Implement new gdb/lldb pretty-printers

Replace old GDB and LLDB pretty-printers with new ones
which were originally written for IntelliJ Rust.
New LLDB pretty-printers support synthetic children.
New GDB/LLDB pretty-printers support all Rust types
supported by old pretty-printers, and also support:
Rc, Arc, Cell, Ref, RefCell, RefMut, HashMap, HashSet.

1 files changed, 385 insertions, 0 deletions

diff --git a/src/etc/gdb_providers.py b/src/etc/gdb_providers.py
new file mode 100644
index 00000000000..cec9c56a235
--- /dev/null
+++ b/src/etc/gdb_providers.py
@@ -0,0 +1,385 @@
+from sys import version_info
+
+import gdb
+from gdb import lookup_type
+
+if version_info[0] >= 3:
+    xrange = range
+
+ZERO_FIELD = "__0"
+FIRST_FIELD = "__1"
+
+
+def unwrap_unique_or_non_null(unique_or_nonnull):
+    # BACKCOMPAT: rust 1.32
+    # https://github.com/rust-lang/rust/commit/7a0911528058e87d22ea305695f4047572c5e067
+    ptr = unique_or_nonnull["pointer"]
+    return ptr if ptr.type.code == gdb.TYPE_CODE_PTR else ptr[ZERO_FIELD]
+
+
+class EnumProvider:
+    def __init__(self, valobj):
+        content = valobj[valobj.type.fields()[0]]
+        fields = content.type.fields()
+        self.empty = len(fields) == 0
+        if not self.empty:
+            if len(fields) == 1:
+                discriminant = 0
+            else:
+                discriminant = int(content[fields[0]]) + 1
+            self.active_variant = content[fields[discriminant]]
+            self.name = fields[discriminant].name
+            self.full_name = "{}::{}".format(valobj.type.name, self.name)
+        else:
+            self.full_name = valobj.type.name
+
+    def to_string(self):
+        return self.full_name
+
+    def children(self):
+        if not self.empty:
+            yield self.name, self.active_variant
+
+
+class StdStringProvider:
+    def __init__(self, valobj):
+        self.valobj = valobj
+        vec = valobj["vec"]
+        self.length = int(vec["len"])
+        self.data_ptr = unwrap_unique_or_non_null(vec["buf"]["ptr"])
+
+    def to_string(self):
+        return self.data_ptr.lazy_string(encoding="utf-8", length=self.length)
+
+    @staticmethod
+    def display_hint():
+        return "string"
+
+
+class StdOsStringProvider:
+    def __init__(self, valobj):
+        self.valobj = valobj
+        buf = self.valobj["inner"]["inner"]
+        is_windows = "Wtf8Buf" in buf.type.name
+        vec = buf[ZERO_FIELD] if is_windows else buf
+
+        self.length = int(vec["len"])
+        self.data_ptr = unwrap_unique_or_non_null(vec["buf"]["ptr"])
+
+    def to_string(self):
+        return self.data_ptr.lazy_string(encoding="utf-8", length=self.length)
+
+    def display_hint(self):
+        return "string"
+
+
+class StdStrProvider:
+    def __init__(self, valobj):
+        self.valobj = valobj
+        self.length = int(valobj["length"])
+        self.data_ptr = valobj["data_ptr"]
+
+    def to_string(self):
+        return self.data_ptr.lazy_string(encoding="utf-8", length=self.length)
+
+    @staticmethod
+    def display_hint():
+        return "string"
+
+
+class StdVecProvider:
+    def __init__(self, valobj):
+        self.valobj = valobj
+        self.length = int(valobj["len"])
+        self.data_ptr = unwrap_unique_or_non_null(valobj["buf"]["ptr"])
+
+    def to_string(self):
+        return "Vec(size={})".format(self.length)
+
+    def children(self):
+        saw_inaccessible = False
+        for index in xrange(self.length):
+            element_ptr = self.data_ptr + index
+            if saw_inaccessible:
+                return
+            try:
+                # rust-lang/rust#64343: passing deref expr to `str` allows
+                # catching exception on garbage pointer
+                str(element_ptr.dereference())
+                yield "[{}]".format(index), element_ptr.dereference()
+            except RuntimeError:
+                saw_inaccessible = True
+                yield str(index), "inaccessible"
+
+    @staticmethod
+    def display_hint():
+        return "array"
+
+
+class StdVecDequeProvider:
+    def __init__(self, valobj):
+        self.valobj = valobj
+        self.head = int(valobj["head"])
+        self.tail = int(valobj["tail"])
+        self.cap = int(valobj["buf"]["cap"])
+        self.data_ptr = unwrap_unique_or_non_null(valobj["buf"]["ptr"])
+        if self.head >= self.tail:
+            self.size = self.head - self.tail
+        else:
+            self.size = self.cap + self.head - self.tail
+
+    def to_string(self):
+        return "VecDeque(size={})".format(self.size)
+
+    def children(self):
+        for index in xrange(0, self.size):
+            value = (self.data_ptr + ((self.tail + index) % self.cap)).dereference()
+            yield "[{}]".format(index), value
+
+    @staticmethod
+    def display_hint():
+        return "array"
+
+
+class StdRcProvider:
+    def __init__(self, valobj, is_atomic=False):
+        self.valobj = valobj
+        self.is_atomic = is_atomic
+        self.ptr = unwrap_unique_or_non_null(valobj["ptr"])
+        self.value = self.ptr["data" if is_atomic else "value"]
+        self.strong = self.ptr["strong"]["v" if is_atomic else "value"]["value"]
+        self.weak = self.ptr["weak"]["v" if is_atomic else "value"]["value"] - 1
+
+    def to_string(self):
+        if self.is_atomic:
+            return "Arc(strong={}, weak={})".format(int(self.strong), int(self.weak))
+        else:
+            return "Rc(strong={}, weak={})".format(int(self.strong), int(self.weak))
+
+    def children(self):
+        yield "value", self.value
+        yield "strong", self.strong
+        yield "weak", self.weak
+
+
+class StdCellProvider:
+    def __init__(self, valobj):
+        self.value = valobj["value"]["value"]
+
+    def to_string(self):
+        return "Cell"
+
+    def children(self):
+        yield "value", self.value
+
+
+class StdRefProvider:
+    def __init__(self, valobj):
+        self.value = valobj["value"].dereference()
+        self.borrow = valobj["borrow"]["borrow"]["value"]["value"]
+
+    def to_string(self):
+        borrow = int(self.borrow)
+        if borrow >= 0:
+            return "Ref(borrow={})".format(borrow)
+        else:
+            return "Ref(borrow_mut={})".format(-borrow)
+
+    def children(self):
+        yield "*value", self.value
+        yield "borrow", self.borrow
+
+
+class StdRefCellProvider:
+    def __init__(self, valobj):
+        self.value = valobj["value"]["value"]
+        self.borrow = valobj["borrow"]["value"]["value"]
+
+    def to_string(self):
+        borrow = int(self.borrow)
+        if borrow >= 0:
+            return "RefCell(borrow={})".format(borrow)
+        else:
+            return "RefCell(borrow_mut={})".format(-borrow)
+
+    def children(self):
+        yield "value", self.value
+        yield "borrow", self.borrow
+
+
+# Yield each key (and optionally value) from a BoxedNode.
+def children_of_node(boxed_node, height, want_values):
+    def cast_to_internal(node):
+        internal_type_name = str(node.type.target()).replace("LeafNode", "InternalNode", 1)
+        internal_type = lookup_type(internal_type_name)
+        return node.cast(internal_type.pointer())
+
+    node_ptr = unwrap_unique_or_non_null(boxed_node["ptr"])
+    node_ptr = cast_to_internal(node_ptr) if height > 0 else node_ptr
+    leaf = node_ptr["data"] if height > 0 else node_ptr.dereference()
+    keys = leaf["keys"]
+    values = leaf["vals"]
+    length = int(leaf["len"])
+
+    for i in xrange(0, length + 1):
+        if height > 0:
+            child_ptr = node_ptr["edges"][i]["value"]["value"]
+            for child in children_of_node(child_ptr, height - 1, want_values):
+                yield child
+        if i < length:
+            if want_values:
+                yield keys[i]["value"]["value"], values[i]["value"]["value"]
+            else:
+                yield keys[i]["value"]["value"]
+
+
+class StdBTreeSetProvider:
+    def __init__(self, valobj):
+        self.valobj = valobj
+
+    def to_string(self):
+        return "BTreeSet(size={})".format(self.valobj["map"]["length"])
+
+    def children(self):
+        inner_map = self.valobj["map"]
+        if inner_map["length"] > 0:
+            root = inner_map["root"]
+            if "core::option::Option<" in root.type.name:
+                type_name = str(root.type.name).replace("core::option::Option<", "", 1)[:-1]
+                root = root.cast(gdb.lookup_type(type_name))
+
+            node_ptr = root["node"]
+            for i, child in enumerate(children_of_node(node_ptr, root["height"], False)):
+                yield "[{}]".format(i), child
+
+    @staticmethod
+    def display_hint():
+        return "array"
+
+
+class StdBTreeMapProvider:
+    def __init__(self, valobj):
+        self.valobj = valobj
+
+    def to_string(self):
+        return "BTreeMap(size={})".format(self.valobj["length"])
+
+    def children(self):
+        if self.valobj["length"] > 0:
+            root = self.valobj["root"]
+            if "core::option::Option<" in root.type.name:
+                type_name = str(root.type.name).replace("core::option::Option<", "", 1)[:-1]
+                root = root.cast(gdb.lookup_type(type_name))
+
+            node_ptr = root["node"]
+            for i, child in enumerate(children_of_node(node_ptr, root["height"], True)):
+                yield "key{}".format(i), child[0]
+                yield "val{}".format(i), child[1]
+
+    @staticmethod
+    def display_hint():
+        return "map"
+
+
+# BACKCOMPAT: rust 1.35
+class StdOldHashMapProvider:
+    def __init__(self, valobj, show_values=True):
+        self.valobj = valobj
+        self.show_values = show_values
+
+        self.table = self.valobj["table"]
+        self.size = int(self.table["size"])
+        self.hashes = self.table["hashes"]
+        self.hash_uint_type = self.hashes.type
+        self.hash_uint_size = self.hashes.type.sizeof
+        self.modulo = 2 ** self.hash_uint_size
+        self.data_ptr = self.hashes[ZERO_FIELD]["pointer"]
+
+        self.capacity_mask = int(self.table["capacity_mask"])
+        self.capacity = (self.capacity_mask + 1) % self.modulo
+
+        marker = self.table["marker"].type
+        self.pair_type = marker.template_argument(0)
+        self.pair_type_size = self.pair_type.sizeof
+
+        self.valid_indices = []
+        for idx in range(self.capacity):
+            data_ptr = self.data_ptr.cast(self.hash_uint_type.pointer())
+            address = data_ptr + idx
+            hash_uint = address.dereference()
+            hash_ptr = hash_uint[ZERO_FIELD]["pointer"]
+            if int(hash_ptr) != 0:
+                self.valid_indices.append(idx)
+
+    def to_string(self):
+        if self.show_values:
+            return "HashMap(size={})".format(self.size)
+        else:
+            return "HashSet(size={})".format(self.size)
+
+    def children(self):
+        start = int(self.data_ptr) & ~1
+
+        hashes = self.hash_uint_size * self.capacity
+        align = self.pair_type_size
+        len_rounded_up = (((((hashes + align) % self.modulo - 1) % self.modulo) & ~(
+                (align - 1) % self.modulo)) % self.modulo - hashes) % self.modulo
+
+        pairs_offset = hashes + len_rounded_up
+        pairs_start = gdb.Value(start + pairs_offset).cast(self.pair_type.pointer())
+
+        for index in range(self.size):
+            table_index = self.valid_indices[index]
+            idx = table_index & self.capacity_mask
+            element = (pairs_start + idx).dereference()
+            if self.show_values:
+                yield "key{}".format(index), element[ZERO_FIELD]
+                yield "val{}".format(index), element[FIRST_FIELD]
+            else:
+                yield "[{}]".format(index), element[ZERO_FIELD]
+
+    def display_hint(self):
+        return "map" if self.show_values else "array"
+
+
+class StdHashMapProvider:
+    def __init__(self, valobj, show_values=True):
+        self.valobj = valobj
+        self.show_values = show_values
+
+        table = self.valobj["base"]["table"]
+        capacity = int(table["bucket_mask"]) + 1
+        ctrl = table["ctrl"]["pointer"]
+
+        self.size = int(table["items"])
+        self.data_ptr = table["data"]["pointer"]
+        self.pair_type = self.data_ptr.dereference().type
+
+        self.valid_indices = []
+        for idx in range(capacity):
+            address = ctrl + idx
+            value = address.dereference()
+            is_presented = value & 128 == 0
+            if is_presented:
+                self.valid_indices.append(idx)
+
+    def to_string(self):
+        if self.show_values:
+            return "HashMap(size={})".format(self.size)
+        else:
+            return "HashSet(size={})".format(self.size)
+
+    def children(self):
+        pairs_start = self.data_ptr
+
+        for index in range(self.size):
+            idx = self.valid_indices[index]
+            element = (pairs_start + idx).dereference()
+            if self.show_values:
+                yield "key{}".format(index), element[ZERO_FIELD]
+                yield "val{}".format(index), element[FIRST_FIELD]
+            else:
+                yield "[{}]".format(index), element[ZERO_FIELD]
+
+    def display_hint(self):
+        return "map" if self.show_values else "array"