From 5bef9f711895e14d15e93cedd8598af510008668 Mon Sep 17 00:00:00 2001
From: Nick Rolfe <nick@semmle.com>
Date: Thu, 9 Aug 2018 16:58:48 +0100
Subject: [PATCH 1/2] C++: test for resolving specialisations dependent on
 template aliases

---
 .../dependent_template_alias/test.cpp         | 37 +++++++++++++++++++
 .../dependent_template_alias/test.expected    |  2 +
 .../dependent_template_alias/test.ql          |  6 +++
 3 files changed, 45 insertions(+)
 create mode 100644 cpp/ql/test/library-tests/templates/dependent_template_alias/test.cpp
 create mode 100644 cpp/ql/test/library-tests/templates/dependent_template_alias/test.expected
 create mode 100644 cpp/ql/test/library-tests/templates/dependent_template_alias/test.ql

diff --git a/cpp/ql/test/library-tests/templates/dependent_template_alias/test.cpp b/cpp/ql/test/library-tests/templates/dependent_template_alias/test.cpp
new file mode 100644
index 00000000000..06ff13df9f6
--- /dev/null
+++ b/cpp/ql/test/library-tests/templates/dependent_template_alias/test.cpp
@@ -0,0 +1,37 @@
+
+template <typename>
+using Z = int;
+
+template <typename T, typename U = int>
+struct Thing {
+  int x;
+};
+
+template <typename T>
+struct Thing<T, Z<typename T::Undefined>> {
+  int y;
+};
+
+// Note that float::Undefined is an error, so this should match the primary
+// template, not the partial specialization.
+Thing<float> thing_float;
+
+void f() {
+  // If we incorrectly matched the partial specialization, this write to x would
+  // be an error.
+  thing_float.x = 1;
+}
+
+// Now, a type that actually does define Undefined
+struct S {
+  using Undefined = int;
+};
+
+// S::Undefined is okay, so this should match the partial specialization.
+Thing<S> thing_s;
+
+void g() {
+  // If we incorrectly matched the primary template, this write to y would be an
+  // error.
+  thing_s.y = 1;
+}
diff --git a/cpp/ql/test/library-tests/templates/dependent_template_alias/test.expected b/cpp/ql/test/library-tests/templates/dependent_template_alias/test.expected
new file mode 100644
index 00000000000..a1127fad4e3
--- /dev/null
+++ b/cpp/ql/test/library-tests/templates/dependent_template_alias/test.expected
@@ -0,0 +1,2 @@
+| test.cpp:17:14:17:24 | thing_float | test.cpp:6:8:6:12 | Thing<float, int> | test.cpp:7:7:7:7 | x |
+| test.cpp:31:10:31:16 | thing_s | test.cpp:11:8:11:41 | Thing<S, int> | test.cpp:12:7:12:7 | y |
diff --git a/cpp/ql/test/library-tests/templates/dependent_template_alias/test.ql b/cpp/ql/test/library-tests/templates/dependent_template_alias/test.ql
new file mode 100644
index 00000000000..d61a33c822c
--- /dev/null
+++ b/cpp/ql/test/library-tests/templates/dependent_template_alias/test.ql
@@ -0,0 +1,6 @@
+import cpp
+
+from Variable v, Class c
+where c = v.getType()
+  and v.getFile().getBaseName() = "test.cpp"
+select v, c, c.getAMemberVariable()

From df1f51463f384089de2b7edbbba6ce4c471779b1 Mon Sep 17 00:00:00 2001
From: Nick Rolfe <nick@semmle.com>
Date: Thu, 9 Aug 2018 17:00:13 +0100
Subject: [PATCH 2/2] C++: extend test to cover template aliases

---
 .../templates/typedefs/template_typedefs.cpp  | 20 ++++++++++++++-----
 .../typedefs/template_typedefs.expected       |  4 +++-
 2 files changed, 18 insertions(+), 6 deletions(-)

diff --git a/cpp/ql/test/library-tests/templates/typedefs/template_typedefs.cpp b/cpp/ql/test/library-tests/templates/typedefs/template_typedefs.cpp
index 6f40c242acc..a755fe1f824 100644
--- a/cpp/ql/test/library-tests/templates/typedefs/template_typedefs.cpp
+++ b/cpp/ql/test/library-tests/templates/typedefs/template_typedefs.cpp
@@ -12,10 +12,10 @@ void functions() {
   b(static_cast<my_int>(0));
   c<int>(0);
   d<my_int>(0);
-  
+
   e<int>(0);
   e<my_int>(0);
-  
+
   f<my_int>(0);
   f<int>(0);
 }
@@ -27,6 +27,7 @@ template <typename TD> struct D {};
 template <typename TE> struct E {};
 template <typename TF> struct F {};
 template <typename TG> struct G {};
+template <typename TH> struct H {};
 
 struct S { int x; };
 typedef S S_t;
@@ -34,18 +35,27 @@ typedef S S_t;
 typedef C<int> C1;
 typedef D<my_int> D1;
 
+template <typename TZ>
+using Z = TZ;
+
 void types() {
   A<int>* a;
   B<my_int>* b;
   C1 c;
   D1 d;
-  
+
   E<int> e1;
   E<my_int> e2;
-  
+  E<Z<int>> e3;
+
   F<my_int> f1;
   F<int> f2;
-  
+  F<Z<int>> f3;
+
+  H<Z<int>> h1;
+  H<my_int> h2;
+  H<int> h3;
+
   G<my_int*> g1;
   G<const my_int* const> g2;
   G<my_int**&> g3;
diff --git a/cpp/ql/test/library-tests/templates/typedefs/template_typedefs.expected b/cpp/ql/test/library-tests/templates/typedefs/template_typedefs.expected
index 23174bb3e9a..33e0f26fb74 100644
--- a/cpp/ql/test/library-tests/templates/typedefs/template_typedefs.expected
+++ b/cpp/ql/test/library-tests/templates/typedefs/template_typedefs.expected
@@ -12,12 +12,14 @@
 | F<int> | int |
 | G<..(*)(..)> | pointer to {function returning {pointer to {int}} with arguments (int)} |
 | G<TG> | TG |
-| G<__attribute((vector_size(32))) int> | {GNU 8 element vector of {int}} |
+| G<__attribute((vector_size(32))) int> | GNU 8 element vector of {int} |
 | G<const int *const> | const {pointer to {const {int}}} |
 | G<int **&> | reference to {pointer to {pointer to {int}}} |
 | G<int *> | pointer to {int} |
 | G<int S::*> | pointer to member of S with type {int} |
 | G<int(&)[3]> | reference to {array of 3 {int}} |
+| H<TH> | TH |
+| H<int> | int |
 | a | Ta |
 | a | int |
 | b | Tb |