[pushed 1/2] [gdb/testsuite] Make is_64_target more robust

[pushed 1/2] [gdb/testsuite] Make is_64_target more robust

[Tom de Vries]

I ran test-case gdb.dwarf2/opt-out-not-implptr.exp with make-check-all.sh, and
with target board dwarf64 ran into:
...
FAIL: gdb.dwarf2/opt-out-not-implptr.exp: print noptr
...
due to is_target_64 failing because of:
...
builtin_spawn -ignore SIGHUP gcc -fno-stack-protector \
  -fdiagnostics-color=never -w -c -gdwarf64 -g -o is_64_target.o \
  is_64_target.c^M
gcc: error: '-gdwarf64' is ambiguous; use '-gdwarf-64' for DWARF version or \
  '-gdwarf -g64' for debug level^M
compiler exited with status 1
...

The FAIL is the same FAIL I run into with target board unix/-m32: is_target_64
fails for both cases.

The reason that is_target_64 is failing for target board dwarf64, is because
of using system compiler 7.5.0 which doesn't support -gdwarf64.

Fix this by making is_target_64 use nodebug instead of debug for compilation.

Tested on x86_64-linux.
---
 gdb/testsuite/lib/gdb.exp | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/gdb/testsuite/lib/gdb.exp b/gdb/testsuite/lib/gdb.exp
index 50c10333df1..010da097766 100644
--- a/gdb/testsuite/lib/gdb.exp
+++ b/gdb/testsuite/lib/gdb.exp
@@ -3492,7 +3492,7 @@ gdb_caching_proc is_lp64_target {} {
 # This cannot be decided simply from looking at the target string,
 # as it might depend on externally passed compiler options like -m64.
 gdb_caching_proc is_64_target {} {
-    return [gdb_can_simple_compile is_64_target {
+    return [gdb_can_simple_compile_nodebug is_64_target {
 	int function(void) { return 3; }
 	int dummy[sizeof (&function) == 8 ? 1 : -1];
     }]
@@ -4736,6 +4736,13 @@ proc gdb_can_simple_compile {name code {type object} {compile_flags ""} {default
     return $ret
 }
 
+# As gdb_can_simple_compile, but defaults to using nodebug instead of debug.
+proc gdb_can_simple_compile_nodebug {name code {type object} {compile_flags ""}
+				     {default_compile_flags "nodebug nowarning quiet"}} {
+    return [gdb_can_simple_compile $name $code $type $compile_flags \
+		$default_compile_flags]
+}
+
 # Some targets need to always link a special object in.  Save its path here.
 global gdb_saved_set_unbuffered_mode_obj
 set gdb_saved_set_unbuffered_mode_obj ""

base-commit: 9827805ce1eea094d5b97bf27acdd120e5cdda86
-- 
2.35.3

[pushed 2/2] [gdb/testsuite] Fix gdb.dwarf2/opt-out-not-implptr.exp for -m32

[Tom de Vries]

When running test-case gdb.dwarf2/opt-out-not-implptr.exp with target board
unix/-m32 we have:
...
(gdb) print noptr^M
$1 = {0, <optimized out>, <optimized out>, <optimized out>}^M
(gdb) FAIL: gdb.dwarf2/opt-out-not-implptr.exp: print noptr
...

The problem happens when evaluating this dwarf expression:
...
  <45> DW_AT_location : 13 byte block: 10 86 ea d7 d0 96 8e cf 92 5c 9f 93 8 \
  (DW_OP_constu: 6639779683436459270; DW_OP_stack_value; DW_OP_piece: 8)
...

The DW_OP_constu pushes a value with "generic type" on to the DWARF stack, and
the "generic type" has the size of an address on the target machine, which for
target board unix/-m32 is 4 bytes.  Consequently, the constant is abbreviated.

Next, the DW_OP_piece declares that the resulting 4-byte value is 8 bytes
large, and we hit this clause in rw_pieced_value:
...
            /* Use zeroes if piece reaches beyond stack value.  */
            if (p->offset + p->size > stack_value_size_bits)
              break;
...
and consequently get a zero.

We could just add require is_target_64 to the test-case, but instead, add a
32-bit case and require is_target_64 just for the 64-bit case.

Tested on x86_64-linux.
---
 .../gdb.dwarf2/opt-out-not-implptr.exp        | 52 ++++++++++++++++---
 1 file changed, 45 insertions(+), 7 deletions(-)

diff --git a/gdb/testsuite/gdb.dwarf2/opt-out-not-implptr.exp b/gdb/testsuite/gdb.dwarf2/opt-out-not-implptr.exp
index 949bc23492a..9b240c9a2af 100644
--- a/gdb/testsuite/gdb.dwarf2/opt-out-not-implptr.exp
+++ b/gdb/testsuite/gdb.dwarf2/opt-out-not-implptr.exp
@@ -21,10 +21,13 @@ standard_testfile main.c -dw.S
 
 set asm_file [standard_output_file $srcfile2]
 
+set c64 6639779683436459270
+set c32 1779823878
+
 Dwarf::assemble $asm_file {
     cu {} {
 	compile_unit {} {
-	    declare_labels i64_type array
+	    declare_labels i64_type i32_type i64_array i32_array
 
 	    i64_type: base_type {
 		{name "int64_t"}
@@ -32,7 +35,13 @@ Dwarf::assemble $asm_file {
 		{byte_size 8 DW_FORM_sdata}
 	    }
 
-	    array: DW_TAG_array_type {
+	    i32_type: base_type {
+		{name "int32_t"}
+		{encoding @DW_ATE_signed}
+		{byte_size 4 DW_FORM_sdata}
+	    }
+
+	    i64_array: DW_TAG_array_type {
 		{DW_AT_name array_type}
 		{DW_AT_type :$i64_type}
 	    } {
@@ -43,15 +52,36 @@ Dwarf::assemble $asm_file {
 		}
 	    }
 
+	    i32_array: DW_TAG_array_type {
+		{DW_AT_name array_type}
+		{DW_AT_type :$i32_type}
+	    } {
+		DW_TAG_subrange_type {
+		    {DW_AT_type        :$i32_type}
+		    {DW_AT_lower_bound 0 DW_FORM_data1}
+		    {DW_AT_upper_bound 3 DW_FORM_data1}
+		}
+	    }
+
 	    DW_TAG_variable {
-		{name noptr}
-		{type :$array}
+		{name i64_noptr}
+		{type :$i64_array}
 		{location {
-		    DW_OP_constu 6639779683436459270
+		    DW_OP_constu $::c64
 		    DW_OP_stack_value
 		    DW_OP_piece 8
 		} SPECIAL_expr}
 	    }
+
+	    DW_TAG_variable {
+		{name i32_noptr}
+		{type :$i32_array}
+		{location {
+		    DW_OP_constu $::c32
+		    DW_OP_stack_value
+		    DW_OP_piece 4
+		} SPECIAL_expr}
+	    }
 	}
     }
 }
@@ -72,5 +102,13 @@ if {![runto_main]} {
     return -1
 }
 
-gdb_test "print noptr" \
-    " = \\{6639779683436459270, <optimized out>, <optimized out>, <optimized out>\\}"
+set cmd "print i64_noptr"
+if { [is_64_target] } {
+    gdb_test $cmd \
+	" = \\{$c64, <optimized out>, <optimized out>, <optimized out>\\}"
+} else {
+    unsupported $cmd
+}
+
+gdb_test "print i32_noptr" \
+    " = \\{$c32, <optimized out>, <optimized out>, <optimized out>\\}"
-- 
2.35.3