Merge pull request #19792 from jketema/sve

C++: Add Arm scalable vector type QL classes

cpp/downgrades/e38346051783182ea75822e4adf8d4c6a949bc37/builtintypes.ql

@@ -0,0 +1,9 @@
+class BuiltinType extends @builtintype {
+  string toString() { none() }
+}
+
+from BuiltinType id, string name, int kind, int new_kind, int size, int sign, int alignment
+where
+  builtintypes(id, name, kind, size, sign, alignment) and
+  if kind = 63 then /* @errortype */ new_kind = 1 else new_kind = kind
+select id, name, new_kind, size, sign, alignment

cpp/downgrades/e38346051783182ea75822e4adf8d4c6a949bc37/derivedtypes.ql

@@ -0,0 +1,9 @@
+class Type extends @type {
+  string toString() { none() }
+}
+
+from Type type, string name, int kind, int new_kind, Type type_id
+where
+  derivedtypes(type, name, kind, type_id) and
+  if kind = 11 then /* @gnu_vector */ new_kind = 5 else new_kind = kind
+select type, name, new_kind, type_id

cpp/downgrades/e38346051783182ea75822e4adf8d4c6a949bc37/upgrade.properties

@@ -0,0 +1,5 @@
+description: Arm scalable vector type support
+compatibility: backwards
+builtintypes.rel: run builtintypes.qlo
+derivedtypes.rel: run derivedtypes.qlo
+tupleelements.rel: delete

cpp/ql/lib/semmle/code/cpp/Type.qll

@@ -352,7 +352,23 @@ class UnknownType extends BuiltInType {
 private predicate isArithmeticType(@builtintype type, int kind) {
   builtintypes(type, _, kind, _, _, _) and
   kind >= 4 and
-  kind != 34 // Exclude decltype(nullptr)
+  kind != 34 and // Exclude decltype(nullptr)
+  kind != 63 // Exclude __SVCount_t
+}
+
+/**
+ * The Arm scalable vector count type.
+ *
+ * In the following example, `a` is declared using the scalable vector
+ * count type:
+ * ```
+ * svcount_t a;
+ * ```
+ */
+class ScalableVectorCount extends BuiltInType {
+  ScalableVectorCount() { builtintypes(underlyingElement(this), _, 63, _, _, _) }
+
+  override string getAPrimaryQlClass() { result = "ScalableVectorCount" }
 }
 
 /**
@@ -1084,7 +1100,7 @@ class NullPointerType extends BuiltInType {
 /**
  * A C/C++ derived type.
  *
- * These are pointer and reference types, array and GNU vector types, and `const` and `volatile` types.
+ * These are pointer and reference types, array and vector types, and `const` and `volatile` types.
  * In all cases, the type is formed from a single base type.  For example:
  * ```
  * int *pi;
@@ -1648,6 +1664,30 @@ class GNUVectorType extends DerivedType {
   override predicate isDeeplyConstBelow() { this.getBaseType().isDeeplyConst() }
 }
 
+/**
+ * An Arm Scalable vector type.
+ *
+ * In the following example, `a` has a scalable vector type consisting
+ * of 8-bit signed integer elements:
+ * ```
+ * svint8_t a;
+ * ```
+ */
+class ScalableVectorType extends DerivedType {
+  ScalableVectorType() { derivedtypes(underlyingElement(this), _, 11, _) }
+
+  /**
+   * Get the number of tuple elements of this scalable vector type.
+   */
+  int getNumTupleElements() { tupleelements(underlyingElement(this), result) }
+
+  override string getAPrimaryQlClass() { result = "ScalableVectorType" }
+
+  override string explain() { result = "scalable vector of {" + this.getBaseType().explain() + "}" }
+
+  override predicate isDeeplyConstBelow() { this.getBaseType().isDeeplyConst() }
+}
+
 /**
  * A C/C++ pointer to a function. See 7.7.
  * ```

cpp/ql/lib/semmle/code/cpp/ir/internal/CppType.qll

@@ -134,6 +134,8 @@ private predicate isOpaqueType(Type type) {
   )
   or
   type instanceof PointerToMemberType // PTMs are missing size info
+  or
+  type instanceof ScalableVectorCount
 }
 
 /**

cpp/ql/lib/semmlecode.cpp.dbscheme

@@ -692,6 +692,7 @@ case @builtintype.kind of
 | 60 = @complex_float64x      // _Complex _Float64x
 | 61 = @complex_std_float128  // _Complex _Float128
 | 62 = @mfp8                  // __mfp8
+| 63 = @scalable_vector_count // __SVCount_t
 ;
 
 builtintypes(
@@ -718,6 +719,7 @@ case @derivedtype.kind of
 |  8 = @rvalue_reference // C++11
 // ... 9 type_conforming_to_protocols deprecated
 | 10 = @block
+| 11 = @scalable_vector // Arm SVE
 ;
 
 derivedtypes(
@@ -738,6 +740,11 @@ arraysizes(
     int alignment: int ref
 );
 
+tupleelements(
+    unique int id: @derivedtype ref,
+    int num_elements: int ref
+);
+
 typedefbase(
     unique int id: @usertype ref,
     int type_id: @type ref

cpp/ql/lib/upgrades/9baef67d1ffc1551429dbe1c1130815693e28218/upgrade.properties

@@ -0,0 +1,2 @@
+description: Arm scalable vector type support
+compatibility: full

cpp/ql/test/library-tests/templates/type_instantiations/types.expected

@@ -21,6 +21,7 @@
 | file://:0:0:0:0 | _Imaginary double |
 | file://:0:0:0:0 | _Imaginary float |
 | file://:0:0:0:0 | _Imaginary long double |
+| file://:0:0:0:0 | __SVCount_t |
 | file://:0:0:0:0 | __bf16 |
 | file://:0:0:0:0 | __float128 |
 | file://:0:0:0:0 | __fp16 |

cpp/ql/test/library-tests/type_sizes/type_sizes.expected

@@ -41,6 +41,7 @@
 | file://:0:0:0:0 | _Imaginary double | 8 |
 | file://:0:0:0:0 | _Imaginary float | 4 |
 | file://:0:0:0:0 | _Imaginary long double | 16 |
+| file://:0:0:0:0 | __SVCount_t | 0 |
 | file://:0:0:0:0 | __attribute((vector_size(16))) int | 16 |
 | file://:0:0:0:0 | __bf16 | 2 |
 | file://:0:0:0:0 | __float128 | 16 |

cpp/ql/test/library-tests/unspecified_type/types/unspecified_type.expected

@@ -23,6 +23,7 @@
 | file://:0:0:0:0 | _Imaginary double | _Imaginary double |
 | file://:0:0:0:0 | _Imaginary float | _Imaginary float |
 | file://:0:0:0:0 | _Imaginary long double | _Imaginary long double |
+| file://:0:0:0:0 | __SVCount_t | __SVCount_t |
 | file://:0:0:0:0 | __bf16 | __bf16 |
 | file://:0:0:0:0 | __float128 | __float128 |
 | file://:0:0:0:0 | __fp16 | __fp16 |

cpp/ql/test/library-tests/variables/variables/types.expected

@@ -22,6 +22,7 @@
 | _Imaginary double | BinaryFloatingPointType, ImaginaryNumberType |  |  |  |  |
 | _Imaginary float | BinaryFloatingPointType, ImaginaryNumberType |  |  |  |  |
 | _Imaginary long double | BinaryFloatingPointType, ImaginaryNumberType |  |  |  |  |
+| __SVCount_t | ScalableVectorCount |  |  |  |  |
 | __bf16 | BinaryFloatingPointType, RealNumberType |  |  |  |  |
 | __float128 | Float128Type |  |  |  |  |
 | __fp16 | BinaryFloatingPointType, RealNumberType |  |  |  |  |