[PATCH v2 17/16] RISC-V: warn about non-boolean unaligned-access attribute

[Jan Beulich]

The attribute being a boolean one, values should be solely 0 or 1.
---
Should libbfd's riscv_merge_attributes() also emit a warning?

Shouldn't settings accumulate, much like what riscv_merge_attributes()
does?
---
v2: New.

--- a/gas/config/tc-riscv.c
+++ b/gas/config/tc-riscv.c
@@ -5859,14 +5859,13 @@ s_riscv_attribute (int ignored ATTRIBUTE
 {
   obj_attr_tag_t tag = obj_attr_process_attribute (OBJ_ATTR_PROC);
   unsigned old_xlen;
-  obj_attribute *attr;
+  const obj_attribute *attr = elf_known_obj_attributes_proc (stdoutput);
 
   explicit_attr = true;
   switch (tag)
     {
     case Tag_RISCV_arch:
       old_xlen = xlen;
-      attr = elf_known_obj_attributes_proc (stdoutput);
       if (!start_assemble)
 	riscv_set_arch (attr[Tag_RISCV_arch].s);
       else
@@ -5892,6 +5891,11 @@ s_riscv_attribute (int ignored ATTRIBUTE
 		   "any instructions"));
       break;
 
+    case Tag_RISCV_unaligned_access:
+      if (attr[Tag_RISCV_unaligned_access].i > 1)
+	as_warn (_("`unaligned_access' attribute with non-boolean value"));
+      break;
+
     default:
       break;
     }
--- /dev/null
+++ b/gas/testsuite/gas/riscv/attribute-warn.d
@@ -0,0 +1,7 @@
+#as: -march-attr
+#readelf: -A
+#warning_output: attribute-warn.l
+
+Attribute Section: riscv
+File Attributes
+  Tag_RISCV_arch: [a-zA-Z0-9_\"].*
--- /dev/null
+++ b/gas/testsuite/gas/riscv/attribute-warn.l
@@ -0,0 +1,2 @@
+.*: Assembler messages:
+.*:2: Warning: `unaligned_access' attribute with non-boolean value
--- /dev/null
+++ b/gas/testsuite/gas/riscv/attribute-warn.s
@@ -0,0 +1,3 @@
+	.attribute unaligned_access, 1
+	.attribute unaligned_access, 0x1234
+	.attribute unaligned_access, 0