From fef55ed3b49c1d1b632685e4079ca7caac759dc9 Mon Sep 17 00:00:00 2001
From: Petr Machata <pmachata@redhat.com>
Date: Thu, 10 Mar 2011 15:39:01 +0100
Subject: [PATCH] dwarflint: Missing DW_LNE_end_sequence OK in empty line
 number program

- also the fact that the line number program is empty is not a problem
  in itself, only when combined with otherwise unused file table
---
 dwarflint/check_debug_line.cc                 | 33 +++++++++++--------
 dwarflint/tests/run-bad.sh                    |  1 -
 dwarflint/tests/run-check_debug_info_refs.sh  |  2 --
 .../run-check_duplicate_DW_tag_variable.sh    |  1 -
 .../run-debug_abbrev-duplicate-attribute.sh   |  1 -
 dwarflint/tests/run-libdl-2.12.so.debug.sh    |  5 +--
 6 files changed, 21 insertions(+), 22 deletions(-)

diff --git a/dwarflint/check_debug_line.cc b/dwarflint/check_debug_line.cc
index 2f32e47ed..7fa097acf 100644
--- a/dwarflint/check_debug_line.cc
+++ b/dwarflint/check_debug_line.cc
@@ -596,22 +596,29 @@ check_debug_line::check_debug_line (checkstack &stack, dwarflint &lint)
 	    << " `" << include_directories[i].name
 	    << "' is not used." << std::endl;
 
+      // We can't do full analysis unless we know which DIEs refer to
+      // files.
       if (_m_info != NULL)
-	// We can't do full analysis unless we know which DIEs refer
-	// to files.
-	for (size_t i = 0; i < files.size (); ++i)
-	  if (!files[i].used)
-	    wr_message (where,
-			cat (mc_impact_3, mc_acc_bloat, mc_line, mc_header))
-	      << "the file #" << i + 1
-	      << " `" << files[i].name << "' is not used." << std::endl;
-
-      if (!seen_opcode)
-	wr_message (where, cat (mc_line, mc_acc_bloat, mc_impact_3))
-	  << "empty line number program." << std::endl;
+	{
+	  bool useful = false;
+
+	  for (size_t i = 0; i < files.size (); ++i)
+	    if (!files[i].used)
+	      wr_message (where,
+			  cat (mc_impact_3, mc_acc_bloat, mc_line, mc_header))
+		<< "the file #" << i + 1
+		<< " `" << files[i].name << "' is not used." << std::endl;
+	    else
+	      useful = true;
+
+	  if (!seen_opcode && !useful)
+	    wr_message (where, cat (mc_line, mc_acc_bloat, mc_impact_3))
+	      << "empty line number program and no references from .debug_info."
+	      << std::endl;
+	}
 
       struct where wh = WHERE (sec_line, NULL);
-      if (!terminated)
+      if (!terminated && seen_opcode)
 	wr_error (where)
 	  << "sequence of opcodes not terminated with DW_LNE_end_sequence."
 	  << std::endl;
diff --git a/dwarflint/tests/run-bad.sh b/dwarflint/tests/run-bad.sh
index a956e2d30..3803336a7 100755
--- a/dwarflint/tests/run-bad.sh
+++ b/dwarflint/tests/run-bad.sh
@@ -46,7 +46,6 @@ EOF
 
 testrun_compare ./dwarflint empty-1 <<EOF
 warning: .debug_line: table 0: the file #1 \`empty.c' is not used.
-error: .debug_line: table 0: sequence of opcodes not terminated with DW_LNE_end_sequence.
 error: .debug_info: DIE 0x29 (abbr. attribute 0x13): references .debug_line table, but CU DIE lacks DW_AT_stmt_list.
 EOF
 
diff --git a/dwarflint/tests/run-check_debug_info_refs.sh b/dwarflint/tests/run-check_debug_info_refs.sh
index a13d04401..604f44415 100755
--- a/dwarflint/tests/run-check_debug_info_refs.sh
+++ b/dwarflint/tests/run-check_debug_info_refs.sh
@@ -43,7 +43,5 @@ EOF
 testrun_compare ./dwarflint --strict --check=check_debug_info_refs check_debug_info_refs-2 <<EOF
 warning: .debug_info: DIE 0xb (abbreviation 0): DIE chain not terminated with null entry.
 warning: .debug_info: DIE 0x54 (abbreviation 48): DIE chain not terminated with null entry.
-warning: .debug_line: table 0: empty line number program.
-error: .debug_line: table 0: sequence of opcodes not terminated with DW_LNE_end_sequence.
 warning: .debug_info: CU 0: no aranges table is associated with this CU.
 EOF
diff --git a/dwarflint/tests/run-check_duplicate_DW_tag_variable.sh b/dwarflint/tests/run-check_duplicate_DW_tag_variable.sh
index 6e62f2801..2134fc277 100755
--- a/dwarflint/tests/run-check_duplicate_DW_tag_variable.sh
+++ b/dwarflint/tests/run-check_duplicate_DW_tag_variable.sh
@@ -32,7 +32,6 @@ testfiles crc7.ko.debug
 testrun_compare ./dwarflint --check check_duplicate_DW_tag_variable crc7.ko.debug <<EOF
 warning: .debug_line: offset 0x3c4: the include #6 \`XXXXXX' is not used.
 warning: .debug_line: table 967: the include #6 \`XXXXXX' is not used.
-error: .debug_line: table 967: sequence of opcodes not terminated with DW_LNE_end_sequence.
 error: .debug_info: DIE 0x3d21: Redeclaration of variable 'console_printk', originally seen at DIE 37f3.
 error: .debug_info: DIE 0x3d2e: Redeclaration of variable 'hex_asc', originally seen at DIE 380b.
 error: .debug_info: DIE 0x3d41: Redeclaration of variable '__per_cpu_offset', originally seen at DIE 382e.
diff --git a/dwarflint/tests/run-debug_abbrev-duplicate-attribute.sh b/dwarflint/tests/run-debug_abbrev-duplicate-attribute.sh
index a750863b7..1e73d2078 100755
--- a/dwarflint/tests/run-debug_abbrev-duplicate-attribute.sh
+++ b/dwarflint/tests/run-debug_abbrev-duplicate-attribute.sh
@@ -33,5 +33,4 @@ testrun_compare ./dwarflint debug_abbrev-duplicate-attribute <<EOF
 error: .debug_abbrev: abbr. attribute 0x19: duplicate attribute byte_size (first was at 0x13).
 error: .debug_abbrev: abbr. attribute 0x1b: duplicate attribute decl_file (first was at 0x15).
 error: .debug_abbrev: abbr. attribute 0x1d: duplicate attribute decl_line (first was at 0x17).
-error: .debug_line: table 0: sequence of opcodes not terminated with DW_LNE_end_sequence.
 EOF
diff --git a/dwarflint/tests/run-libdl-2.12.so.debug.sh b/dwarflint/tests/run-libdl-2.12.so.debug.sh
index 36ab399ae..825162c68 100755
--- a/dwarflint/tests/run-libdl-2.12.so.debug.sh
+++ b/dwarflint/tests/run-libdl-2.12.so.debug.sh
@@ -36,12 +36,9 @@ error: .debug_abbrev: abbr. attribute 0x330: invalid or unknown name 0x2107.
 error: .debug_abbrev: abbr. attribute 0xa28: invalid or unknown name 0x2107.
 error: .debug_abbrev: abbr. attribute 0x108e: invalid or unknown name 0x2107.
 error: .debug_abbrev: abbr. attribute 0x1300: invalid or unknown name 0x2107.
-error: .debug_line: table 4508: sequence of opcodes not terminated with DW_LNE_end_sequence.
-error: .debug_line: table 4606: sequence of opcodes not terminated with DW_LNE_end_sequence.
 EOF
 
 # Here we test proper support for DW_AT_GNU_vector
 testrun_compare ./dwarflint --check=@low libdl-2.12.so.debug <<EOF
-error: .debug_line: table 4508: sequence of opcodes not terminated with DW_LNE_end_sequence.
-error: .debug_line: table 4606: sequence of opcodes not terminated with DW_LNE_end_sequence.
+No errors
 EOF
-- 
2.47.2