C++: Fix provenance for sources/sinks.

Author: geoffw0

cpp/ql/lib/semmle/code/cpp/ir/dataflow/internal/DataFlowPrivate.qll

@@ -11,6 +11,7 @@ private import Node0ToString
 private import ModelUtil
 private import semmle.code.cpp.models.interfaces.FunctionInputsAndOutputs as IO
 private import semmle.code.cpp.models.interfaces.DataFlow as DF
+private import semmle.code.cpp.dataflow.ExternalFlow as External
 
 cached
 private module Cached {
@@ -1362,9 +1363,9 @@ predicate lambdaCall(DataFlowCall call, LambdaCallKind kind, Node receiver) {
 /** Extra data-flow steps needed for lambda flow analysis. */
 predicate additionalLambdaFlowStep(Node nodeFrom, Node nodeTo, boolean preservesValue) { none() }
 
-predicate knownSourceModel(Node source, string model) { none() }
+predicate knownSourceModel(Node source, string model) { External::sourceNode(source, _, model) }
 
-predicate knownSinkModel(Node sink, string model) { none() }
+predicate knownSinkModel(Node sink, string model) { External::sinkNode(sink, _, model) }
 
 /**
  * Holds if flow is allowed to pass from parameter `p` and back to itself as a

cpp/ql/test/library-tests/dataflow/external-models/flow.expected

@@ -2,21 +2,21 @@ testFailures
 failures
 edges
 | asio_streams.cpp:56:18:56:23 | [summary param] *0 in buffer | asio_streams.cpp:56:18:56:23 | [summary] to write: ReturnValue in buffer | provenance | MaD:10 |
-| asio_streams.cpp:87:34:87:44 | read_until output argument | asio_streams.cpp:91:7:91:17 | recv_buffer | provenance |  |
-| asio_streams.cpp:87:34:87:44 | read_until output argument | asio_streams.cpp:93:29:93:39 | *recv_buffer | provenance |  |
+| asio_streams.cpp:87:34:87:44 | read_until output argument | asio_streams.cpp:91:7:91:17 | recv_buffer | provenance | Src:MaD:2  |
+| asio_streams.cpp:87:34:87:44 | read_until output argument | asio_streams.cpp:93:29:93:39 | *recv_buffer | provenance | Src:MaD:2  Sink:MaD:6 |
 | asio_streams.cpp:97:37:97:44 | call to source | asio_streams.cpp:98:7:98:14 | send_str | provenance | TaintFunction |
 | asio_streams.cpp:97:37:97:44 | call to source | asio_streams.cpp:100:64:100:71 | *send_str | provenance | TaintFunction |
 | asio_streams.cpp:100:44:100:62 | call to buffer | asio_streams.cpp:100:44:100:62 | call to buffer | provenance |  |
 | asio_streams.cpp:100:44:100:62 | call to buffer | asio_streams.cpp:101:7:101:17 | send_buffer | provenance |  |
-| asio_streams.cpp:100:44:100:62 | call to buffer | asio_streams.cpp:103:29:103:39 | *send_buffer | provenance |  |
+| asio_streams.cpp:100:44:100:62 | call to buffer | asio_streams.cpp:103:29:103:39 | *send_buffer | provenance |  Sink:MaD:6 |
 | asio_streams.cpp:100:64:100:71 | *send_str | asio_streams.cpp:56:18:56:23 | [summary param] *0 in buffer | provenance |  |
 | asio_streams.cpp:100:64:100:71 | *send_str | asio_streams.cpp:100:44:100:62 | call to buffer | provenance | MaD:10 |
 | test.cpp:4:5:4:11 | [summary param] 0 in ymlStep | test.cpp:4:5:4:11 | [summary] to write: ReturnValue in ymlStep | provenance | MaD:2 |
-| test.cpp:7:10:7:18 | call to ymlSource | test.cpp:7:10:7:18 | call to ymlSource | provenance |  |
-| test.cpp:7:10:7:18 | call to ymlSource | test.cpp:11:10:11:10 | x | provenance |  |
+| test.cpp:7:10:7:18 | call to ymlSource | test.cpp:7:10:7:18 | call to ymlSource | provenance | Src:MaD:0  |
+| test.cpp:7:10:7:18 | call to ymlSource | test.cpp:11:10:11:10 | x | provenance |  Sink:MaD:1 |
 | test.cpp:7:10:7:18 | call to ymlSource | test.cpp:13:18:13:18 | x | provenance |  |
 | test.cpp:13:10:13:16 | call to ymlStep | test.cpp:13:10:13:16 | call to ymlStep | provenance |  |
-| test.cpp:13:10:13:16 | call to ymlStep | test.cpp:15:10:15:10 | y | provenance |  |
+| test.cpp:13:10:13:16 | call to ymlStep | test.cpp:15:10:15:10 | y | provenance |  Sink:MaD:1 |
 | test.cpp:13:18:13:18 | x | test.cpp:4:5:4:11 | [summary param] 0 in ymlStep | provenance |  |
 | test.cpp:13:18:13:18 | x | test.cpp:13:10:13:16 | call to ymlStep | provenance | MaD:2 |
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