Fix field lookup in cyclic structs.

github · Jun 19, 2020 · 2df8c27 · 2df8c27
1 parent 7c2358c
commit 2df8c27
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diff --git a/change-notes/2020-06-19-cyclic-field-lookup.md b/change-notes/2020-06-19-cyclic-field-lookup.md
@@ -0,0 +1,2 @@
+lgtm,codescanning
+* A bug has been fixed that could cause the analysis not to terminate in the presence of cycles through embedded struct fields.
diff --git a/ql/src/semmle/go/Types.qll b/ql/src/semmle/go/Types.qll
@@ -389,6 +389,7 @@ class StructType extends @structtype, CompositeType {
   ) {
     hasOwnField(_, name, tp, isEmbedded) and depth = 0 and isMethod = false
     or
+    not hasOwnField(_, name, _, _) and
     exists(Type embedded | hasEmbeddedField(embedded, depth - 1) |
       embedded.getUnderlyingType().(StructType).hasOwnField(_, name, tp, isEmbedded) and
       isMethod = false

diff --git a/ql/test/library-tests/semmle/go/Types/Field_getPackage.expected b/ql/test/library-tests/semmle/go/Types/Field_getPackage.expected
@@ -1,3 +1,4 @@
+| cyclic.go:4:3:4:3 | s | package github.com/github/codeql-go/ql/test/library-tests/semmle/go/Types |
 | pkg1/embedding.go:19:23:19:26 | base | package github.com/github/codeql-go/ql/test/library-tests/semmle/go/Types/pkg1 |
 | pkg1/embedding.go:22:27:22:30 | base | package github.com/github/codeql-go/ql/test/library-tests/semmle/go/Types/pkg1 |
 | pkg1/embedding.go:25:24:25:31 | embedder | package github.com/github/codeql-go/ql/test/library-tests/semmle/go/Types/pkg1 |

diff --git a/ql/test/library-tests/semmle/go/Types/Field_hasQualifiedName2.expected b/ql/test/library-tests/semmle/go/Types/Field_hasQualifiedName2.expected
@@ -1,3 +1,4 @@
+| cyclic.go:4:3:4:3 | s | github.com/github/codeql-go/ql/test/library-tests/semmle/go/Types.s | s |
 | pkg1/embedding.go:19:23:19:26 | base | github.com/github/codeql-go/ql/test/library-tests/semmle/go/Types/pkg1.embedder | base |
 | pkg1/embedding.go:19:23:19:26 | base | github.com/github/codeql-go/ql/test/library-tests/semmle/go/Types/pkg1.embedder2 | base |
 | pkg1/embedding.go:19:23:19:26 | base | github.com/github/codeql-go/ql/test/library-tests/semmle/go/Types/pkg1.embedder3 | base |

diff --git a/ql/test/library-tests/semmle/go/Types/Field_hasQualifiedName3.expected b/ql/test/library-tests/semmle/go/Types/Field_hasQualifiedName3.expected
@@ -1,3 +1,4 @@
+| cyclic.go:4:3:4:3 | s | github.com/github/codeql-go/ql/test/library-tests/semmle/go/Types | s | s |
 | pkg1/embedding.go:19:23:19:26 | base | github.com/github/codeql-go/ql/test/library-tests/semmle/go/Types/pkg1 | embedder | base |
 | pkg1/embedding.go:19:23:19:26 | base | github.com/github/codeql-go/ql/test/library-tests/semmle/go/Types/pkg1 | embedder2 | base |
 | pkg1/embedding.go:19:23:19:26 | base | github.com/github/codeql-go/ql/test/library-tests/semmle/go/Types/pkg1 | embedder3 | base |

diff --git a/ql/test/library-tests/semmle/go/Types/QualifiedNames.expected b/ql/test/library-tests/semmle/go/Types/QualifiedNames.expected
@@ -19,3 +19,4 @@
 | embedder3 | github.com/github/codeql-go/ql/test/library-tests/semmle/go/Types/pkg1.embedder3 |
 | embedder4 | github.com/github/codeql-go/ql/test/library-tests/semmle/go/Types/pkg1.embedder4 |
 | ptrembedder | github.com/github/codeql-go/ql/test/library-tests/semmle/go/Types/pkg1.ptrembedder |
+| s | github.com/github/codeql-go/ql/test/library-tests/semmle/go/Types.s |
diff --git a/ql/test/library-tests/semmle/go/Types/StructFields.expected b/ql/test/library-tests/semmle/go/Types/StructFields.expected
@@ -31,3 +31,4 @@
 | embedder4 | pkg1/embedding.go:35:16:38:1 | struct type | base | base |
 | embedder4 | pkg1/embedding.go:35:16:38:1 | struct type | f | int |
 | ptrembedder | pkg1/embedding.go:22:18:22:32 | struct type | base | * base |
+| s | cyclic.go:3:8:5:1 | struct type | s | * s |
diff --git a/ql/test/library-tests/semmle/go/Types/Types.expected b/ql/test/library-tests/semmle/go/Types/Types.expected
@@ -19,3 +19,4 @@
 | embedder3 | embedder3 |
 | embedder4 | embedder4 |
 | ptrembedder | ptrembedder |
+| s | s |
diff --git a/ql/test/library-tests/semmle/go/Types/cyclic.go b/ql/test/library-tests/semmle/go/Types/cyclic.go
@@ -0,0 +1,5 @@
+package main
+
+type s struct {
+	*s
+}