From 14993e89e2d508760450c40eac6516ee9a1bfbfa Mon Sep 17 00:00:00 2001
From: whitequark <whitequark@whitequark.org>
Date: Tue, 24 Nov 2015 17:44:58 +0800
Subject: [PATCH] compiler.embedding: show suggestions for mistyped host object
 attributes.

---
 artiq/compiler/embedding.py                   | 47 ++++++++++++-------
 lit-test/test/embedding/device_db.pyon        |  6 +++
 .../embedding/error_attr_absent_suggest.py    | 16 +++++++
 .../embedding/error_name_absent_suggest.py    | 10 ++++
 4 files changed, 63 insertions(+), 16 deletions(-)
 create mode 100644 lit-test/test/embedding/error_attr_absent_suggest.py
 create mode 100644 lit-test/test/embedding/error_name_absent_suggest.py

diff --git a/artiq/compiler/embedding.py b/artiq/compiler/embedding.py
index 637153dc0..309aeb598 100644
--- a/artiq/compiler/embedding.py
+++ b/artiq/compiler/embedding.py
@@ -207,6 +207,13 @@ class ASTSynthesizer:
         return ast.Assign(targets=[attr_node], value=value_node,
                           op_locs=[equals_loc], loc=name_loc.join(value_node.loc))
 
+
+def suggest_identifier(id, names):
+    sorted_names = sorted(names, key=lambda other: jaro_winkler(id, other), reverse=True)
+    if len(sorted_names) > 0:
+        if jaro_winkler(id, sorted_names[0]) > 0.0:
+            return sorted_names[0]
+
 class StitchingASTTypedRewriter(ASTTypedRewriter):
     def __init__(self, engine, prelude, globals, host_environment, quote):
         super().__init__(engine, prelude)
@@ -227,7 +234,12 @@ class StitchingASTTypedRewriter(ASTTypedRewriter):
             if node.id in self.host_environment:
                 return self.quote(self.host_environment[node.id], node.loc)
             else:
-                suggestion = self._most_similar_ident(node.id)
+                names = set()
+                names.update(self.host_environment.keys())
+                for typing_env in reversed(self.env_stack):
+                    names.update(typing_env.keys())
+
+                suggestion = suggest_identifier(node.id, names)
                 if suggestion is not None:
                     diag = diagnostic.Diagnostic("fatal",
                         "name '{name}' is not bound to anything; did you mean '{suggestion}'?",
@@ -240,17 +252,6 @@ class StitchingASTTypedRewriter(ASTTypedRewriter):
                         node.loc)
                     self.engine.process(diag)
 
-    def _most_similar_ident(self, id):
-        names = set()
-        names.update(self.host_environment.keys())
-        for typing_env in reversed(self.env_stack):
-            names.update(typing_env.keys())
-
-        sorted_names = sorted(names, key=lambda other: jaro_winkler(id, other), reverse=True)
-        if len(sorted_names) > 0:
-            if jaro_winkler(id, sorted_names[0]) > 0.0:
-                return sorted_names[0]
-
 class StitchingInferencer(Inferencer):
     def __init__(self, engine, value_map, quote):
         super().__init__(engine)
@@ -277,13 +278,27 @@ class StitchingInferencer(Inferencer):
         # which would be the optimal solution.
         for object_value, object_loc in self.value_map[object_type]:
             if not hasattr(object_value, node.attr):
+                if node.attr.startswith('_'):
+                    names = set(filter(lambda name: not name.startswith('_'),
+                                       dir(object_value)))
+                else:
+                    names = set(dir(object_value))
+                suggestion = suggest_identifier(node.attr, names)
+
                 note = diagnostic.Diagnostic("note",
                     "attribute accessed here", {},
                     node.loc)
-                diag = diagnostic.Diagnostic("error",
-                    "host object does not have an attribute '{attr}'",
-                    {"attr": node.attr},
-                    object_loc, notes=[note])
+                if suggestion is not None:
+                    diag = diagnostic.Diagnostic("error",
+                        "host object does not have an attribute '{attr}'; "
+                        "did you mean '{suggestion}'?",
+                        {"attr": node.attr, "suggestion": suggestion},
+                        object_loc, notes=[note])
+                else:
+                    diag = diagnostic.Diagnostic("error",
+                        "host object does not have an attribute '{attr}'",
+                        {"attr": node.attr},
+                        object_loc, notes=[note])
                 self.engine.process(diag)
                 return
 
diff --git a/lit-test/test/embedding/device_db.pyon b/lit-test/test/embedding/device_db.pyon
index 7c1bb62ef..02d4e06bb 100644
--- a/lit-test/test/embedding/device_db.pyon
+++ b/lit-test/test/embedding/device_db.pyon
@@ -4,5 +4,11 @@
         "module": "artiq.coredevice.comm_dummy",
         "class": "Comm",
         "arguments": {}
+    },
+    "core": {
+        "type": "local",
+        "module": "artiq.coredevice.core",
+        "class": "Core",
+        "arguments": {"ref_period": 1e-9}
     }
 }
diff --git a/lit-test/test/embedding/error_attr_absent_suggest.py b/lit-test/test/embedding/error_attr_absent_suggest.py
new file mode 100644
index 000000000..f6b90a338
--- /dev/null
+++ b/lit-test/test/embedding/error_attr_absent_suggest.py
@@ -0,0 +1,16 @@
+# RUN: %python -m artiq.compiler.testbench.embedding %s >%t
+# RUN: OutputCheck %s --file-to-check=%t
+
+from artiq.language.core import *
+from artiq.language.types import *
+
+class c:
+    xx = 1
+
+@kernel
+def entrypoint():
+    # CHECK-L: <synthesized>:1: error: host object does not have an attribute 'x'; did you mean 'xx'?
+    # CHECK-L: ${LINE:+1}: note: expanded from here
+    a = c
+    # CHECK-L: ${LINE:+1}: note: attribute accessed here
+    a.x
diff --git a/lit-test/test/embedding/error_name_absent_suggest.py b/lit-test/test/embedding/error_name_absent_suggest.py
new file mode 100644
index 000000000..76b6af313
--- /dev/null
+++ b/lit-test/test/embedding/error_name_absent_suggest.py
@@ -0,0 +1,10 @@
+# RUN: %python -m artiq.compiler.testbench.embedding %s >%t
+# RUN: OutputCheck %s --file-to-check=%t
+
+from artiq.language.core import *
+from artiq.language.types import *
+
+@kernel
+def entrypoint():
+    # CHECK-L: ${LINE:+1}: fatal: name 'prnt' is not bound to anything; did you mean 'print'?
+    prnt()