Support searching for raw text patterns

Summary: We can use this to match functions of a specific name, or to match specific operators (such as by matching binary expressions that have their operator's raw text be `+`).

Reviewed By: pittsw

Differential Revision: D7760889

fbshipit-source-id: d7248c1f0a0f16def365a87ab9ff6bca58bd04fb

hphp/hack/src/server/cstSearchService.ml

@@ -85,6 +85,14 @@ type pattern =
       pattern: pattern;
     }
 
+  (**
+   * Matches a given node if its raw text is exactly the specified string. The
+   * "raw" text doesn't include trivia.
+   *)
+  | RawTextPattern of {
+      raw_text: string;
+    }
+
 type matched_node = {
   match_name: match_name;
   node: Syntax.t;
@@ -168,6 +176,11 @@ let rec search_node
   | DescendantPattern { pattern } ->
     search_descendants ~env ~pattern ~node
 
+  | RawTextPattern { raw_text } ->
+    if Syntax.text node = raw_text
+    then (env, empty_result)
+    else (env, None)
+
 (* TODO: this will likely have to become more intelligent *)
 and search_descendants
     ~(env: env)
@@ -213,6 +226,8 @@ let compile_pattern (json: Hh_json.json): (pattern, string) Core_result.t =
       compile_match_pattern ~json ~keytrace
     | "descendant_pattern" ->
       compile_descendant_pattern ~json ~keytrace
+    | "raw_text_pattern" ->
+      compile_raw_text_pattern ~json ~keytrace
     | pattern_type ->
       error_at_keytrace ~keytrace:pattern_type_keytrace
         (Printf.sprintf "Unknown pattern type '%s'" pattern_type)
@@ -293,6 +308,13 @@ let compile_pattern (json: Hh_json.json): (pattern, string) Core_result.t =
       pattern;
     }
 
+  and compile_raw_text_pattern ~json ~keytrace =
+    get_string "raw_text" (json, keytrace)
+    >>| fun (raw_text, _raw_text_keytrace) ->
+    RawTextPattern {
+      raw_text;
+    }
+
   in
   compile_pattern ~json ~keytrace:[]
 

hphp/hack/test/cst_search/raw_text_match.flags

@@ -0,0 +1 @@
+--cst-search basic_class.php

hphp/hack/test/cst_search/raw_text_match.json

@@ -0,0 +1,19 @@
+{
+  "pattern_type": "descendant_pattern",
+  "pattern": {
+    "pattern_type": "node_pattern",
+    "kind": "methodish_declaration",
+    "children": {
+      "methodish_function_decl_header": {
+        "pattern_type": "node_pattern",
+        "kind": "function_declaration_header",
+        "children": {
+          "function_name": {
+            "pattern_type": "raw_text_pattern",
+            "raw_text": "bar"
+          }
+        }
+      }
+    }
+  }
+}

hphp/hack/test/cst_search/raw_text_match.json.exp

@@ -0,0 +1 @@
+{"matched_nodes":[]}

hphp/hack/test/cst_search/raw_text_no_match.flags

@@ -0,0 +1 @@
+--cst-search basic_class.php

hphp/hack/test/cst_search/raw_text_no_match.json

@@ -0,0 +1,19 @@
+{
+  "pattern_type": "descendant_pattern",
+  "pattern": {
+    "pattern_type": "node_pattern",
+    "kind": "methodish_declaration",
+    "children": {
+      "methodish_function_decl_header": {
+        "pattern_type": "node_pattern",
+        "kind": "function_declaration_header",
+        "children": {
+          "function_name": {
+            "pattern_type": "raw_text_pattern",
+            "raw_text": "foo"
+          }
+        }
+      }
+    }
+  }
+}

hphp/hack/test/cst_search/raw_text_no_match.json.exp

@@ -0,0 +1 @@
+null