build/clang-plugin/VariableUsageHelpers.h

   1 /* This Source Code Form is subject to the terms of the Mozilla Public
   2  * License, v. 2.0. If a copy of the MPL was not distributed with this
   3  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   4
   5 #ifndef VariableUsageHelpers_h__
   6 #define VariableUsageHelpers_h__
   7
   8 #include "plugin.h"
   9
  10 /// Returns a list of the statements where the given declaration is used as an
  11 /// rvalue (within the provided function).
  12 ///
  13 /// WARNING: incomplete behaviour/implementation for general-purpose use outside
  14 /// of escapesFunction(). This only detects very basic usages (see
  15 /// implementation for more details).
  16 std::vector<const Stmt *> getUsageAsRvalue(const ValueDecl *ValueDeclaration,
  17                                            const FunctionDecl *FuncDecl);
  18
  19 /// This is the error enumeration for escapesFunction(), describing all the
  20 /// possible error cases.
  21 enum class EscapesFunctionError {
  22   ConstructorDeclNotFound = 1,
  23   FunctionDeclNotFound,
  24   FunctionIsBuiltin,
  25   FunctionIsVariadic,
  26   ExprNotInCall,
  27   NoParamForArg,
  28   ArgAndParamNotPointers
  29 };
  30
  31 /// Required by the std::error_code system to convert our enum into a general
  32 /// error code.
  33 std::error_code make_error_code(EscapesFunctionError);
  34
  35 /// Returns a (statement, decl) tuple if an argument from an argument list
  36 /// escapes the function scope through globals/statics/other things. The
  37 /// statement is where the value escapes the function, while the declaration
  38 /// points to what it escapes through. If the argument doesn't escape the
  39 /// function, the tuple will only contain nullptrs.
  40 /// If the analysis runs into an unexpected error or into an unimplemented
  41 /// configuration, it will return an error_code of type EscapesFunctionError
  42 /// representing the precise issue.
  43 ///
  44 /// WARNING: incomplete behaviour/implementation for general-purpose use outside
  45 /// of DanglingOnTemporaryChecker. This only covers a limited set of cases,
  46 /// mainly in terms of arguments and parameter types.
  47 ErrorOr<std::tuple<const Stmt *, const Decl *>>
  48 escapesFunction(const Expr *Arg, const FunctionDecl *FuncDecl,
  49                 const Expr *const *Arguments, unsigned NumArgs);
  50
  51 /// Helper function taking a call expression.
  52 ErrorOr<std::tuple<const Stmt *, const Decl *>>
  53 escapesFunction(const Expr *Arg, const CallExpr *Call);
  54
  55 /// Helper function taking a construct expression.
  56 ErrorOr<std::tuple<const Stmt *, const Decl *>>
  57 escapesFunction(const Expr *Arg, const CXXConstructExpr *Construct);
  58
  59 /// Helper function taking an operator call expression.
  60 ErrorOr<std::tuple<const Stmt *, const Decl *>>
  61 escapesFunction(const Expr *Arg, const CXXOperatorCallExpr *OpCall);
  62
  63 #endif