Merge branch 'main' into django-rest-framework

Author: RasmusWL

cpp/change-notes/2021-11-01-isFromSystemMacroDefinition.md

@@ -0,0 +1,4 @@
+lgtm,codescanning
+* The QL library `semmle.code.cpp.commons.Exclusions` now contains a predicate
+  `isFromSystemMacroDefinition` for identifying code that originates from a
+  macro outside the project being analyzed.

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

@@ -237,7 +237,7 @@ class Class extends UserType {
     exists(ClassDerivation cd | cd.getBaseClass() = base |
       result =
         this.accessOfBaseMemberMulti(cd.getDerivedClass(),
-          fieldInBase.accessInDirectDerived(cd.getASpecifier().(AccessSpecifier)))
+          fieldInBase.accessInDirectDerived(cd.getASpecifier()))
     )
   }
 
@@ -261,8 +261,7 @@ class Class extends UserType {
    * includes the case of `base` = `this`.
    */
   AccessSpecifier accessOfBaseMember(Declaration member) {
-    result =
-      this.accessOfBaseMember(member.getDeclaringType(), member.getASpecifier().(AccessSpecifier))
+    result = this.accessOfBaseMember(member.getDeclaringType(), member.getASpecifier())
   }
 
   /**
@@ -319,7 +318,7 @@ class Class extends UserType {
     exists(Type t | t = this.getAFieldSubobjectType().getUnspecifiedType() |
       // Note: Overload resolution is not implemented -- all copy
       // constructors are considered equal.
-      this.cannotAccessCopyConstructorOnAny(t.(Class))
+      this.cannotAccessCopyConstructorOnAny(t)
     )
     or
     // - T has direct or virtual base class that cannot be copied (has deleted,
@@ -392,7 +391,7 @@ class Class extends UserType {
     exists(Type t | t = this.getAFieldSubobjectType().getUnspecifiedType() |
       // Note: Overload resolution is not implemented -- all copy assignment
       // operators are considered equal.
-      this.cannotAccessCopyAssignmentOperatorOnAny(t.(Class))
+      this.cannotAccessCopyAssignmentOperatorOnAny(t)
     )
     or
     exists(Class c | c = this.getADirectOrVirtualBase() |

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

@@ -490,8 +490,7 @@ class AccessHolder extends Declaration, TAccessHolder {
    */
   pragma[inline]
   predicate canAccessMember(Declaration member, Class derived) {
-    this.couldAccessMember(member.getDeclaringType(), member.getASpecifier().(AccessSpecifier),
-      derived)
+    this.couldAccessMember(member.getDeclaringType(), member.getASpecifier(), derived)
   }
 
   /**

cpp/ql/lib/semmle/code/cpp/commons/Dependency.qll

@@ -275,17 +275,17 @@ private predicate dependsOnDeclarationEntry(Element src, DeclarationEntry dest)
     dependsOnTransitive(src, mid) and
     not mid instanceof Type and
     not mid instanceof EnumConstant and
-    getDeclarationEntries(mid, dest.(DeclarationEntry)) and
+    getDeclarationEntries(mid, dest) and
     not dest instanceof TypeDeclarationEntry
   )
   or
   exists(Declaration mid |
     // dependency from a Type / Variable / Function use -> any (visible) definition
     dependsOnTransitive(src, mid) and
     not mid instanceof EnumConstant and
-    getDeclarationEntries(mid, dest.(DeclarationEntry)) and
+    getDeclarationEntries(mid, dest) and
     // must be definition
-    dest.(DeclarationEntry).isDefinition()
+    dest.isDefinition()
   )
 }
 
@@ -307,7 +307,7 @@ private predicate dependsOnFull(DependsSource src, Symbol dest, int category) {
     // dependency from a Variable / Function use -> non-visible definition (link time)
     dependsOnTransitive(src, mid) and
     not mid instanceof EnumConstant and
-    getDeclarationEntries(mid, dest.(DeclarationEntry)) and
+    getDeclarationEntries(mid, dest) and
     not dest instanceof TypeDeclarationEntry and
     // must be definition
     dest.(DeclarationEntry).isDefinition() and

cpp/ql/lib/semmle/code/cpp/commons/Exclusions.qll

@@ -81,8 +81,8 @@ predicate functionContainsPreprocCode(Function f) {
 }
 
 /**
- * Holds if `e` is completely or partially from a macro definition, as opposed
- * to being passed in as an argument.
+ * Holds if `e` is completely or partially from a macro invocation `mi`, as
+ * opposed to being passed in as an argument.
  *
  * In the following example, the call to `f` is from a macro definition,
  * while `y`, `+`, `1`, and `;` are not. This assumes that no identifier apart
@@ -93,8 +93,8 @@ predicate functionContainsPreprocCode(Function f) {
  *   M(y + 1);
  * ```
  */
-predicate isFromMacroDefinition(Element e) {
-  exists(MacroInvocation mi, Location eLocation, Location miLocation |
+private predicate isFromMacroInvocation(Element e, MacroInvocation mi) {
+  exists(Location eLocation, Location miLocation |
     mi.getAnExpandedElement() = e and
     eLocation = e.getLocation() and
     miLocation = mi.getLocation() and
@@ -109,3 +109,36 @@ predicate isFromMacroDefinition(Element e) {
     eLocation.getEndColumn() >= miLocation.getEndColumn()
   )
 }
+
+/**
+ * Holds if `e` is completely or partially from a macro definition, as opposed
+ * to being passed in as an argument.
+ *
+ * In the following example, the call to `f` is from a macro definition,
+ * while `y`, `+`, `1`, and `;` are not. This assumes that no identifier apart
+ * from `M` refers to a macro.
+ * ```
+ * #define M(x) f(x)
+ * ...
+ *   M(y + 1);
+ * ```
+ */
+predicate isFromMacroDefinition(Element e) { isFromMacroInvocation(e, _) }
+
+/**
+ * Holds if `e` is completely or partially from a _system macro_ definition, as
+ * opposed to being passed in as an argument. A system macro is a macro whose
+ * definition is outside the source directory of the database.
+ *
+ * If the system macro is invoked through a non-system macro, then this
+ * predicate does not hold.
+ *
+ * See also `isFromMacroDefinition`.
+ */
+predicate isFromSystemMacroDefinition(Element e) {
+  exists(MacroInvocation mi |
+    isFromMacroInvocation(e, mi) and
+    // Has no relative path in the database, meaning it's a system file.
+    not exists(mi.getMacro().getFile().getRelativePath())
+  )
+}

cpp/ql/lib/semmle/code/cpp/commons/Printf.qll

@@ -175,9 +175,7 @@ class FormattingFunctionCall extends Expr {
   /**
    * Gets the index at which the format string occurs in the argument list.
    */
-  int getFormatParameterIndex() {
-    result = this.getTarget().(FormattingFunction).getFormatParameterIndex()
-  }
+  int getFormatParameterIndex() { result = this.getTarget().getFormatParameterIndex() }
 
   /**
    * Gets the format expression used in this call.
@@ -191,7 +189,7 @@ class FormattingFunctionCall extends Expr {
     exists(int i |
       result = this.getArgument(i) and
       n >= 0 and
-      n = i - this.getTarget().(FormattingFunction).getFirstFormatArgumentIndex()
+      n = i - this.getTarget().getFirstFormatArgumentIndex()
     )
   }
 
@@ -251,7 +249,7 @@ class FormattingFunctionCall extends Expr {
   int getNumFormatArgument() {
     result = count(this.getFormatArgument(_)) and
     // format arguments must be known
-    exists(this.getTarget().(FormattingFunction).getFirstFormatArgumentIndex())
+    exists(this.getTarget().getFirstFormatArgumentIndex())
   }
 
   /**
@@ -289,35 +287,27 @@ class FormatLiteral extends Literal {
    * a `char *` (either way, `%S` will have the opposite meaning).
    * DEPRECATED: Use getDefaultCharType() instead.
    */
-  deprecated predicate isWideCharDefault() {
-    this.getUse().getTarget().(FormattingFunction).isWideCharDefault()
-  }
+  deprecated predicate isWideCharDefault() { this.getUse().getTarget().isWideCharDefault() }
 
   /**
    * Gets the default character type expected for `%s` by this format literal.  Typically
    * `char` or `wchar_t`.
    */
-  Type getDefaultCharType() {
-    result = this.getUse().getTarget().(FormattingFunction).getDefaultCharType()
-  }
+  Type getDefaultCharType() { result = this.getUse().getTarget().getDefaultCharType() }
 
   /**
    * Gets the non-default character type expected for `%S` by this format literal.  Typically
    * `wchar_t` or `char`.  On some snapshots there may be multiple results where we can't tell
    * which is correct for a particular function.
    */
-  Type getNonDefaultCharType() {
-    result = this.getUse().getTarget().(FormattingFunction).getNonDefaultCharType()
-  }
+  Type getNonDefaultCharType() { result = this.getUse().getTarget().getNonDefaultCharType() }
 
   /**
    * Gets the wide character type for this format literal.  This is usually `wchar_t`.  On some
    * snapshots there may be multiple results where we can't tell which is correct for a
    * particular function.
    */
-  Type getWideCharType() {
-    result = this.getUse().getTarget().(FormattingFunction).getWideCharType()
-  }
+  Type getWideCharType() { result = this.getUse().getTarget().getWideCharType() }
 
   /**
    * Holds if this `FormatLiteral` is in a context that supports
@@ -896,7 +886,7 @@ class FormatLiteral extends Literal {
     exists(string len, string conv |
       this.parseConvSpec(n, _, _, _, _, _, len, conv) and
       (len != "l" and len != "w" and len != "h") and
-      this.getUse().getTarget().(FormattingFunction).getFormatCharType().getSize() > 1 and // wide function
+      this.getUse().getTarget().getFormatCharType().getSize() > 1 and // wide function
       (
         conv = "c" and
         result = this.getNonDefaultCharType()

cpp/ql/lib/semmle/code/cpp/controlflow/DefinitionsAndUses.qll

@@ -25,7 +25,7 @@ predicate definitionUsePair(SemanticStackVariable var, Expr def, Expr use) {
  * Holds if the definition `def` of some stack variable can reach `node`, which
  * is a definition or use, without crossing definitions of the same variable.
  */
-predicate definitionReaches(Expr def, Expr node) { def.(Def).reaches(true, _, node.(DefOrUse)) }
+predicate definitionReaches(Expr def, Expr node) { def.(Def).reaches(true, _, node) }
 
 private predicate hasAddressOfAccess(SemanticStackVariable var) {
   var.getAnAccess().isAddressOfAccessNonConst()

cpp/ql/lib/semmle/code/cpp/controlflow/SSA.qll

@@ -62,7 +62,7 @@ class SsaDefinition extends ControlFlowNodeBase {
   BasicBlock getBasicBlock() { result.contains(this.getDefinition()) }
 
   /** Holds if this definition is a phi node for variable `v`. */
-  predicate isPhiNode(StackVariable v) { exists(StandardSSA x | x.phi_node(v, this.(BasicBlock))) }
+  predicate isPhiNode(StackVariable v) { exists(StandardSSA x | x.phi_node(v, this)) }
 
   /** Gets the location of this definition. */
   Location getLocation() { result = this.(ControlFlowNode).getLocation() }

cpp/ql/lib/semmle/code/cpp/controlflow/SSAUtils.qll

@@ -292,7 +292,7 @@ library class SSAHelper extends int {
    */
   cached
   string toString(ControlFlowNode node, StackVariable v) {
-    if phi_node(v, node.(BasicBlock))
+    if phi_node(v, node)
     then result = "SSA phi(" + v.getName() + ")"
     else (
       ssa_defn(v, node, _, _) and result = "SSA def(" + v.getName() + ")"

cpp/ql/lib/semmle/code/cpp/controlflow/internal/CFG.qll

@@ -231,7 +231,7 @@ private class PostOrderInitializer extends Initializer {
       or
       this.getDeclaration() = for.getRangeVariable()
       or
-      this.getDeclaration() = for.getBeginEndDeclaration().(DeclStmt).getADeclaration()
+      this.getDeclaration() = for.getBeginEndDeclaration().getADeclaration()
     )
   }
 }
@@ -1143,7 +1143,7 @@ private class ExceptionSource extends Node {
       this.reachesParent(mid) and
       not mid = any(TryStmt try).getStmt() and
       not mid = any(MicrosoftTryStmt try).getStmt() and
-      parent = mid.(Node).getParentNode()
+      parent = mid.getParentNode()
     )
   }