-15  Mark Wielaard  <mark@klomp.org>
 
 	* Makefile.am (libdw_a_SOURCES): Add libdw_find_split_unit.c.
diff --git a/libdw/dwarf_attr_integrate.c b/libdw/dwarf_attr_integrate.c
index 812d74b9..748d988d 100644
--- a/libdw/dwarf_attr_integrate.c
+++ b/libdw/dwarf_attr_integrate.c
@@ -1,5 +1,5 @@
 /* Return specific DWARF attribute of a DIE, integrating indirections.
-   Copyright (C) 2005 Red Hat, Inc.
+   Copyright (C) 2005, 2018 Red Hat, Inc.
    This file is part of elfutils.
 
    This file is free software; you can redistribute it and/or modify
@@ -55,6 +55,19 @@ dwarf_attr_integrate (Dwarf_Die *die, unsigned int search_name,
     }
   while (die != NULL);
 
+  /* Not NULL if it didn't have abstract_origin and specification
+     attributes.  If it is a split CU then see if the skeleton
+     has it.  */
+  if (die != NULL && is_cudie (die)
+      && die->cu->unit_type == DW_UT_split_compile)
+    {
+      Dwarf_CU *skel_cu = __libdw_find_split_unit (die->cu);
+      if (skel_cu != NULL)
+	{
+	  Dwarf_Die skel_die = CUDIE (skel_cu);
+	  return INTUSE(dwarf_attr) (&skel_die, search_name, result);
+	}
+    }
   return NULL;
 }
 INTDEF (dwarf_attr_integrate)
diff --git a/libdw/dwarf_hasattr_integrate.c b/libdw/dwarf_hasattr_integrate.c
index 2d5348cf..4d4b4c54 100644
--- a/libdw/dwarf_hasattr_integrate.c
+++ b/libdw/dwarf_hasattr_integrate.c
@@ -1,5 +1,5 @@
 /* Check whether DIE has specific attribute, integrating DW_AT_abstract_origin.
-   Copyright (C) 2005 Red Hat, Inc.
+   Copyright (C) 2005, 2018 Red Hat, Inc.
    This file is part of elfutils.
 
    This file is free software; you can redistribute it and/or modify
@@ -55,5 +55,19 @@ dwarf_hasattr_integrate (Dwarf_Die *die, unsigned int search_name)
     }
   while (die != NULL);
 
+  /* Not NULL if it didn't have abstract_origin and specification
+     attributes.  If it is a split CU then see if the skeleton
+     has it.  */
+  if (die != NULL && is_cudie (die)
+      && die->cu->unit_type == DW_UT_split_compile)
+    {
+      Dwarf_CU *skel_cu = __libdw_find_split_unit (die->cu);
+      if (skel_cu != NULL)
+	{
+	  Dwarf_Die skel_die = CUDIE (skel_cu);
+	  return INTUSE(dwarf_hasattr) (&skel_die, search_name);
+	}
+    }
+
   return 0;
 }
diff --git a/libdw/libdwP.h b/libdw/libdwP.h
index 60572276..08d144ba 100644
--- a/libdw/libdwP.h
+++ b/libdw/libdwP.h
@@ -892,7 +892,7 @@ cu_sec_idx (struct Dwarf_CU *cu)
 static inline bool
 is_cudie (Dwarf_Die *cudie)
 {
-  return CUDIE (cudie->cu).addr == cudie->addr;
+  return cudie->cu != NULL && CUDIE (cudie->cu).addr == cudie->addr;
 }
 
 /* Read up begin/end pair and increment read pointer.
diff --git a/tests/ChangeLog b/tests/ChangeLog
index b865ad54..05e8f26c 100644
--- a/tests/ChangeLog
+++ b/tests/ChangeLog
@@ -1,3 +1,12 @@
+2018-05-17  Mark Wielaard  <mark@klomp.org>
+
+	* Makefile.am (check_PROGRAMS): Add attr-integrate-skel.
+	(TESTS): Add run-attr-integrate-skel.
+	(EXTRA_DIST): Likewise.
+	(attr_integrate_skel_LDADD): New variable.
+	* attr-integrate-skel.c: New test.
+	* run-attr-integrate-skel.sh: New test runner.
+
 2018-05-16  Mark Wielaard  <mark@klomp.org>
 
 	* Makefile.am (check_PROGRAMS): Add get-units-split.
diff --git a/tests/Makefile.am b/tests/Makefile.am
index 07165d84..05a5441b 100644
--- a/tests/Makefile.am
+++ b/tests/Makefile.am
@@ -1,6 +1,6 @@
 ## Process this file with automake to create Makefile.in
 ##
-## Copyright (C) 1996-2017 Red Hat, Inc.
+## Copyright (C) 1996-2018 Red Hat, Inc.
 ## This file is part of elfutils.
 ##
 ## This file is free software; you can redistribute it and/or modify
@@ -56,7 +56,7 @@ check_PROGRAMS = arextract arsymtest newfile saridx scnnames sectiondump \
 		  elfshphehdr elfstrmerge dwelfgnucompressed elfgetchdr \
 		  elfgetzdata elfputzdata zstrptr emptyfile vendorelf \
 		  fillfile dwarf_default_lower_bound dwarf-die-addr-die \
-		  get-units-invalid get-units-split
+		  get-units-invalid get-units-split attr-integrate-skel
 
 asm_TESTS = asm-tst1 asm-tst2 asm-tst3 asm-tst4 asm-tst5 \
 	    asm-tst6 asm-tst7 asm-tst8 asm-tst9
@@ -140,7 +140,8 @@ TESTS = run-arextract.sh run-arsymtest.sh run-ar.sh newfile test-nlist \
 	run-readelf-zdebug.sh run-readelf-zdebug-rel.sh \
 	emptyfile vendorelf fillfile dwarf_default_lower_bound \
 	run-dwarf-die-addr-die.sh \
-	run-get-units-invalid.sh run-get-units-split.sh
+	run-get-units-invalid.sh run-get-units-split.sh \
+	run-attr-integrate-skel.sh
 
 if !BIARCH
 export ELFUTILS_DISABLE_BIARCH = 1
@@ -364,7 +365,8 @@ EXTRA_DIST = run-arextract.sh run-arsymtest.sh run-ar.sh \
 	     run-get-units-invalid.sh run-get-units-split.sh \
 	     testfile-hello4.dwo.bz2 testfile-hello5.dwo.bz2 \
 	     testfile-splitdwarf-4.bz2 testfile-splitdwarf-5.bz2 \
-	     testfile-world5.dwo.bz2 testfile-world4.dwo.bz2
+	     testfile-world5.dwo.bz2 testfile-world4.dwo.bz2 \
+	     run-attr-integrate-skel.sh
 
 if USE_VALGRIND
 valgrind_cmd='valgrind -q --leak-check=full --error-exitcode=1'
@@ -525,6 +527,7 @@ dwarf_default_lower_bound_LDADD = $(libdw)
 dwarf_die_addr_die_LDADD = $(libdw)
 get_units_invalid_LDADD = $(libdw)
 get_units_split_LDADD = $(libdw)
+attr_integrate_skel_LDADD = $(libdw)
 
 # We want to test the libelf header against the system elf.h header.
 # Don't include any -I CPPFLAGS.
diff --git a/tests/attr-integrate-skel.c b/tests/attr-integrate-skel.c
new file mode 100644
index 00000000..644cd272
--- /dev/null
+++ b/tests/attr-integrate-skel.c
@@ -0,0 +1,109 @@
+/* Test dwarf_get_units finds split DWO CUs.
+   Copyright (C) 2018 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 <dwarf.h>
+#include ELFUTILS_HEADER(dw)
+#include <stdio.h>
+#include <inttypes.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <unistd.h>
+
+
+int
+main (int argc, char *argv[])
+{
+  for (int i = 1; i < argc; i++)
+    {
+      printf ("file: %s\n", argv[i]);
+      int fd = open (argv[i], O_RDONLY);
+      Dwarf *dbg = dwarf_begin (fd, DWARF_C_READ);
+      if (dbg == NULL)
+	{
+	  printf ("%s not usable: %s\n", argv[i], dwarf_errmsg (-1));
+	  return -1;
+	}
+
+      Dwarf_CU *cu = NULL;
+      Dwarf_Die cudie, subdie;
+      uint8_t unit_type;
+      Dwarf_Half version;
+      int count = 0;
+      while (dwarf_get_units (dbg, cu, &cu, &version,
+			      &unit_type, &cudie, &subdie) == 0)
+	{
+	  count++;
+	  if (unit_type == DW_UT_skeleton)
+	    {
+	      Dwarf_Attribute attr;
+	      Dwarf_Word word;
+	      Dwarf_Addr addr;
+
+	      printf ("Split DIE: %s\n", dwarf_diename (&subdie));
+
+	      if (dwarf_attr_integrate (&subdie,
+					DW_AT_GNU_addr_base, &attr) == NULL
+		  && dwarf_attr_integrate (&subdie,
+					   DW_AT_addr_base, &attr) == NULL)
+		printf ("No addr_base");
+	      else if (dwarf_formudata (&attr, &word) != 0)
+		printf ("Bad addr_base: %s\n", dwarf_errmsg (-1));
+	      else
+		printf ("addr_base secoff: 0x%" PRIx64 "\n", word);
+
+	      if (dwarf_attr (&subdie, DW_AT_low_pc, &attr) != NULL)
+		printf ("Unexpected low_pc on split DIE.\n");
+
+	      if (dwarf_attr_integrate (&subdie,
+					DW_AT_low_pc, &attr) == NULL)
+		printf ("No low_pc");
+	      else if (dwarf_formaddr (&attr, &addr) != 0)
+		printf ("Bad low_pc: %s\n", dwarf_errmsg (-1));
+	      else
+		printf ("low_pc addr: 0x%" PRIx64 "\n", addr);
+
+	      if (dwarf_hasattr (&subdie, DW_AT_high_pc))
+		printf ("Unexpected highpc on split DIE\n");
+	      if (dwarf_hasattr (&subdie, DW_AT_ranges))
+		printf ("Unexpected ranges on split DIE\n");
+
+	      if (dwarf_hasattr_integrate (&subdie, DW_AT_high_pc))
+		printf ("Skel has high_pc.\n");
+	      if (dwarf_hasattr_integrate (&subdie, DW_AT_ranges))
+		printf ("Skel has ranges.\n");
+
+	      printf ("\n");
+	    }
+	}
+
+      if (count == 0)
+	{
+	  printf ("No units found\n");
+	  return -1;
+	}
+
+      dwarf_end (dbg);
+      close (fd);
+    }
+
+  return 0;
+}
diff --git a/tests/run-attr-integrate-skel.sh b/tests/run-attr-integrate-skel.sh
new file mode 100755
index 00000000..a9a9409a
--- /dev/null
+++ b/tests/run-attr-integrate-skel.sh
@@ -0,0 +1,52 @@
+#! /bin/sh
+# Copyright (C) 2018 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 tests/testfile-dwarf-45.source
+testfiles testfile-splitdwarf-4 testfile-hello4.dwo testfile-world4.dwo
+testfiles testfile-splitdwarf-5 testfile-hello5.dwo testfile-world5.dwo
+
+testrun_compare ${abs_builddir}/attr-integrate-skel testfile-splitdwarf-4 << EOF
+file: testfile-splitdwarf-4
+Split DIE: hello.c
+addr_base secoff: 0x0
+low_pc addr: 0x401160
+Skel has high_pc.
+
+Split DIE: world.c
+addr_base secoff: 0x98
+low_pc addr: 0x0
+Skel has ranges.
+
+EOF
+
+testrun_compare ${abs_builddir}/attr-integrate-skel testfile-splitdwarf-5 << EOF
+file: testfile-splitdwarf-5
+Split DIE: hello.c
+addr_base secoff: 0x8
+low_pc addr: 0x401160
+Skel has high_pc.
+
+Split DIE: world.c
+addr_base secoff: 0xa8
+low_pc addr: 0x0
+Skel has ranges.
+
+EOF
+
+exit 0
-- 
2.17.0