[LibTooling] Add function to translate and validate source range for …

…editing

Summary:
Adds the function `getRangeForEdit` to validate that a given source range is
editable and, if needed, translate it into a range in the source file (for
example, if it's sourced in macro expansions).

Reviewers: ilya-biryukov

Subscribers: cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D64924

llvm-svn: 366469

clang/include/clang/Tooling/Refactoring/SourceCode.h

@@ -72,6 +72,19 @@ StringRef getExtendedText(const T &Node, tok::TokenKind Next,
                           ASTContext &Context) {
   return getText(getExtendedRange(Node, Next, Context), Context);
 }
+
+// Attempts to resolve the given range to one that can be edited by a rewrite;
+// generally, one that starts and ends within a particular file. It supports
+// a limited set of cases involving source locations in macro expansions.
+llvm::Optional<CharSourceRange>
+getRangeForEdit(const CharSourceRange &EditRange, const SourceManager &SM,
+                const LangOptions &LangOpts);
+
+inline llvm::Optional<CharSourceRange>
+getRangeForEdit(const CharSourceRange &EditRange, const ASTContext &Context) {
+  return getRangeForEdit(EditRange, Context.getSourceManager(),
+                         Context.getLangOpts());
+}
 } // namespace tooling
 } // namespace clang
 #endif // LLVM_CLANG_TOOLING_REFACTOR_SOURCE_CODE_H

clang/lib/Tooling/Refactoring/SourceCode.cpp

@@ -29,3 +29,37 @@ CharSourceRange clang::tooling::maybeExtendRange(CharSourceRange Range,
     return Range;
   return CharSourceRange::getTokenRange(Range.getBegin(), Tok->getLocation());
 }
+
+llvm::Optional<CharSourceRange>
+clang::tooling::getRangeForEdit(const CharSourceRange &EditRange,
+                                const SourceManager &SM,
+                                const LangOptions &LangOpts) {
+  // FIXME: makeFileCharRange() has the disadvantage of stripping off "identity"
+  // macros. For example, if we're looking to rewrite the int literal 3 to 6,
+  // and we have the following definition:
+  //    #define DO_NOTHING(x) x
+  // then
+  //    foo(DO_NOTHING(3))
+  // will be rewritten to
+  //    foo(6)
+  // rather than the arguably better
+  //    foo(DO_NOTHING(6))
+  // Decide whether the current behavior is desirable and modify if not.
+  CharSourceRange Range = Lexer::makeFileCharRange(EditRange, SM, LangOpts);
+  if (Range.isInvalid())
+    return None;
+
+  if (Range.getBegin().isMacroID() || Range.getEnd().isMacroID())
+    return None;
+  if (SM.isInSystemHeader(Range.getBegin()) ||
+      SM.isInSystemHeader(Range.getEnd()))
+    return None;
+
+  std::pair<FileID, unsigned> BeginInfo = SM.getDecomposedLoc(Range.getBegin());
+  std::pair<FileID, unsigned> EndInfo = SM.getDecomposedLoc(Range.getEnd());
+  if (BeginInfo.first != EndInfo.first ||
+      BeginInfo.second > EndInfo.second)
+    return None;
+
+  return Range;
+}

clang/unittests/Tooling/SourceCodeTest.cpp

@@ -6,17 +6,32 @@
 //
 //===----------------------------------------------------------------------===//
 
+#include "clang/Tooling/Refactoring/SourceCode.h"
 #include "TestVisitor.h"
 #include "clang/Basic/Diagnostic.h"
-#include "clang/Tooling/Refactoring/SourceCode.h"
+#include "llvm/Testing/Support/Annotations.h"
+#include "llvm/Testing/Support/SupportHelpers.h"
+#include <gmock/gmock.h>
+#include <gtest/gtest.h>
 
 using namespace clang;
 
-using tooling::getText;
+using llvm::ValueIs;
 using tooling::getExtendedText;
+using tooling::getRangeForEdit;
+using tooling::getText;
 
 namespace {
 
+struct IntLitVisitor : TestVisitor<IntLitVisitor> {
+  bool VisitIntegerLiteral(IntegerLiteral *Expr) {
+    OnIntLit(Expr, Context);
+    return true;
+  }
+
+  std::function<void(IntegerLiteral *, ASTContext *Context)> OnIntLit;
+};
+
 struct CallsVisitor : TestVisitor<CallsVisitor> {
   bool VisitCallExpr(CallExpr *Expr) {
     OnCall(Expr, Context);
@@ -26,6 +41,19 @@ struct CallsVisitor : TestVisitor<CallsVisitor> {
   std::function<void(CallExpr *, ASTContext *Context)> OnCall;
 };
 
+// Equality matcher for `clang::CharSourceRange`, which lacks `operator==`.
+MATCHER_P(EqualsRange, R, "") {
+  return arg.isTokenRange() == R.isTokenRange() &&
+         arg.getBegin() == R.getBegin() && arg.getEnd() == R.getEnd();
+}
+
+static ::testing::Matcher<CharSourceRange> AsRange(const SourceManager &SM,
+                                                   llvm::Annotations::Range R) {
+  return EqualsRange(CharSourceRange::getCharRange(
+      SM.getLocForStartOfFile(SM.getMainFileID()).getLocWithOffset(R.Begin),
+      SM.getLocForStartOfFile(SM.getMainFileID()).getLocWithOffset(R.End)));
+}
+
 TEST(SourceCodeTest, getText) {
   CallsVisitor Visitor;
 
@@ -94,4 +122,82 @@ TEST(SourceCodeTest, getExtendedText) {
   Visitor.runOver("int foo() { return foo() + 3; }");
 }
 
+TEST(SourceCodeTest, EditRangeWithMacroExpansionsShouldSucceed) {
+  // The call expression, whose range we are extracting, includes two macro
+  // expansions.
+  llvm::Annotations Code(R"cpp(
+#define M(a) a * 13
+int foo(int x, int y);
+int a = $r[[foo(M(1), M(2))]];
+)cpp");
+
+  CallsVisitor Visitor;
+
+  Visitor.OnCall = [&Code](CallExpr *CE, ASTContext *Context) {
+    auto Range = CharSourceRange::getTokenRange(CE->getSourceRange());
+    EXPECT_THAT(getRangeForEdit(Range, *Context),
+                ValueIs(AsRange(Context->getSourceManager(), Code.range("r"))));
+  };
+  Visitor.runOver(Code.code());
+}
+
+TEST(SourceCodeTest, EditWholeMacroExpansionShouldSucceed) {
+  llvm::Annotations Code(R"cpp(
+#define FOO 10
+int a = $r[[FOO]];
+)cpp");
+
+  IntLitVisitor Visitor;
+  Visitor.OnIntLit = [&Code](IntegerLiteral *Expr, ASTContext *Context) {
+    auto Range = CharSourceRange::getTokenRange(Expr->getSourceRange());
+    EXPECT_THAT(getRangeForEdit(Range, *Context),
+                ValueIs(AsRange(Context->getSourceManager(), Code.range("r"))));
+  };
+  Visitor.runOver(Code.code());
+}
+
+TEST(SourceCodeTest, EditPartialMacroExpansionShouldFail) {
+  std::string Code = R"cpp(
+#define BAR 10+
+int c = BAR 3.0;
+)cpp";
+
+  IntLitVisitor Visitor;
+  Visitor.OnIntLit = [](IntegerLiteral *Expr, ASTContext *Context) {
+    auto Range = CharSourceRange::getTokenRange(Expr->getSourceRange());
+    EXPECT_FALSE(getRangeForEdit(Range, *Context).hasValue());
+  };
+  Visitor.runOver(Code);
+}
+
+TEST(SourceCodeTest, EditWholeMacroArgShouldSucceed) {
+  llvm::Annotations Code(R"cpp(
+#define FOO(a) a + 7.0;
+int a = FOO($r[[10]]);
+)cpp");
+
+  IntLitVisitor Visitor;
+  Visitor.OnIntLit = [&Code](IntegerLiteral *Expr, ASTContext *Context) {
+    auto Range = CharSourceRange::getTokenRange(Expr->getSourceRange());
+    EXPECT_THAT(getRangeForEdit(Range, *Context),
+                ValueIs(AsRange(Context->getSourceManager(), Code.range("r"))));
+  };
+  Visitor.runOver(Code.code());
+}
+
+TEST(SourceCodeTest, EditPartialMacroArgShouldSucceed) {
+  llvm::Annotations Code(R"cpp(
+#define FOO(a) a + 7.0;
+int a = FOO($r[[10]] + 10.0);
+)cpp");
+
+  IntLitVisitor Visitor;
+  Visitor.OnIntLit = [&Code](IntegerLiteral *Expr, ASTContext *Context) {
+    auto Range = CharSourceRange::getTokenRange(Expr->getSourceRange());
+    EXPECT_THAT(getRangeForEdit(Range, *Context),
+                ValueIs(AsRange(Context->getSourceManager(), Code.range("r"))));
+  };
+  Visitor.runOver(Code.code());
+}
+
 } // end anonymous namespace