Teach libdwarf about the DW_FORM_flag_present dwarf attribute, so

programs using libdwarf (such as ctfconvert) don't error out on files
containing the attribute.

MFC after:	2 weeks

4 files changed, 9 insertions, 0 deletions

diff --git a/lib/libdwarf/dwarf.h b/lib/libdwarf/dwarf.h
index ecbafcf..6eb2077 100644
--- a/lib/libdwarf/dwarf.h
+++ b/lib/libdwarf/dwarf.h
@@ -184,6 +184,7 @@
 #define DW_FORM_ref8			0x14
 #define DW_FORM_ref_udata		0x15
 #define DW_FORM_indirect		0x16
+#define DW_FORM_flag_present		0x19
 
 #define DW_OP_addr			0x03
 #define DW_OP_deref			0x06
diff --git a/lib/libdwarf/dwarf_attrval.c b/lib/libdwarf/dwarf_attrval.c
index db07ee7..25286de 100644
--- a/lib/libdwarf/dwarf_attrval.c
+++ b/lib/libdwarf/dwarf_attrval.c
@@ -101,6 +101,7 @@ dwarf_attrval_flag(Dwarf_Die die, uint64_t attr, Dwarf_Bool *valp, Dwarf_Error *
 	} else {
 		switch (av->av_form) {
 		case DW_FORM_flag:
+		case DW_FORM_flag_present:
 			*valp = (Dwarf_Bool) av->u[0].u64;
 			break;
 		default:
diff --git a/lib/libdwarf/dwarf_dump.c b/lib/libdwarf/dwarf_dump.c
index e92fee0d..dc22800 100644
--- a/lib/libdwarf/dwarf_dump.c
+++ b/lib/libdwarf/dwarf_dump.c
@@ -240,6 +240,8 @@ get_form_desc(uint32_t form)
 		return "DW_FORM_data8";
 	case DW_FORM_flag:
 		return "DW_FORM_flag";
+	case DW_FORM_flag_present:
+		return "DW_FORM_flag_present";
 	case DW_FORM_indirect:
 		return "DW_FORM_indirect";
 	case DW_FORM_ref1:
@@ -648,6 +650,7 @@ dwarf_dump_av(Dwarf_Die die, Dwarf_AttrValue av)
 	case DW_FORM_data4:
 	case DW_FORM_data8:
 	case DW_FORM_flag:
+	case DW_FORM_flag_present:
 		printf("%llu", (unsigned long long) av->u[0].u64);
 		break;
 	case DW_FORM_ref1:
diff --git a/lib/libdwarf/dwarf_init.c b/lib/libdwarf/dwarf_init.c
index 95642a0..aca6cef 100644
--- a/lib/libdwarf/dwarf_init.c
+++ b/lib/libdwarf/dwarf_init.c
@@ -396,6 +396,10 @@ dwarf_init_attr(Dwarf_Debug dbg, Elf_Data **dp, uint64_t *offsetp,
 		avref.u[1].s = elf_strptr(dbg->dbg_elf,
 		    dbg->dbg_s[DWARF_debug_str].s_shnum, avref.u[0].u64);
 		break;
+	case DW_FORM_flag_present:
+		/* This form has no value encoded in the DIE. */
+		avref.u[0].u64 = 1;
+		break;
 	default:
 		DWARF_SET_ERROR(error, DWARF_E_NOT_IMPLEMENTED);
 		ret = DWARF_E_NOT_IMPLEMENTED;