C++: Add inline namespace support

change-notes/1.20/analysis-cpp.md

@@ -18,3 +18,5 @@
 | Resource not released in destructor (`cpp/resource-not-released-in-destructor`) | Fewer false positive results | Fix false positives where a resource is released via a virtual method call. |
 
 ## Changes to QL libraries
+
+There is a new `Namespace.isInline()` predicate, which holds if the namespace was declared as `inline namespace`.

cpp/ql/src/semmle/code/cpp/Namespace.qll

@@ -66,6 +66,11 @@ class Namespace extends NameQualifyingElement, @namespace {
   /** Gets a child namespace of this namespace. */
   Namespace getAChildNamespace() { namespacembrs(underlyingElement(this),unresolveElement(result)) }
 
+  /** Holds if the namespace is inline. */
+  predicate isInline() {
+    namespace_inline(underlyingElement(this))
+  }
+
   /** Holds if this namespace may be from source. */
   override predicate fromSource() { this.getADeclaration().fromSource() }
 

cpp/ql/src/semmlecode.cpp.dbscheme

@@ -1039,6 +1039,10 @@ namespaces(
     string name: string ref
 );
 
+namespace_inline(
+    unique int id: @namespace ref
+);
+
 namespacembrs(
     int parentid: @namespace ref,
     unique int memberid: @namespacembr ref