Import vhdl_langserver from ghdl-language-server

1 files changed, 92 insertions, 0 deletions

diff --git a/python/vhdl_langserver/references.py b/python/vhdl_langserver/references.py
new file mode 100644
index 000000000..fa1033c04
--- /dev/null
+++ b/python/vhdl_langserver/references.py
@@ -0,0 +1,92 @@
+import logging
+import libghdl.thin.vhdl.nodes as nodes
+import libghdl.thin.vhdl.nodes_meta as nodes_meta
+import libghdl.thin.vhdl.pyutils as pyutils
+import libghdl.thin.name_table as name_table
+
+log = logging.getLogger(__name__)
+
+def find_def_chain(first, loc):
+    n1 = first
+    while n1 != nodes.Null_Iir:
+        res = find_def(n1, loc)
+        if res is not None:
+            return res
+        n1 = nodes.Get_Chain(n1)
+    return None
+
+
+def find_def(n, loc):
+    "Return the node at location :param loc:, or None if not under :param n:"
+    if n == nodes.Null_Iir:
+        return None
+    k = nodes.Get_Kind(n)
+    if k in [nodes.Iir_Kind.Simple_Name,
+             nodes.Iir_Kind.Character_Literal,
+             nodes.Iir_Kind.Operator_Symbol,
+             nodes.Iir_Kind.Selected_Name,
+             nodes.Iir_Kind.Attribute_Name,
+             nodes.Iir_Kind.Selected_Element]:
+        n_loc = nodes.Get_Location(n)
+        if loc >= n_loc:
+            ident = nodes.Get_Identifier(n)
+            id_len = name_table.Get_Name_Length(ident)
+            if loc < n_loc + id_len:
+                return n
+        if k == nodes.Iir_Kind.Simple_Name:
+            return None
+    elif k == nodes.Iir_Kind.Design_File:
+        return find_def_chain(nodes.Get_First_Design_Unit(n), loc)
+    elif k == nodes.Iir_Kind.Design_Unit:
+        #if loc > elocations.Get_End_Location(unit):
+        #    return None
+        res = find_def_chain(nodes.Get_Context_Items(n), loc)
+        if res is not None:
+            return res
+        unit = nodes.Get_Library_Unit(n)
+        return find_def(unit, loc)
+
+    # This is *much* faster than using node_iter!
+    for f in pyutils.fields_iter(n):
+        typ = nodes_meta.get_field_type(f)
+        if typ == nodes_meta.types.Iir:
+            attr = nodes_meta.get_field_attribute(f)
+            if attr == nodes_meta.Attr.ANone:
+                res = find_def(nodes_meta.Get_Iir(n, f), loc)
+                if res is not None:
+                    return res
+            elif attr == nodes_meta.Attr.Chain:
+                res = find_def_chain(nodes_meta.Get_Iir(n, f), loc)
+                if res is not None:
+                    return res
+            elif attr == nodes_meta.Attr.Maybe_Ref:
+                if not nodes.Get_Is_Ref(n, f):
+                    res = find_def(nodes_meta.Get_Iir(n, f), loc)
+                    if res is not None:
+                        return res
+        elif typ == nodes_meta.types.Iir_List:
+            attr = nodes_meta.get_field_attribute(f)
+            if attr == nodes_meta.Attr.ANone:
+                for n1 in pyutils.list_iter(nodes_meta.Get_Iir_List(n, f)):
+                    res = find_def(n1, loc)
+                    if res is not None:
+                        return res
+        elif typ == nodes_meta.types.Iir_Flist:
+            attr = nodes_meta.get_field_attribute(f)
+            if attr == nodes_meta.Attr.ANone:
+                for n1 in pyutils.flist_iter(nodes_meta.Get_Iir_Flist(n, f)):
+                    res = find_def(n1, loc)
+                    if res is not None:
+                        return res
+
+    return None
+
+def goto_definition(n, loc):
+    "Return the declaration (as a node) under :param loc: or None"
+    ref = find_def(n, loc)
+    log.debug("for loc %u found node %s", loc, ref)
+    if ref is None:
+        return None
+    log.debug("for loc %u id=%s", loc, name_table.Get_Name_Ptr(nodes.Get_Identifier(ref)).decode('utf-8'))
+    ent = nodes.Get_Named_Entity(ref)
+    return None if ent == nodes.Null_Iir else ent