Ruby: Small change to isArrayExpr

Author: hmac

ruby/ql/lib/codeql/ruby/ast/internal/Constant.qll

@@ -552,5 +552,10 @@ predicate isArrayExpr(Expr e, ArrayLiteralCfgNode arr) {
   // We map from A to a via ConstantReadAccess::getValue, yielding the Expr a.
   // To get to [...] we need to go via getSource(ExprCfgNode e), so we find a
   // CFG node for a and call `isArrayConstant`.
-  isArrayConstant(e.getAControlFlowNode(), arr)
+  //
+  // The use of `forex` is intended to ensure that a is an array constant in all
+  // control flow paths.
+  // Note(hmac): I don't think this is necessary, as `getSource` will not return
+  // results if the source is a phi node.
+  forex(ExprCfgNode n | n = e.getAControlFlowNode() | isArrayConstant(n, arr))
 }

ruby/ql/test/library-tests/ast/constants/constants.expected

@@ -78,23 +78,41 @@ getConst
 | constants.rb:54:3:58:5 | ModuleA::ModuleB::ClassB | FOURTY_ONE | constants.rb:48:18:48:19 | 41 |
 | constants.rb:62:3:64:5 | Mod1::Mod3 | FOURTY_FIVE | constants.rb:63:19:63:20 | 45 |
 | constants.rb:70:3:72:5 | Mod1::Mod3::Mod5 | FOURTY_SIX | constants.rb:71:18:71:19 | 46 |
+| file://:0:0:0:0 | Object | A | constants.rb:79:5:79:13 | [...] |
+| file://:0:0:0:0 | Object | B | constants.rb:80:5:80:5 | a |
+| file://:0:0:0:0 | Object | C | constants.rb:81:5:81:5 | A |
 | file://:0:0:0:0 | Object | GREETING | constants.rb:17:12:17:64 | ... + ... |
 lookupConst
 | constants.rb:1:1:15:3 | ModuleA | CONST_B | constants.rb:6:15:6:23 | "const_b" |
 | constants.rb:1:1:15:3 | ModuleA | FOURTY_FOUR | constants.rb:53:17:53:29 | "fourty-four" |
+| constants.rb:2:5:4:7 | ModuleA::ClassA | A | constants.rb:79:5:79:13 | [...] |
+| constants.rb:2:5:4:7 | ModuleA::ClassA | B | constants.rb:80:5:80:5 | a |
+| constants.rb:2:5:4:7 | ModuleA::ClassA | C | constants.rb:81:5:81:5 | A |
 | constants.rb:2:5:4:7 | ModuleA::ClassA | CONST_A | constants.rb:3:19:3:27 | "const_a" |
 | constants.rb:2:5:4:7 | ModuleA::ClassA | GREETING | constants.rb:17:12:17:64 | ... + ... |
 | constants.rb:8:5:14:7 | ModuleA::ModuleB | MAX_SIZE | constants.rb:39:30:39:33 | 1024 |
+| constants.rb:12:9:13:11 | ModuleA::ModuleB::ClassC | A | constants.rb:79:5:79:13 | [...] |
+| constants.rb:12:9:13:11 | ModuleA::ModuleB::ClassC | B | constants.rb:80:5:80:5 | a |
+| constants.rb:12:9:13:11 | ModuleA::ModuleB::ClassC | C | constants.rb:81:5:81:5 | A |
 | constants.rb:12:9:13:11 | ModuleA::ModuleB::ClassC | GREETING | constants.rb:17:12:17:64 | ... + ... |
+| constants.rb:31:1:33:3 | ModuleA::ClassD | A | constants.rb:79:5:79:13 | [...] |
+| constants.rb:31:1:33:3 | ModuleA::ClassD | B | constants.rb:80:5:80:5 | a |
+| constants.rb:31:1:33:3 | ModuleA::ClassD | C | constants.rb:81:5:81:5 | A |
 | constants.rb:31:1:33:3 | ModuleA::ClassD | CONST_A | constants.rb:3:19:3:27 | "const_a" |
 | constants.rb:31:1:33:3 | ModuleA::ClassD | FOURTY_TWO | constants.rb:32:16:32:17 | 42 |
 | constants.rb:31:1:33:3 | ModuleA::ClassD | GREETING | constants.rb:17:12:17:64 | ... + ... |
 | constants.rb:35:1:37:3 | ModuleA::ModuleC | FOURTY_THREE | constants.rb:36:18:36:19 | 43 |
+| constants.rb:54:3:58:5 | ModuleA::ModuleB::ClassB | A | constants.rb:79:5:79:13 | [...] |
+| constants.rb:54:3:58:5 | ModuleA::ModuleB::ClassB | B | constants.rb:80:5:80:5 | a |
+| constants.rb:54:3:58:5 | ModuleA::ModuleB::ClassB | C | constants.rb:81:5:81:5 | A |
 | constants.rb:54:3:58:5 | ModuleA::ModuleB::ClassB | FOURTY_FOUR | constants.rb:56:19:56:20 | 44 |
 | constants.rb:54:3:58:5 | ModuleA::ModuleB::ClassB | FOURTY_ONE | constants.rb:48:18:48:19 | 41 |
 | constants.rb:54:3:58:5 | ModuleA::ModuleB::ClassB | GREETING | constants.rb:17:12:17:64 | ... + ... |
 | constants.rb:62:3:64:5 | Mod1::Mod3 | FOURTY_FIVE | constants.rb:63:19:63:20 | 45 |
 | constants.rb:70:3:72:5 | Mod1::Mod3::Mod5 | FOURTY_SIX | constants.rb:71:18:71:19 | 46 |
+| file://:0:0:0:0 | Object | A | constants.rb:79:5:79:13 | [...] |
+| file://:0:0:0:0 | Object | B | constants.rb:80:5:80:5 | a |
+| file://:0:0:0:0 | Object | C | constants.rb:81:5:81:5 | A |
 | file://:0:0:0:0 | Object | GREETING | constants.rb:17:12:17:64 | ... + ... |
 constantValue
 | constants.rb:17:22:17:45 | CONST_A | constants.rb:3:19:3:27 | "const_a" |
@@ -108,6 +126,8 @@ constantValue
 | constants.rb:57:21:57:31 | FOURTY_FOUR | constants.rb:53:17:53:29 | "fourty-four" |
 | constants.rb:57:21:57:31 | FOURTY_FOUR | constants.rb:56:19:56:20 | 44 |
 | constants.rb:65:19:65:35 | FOURTY_FIVE | constants.rb:63:19:63:20 | 45 |
+| constants.rb:81:5:81:5 | A | constants.rb:79:5:79:13 | [...] |
+| constants.rb:82:5:82:5 | B | constants.rb:80:5:80:5 | a |
 constantWriteAccessQualifiedName
 | constants.rb:1:1:15:3 | ModuleA | ModuleA |
 | constants.rb:2:5:4:7 | ClassA | ModuleA::ClassA |
@@ -149,3 +169,5 @@ arrayConstant
 | constants.rb:79:5:79:13 | call to [] | constants.rb:79:5:79:13 | call to [] |
 | constants.rb:80:5:80:5 | a | constants.rb:78:5:78:13 | call to [] |
 | constants.rb:81:5:81:5 | A | constants.rb:79:5:79:13 | call to [] |
+| constants.rb:82:5:82:5 | B | constants.rb:78:5:78:13 | call to [] |
+| constants.rb:85:7:85:7 | b | constants.rb:78:5:78:13 | call to [] |

ruby/ql/test/library-tests/ast/constants/constants.rb

@@ -79,4 +79,9 @@ module Mod3::Mod5
 A = [1, 2, 3]
 B = a
 C = A
-b = B
+b = B
+
+if condition
+  c = b
+end
+c # not recognised