From e87bf57bc5d45ce40347c2190d91aa0a0a9a8da4 Mon Sep 17 00:00:00 2001
From: Nick Rolfe <nickrolfe@github.com>
Date: Thu, 29 Apr 2021 18:04:15 +0100
Subject: [PATCH] Avoid recursion in IPA construction

---
 ql/src/codeql_ruby/ast/internal/AST.qll       | 16 +++++--
 .../controlflow/graph/Cfg.expected            | 48 +++++++++----------
 2 files changed, 36 insertions(+), 28 deletions(-)

diff --git a/ql/src/codeql_ruby/ast/internal/AST.qll b/ql/src/codeql_ruby/ast/internal/AST.qll
index 8b426edacc5..a7ad94ec652 100644
--- a/ql/src/codeql_ruby/ast/internal/AST.qll
+++ b/ql/src/codeql_ruby/ast/internal/AST.qll
@@ -119,13 +119,13 @@ private module Cached {
     THashSplatArgument(Generated::HashSplatArgument g) or
     THashSplatParameter(Generated::HashSplatParameter g) or
     THereDoc(Generated::HeredocBeginning g) or
-    TIdentifierMethodCall(Generated::Identifier g) { vcall(g) and not access(g, _) } or
+    TIdentifierMethodCall(Generated::Identifier g) { isIdentifierMethodCall(g) } or
     TIf(Generated::If g) or
     TIfModifierExpr(Generated::IfModifier g) or
     TImplicitSelf(Generated::AstNode g) {
-      exists(TIdentifierMethodCall(g))
+      isIdentifierMethodCall(g)
       or
-      exists(TRegularMethodCall(g)) and
+      isRegularMethodCall(g) and
       not exists(g.(Generated::Call).getReceiver()) and
       not exists(g.(Generated::Call).getMethod().(Generated::ScopeResolution).getScope())
     } or
@@ -165,7 +165,7 @@ private module Cached {
     TRegexLiteral(Generated::Regex g) or
     TRegexMatchExpr(Generated::Binary g) { g instanceof @binary_equaltilde } or
     TRegularArrayLiteral(Generated::Array g) or
-    TRegularMethodCall(Generated::Call g) { not g.getMethod() instanceof Generated::Super } or
+    TRegularMethodCall(Generated::Call g) { isRegularMethodCall(g) } or
     TRegularStringLiteral(Generated::String g) or
     TRegularSuperCall(Generated::Call g) { g.getMethod() instanceof Generated::Super } or
     TRescueClause(Generated::Rescue g) or
@@ -230,6 +230,14 @@ private module Cached {
     TWhileModifierExpr(Generated::WhileModifier g) or
     TYieldCall(Generated::Yield g)
 
+  private predicate isIdentifierMethodCall(Generated::Identifier g) {
+    vcall(g) and not access(g, _)
+  }
+
+  private predicate isRegularMethodCall(Generated::Call g) {
+    not g.getMethod() instanceof Generated::Super
+  }
+
   /**
    * Gets the underlying TreeSitter entity for a given AST node. This does not
    * include synthesized AST nodes, because they are not the primary AST node
diff --git a/ql/test/library-tests/controlflow/graph/Cfg.expected b/ql/test/library-tests/controlflow/graph/Cfg.expected
index f16443b7326..0eef0e36873 100644
--- a/ql/test/library-tests/controlflow/graph/Cfg.expected
+++ b/ql/test/library-tests/controlflow/graph/Cfg.expected
@@ -262,18 +262,18 @@ break_ensure.rb:
 #-----| true -> [ensure: return] then ...
 #-----| false -> [ensure: return] if ...
 
-#   35| call to x
-#-----|  -> 0
-
-#   35| [ensure: return] call to x
-#-----|  -> [ensure: return] 0
-
 #   35| self
 #-----|  -> call to x
 
 #   35| [ensure: return] self
 #-----|  -> [ensure: return] call to x
 
+#   35| call to x
+#-----|  -> 0
+
+#   35| [ensure: return] call to x
+#-----|  -> [ensure: return] 0
+
 #   35| 0
 #-----|  -> ... > ...
 
@@ -429,12 +429,12 @@ case.rb:
 #    2| case ...
 #-----|  -> self
 
-#    2| call to x1
-#-----|  -> when ...
-
 #    2| self
 #-----|  -> call to x1
 
+#    2| call to x1
+#-----|  -> when ...
+
 #    3| when ...
 #-----|  -> 1
 
@@ -451,13 +451,13 @@ case.rb:
 #    3| if ...
 #-----|  -> ( ... )
 
+#    3| self
+#-----|  -> call to x2
+
 #    3| call to x2
 #-----| true -> then ...
 #-----| false -> if ...
 
-#    3| self
-#-----|  -> call to x2
-
 #    3| then ...
 #-----|  -> self
 
@@ -881,12 +881,12 @@ cfg.rb:
 #-----| true -> "hello"
 #-----| false -> "bye"
 
-#   60| call to b
-#-----|  -> 10
-
 #   60| self
 #-----|  -> call to b
 
+#   60| call to b
+#-----|  -> 10
+
 #   60| 10
 #-----|  -> ... < ...
 
@@ -1330,21 +1330,21 @@ cfg.rb:
 #  109| #{...}
 #-----|  -> self
 
-#  109| call to table
-#-----|  -> #{...}
-
 #  109| self
 #-----|  -> call to table
 
+#  109| call to table
+#-----|  -> #{...}
+
 #  110| #{...}
 #-----|  -> ( ... )
 
-#  110| call to type
-#-----|  -> #{...}
-
 #  110| self
 #-----|  -> call to type
 
+#  110| call to type
+#-----|  -> #{...}
+
 #  113| call to puts
 #-----|  -> ... if ...
 
@@ -1730,12 +1730,12 @@ cfg.rb:
 #  160| #{...}
 #-----|  -> `cat "#{...}"`
 
-#  160| call to __FILE__
-#-----|  -> #{...}
-
 #  160| self
 #-----|  -> call to __FILE__
 
+#  160| call to __FILE__
+#-----|  -> #{...}
+
 #  162| ... = ...
 #-----|  -> delimited_symbol