gdb/dwarf: factor out to cutu_reader::skip_one_attribute method
I was reading cutu_reader::skip_one_die, and thought that the code to
skip one attribute made it quite difficult to read. Factor this code
out to a new method, to get it out of the way.
As a bonus, it transforms one goto in a recursion call, which is also
easier to follow. Unfortunately, I have no idea how to test
DW_FORM_indirect, as it doesn't seem to appear anywhere in the
testsuite, and I don't think that compilers often emit that.
Change-Id: I2257b3e594aafb7c7da52ddd55baa651cefb802f
Approved-By: Tom Tromey <tom@tromey.com>
diff --git a/gdb/dwarf2/read.c b/gdb/dwarf2/read.c
index da6a4fe..3ff7a82 100644
--- a/gdb/dwarf2/read.c
+++ b/gdb/dwarf2/read.c
@@ -4044,6 +4044,106 @@ cutu_reader::skip_children (const gdb_byte *info_ptr)
}
}
+/* See read.h. */
+
+const gdb_byte *
+cutu_reader::skip_one_attribute (dwarf_form form, const gdb_byte *info_ptr)
+{
+ unsigned int bytes_read;
+
+ switch (form)
+ {
+ case DW_FORM_ref_addr:
+ /* In DWARF 2, DW_FORM_ref_addr is address sized; in DWARF 3
+ and later it is offset sized. */
+ if (m_cu->header.version == 2)
+ return info_ptr + m_cu->header.addr_size;
+ else
+ return info_ptr + m_cu->header.offset_size;
+
+ case DW_FORM_GNU_ref_alt:
+ return info_ptr + m_cu->header.offset_size;
+
+ case DW_FORM_addr:
+ return info_ptr + m_cu->header.addr_size;
+
+ case DW_FORM_data1:
+ case DW_FORM_ref1:
+ case DW_FORM_flag:
+ case DW_FORM_strx1:
+ return info_ptr + 1;
+
+ case DW_FORM_flag_present:
+ case DW_FORM_implicit_const:
+ return info_ptr;
+
+ case DW_FORM_data2:
+ case DW_FORM_ref2:
+ case DW_FORM_strx2:
+ return info_ptr + 2;
+
+ case DW_FORM_strx3:
+ return info_ptr + 3;
+
+ case DW_FORM_data4:
+ case DW_FORM_ref4:
+ case DW_FORM_strx4:
+ return info_ptr + 4;
+
+ case DW_FORM_data8:
+ case DW_FORM_ref8:
+ case DW_FORM_ref_sig8:
+ return info_ptr + 8;
+
+ case DW_FORM_data16:
+ return info_ptr + 16;
+
+ case DW_FORM_string:
+ read_direct_string (m_abfd, info_ptr, &bytes_read);
+ return info_ptr + bytes_read;
+
+ case DW_FORM_sec_offset:
+ case DW_FORM_strp:
+ case DW_FORM_GNU_strp_alt:
+ return info_ptr + m_cu->header.offset_size;
+
+ case DW_FORM_exprloc:
+ case DW_FORM_block:
+ info_ptr += read_unsigned_leb128 (m_abfd, info_ptr, &bytes_read);
+ return info_ptr + bytes_read;
+
+ case DW_FORM_block1:
+ return info_ptr + 1 + read_1_byte (m_abfd, info_ptr);
+
+ case DW_FORM_block2:
+ return info_ptr + 2 + read_2_bytes (m_abfd, info_ptr);
+
+ case DW_FORM_block4:
+ return info_ptr + 4 + read_4_bytes (m_abfd, info_ptr);
+
+ case DW_FORM_addrx:
+ case DW_FORM_strx:
+ case DW_FORM_sdata:
+ case DW_FORM_udata:
+ case DW_FORM_ref_udata:
+ case DW_FORM_GNU_addr_index:
+ case DW_FORM_GNU_str_index:
+ case DW_FORM_rnglistx:
+ case DW_FORM_loclistx:
+ return safe_skip_leb128 (info_ptr, m_buffer_end);
+
+ case DW_FORM_indirect:
+ form = static_cast<dwarf_form> (read_unsigned_leb128 (m_abfd, info_ptr,
+ &bytes_read));
+ return this->skip_one_attribute(form, info_ptr + bytes_read);
+
+ default:
+ error (_ (DWARF_ERROR_PREFIX
+ "Cannot handle %s in DWARF reader [in module %s]"),
+ dwarf_form_name (form), bfd_get_filename (m_abfd));
+ }
+}
+
/* Scan the debug information for CU starting at INFO_PTR in buffer BUFFER.
INFO_PTR should point just after the initial uleb128 of a DIE, and the
abbrev corresponding to that skipped uleb128 should be passed in
@@ -4057,10 +4157,6 @@ const gdb_byte *
cutu_reader::skip_one_die (const gdb_byte *info_ptr, const abbrev_info *abbrev,
bool do_skip_children)
{
- unsigned int bytes_read;
- struct attribute attr;
- unsigned int form, i;
-
if (do_skip_children && abbrev->sibling_offset != (unsigned short) -1)
{
/* We only handle DW_FORM_ref4 here. */
@@ -4080,7 +4176,7 @@ cutu_reader::skip_one_die (const gdb_byte *info_ptr, const abbrev_info *abbrev,
return info_ptr;
}
- for (i = 0; i < abbrev->num_attrs; i++)
+ for (unsigned int i = 0; i < abbrev->num_attrs; i++)
{
/* The only abbrev we care about is DW_AT_sibling. */
if (do_skip_children && abbrev->attrs[i].name == DW_AT_sibling)
@@ -4088,6 +4184,7 @@ cutu_reader::skip_one_die (const gdb_byte *info_ptr, const abbrev_info *abbrev,
/* Note there is no need for the extra work of
"reprocessing" here, so we pass false for that
argument. */
+ attribute attr;
this->read_attribute (&attr, &abbrev->attrs[i], info_ptr, false);
if (attr.form == DW_FORM_ref_addr)
complaint (_("ignoring absolute DW_AT_sibling"));
@@ -4106,100 +4203,7 @@ cutu_reader::skip_one_die (const gdb_byte *info_ptr, const abbrev_info *abbrev,
}
/* If it isn't DW_AT_sibling, skip this attribute. */
- form = abbrev->attrs[i].form;
- skip_attribute:
- switch (form)
- {
- case DW_FORM_ref_addr:
- /* In DWARF 2, DW_FORM_ref_addr is address sized; in DWARF 3
- and later it is offset sized. */
- if (m_cu->header.version == 2)
- info_ptr += m_cu->header.addr_size;
- else
- info_ptr += m_cu->header.offset_size;
- break;
- case DW_FORM_GNU_ref_alt:
- info_ptr += m_cu->header.offset_size;
- break;
- case DW_FORM_addr:
- info_ptr += m_cu->header.addr_size;
- break;
- case DW_FORM_data1:
- case DW_FORM_ref1:
- case DW_FORM_flag:
- case DW_FORM_strx1:
- info_ptr += 1;
- break;
- case DW_FORM_flag_present:
- case DW_FORM_implicit_const:
- break;
- case DW_FORM_data2:
- case DW_FORM_ref2:
- case DW_FORM_strx2:
- info_ptr += 2;
- break;
- case DW_FORM_strx3:
- info_ptr += 3;
- break;
- case DW_FORM_data4:
- case DW_FORM_ref4:
- case DW_FORM_strx4:
- info_ptr += 4;
- break;
- case DW_FORM_data8:
- case DW_FORM_ref8:
- case DW_FORM_ref_sig8:
- info_ptr += 8;
- break;
- case DW_FORM_data16:
- info_ptr += 16;
- break;
- case DW_FORM_string:
- read_direct_string (m_abfd, info_ptr, &bytes_read);
- info_ptr += bytes_read;
- break;
- case DW_FORM_sec_offset:
- case DW_FORM_strp:
- case DW_FORM_GNU_strp_alt:
- info_ptr += m_cu->header.offset_size;
- break;
- case DW_FORM_exprloc:
- case DW_FORM_block:
- info_ptr += read_unsigned_leb128 (m_abfd, info_ptr, &bytes_read);
- info_ptr += bytes_read;
- break;
- case DW_FORM_block1:
- info_ptr += 1 + read_1_byte (m_abfd, info_ptr);
- break;
- case DW_FORM_block2:
- info_ptr += 2 + read_2_bytes (m_abfd, info_ptr);
- break;
- case DW_FORM_block4:
- info_ptr += 4 + read_4_bytes (m_abfd, info_ptr);
- break;
- case DW_FORM_addrx:
- case DW_FORM_strx:
- case DW_FORM_sdata:
- case DW_FORM_udata:
- case DW_FORM_ref_udata:
- case DW_FORM_GNU_addr_index:
- case DW_FORM_GNU_str_index:
- case DW_FORM_rnglistx:
- case DW_FORM_loclistx:
- info_ptr = safe_skip_leb128 (info_ptr, m_buffer_end);
- break;
- case DW_FORM_indirect:
- form = read_unsigned_leb128 (m_abfd, info_ptr, &bytes_read);
- info_ptr += bytes_read;
- /* We need to continue parsing from here, so just go back to
- the top. */
- goto skip_attribute;
-
- default:
- error (_(DWARF_ERROR_PREFIX
- "Cannot handle %s in DWARF reader [in module %s]"),
- dwarf_form_name (form), bfd_get_filename (m_abfd));
- }
+ info_ptr = this->skip_one_attribute (abbrev->attrs[i].form, info_ptr);
}
if (do_skip_children && abbrev->has_children)
diff --git a/gdb/dwarf2/read.h b/gdb/dwarf2/read.h
index 4e8ccb3..a8d7428 100644
--- a/gdb/dwarf2/read.h
+++ b/gdb/dwarf2/read.h
@@ -970,6 +970,11 @@ class cutu_reader
const gdb_byte *skip_children (const gdb_byte *info_ptr);
private:
+ /* Skip the attribute at INFO_PTR, knowing it has form FORM. Return a pointer
+ just past the attribute. */
+ const gdb_byte *skip_one_attribute (dwarf_form form,
+ const gdb_byte *info_ptr);
+
void init_cu_die_reader (dwarf2_cu *cu, dwarf2_section_info *section,
struct dwo_file *dwo_file,
const struct abbrev_table *abbrev_table);
