Creating branches/google/testing and tags/google/testing/2017-11-14 from r317716google/testing

git-svn-id: https://llvm.org/svn/llvm-project/cfe/branches/google/testing@318248 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 199 insertions, 0 deletions

diff --git a/lib/Tooling/Refactoring/Extract/Extract.cpp b/lib/Tooling/Refactoring/Extract/Extract.cpp
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+++ b/lib/Tooling/Refactoring/Extract/Extract.cpp
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+//===--- Extract.cpp - Clang refactoring library --------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+///
+/// \file
+/// \brief Implements the "extract" refactoring that can pull code into
+/// new functions, methods or declare new variables.
+///
+//===----------------------------------------------------------------------===//
+
+#include "clang/Tooling/Refactoring/Extract/Extract.h"
+#include "SourceExtraction.h"
+#include "clang/AST/ASTContext.h"
+#include "clang/AST/DeclCXX.h"
+#include "clang/AST/Expr.h"
+#include "clang/AST/ExprObjC.h"
+#include "clang/Rewrite/Core/Rewriter.h"
+
+namespace clang {
+namespace tooling {
+
+namespace {
+
+/// Returns true if \c E is a simple literal or a reference expression that
+/// should not be extracted.
+bool isSimpleExpression(const Expr *E) {
+  if (!E)
+    return false;
+  switch (E->IgnoreParenCasts()->getStmtClass()) {
+  case Stmt::DeclRefExprClass:
+  case Stmt::PredefinedExprClass:
+  case Stmt::IntegerLiteralClass:
+  case Stmt::FloatingLiteralClass:
+  case Stmt::ImaginaryLiteralClass:
+  case Stmt::CharacterLiteralClass:
+  case Stmt::StringLiteralClass:
+    return true;
+  default:
+    return false;
+  }
+}
+
+SourceLocation computeFunctionExtractionLocation(const Decl *D) {
+  if (isa<CXXMethodDecl>(D)) {
+    // Code from method that is defined in class body should be extracted to a
+    // function defined just before the class.
+    while (const auto *RD = dyn_cast<CXXRecordDecl>(D->getLexicalDeclContext()))
+      D = RD;
+  }
+  return D->getLocStart();
+}
+
+} // end anonymous namespace
+
+const RefactoringDescriptor &ExtractFunction::describe() {
+  static const RefactoringDescriptor Descriptor = {
+      "extract-function",
+      "Extract Function",
+      "(WIP action; use with caution!) Extracts code into a new function",
+  };
+  return Descriptor;
+}
+
+Expected<ExtractFunction>
+ExtractFunction::initiate(RefactoringRuleContext &Context,
+                          CodeRangeASTSelection Code,
+                          Optional<std::string> DeclName) {
+  // We would like to extract code out of functions/methods/blocks.
+  // Prohibit extraction from things like global variable / field
+  // initializers and other top-level expressions.
+  if (!Code.isInFunctionLikeBodyOfCode())
+    return Context.createDiagnosticError(
+        diag::err_refactor_code_outside_of_function);
+
+  if (Code.size() == 1) {
+    // Avoid extraction of simple literals and references.
+    if (isSimpleExpression(dyn_cast<Expr>(Code[0])))
+      return Context.createDiagnosticError(
+          diag::err_refactor_extract_simple_expression);
+
+    // Property setters can't be extracted.
+    if (const auto *PRE = dyn_cast<ObjCPropertyRefExpr>(Code[0])) {
+      if (!PRE->isMessagingGetter())
+        return Context.createDiagnosticError(
+            diag::err_refactor_extract_prohibited_expression);
+    }
+  }
+
+  return ExtractFunction(std::move(Code), DeclName);
+}
+
+// FIXME: Support C++ method extraction.
+// FIXME: Support Objective-C method extraction.
+Expected<AtomicChanges>
+ExtractFunction::createSourceReplacements(RefactoringRuleContext &Context) {
+  const Decl *ParentDecl = Code.getFunctionLikeNearestParent();
+  assert(ParentDecl && "missing parent");
+
+  // Compute the source range of the code that should be extracted.
+  SourceRange ExtractedRange(Code[0]->getLocStart(),
+                             Code[Code.size() - 1]->getLocEnd());
+  // FIXME (Alex L): Add code that accounts for macro locations.
+
+  ASTContext &AST = Context.getASTContext();
+  SourceManager &SM = AST.getSourceManager();
+  const LangOptions &LangOpts = AST.getLangOpts();
+  Rewriter ExtractedCodeRewriter(SM, LangOpts);
+
+  // FIXME: Capture used variables.
+
+  // Compute the return type.
+  QualType ReturnType = AST.VoidTy;
+  // FIXME (Alex L): Account for the return statement in extracted code.
+  // FIXME (Alex L): Check for lexical expression instead.
+  bool IsExpr = Code.size() == 1 && isa<Expr>(Code[0]);
+  if (IsExpr) {
+    // FIXME (Alex L): Get a more user-friendly type if needed.
+    ReturnType = cast<Expr>(Code[0])->getType();
+  }
+
+  // FIXME: Rewrite the extracted code performing any required adjustments.
+
+  // FIXME: Capture any field if necessary (method -> function extraction).
+
+  // FIXME: Sort captured variables by name.
+
+  // FIXME: Capture 'this' / 'self' if necessary.
+
+  // FIXME: Compute the actual parameter types.
+
+  // Compute the location of the extracted declaration.
+  SourceLocation ExtractedDeclLocation =
+      computeFunctionExtractionLocation(ParentDecl);
+  // FIXME: Adjust the location to account for any preceding comments.
+
+  // FIXME: Adjust with PP awareness like in Sema to get correct 'bool'
+  // treatment.
+  PrintingPolicy PP = AST.getPrintingPolicy();
+  // FIXME: PP.UseStdFunctionForLambda = true;
+  PP.SuppressStrongLifetime = true;
+  PP.SuppressLifetimeQualifiers = true;
+  PP.SuppressUnwrittenScope = true;
+
+  ExtractionSemicolonPolicy Semicolons = ExtractionSemicolonPolicy::compute(
+      Code[Code.size() - 1], ExtractedRange, SM, LangOpts);
+  AtomicChange Change(SM, ExtractedDeclLocation);
+  // Create the replacement for the extracted declaration.
+  {
+    std::string ExtractedCode;
+    llvm::raw_string_ostream OS(ExtractedCode);
+    // FIXME: Use 'inline' in header.
+    OS << "static ";
+    ReturnType.print(OS, PP, DeclName);
+    OS << '(';
+    // FIXME: Arguments.
+    OS << ')';
+
+    // Function body.
+    OS << " {\n";
+    if (IsExpr && !ReturnType->isVoidType())
+      OS << "return ";
+    OS << ExtractedCodeRewriter.getRewrittenText(ExtractedRange);
+    if (Semicolons.isNeededInExtractedFunction())
+      OS << ';';
+    OS << "\n}\n\n";
+    auto Err = Change.insert(SM, ExtractedDeclLocation, OS.str());
+    if (Err)
+      return std::move(Err);
+  }
+
+  // Create the replacement for the call to the extracted declaration.
+  {
+    std::string ReplacedCode;
+    llvm::raw_string_ostream OS(ReplacedCode);
+
+    OS << DeclName << '(';
+    // FIXME: Forward arguments.
+    OS << ')';
+    if (Semicolons.isNeededInOriginalFunction())
+      OS << ';';
+
+    auto Err = Change.replace(
+        SM, CharSourceRange::getTokenRange(ExtractedRange), OS.str());
+    if (Err)
+      return std::move(Err);
+  }
+
+  // FIXME: Add support for assocciated symbol location to AtomicChange to mark
+  // the ranges of the name of the extracted declaration.
+  return AtomicChanges{std::move(Change)};
+}
+
+} // end namespace tooling
+} // end namespace clang