[PATCH] readelf: Fix regression with multiple files and implicit debug_info reading.

[PATCH] readelf: Fix regression with multiple files and implicit debug_info reading.

[Mark Wielaard]

Commit 314e9d7d "readelf: Handle .debug_info first if any other debug
section needs it" introduced a regression when handling multiple files.
The implicit and explicit printing of debuginfo weren't reset and so
the second file would not show (or scan) the .debug_info section when
needed.

Fix by resetting the implicit and explicit section printing flags.
Add a testcase that prints the .debug_loc section for two files and
check that the CUs are resolved.

Signed-off-by: Mark Wielaard <mark@klomp.org>
---
 src/ChangeLog                 |  5 +++++
 src/readelf.c                 | 10 +++++++++-
 tests/ChangeLog               |  4 ++++
 tests/run-readelf-twofiles.sh | 43 ++++++++++++++++++++++++++++++++++++++++++-
 4 files changed, 60 insertions(+), 2 deletions(-)

diff --git a/src/ChangeLog b/src/ChangeLog
index b6f66bd..e7ba6cb 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,3 +1,8 @@
+2018-05-29  Mark Wielaard  <mark@klomp.org>
+
+	* readelf.c (print_debug): Record and reset section_info status in
+	implicit_debug_sections and print_debug_sections.
+
 2018-05-28  Mark Wielaard  <mark@klomp.org>
 
 	* readelf.c (print_debug_units): Turn "Could not find split compile
diff --git a/src/readelf.c b/src/readelf.c
index bfa1d16..390f244 100644
--- a/src/readelf.c
+++ b/src/readelf.c
@@ -10894,7 +10894,9 @@ print_debug (Dwfl_Module *dwflmod, Ebl *ebl, GElf_Ehdr *ehdr)
      we must make sure to handle it before handling any other debug
      section.  Various other sections depend on the CU DIEs being
      scanned (silently) first.  */
-  if ((implicit_debug_sections & section_info) != 0)
+  bool implicit_info = (implicit_debug_sections & section_info) != 0;
+  bool explicit_info = (print_debug_sections & section_info) != 0;
+  if (implicit_info)
     {
       Elf_Scn *scn = NULL;
       while ((scn = elf_nextscn (ebl->elf, scn)) != NULL)
@@ -11012,6 +11014,12 @@ print_debug (Dwfl_Module *dwflmod, Ebl *ebl, GElf_Ehdr *ehdr)
   dwfl_end (skel_dwfl);
   free (skel_name);
 
+  /* Turn implicit and/or explicit back on in case we go over another file.  */
+  if (implicit_info)
+    implicit_debug_sections |= section_info;
+  if (explicit_info)
+    print_debug_sections |= section_info;
+
   reset_listptr (&known_locsptr);
   reset_listptr (&known_loclistsptr);
   reset_listptr (&known_rangelistptr);
diff --git a/tests/ChangeLog b/tests/ChangeLog
index 4d69515..682fffc 100644
--- a/tests/ChangeLog
+++ b/tests/ChangeLog
@@ -1,3 +1,7 @@
+2018-05-29  Mark Wielaard  <mark@klomp.org>
+
+	* run-readelf-twofiles.sh: Add --debug-dump=loc testcase.
+
 2018-05-28  Mark Wielaard  <mark@klomp.org>
 
 	* run-readelf-info-plus.sh: New test.
diff --git a/tests/run-readelf-twofiles.sh b/tests/run-readelf-twofiles.sh
index 46eec7b..fc5f3e7 100755
--- a/tests/run-readelf-twofiles.sh
+++ b/tests/run-readelf-twofiles.sh
@@ -1,5 +1,5 @@
 #! /bin/sh
-# Copyright (C) 2011 Red Hat, Inc.
+# Copyright (C) 2011, 2018 Red Hat, Inc.
 # This file is part of elfutils.
 #
 # This file is free software; you can redistribute it and/or modify
@@ -21,4 +21,45 @@ testfiles testfile14
 
 testrun >/dev/null ${abs_top_builddir}/src/readelf -w testfile14 testfile14
 
+testrun_compare ${abs_top_builddir}/src/readelf --debug-dump=loc testfile14 testfile14 << EOF
+
+testfile14:
+
+
+DWARF section [33] '.debug_loc' at offset 0xca9:
+
+ CU [     b] base: 0x0000000000400468 <caller>
+ [     0] range 34, 35
+          0x000000000040049c <main>..
+          0x000000000040049c <main>
+           [ 0] breg7 -8
+          range 35, 46
+          0x000000000040049d <main+0x1>..
+          0x00000000004004ad <main+0x11>
+           [ 0] breg7 0
+          range 46, 47
+          0x00000000004004ae <main+0x12>..
+          0x00000000004004ae <main+0x12>
+           [ 0] breg7 -8
+
+testfile14:
+
+
+DWARF section [33] '.debug_loc' at offset 0xca9:
+
+ CU [     b] base: 0x0000000000400468 <caller>
+ [     0] range 34, 35
+          0x000000000040049c <main>..
+          0x000000000040049c <main>
+           [ 0] breg7 -8
+          range 35, 46
+          0x000000000040049d <main+0x1>..
+          0x00000000004004ad <main+0x11>
+           [ 0] breg7 0
+          range 46, 47
+          0x00000000004004ae <main+0x12>..
+          0x00000000004004ae <main+0x12>
+           [ 0] breg7 -8
+EOF
+
 exit 0
-- 
1.8.3.1

Re: [PATCH] readelf: Fix regression with multiple files and implicit debug_info reading.

[Mark Wielaard]

On Tue, 2018-05-29 at 09:57 +0200, Mark Wielaard wrote:
> Commit 314e9d7d "readelf: Handle .debug_info first if any other debug
> section needs it" introduced a regression when handling multiple files.
> The implicit and explicit printing of debuginfo weren't reset and so
> the second file would not show (or scan) the .debug_info section when
> needed.
> 
> Fix by resetting the implicit and explicit section printing flags.
> Add a testcase that prints the .debug_loc section for two files and
> check that the CUs are resolved.

Pushed to master.