From cbd24a9f11feea879c2f1857053854ef329efbd8 Mon Sep 17 00:00:00 2001
From: Tom de Vries <tdevries@suse.de>
Date: Fri, 12 May 2023 11:43:41 +0200
Subject: [PATCH] [gdb/testsuite] Fix gdb.dwarf2/opt-out-not-implptr.exp for
 -m32

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>\\}"
-- 
2.30.2