[gdb/testsuite] Require address update for DW_LNE_end_sequence

With test-case gdb.dwarf2/dw2-epilogue-begin.exp, we have an end_sequence
entry with the same address as the line entry before it:
...
File name                    Line number    Starting address    View    Stmt

dw2-epilogue-begin.c                  44            0x4101e8               x
dw2-epilogue-begin.c                  47            0x4101ec               x
dw2-epilogue-begin.c                   -            0x4101ec
...
and consequently the line entry is removed by gdb:
...
INDEX  LINE   REL-ADDRESS        UNREL-ADDRESS      IS-STMT PRO EPI
0      20     0x00000000004101a8 0x00000000004101a8 Y       Y   Y
1      27     0x00000000004101b0 0x00000000004101b0 Y
2      32     0x00000000004101b8 0x00000000004101b8 Y       Y
3      34     0x00000000004101c0 0x00000000004101c0 Y           Y
4      35     0x00000000004101c8 0x00000000004101c8 Y
5      40     0x00000000004101d4 0x00000000004101d4 Y       Y
6      44     0x00000000004101e8 0x00000000004101e8 Y
7      END    0x00000000004101ec 0x00000000004101ec Y
...

This is a common mistake in dwarf assembly test-cases.

Fix this by:
- requiring an address update for each DW_LNE_end_sequence, and
- fixing the test-cases where that triggers an error.

I also encountered the error in test-case gdb.dwarf2/dw2-bad-elf.exp, and in
this case I worked around it using "DW_LNS_advance_pc 0".

Tested on aarch64-linux.

PR testsuite/31592
Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=31592

11 files changed, 32 insertions, 27 deletions

diff --git a/gdb/testsuite/gdb.base/until-trailing-insns.exp b/gdb/testsuite/gdb.base/until-trailing-insns.exp
index aed3681..baa5f1f 100644
--- a/gdb/testsuite/gdb.base/until-trailing-insns.exp
+++ b/gdb/testsuite/gdb.base/until-trailing-insns.exp
@@ -147,9 +147,8 @@ Dwarf::assemble $asm_file {
 	    line [gdb_get_line_number "TAG: main return"]
 	    DW_LNS_negate_stmt
 	    DW_LNS_copy
+
 	    DW_LNE_set_address $main_end
-	    line [expr [gdb_get_line_number "TAG: main return"] + 1]
-	    DW_LNS_copy
 	    DW_LNE_end_sequence
 	}
     }
diff --git a/gdb/testsuite/gdb.dwarf2/dw2-bad-elf.exp b/gdb/testsuite/gdb.dwarf2/dw2-bad-elf.exp
index 71c5bf9..63d83fb 100644
--- a/gdb/testsuite/gdb.dwarf2/dw2-bad-elf.exp
+++ b/gdb/testsuite/gdb.dwarf2/dw2-bad-elf.exp
@@ -128,9 +128,12 @@ Dwarf::assemble $asm_file {
 	    DW_LNE_set_address [lindex $main_result 0]
 	    DW_LNS_advance_line 10
 	    DW_LNS_copy
+
 	    DW_LNS_advance_pc [lindex $main_result 1]
 	    DW_LNS_advance_line 19
 	    DW_LNS_copy
+
+	    DW_LNS_advance_pc 0
 	    DW_LNE_end_sequence
 	}
     }
@@ -144,9 +147,12 @@ Dwarf::assemble $asm_file {
 	    DW_LNE_set_address some_func
 	    DW_LNS_advance_line 5
 	    DW_LNS_copy
+
 	    DW_LNS_advance_pc 64
 	    DW_LNS_advance_line 8
 	    DW_LNS_copy
+
+	    DW_LNS_advance_pc 0
 	    DW_LNE_end_sequence
 	}
     }
diff --git a/gdb/testsuite/gdb.dwarf2/dw2-disasm-over-non-stmt.exp b/gdb/testsuite/gdb.dwarf2/dw2-disasm-over-non-stmt.exp
index 425dd97..aa84a20 100644
--- a/gdb/testsuite/gdb.dwarf2/dw2-disasm-over-non-stmt.exp
+++ b/gdb/testsuite/gdb.dwarf2/dw2-disasm-over-non-stmt.exp
@@ -87,7 +87,6 @@ Dwarf::assemble $asm_file {
 	    DW_LNS_copy
 
 	    DW_LNE_set_address $main_end
-	    DW_LNS_copy
 	    DW_LNE_end_sequence
 	}
     }
diff --git a/gdb/testsuite/gdb.dwarf2/dw2-epilogue-begin.exp b/gdb/testsuite/gdb.dwarf2/dw2-epilogue-begin.exp
index f646e23..7ae14fa 100644
--- a/gdb/testsuite/gdb.dwarf2/dw2-epilogue-begin.exp
+++ b/gdb/testsuite/gdb.dwarf2/dw2-epilogue-begin.exp
@@ -134,6 +134,7 @@ Dwarf::assemble $asm_file {
 	    DW_LNS_set_epilogue_begin
 	    DW_LNS_copy
 
+	    DW_LNE_set_address "$main_start + $main_len"
 	    DW_LNE_end_sequence
 	}
     }
diff --git a/gdb/testsuite/gdb.dwarf2/dw2-inline-small-func.exp b/gdb/testsuite/gdb.dwarf2/dw2-inline-small-func.exp
index 1ba346b..b117c89 100644
--- a/gdb/testsuite/gdb.dwarf2/dw2-inline-small-func.exp
+++ b/gdb/testsuite/gdb.dwarf2/dw2-inline-small-func.exp
@@ -108,6 +108,8 @@ Dwarf::assemble $asm_file {
 
 	    DW_LNE_set_address line_label_3
 	    DW_LNS_copy
+
+	    DW_LNE_set_address "$main_start + $main_len"
 	    DW_LNE_end_sequence
 	}
     }
diff --git a/gdb/testsuite/gdb.dwarf2/dw2-prologue-end.exp b/gdb/testsuite/gdb.dwarf2/dw2-prologue-end.exp
index 8d85464..caa4086 100644
--- a/gdb/testsuite/gdb.dwarf2/dw2-prologue-end.exp
+++ b/gdb/testsuite/gdb.dwarf2/dw2-prologue-end.exp
@@ -72,6 +72,7 @@ Dwarf::assemble $asm_file {
 	    line [gdb_get_line_number "main end"]
 	    DW_LNS_copy
 
+	    DW_LNE_set_address "$main_start + $main_len"
 	    DW_LNE_end_sequence
 	}
     }
diff --git a/gdb/testsuite/gdb.dwarf2/dw2-ranges-base.exp b/gdb/testsuite/gdb.dwarf2/dw2-ranges-base.exp
index 13e7c98..1a3d53c 100644
--- a/gdb/testsuite/gdb.dwarf2/dw2-ranges-base.exp
+++ b/gdb/testsuite/gdb.dwarf2/dw2-ranges-base.exp
@@ -79,24 +79,18 @@ Dwarf::assemble $asm_file {
 	    DW_LNS_advance_line 10
 	    DW_LNS_copy
 	    DW_LNS_advance_pc [lindex $main_func 1]
-	    DW_LNS_advance_line 19
-	    DW_LNS_copy
 	    DW_LNE_end_sequence
 
 	    DW_LNE_set_address [lindex $frame2_func 0]
 	    DW_LNS_advance_line 20
 	    DW_LNS_copy
 	    DW_LNS_advance_pc [lindex $frame2_func 1]
-	    DW_LNS_advance_line 29
-	    DW_LNS_copy
 	    DW_LNE_end_sequence
 
 	    DW_LNE_set_address [lindex $frame3_func 0]
 	    DW_LNS_advance_line 30
 	    DW_LNS_copy
 	    DW_LNS_advance_pc [lindex $frame3_func 1]
-	    DW_LNS_advance_line 39
-	    DW_LNS_copy
 	    DW_LNE_end_sequence
 	}
     }
diff --git a/gdb/testsuite/gdb.dwarf2/dw2-ranges-func.exp b/gdb/testsuite/gdb.dwarf2/dw2-ranges-func.exp
index ea69af4..c952e82 100644
--- a/gdb/testsuite/gdb.dwarf2/dw2-ranges-func.exp
+++ b/gdb/testsuite/gdb.dwarf2/dw2-ranges-func.exp
@@ -133,9 +133,8 @@ proc do_test {suffix} {
 		DW_LNE_set_address main_label2
 		line [gdb_get_line_number "main return"]
 		DW_LNS_copy
+
 		DW_LNE_set_address $main_end
-		line [expr [gdb_get_line_number "main end"] + 1]
-		DW_LNS_copy
 		DW_LNE_end_sequence
 
 		DW_LNE_set_address $foo_start
@@ -150,25 +149,22 @@ proc do_test {suffix} {
 		DW_LNE_set_address foo_label3
 		line [gdb_get_line_number "foo end"]
 		DW_LNS_copy
+
 		DW_LNE_set_address $foo_end
-		DW_LNS_advance_line 1
-		DW_LNS_copy
 		DW_LNE_end_sequence
 
 		DW_LNE_set_address $bar_start
 		line [gdb_get_line_number "bar end"]
 		DW_LNS_copy
+
 		DW_LNS_advance_pc $bar_len
-		DW_LNS_advance_line 1
-		DW_LNS_copy
 		DW_LNE_end_sequence
 
 		DW_LNE_set_address $baz_start
 		line [gdb_get_line_number "baz end"]
 		DW_LNS_copy
+
 		DW_LNS_advance_pc $baz_len
-		DW_LNS_advance_line 1
-		DW_LNS_copy
 		DW_LNE_end_sequence
 
 		DW_LNE_set_address $foo_cold_start
@@ -180,9 +176,8 @@ proc do_test {suffix} {
 		DW_LNE_set_address foo_cold_label2
 		line [gdb_get_line_number "foo_cold end"]
 		DW_LNS_copy
+
 		DW_LNE_set_address $foo_cold_end
-		DW_LNS_advance_line 1
-		DW_LNS_copy
 		DW_LNE_end_sequence
 	    }
 	}
diff --git a/gdb/testsuite/gdb.dwarf2/fission-multi-cu.exp b/gdb/testsuite/gdb.dwarf2/fission-multi-cu.exp
index d2ea91e..567049a 100644
--- a/gdb/testsuite/gdb.dwarf2/fission-multi-cu.exp
+++ b/gdb/testsuite/gdb.dwarf2/fission-multi-cu.exp
@@ -93,8 +93,6 @@ Dwarf::assemble $asm_file_1 {
 	    DW_LNS_copy
 
 	    DW_LNE_set_address $func_end
-	    DW_LNS_advance_line 1
-	    DW_LNS_copy
 	    DW_LNE_end_sequence
 	}
     }
@@ -177,8 +175,6 @@ Dwarf::assemble $asm_file_2 {
 	    DW_LNS_copy
 
 	    DW_LNE_set_address $main_end
-	    DW_LNS_advance_line 2
-	    DW_LNS_copy
 	    DW_LNE_end_sequence
 	}
     }
diff --git a/gdb/testsuite/gdb.dwarf2/locexpr-data-member-location.exp b/gdb/testsuite/gdb.dwarf2/locexpr-data-member-location.exp
index ca597aa..a1c0e77 100644
--- a/gdb/testsuite/gdb.dwarf2/locexpr-data-member-location.exp
+++ b/gdb/testsuite/gdb.dwarf2/locexpr-data-member-location.exp
@@ -283,11 +283,11 @@ Dwarf::assemble ${asm_file} {
 	    DW_LNS_copy
 	    line [gdb_get_line_number "foo end" $libsrc]
 	    DW_LNS_copy
+
 	    DW_LNE_set_address $foo_end
-	    DW_LNS_advance_line 1
-	    DW_LNS_copy
 	    DW_LNE_end_sequence
 
+
 	    DW_LNE_set_address $bar_start
 	    line [gdb_get_line_number "bar prologue" $libsrc]
 	    DW_LNS_copy
@@ -296,9 +296,8 @@ Dwarf::assemble ${asm_file} {
 	    DW_LNS_copy
 	    line [gdb_get_line_number "bar end" $libsrc]
 	    DW_LNS_copy
+
 	    DW_LNE_set_address $bar_end
-	    DW_LNS_advance_line 1
-	    DW_LNS_copy
 	    DW_LNE_end_sequence
 	}
     }
diff --git a/gdb/testsuite/lib/dwarf.exp b/gdb/testsuite/lib/dwarf.exp
index d085f83..816440f 100644
--- a/gdb/testsuite/lib/dwarf.exp
+++ b/gdb/testsuite/lib/dwarf.exp
@@ -2545,13 +2545,17 @@ namespace eval Dwarf {
 	proc program { body } {
 	    variable _line_header_end_label
 	    variable _line
+	    variable _line_address_update
 
 
 	    set _line 1
+	    set _line_address_update 0
 
 	    _line_finalize_header
 
 	    proc DW_LNE_set_address {addr} {
+		variable _line_address_update
+		set _line_address_update 1
 		_op .byte 0
 		set start [new_label "set_address_start"]
 		set end [new_label "set_address_end"]
@@ -2567,6 +2571,11 @@ namespace eval Dwarf {
 	    }
 
 	    proc DW_LNE_end_sequence {} {
+		variable _line_address_update
+		if { $_line_address_update == 0 } {
+		    error "Missing address update for end_sequence"
+		}
+		set _line_address_update 0
 		variable _line
 		_op .byte 0
 		_op .uleb128 1
@@ -2591,6 +2600,8 @@ namespace eval Dwarf {
 	    }
 
 	    proc DW_LNS_copy {} {
+		variable _line_address_update
+		set _line_address_update 0
 		_op .byte 1
 	    }
 
@@ -2607,6 +2618,8 @@ namespace eval Dwarf {
 	    }
 
 	    proc DW_LNS_advance_pc {offset} {
+		variable _line_address_update
+		set _line_address_update 1
 		_op .byte 2
 		_op .uleb128 ${offset}
 	    }