From d717734820c0a764a7fcfbb636bbea72fd019c73 Mon Sep 17 00:00:00 2001
From: Owen Mansel-Chan <owen-mc@github.com>
Date: Fri, 3 Dec 2021 06:02:05 -0500
Subject: [PATCH] Do not allow "Argument" on its own

---
 ql/lib/semmle/go/dataflow/ExternalFlow.qll           |  3 +--
 .../semmle/go/dataflow/internal/FlowSummaryImpl.qll  | 12 +++---------
 .../semmle/go/dataflow/ExternalFlow/srcs.expected    |  1 -
 .../semmle/go/dataflow/ExternalFlow/srcs.ql          |  2 +-
 4 files changed, 5 insertions(+), 13 deletions(-)

diff --git a/ql/lib/semmle/go/dataflow/ExternalFlow.qll b/ql/lib/semmle/go/dataflow/ExternalFlow.qll
index 48872777e82..24dd105f453 100644
--- a/ql/lib/semmle/go/dataflow/ExternalFlow.qll
+++ b/ql/lib/semmle/go/dataflow/ExternalFlow.qll
@@ -293,7 +293,6 @@ module CsvValidation {
       (
         invalidSpecComponent(input, part) and
         not part = "" and
-        not (part = "Argument" and pred = "sink") and
         not parseArg(part, _)
         or
         specSplit(input, part, _) and
@@ -309,7 +308,7 @@ module CsvValidation {
     |
       invalidSpecComponent(output, part) and
       not part = "" and
-      not (part = ["Argument", "Parameter"] and pred = "source") and
+      not (part = "Parameter" and pred = "source") and
       msg = "Unrecognized output specification \"" + part + "\" in " + pred + " model."
     )
     or
diff --git a/ql/lib/semmle/go/dataflow/internal/FlowSummaryImpl.qll b/ql/lib/semmle/go/dataflow/internal/FlowSummaryImpl.qll
index bb6ab8867ea..e655419f454 100644
--- a/ql/lib/semmle/go/dataflow/internal/FlowSummaryImpl.qll
+++ b/ql/lib/semmle/go/dataflow/internal/FlowSummaryImpl.qll
@@ -721,13 +721,9 @@ module Private {
       not exists(interpretComponent(c))
     }
 
-    private predicate inputNeedsReference(string c) {
-      c = "Argument" or
-      parseArg(c, _)
-    }
+    private predicate inputNeedsReference(string c) { parseArg(c, _) }
 
     private predicate outputNeedsReference(string c) {
-      c = "Argument" or
       parseArg(c, _) or
       c = "ReturnValue" or
       parseReturn(c, _)
@@ -763,7 +759,7 @@ module Private {
         exists(int pos |
           node.asNode().(PostUpdateNode).getPreUpdateNode().(ArgNode).argumentOf(mid.asCall(), pos)
         |
-          c = "Argument" or parseArg(c, pos)
+          parseArg(c, pos)
         )
         or
         exists(int pos | node.asNode().(ParamNode).isParameterOf(mid.asCallable(), pos) |
@@ -791,9 +787,7 @@ module Private {
         interpretInput(input, idx + 1, ref, mid) and
         specSplit(input, c, idx)
       |
-        exists(int pos | node.asNode().(ArgNode).argumentOf(mid.asCall(), pos) |
-          c = "Argument" or parseArg(c, pos)
-        )
+        exists(int pos | node.asNode().(ArgNode).argumentOf(mid.asCall(), pos) | parseArg(c, pos))
         or
         exists(int pos, ReturnNodeExt ret |
           (
diff --git a/ql/test/library-tests/semmle/go/dataflow/ExternalFlow/srcs.expected b/ql/test/library-tests/semmle/go/dataflow/ExternalFlow/srcs.expected
index 1bcc0daddac..a91ada0e749 100644
--- a/ql/test/library-tests/semmle/go/dataflow/ExternalFlow/srcs.expected
+++ b/ql/test/library-tests/semmle/go/dataflow/ExternalFlow/srcs.expected
@@ -1,7 +1,6 @@
 invalidModelRow
 #select
 | test.go:12:6:12:8 | definition of arg | qltest-arg |
-| test.go:37:6:37:6 | definition of a | qltest-arg |
 | test.go:40:8:40:15 | call to Src1 | qltest |
 | test.go:41:8:41:15 | call to Src2 | qltest |
 | test.go:41:8:41:15 | call to Src2 | qltest-w-subtypes |
diff --git a/ql/test/library-tests/semmle/go/dataflow/ExternalFlow/srcs.ql b/ql/test/library-tests/semmle/go/dataflow/ExternalFlow/srcs.ql
index 72e728271f9..4554effe729 100644
--- a/ql/test/library-tests/semmle/go/dataflow/ExternalFlow/srcs.ql
+++ b/ql/test/library-tests/semmle/go/dataflow/ExternalFlow/srcs.ql
@@ -11,7 +11,7 @@ class SourceModelTest extends SourceModelCsv {
         "github.com/nonexistent/test;A;false;Src1;;;ReturnValue;qltest",
         "github.com/nonexistent/test;A;false;Src2;;;ReturnValue;qltest",
         "github.com/nonexistent/test;A;true;Src2;;;ReturnValue;qltest-w-subtypes",
-        "github.com/nonexistent/test;A;false;SrcArg;;;Argument;qltest-arg",
+        "github.com/nonexistent/test;A;false;SrcArg;;;Argument[0];qltest-arg",
         "github.com/nonexistent/test;A;false;Src3;;;ReturnValue[0];qltest",
         "github.com/nonexistent/test;A;true;Src3;;;ReturnValue[1];qltest-w-subtypes"
       ]