Merge pull request #11191 from Snektron/zig-gdb-improvements

Zig gdb improvements

lib/std/hash_map.zig

@@ -1,4 +1,5 @@
 const std = @import("std.zig");
+const builtin = @import("builtin");
 const assert = debug.assert;
 const autoHash = std.hash.autoHash;
 const debug = std.debug;
@@ -1576,6 +1577,19 @@ pub fn HashMapUnmanaged(
             self.metadata = null;
             self.available = 0;
         }
+
+        /// This function is used in tools/zig-gdb.py to fetch the header type to facilitate
+        /// fancy debug printing for this type.
+        fn gdbHelper(self: *Self, hdr: *Header) void {
+            _ = self;
+            _ = hdr;
+        }
+
+        comptime {
+            if (builtin.mode == .Debug) {
+                _ = gdbHelper;
+            }
+        }
     };
 }
 

lib/std/multi_array_list.zig

@@ -1,4 +1,5 @@
 const std = @import("std.zig");
+const builtin = @import("builtin");
 const assert = std.debug.assert;
 const meta = std.meta;
 const mem = std.mem;
@@ -433,6 +434,19 @@ pub fn MultiArrayList(comptime S: type) type {
         fn FieldType(field: Field) type {
             return meta.fieldInfo(S, field).field_type;
         }
+
+        /// This function is used in tools/zig-gdb.py to fetch the child type to facilitate
+        /// fancy debug printing for this type.
+        fn gdbHelper(self: *Self, child: *S) void {
+            _ = self;
+            _ = child;
+        }
+
+        comptime {
+            if (builtin.mode == .Debug) {
+                _ = gdbHelper;
+            }
+        }
     };
 }
 

src/type.zig

@@ -5093,6 +5093,7 @@ pub const Type = extern union {
         pub const no_payload_count = @enumToInt(last_no_payload_tag) + 1;
 
         pub fn Type(comptime t: Tag) type {
+            // Keep in sync with tools/zig-gdb.py
             return switch (t) {
                 .u1,
                 .u8,

src/value.zig

@@ -20,6 +20,7 @@ pub const Value = extern union {
     tag_if_small_enough: Tag,
     ptr_otherwise: *Payload,
 
+    // Keep in sync with tools/zig-gdb.py
     pub const Tag = enum(usize) {
         // The first section of this enum are tags that require no payload.
         u1_type,

tools/stage1_gdb_pretty_printers.py

@@ -1,6 +1,5 @@
-# pretty printing for stage1
-# put "source /path/to/zig-gdb.py" in ~/.gdbinit to load it automatically
-
+# pretty printing for stage1.
+# put "source /path/to/stage1_gdb_pretty_printers.py" in ~/.gdbinit to load it automatically.
 import gdb.printing
 
 class ZigListPrinter:
@@ -35,5 +34,4 @@ pp = gdb.printing.RegexpCollectionPrettyPrinter('Zig stage1 compiler')
 pp.add_printer('Buf', '^Buf$', BufPrinter)
 pp.add_printer('ZigList<char>', '^ZigList<char>$', BufPrinter)
 pp.add_printer('ZigList', '^ZigList<.*>$', ZigListPrinter)
-
 gdb.printing.register_pretty_printer(gdb.current_objfile(), pp)

tools/stage2_gdb_pretty_printers.py

@@ -0,0 +1,189 @@
+# pretty printing for stage 2.
+# put "source /path/to/stage2_gdb_pretty_printers.py" in ~/.gdbinit to load it automatically.
+import re
+import gdb.printing
+
+class TypePrinter:
+    no_payload_count = 4096
+
+    # Keep in sync with src/type.zig
+    # Types which have no payload do not need to be entered here.
+    payload_type_names = {
+        'array_u8': 'type.Len',
+        'array_u8_sentinel_0': 'Len',
+
+        'single_const_pointer': 'ElemType',
+        'single_mut_pointer': 'ElemType',
+        'many_const_pointer': 'ElemType',
+        'many_mut_pointer': 'ElemType',
+        'c_const_pointer': 'ElemType',
+        'c_mut_pointer': 'ElemType',
+        'const_slice': 'ElemType',
+        'mut_slice': 'ElemType',
+        'optional': 'ElemType',
+        'optional_single_mut_pointer': 'ElemType',
+        'optional_single_const_pointer': 'ElemType',
+        'anyframe_T': 'ElemType',
+
+        'int_signed': 'Bits',
+        'int_unsigned': 'Bits',
+
+        'error_set': 'ErrorSet',
+        'error_set_inferred': 'ErrorSetInferred',
+        'error_set_merged': 'ErrorSetMerged',
+
+        'array': 'Array',
+        'vector': 'Array',
+
+        'array_sentinel': 'ArraySentinel',
+        'pointer': 'Pointer',
+        'function': 'Function',
+        'error_union': 'ErrorUnion',
+        'error_set_single': 'Name',
+        'opaque': 'Opaque',
+        'struct': 'Struct',
+        'union': 'Union',
+        'union_tagged': 'Union',
+        'enum_full, .enum_nonexhaustive': 'EnumFull',
+        'enum_simple': 'EnumSimple',
+        'enum_numbered': 'EnumNumbered',
+        'empty_struct': 'ContainerScope',
+        'tuple': 'Tuple',
+        'anon_struct': 'AnonStruct',
+    }
+
+    def __init__(self, val):
+        self.val = val
+
+    def tag(self):
+        tag_if_small_enough = self.val['tag_if_small_enough']
+        tag_type = tag_if_small_enough.type
+
+        if tag_if_small_enough < TypePrinter.no_payload_count:
+            return tag_if_small_enough
+        else:
+            return self.val['ptr_otherwise'].dereference()['tag']
+
+    def payload_type(self):
+        tag = self.tag()
+        if tag is None:
+            return None
+
+        type_name = TypePrinter.payload_type_names.get(str(tag))
+        if type_name is None:
+            return None
+        return gdb.lookup_type('struct type.%s' % type_name)
+
+    def to_string(self):
+        tag = self.tag()
+        if tag is None:
+            return '(invalid type)'
+        if self.val['tag_if_small_enough'] < TypePrinter.no_payload_count:
+            return '.%s' % str(tag)
+        return None
+
+    def children(self):
+        if self.val['tag_if_small_enough'] < TypePrinter.no_payload_count:
+            return
+
+        yield ('tag', '.%s' % str(self.tag()))
+
+        payload_type = self.payload_type()
+        if payload_type is not None:
+            yield ('payload', self.val['ptr_otherwise'].cast(payload_type.pointer()).dereference()['data'])
+
+class ValuePrinter:
+    no_payload_count = 4096
+
+    # Keep in sync with src/value.zig
+    # Values which have no payload do not need to be entered here.
+    payload_type_names = {
+        'big_int_positive': 'BigInt',
+        'big_int_negative': 'BigInt',
+
+        'extern_fn': 'ExternFn',
+
+        'decl_ref': 'Decl',
+
+        'repeated': 'SubValue',
+        'eu_payload': 'SubValue',
+        'opt_payload': 'SubValue',
+        'empty_array_sentinel': 'SubValue',
+
+        'eu_payload_ptr': 'PayloadPtr',
+        'opt_payload_ptr': 'PayloadPtr',
+
+        'bytes': 'Bytes',
+        'enum_literal': 'Bytes',
+
+        'slice': 'Slice',
+
+        'enum_field_index': 'U32',
+
+        'ty': 'Ty',
+        'int_type': 'IntType',
+        'int_u64': 'U64',
+        'int_i64': 'I64',
+        'function': 'Function',
+        'variable': 'Variable',
+        'decl_ref_mut': 'DeclRefMut',
+        'elem_ptr': 'ElemPtr',
+        'field_ptr': 'FieldPtr',
+        'float_16': 'Float_16',
+        'float_32': 'Float_32',
+        'float_64': 'Float_64',
+        'float_80': 'Float_80',
+        'float_128': 'Float_128',
+        'error': 'Error',
+        'inferred_alloc': 'InferredAlloc',
+        'inferred_alloc_comptime': 'InferredAllocComptime',
+        'aggregate': 'Aggregate',
+        'union': 'Union',
+        'bound_fn': 'BoundFn',
+    }
+
+    def __init__(self, val):
+        self.val = val
+
+    def tag(self):
+        tag_if_small_enough = self.val['tag_if_small_enough']
+        tag_type = tag_if_small_enough.type
+
+        if tag_if_small_enough < ValuePrinter.no_payload_count:
+            return tag_if_small_enough
+        else:
+            return self.val['ptr_otherwise'].dereference()['tag']
+
+    def payload_type(self):
+        tag = self.tag()
+        if tag is None:
+            return None
+
+        type_name = ValuePrinter.payload_type_names.get(str(tag))
+        if type_name is None:
+            return None
+        return gdb.lookup_type('struct value.%s' % type_name)
+
+    def to_string(self):
+        tag = self.tag()
+        if tag is None:
+            return '(invalid value)'
+        if self.val['tag_if_small_enough'] < ValuePrinter.no_payload_count:
+            return '.%s' % str(tag)
+        return None
+
+    def children(self):
+        if self.val['tag_if_small_enough'] < ValuePrinter.no_payload_count:
+            return
+
+        yield ('tag', '.%s' % str(self.tag()))
+
+        payload_type = self.payload_type()
+        if payload_type is not None:
+            yield ('payload', self.val['ptr_otherwise'].cast(payload_type.pointer()).dereference()['data'])
+
+pp = gdb.printing.RegexpCollectionPrettyPrinter('Zig stage2 compiler')
+pp.add_printer('Type', r'^type\.Type$', TypePrinter)
+pp.add_printer('Value', r'^value\.Value$', ValuePrinter)
+gdb.printing.register_pretty_printer(gdb.current_objfile(), pp)
+

tools/std_gdb_pretty_printers.py

@@ -0,0 +1,142 @@
+# pretty printing for the standard library.
+# put "source /path/to/stage2_gdb_pretty_printers.py" in ~/.gdbinit to load it automatically.
+import re
+import gdb.printing
+
+# Handles both ArrayList and ArrayListUnmanaged.
+class ArrayListPrinter:
+    def __init__(self, val):
+        self.val = val
+
+    def to_string(self):
+        type = self.val.type.name[len('std.array_list.'):]
+        type = re.sub(r'^ArrayListAligned(Unmanaged)?\((.*),null\)$', r'ArrayList\1(\2)', type)
+        return '%s of length %s, capacity %s' % (type, self.val['items']['len'], self.val['capacity'])
+
+    def children(self):
+        for i in range(self.val['items']['len']):
+            item = self.val['items']['ptr'] + i
+            yield ('[%d]' % i, item.dereference())
+
+    def display_hint(self):
+        return 'array'
+
+class MultiArrayListPrinter:
+    def __init__(self, val):
+        self.val = val
+
+    def child_type(self):
+        (helper_fn, _) = gdb.lookup_symbol('%s.gdbHelper' % self.val.type.name)
+        return helper_fn.type.fields()[1].type.target()
+
+    def to_string(self):
+        type = self.val.type.name[len('std.multi_array_list.'):]
+        return '%s of length %s, capacity %s' % (type, self.val['len'], self.val['capacity'])
+
+    def slice(self):
+        fields = self.child_type().fields()
+        base = self.val['bytes']
+        cap = self.val['capacity']
+        len = self.val['len']
+
+        if len == 0:
+            return
+
+        fields = sorted(fields, key=lambda field: field.type.alignof, reverse=True)
+
+        for field in fields:
+            ptr = base.cast(field.type.pointer()).dereference().cast(field.type.array(len - 1))
+            base += field.type.sizeof * cap
+            yield (field.name, ptr)
+
+    def children(self):
+        for i, (name, ptr) in enumerate(self.slice()):
+            yield ('[%d]' % i, name)
+            yield ('[%d]' % i, ptr)
+
+    def display_hint(self):
+        return 'map'
+
+# Handles both HashMap and HashMapUnmanaged.
+class HashMapPrinter:
+    def __init__(self, val):
+        self.type = val.type
+        is_managed = re.search(r'^std\.hash_map\.HashMap\(', self.type.name)
+        self.val = val['unmanaged'] if is_managed else val
+
+    def header_ptr_type(self):
+        (helper_fn, _) = gdb.lookup_symbol('%s.gdbHelper' % self.val.type.name)
+        return helper_fn.type.fields()[1].type
+
+    def header(self):
+        if self.val['metadata'] == 0:
+            return None
+        return (self.val['metadata'].cast(self.header_ptr_type()) - 1).dereference()
+
+    def to_string(self):
+        type = self.type.name[len('std.hash_map.'):]
+        type = re.sub(r'^HashMap(Unmanaged)?\((.*),std.hash_map.AutoContext\(.*$', r'AutoHashMap\1(\2)', type)
+        hdr = self.header()
+        if hdr is not None:
+            cap = hdr['capacity']
+        else:
+            cap = 0
+        return '%s of length %s, capacity %s' % (type, self.val['size'], cap)
+
+    def children(self):
+        hdr = self.header()
+        if hdr is None:
+            return
+        is_map = self.display_hint() == 'map'
+        for i in range(hdr['capacity']):
+            metadata = self.val['metadata'] + i
+            if metadata.dereference()['used'] == 1:
+                yield ('[%d]' % i, (hdr['keys'] + i).dereference())
+                if is_map:
+                    yield ('[%d]' % i, (hdr['values'] + i).dereference())
+
+    def display_hint(self):
+        for field in self.header_ptr_type().target().fields():
+            if field.name == 'values':
+                return 'map'
+        return 'array'
+
+# Handles both ArrayHashMap and ArrayHashMapUnmanaged.
+class ArrayHashMapPrinter:
+    def __init__(self, val):
+        self.type = val.type
+        is_managed = re.search(r'^std\.array_hash_map\.ArrayHashMap\(', self.type.name)
+        self.val = val['unmanaged'] if is_managed else val
+
+    def to_string(self):
+        type = self.type.name[len('std.array_hash_map.'):]
+        type = re.sub(r'^ArrayHashMap(Unmanaged)?\((.*),std.array_hash_map.AutoContext\(.*$', r'AutoArrayHashMap\1(\2)', type)
+        return '%s of length %s' % (type, self.val['entries']['len'])
+
+    def children(self):
+        entries = MultiArrayListPrinter(self.val['entries'])
+        len = self.val['entries']['len']
+        fields = {}
+        for name, ptr in entries.slice():
+            fields[str(name)] = ptr
+
+        for i in range(len):
+            if 'key' in fields:
+                yield ('[%d]' % i, fields['key'][i])
+            else:
+                yield ('[%d]' % i, '{}')
+            if 'value' in fields:
+                yield ('[%d]' % i, fields['value'][i])
+
+    def display_hint(self):
+        for name, ptr in MultiArrayListPrinter(self.val['entries']).slice():
+            if name == 'value':
+                return 'map'
+        return 'array'
+
+pp = gdb.printing.RegexpCollectionPrettyPrinter('Zig standard library')
+pp.add_printer('ArrayList', r'^std\.array_list\.ArrayListAligned(Unmanaged)?\(.*\)$', ArrayListPrinter)
+pp.add_printer('MultiArrayList', r'^std\.multi_array_list\.MultiArrayList\(.*\)$', MultiArrayListPrinter)
+pp.add_printer('HashMap', r'^std\.hash_map\.HashMap(Unmanaged)?\(.*\)$', HashMapPrinter)
+pp.add_printer('ArrayHashMap', r'^std\.array_hash_map\.ArrayHashMap(Unmanaged)?\(.*\)$', ArrayHashMapPrinter)
+gdb.printing.register_pretty_printer(gdb.current_objfile(), pp)

tools/zig_gdb_pretty_printers.py

@@ -1,5 +1,5 @@
-# gdb pretty printers for Zig language constructs
-
+# pretty printing for the language.
+# put "source /path/to/zig_gdb_pretty_printers.py" in ~/.gdbinit to load it automatically.
 import gdb.printing
 
 class ZigPrettyPrinter(gdb.printing.PrettyPrinter):