[PATCH 06/11] [gdb/macros] Handle v4 dwarf in gdb.base/fission-macro.exp

[Tom de Vries <tdevries@suse.de>]

When running test-case gdb.base/fission-macro.exp with dwarf v4 enabled and a
gcc trunk build containing the fix for gcc PR debug/115066, we run into:
...
(gdb) info macro FIRST^M
Defined at /data/vries/gdb/src/gdb/testsuite/gdb.base/fission-macro.c:0^M
-DFIRST=1^M
(gdb) FAIL: gdb.base/fission-macro.exp: dwarf_version=4: dwarf_bits=32: \
  strict_dwarf=0: info macro FIRST
...

The problem is in dwarf_decode_macros, where we're setting str_offsets_base
effectively to 8:
...
      if (cu->per_cu->version () <= 4)
	str_offsets_base = cu->header.addr_size;
...

Fix this by setting it to 0.

Tested on x86_64-linux.

Tested test-case (and gdb.base/fission-macro-i.exp) using a current gcc trunk
build and gcc 7-14.
---
 gdb/dwarf2/read.c                          | 2 +-
 gdb/testsuite/gdb.base/fission-macro-i.exp | 6 +++++-
 gdb/testsuite/gdb.base/fission-macro.exp   | 6 +++++-
 3 files changed, 11 insertions(+), 3 deletions(-)

diff --git a/gdb/dwarf2/read.c b/gdb/dwarf2/read.c
index abe128f35df..e5f65ad28f2 100644
--- a/gdb/dwarf2/read.c
+++ b/gdb/dwarf2/read.c
@@ -21259,7 +21259,7 @@ dwarf_decode_macros (struct dwarf2_cu *cu, unsigned int offset,
 			       ->sections.str_offsets;
       str_section = &cu->dwo_unit->dwo_file->sections.str;
       if (cu->per_cu->version () <= 4)
-	str_offsets_base = cu->header.addr_size;
+	str_offsets_base = 0;
       else
 	{
 	  bfd *abfd = str_offsets_section->get_bfd_owner ();
diff --git a/gdb/testsuite/gdb.base/fission-macro-i.exp b/gdb/testsuite/gdb.base/fission-macro-i.exp
index ae211d0e09b..62304f9b69e 100644
--- a/gdb/testsuite/gdb.base/fission-macro-i.exp
+++ b/gdb/testsuite/gdb.base/fission-macro-i.exp
@@ -65,7 +65,11 @@ proc do_tests { dwarf_version dwarf_bits strict_dwarf } {
     gdb_test "info macro FOURTH" "#define FOURTH 4"
 }
 
-foreach_with_prefix dwarf_version {5} {
+foreach_with_prefix dwarf_version {4 5} {
+    if { $dwarf_version == 4 && [gcc_major_version] < 15 } {
+	# Gcc does not contain fix for PR debug/115066.
+	continue
+    }
     foreach_with_prefix dwarf_bits {32 64} {
 	foreach_with_prefix strict_dwarf {0 1} {
 	    do_tests $dwarf_version $dwarf_bits $strict_dwarf
diff --git a/gdb/testsuite/gdb.base/fission-macro.exp b/gdb/testsuite/gdb.base/fission-macro.exp
index 4eb9c0efe21..9e5d5c0a0d5 100644
--- a/gdb/testsuite/gdb.base/fission-macro.exp
+++ b/gdb/testsuite/gdb.base/fission-macro.exp
@@ -66,7 +66,11 @@ proc do_tests { dwarf_version dwarf_bits strict_dwarf } {
     gdb_test "info macro FOURTH" "#define FOURTH 4"
 }
 
-foreach_with_prefix dwarf_version {5} {
+foreach_with_prefix dwarf_version {4 5} {
+    if { $dwarf_version == 4 && [gcc_major_version] < 15 } {
+	# Gcc does not contain fix for PR debug/115066.
+	continue
+    }
     foreach_with_prefix dwarf_bits {32 64} {
 	foreach_with_prefix strict_dwarf {0 1} {
 	    do_tests $dwarf_version $dwarf_bits $strict_dwarf
-- 
2.35.3