Make tooling::applyAllReplacements return llvm::Expected<string> instead of empty string to indicate potential error.

Summary:
return llvm::Expected<> to carry error status and error information.
This is the first step towards introducing "Error" into tooling::Replacements.

Reviewers: djasper, klimek

Subscribers: ioeric, klimek, cfe-commits

Differential Revision: http://reviews.llvm.org/D21601

llvm-svn: 275062

10 files changed, 83 insertions, 53 deletions

diff --git a/clang/unittests/Format/CleanupTest.cpp b/clang/unittests/Format/CleanupTest.cpp
index f51e3acf9ac..5f85c53b780 100644
--- a/clang/unittests/Format/CleanupTest.cpp
+++ b/clang/unittests/Format/CleanupTest.cpp
@@ -25,9 +25,9 @@ protected:
                       const FormatStyle &Style = getLLVMStyle()) {
     tooling::Replacements Replaces = format::cleanup(Style, Code, Ranges);
 
-    std::string Result = applyAllReplacements(Code, Replaces);
-    EXPECT_NE("", Result);
-    return Result;
+    auto Result = applyAllReplacements(Code, Replaces);
+    EXPECT_TRUE(static_cast<bool>(Result));
+    return *Result;
   }
 };
 
@@ -254,16 +254,26 @@ protected:
 
   inline std::string apply(StringRef Code,
                            const tooling::Replacements Replaces) {
-    return applyAllReplacements(
-        Code, cleanupAroundReplacements(Code, Replaces, Style));
+    auto CleanReplaces = cleanupAroundReplacements(Code, Replaces, Style);
+    EXPECT_TRUE(static_cast<bool>(CleanReplaces))
+        << llvm::toString(CleanReplaces.takeError()) << "\n";
+    auto Result = applyAllReplacements(Code, *CleanReplaces);
+    EXPECT_TRUE(static_cast<bool>(Result));
+    return *Result;
   }
 
   inline std::string formatAndApply(StringRef Code,
                                     const tooling::Replacements Replaces) {
-    return applyAllReplacements(
-        Code,
-        formatReplacements(
-            Code, cleanupAroundReplacements(Code, Replaces, Style), Style));
+
+    auto CleanReplaces = cleanupAroundReplacements(Code, Replaces, Style);
+    EXPECT_TRUE(static_cast<bool>(CleanReplaces))
+        << llvm::toString(CleanReplaces.takeError()) << "\n";
+    auto FormattedReplaces = formatReplacements(Code, *CleanReplaces, Style);
+    EXPECT_TRUE(static_cast<bool>(FormattedReplaces))
+        << llvm::toString(FormattedReplaces.takeError()) << "\n";
+    auto Result = applyAllReplacements(Code, *FormattedReplaces);
+    EXPECT_TRUE(static_cast<bool>(Result));
+    return *Result;
   }
 
   int getOffset(StringRef Code, int Line, int Column) {
diff --git a/clang/unittests/Format/FormatTest.cpp b/clang/unittests/Format/FormatTest.cpp
index 218243380c3..8d46ba6efcf 100644
--- a/clang/unittests/Format/FormatTest.cpp
+++ b/clang/unittests/Format/FormatTest.cpp
@@ -47,10 +47,10 @@ protected:
       EXPECT_EQ(ExpectedIncompleteFormat, IncompleteFormat) << Code << "\n\n";
     }
     ReplacementCount = Replaces.size();
-    std::string Result = applyAllReplacements(Code, Replaces);
-    EXPECT_NE("", Result);
-    DEBUG(llvm::errs() << "\n" << Result << "\n\n");
-    return Result;
+    auto Result = applyAllReplacements(Code, Replaces);
+    EXPECT_TRUE(static_cast<bool>(Result));
+    DEBUG(llvm::errs() << "\n" << *Result << "\n\n");
+    return *Result;
   }
 
   FormatStyle getLLVMStyleWithColumns(unsigned ColumnLimit) {
@@ -11553,8 +11553,12 @@ TEST_F(ReplacementTest, FormatCodeAfterReplacements) {
 
   format::FormatStyle Style = format::getLLVMStyle();
   Style.ColumnLimit = 20; // Set column limit to 20 to increase readibility.
-  EXPECT_EQ(Expected, applyAllReplacements(
-                          Code, formatReplacements(Code, Replaces, Style)));
+  auto FormattedReplaces = formatReplacements(Code, Replaces, Style);
+  EXPECT_TRUE(static_cast<bool>(FormattedReplaces))
+      << llvm::toString(FormattedReplaces.takeError()) << "\n";
+  auto Result = applyAllReplacements(Code, *FormattedReplaces);
+  EXPECT_TRUE(static_cast<bool>(Result));
+  EXPECT_EQ(Expected, *Result);
 }
 
 TEST_F(ReplacementTest, SortIncludesAfterReplacement) {
@@ -11578,8 +11582,12 @@ TEST_F(ReplacementTest, SortIncludesAfterReplacement) {
 
   format::FormatStyle Style = format::getLLVMStyle();
   Style.SortIncludes = true;
-  auto FinalReplaces = formatReplacements(Code, Replaces, Style);
-  EXPECT_EQ(Expected, applyAllReplacements(Code, FinalReplaces));
+  auto FormattedReplaces = formatReplacements(Code, Replaces, Style);
+  EXPECT_TRUE(static_cast<bool>(FormattedReplaces))
+      << llvm::toString(FormattedReplaces.takeError()) << "\n";
+  auto Result = applyAllReplacements(Code, *FormattedReplaces);
+  EXPECT_TRUE(static_cast<bool>(Result));
+  EXPECT_EQ(Expected, *Result);
 }
 
 } // end namespace
diff --git a/clang/unittests/Format/FormatTestJS.cpp b/clang/unittests/Format/FormatTestJS.cpp
index a5f0b19577a..5fda89d45d6 100644
--- a/clang/unittests/Format/FormatTestJS.cpp
+++ b/clang/unittests/Format/FormatTestJS.cpp
@@ -28,10 +28,10 @@ protected:
     tooling::Replacements Replaces =
         reformat(Style, Code, Ranges, "<stdin>", &IncompleteFormat);
     EXPECT_FALSE(IncompleteFormat);
-    std::string Result = applyAllReplacements(Code, Replaces);
-    EXPECT_NE("", Result);
-    DEBUG(llvm::errs() << "\n" << Result << "\n\n");
-    return Result;
+    auto Result = applyAllReplacements(Code, Replaces);
+    EXPECT_TRUE(static_cast<bool>(Result));
+    DEBUG(llvm::errs() << "\n" << *Result << "\n\n");
+    return *Result;
   }
 
   static std::string format(
diff --git a/clang/unittests/Format/FormatTestJava.cpp b/clang/unittests/Format/FormatTestJava.cpp
index 30d1bc8baf8..dfc3debc46e 100644
--- a/clang/unittests/Format/FormatTestJava.cpp
+++ b/clang/unittests/Format/FormatTestJava.cpp
@@ -25,10 +25,10 @@ protected:
     DEBUG(llvm::errs() << Code << "\n\n");
     std::vector<tooling::Range> Ranges(1, tooling::Range(Offset, Length));
     tooling::Replacements Replaces = reformat(Style, Code, Ranges);
-    std::string Result = applyAllReplacements(Code, Replaces);
-    EXPECT_NE("", Result);
-    DEBUG(llvm::errs() << "\n" << Result << "\n\n");
-    return Result;
+    auto Result = applyAllReplacements(Code, Replaces);
+    EXPECT_TRUE(static_cast<bool>(Result));
+    DEBUG(llvm::errs() << "\n" << *Result << "\n\n");
+    return *Result;
   }
 
   static std::string
diff --git a/clang/unittests/Format/FormatTestProto.cpp b/clang/unittests/Format/FormatTestProto.cpp
index d9fb1409139..6881af4361c 100644
--- a/clang/unittests/Format/FormatTestProto.cpp
+++ b/clang/unittests/Format/FormatTestProto.cpp
@@ -25,10 +25,10 @@ protected:
     DEBUG(llvm::errs() << Code << "\n\n");
     std::vector<tooling::Range> Ranges(1, tooling::Range(Offset, Length));
     tooling::Replacements Replaces = reformat(Style, Code, Ranges);
-    std::string Result = applyAllReplacements(Code, Replaces);
-    EXPECT_NE("", Result);
-    DEBUG(llvm::errs() << "\n" << Result << "\n\n");
-    return Result;
+    auto Result = applyAllReplacements(Code, Replaces);
+    EXPECT_TRUE(static_cast<bool>(Result));
+    DEBUG(llvm::errs() << "\n" << *Result << "\n\n");
+    return *Result;
   }
 
   static std::string format(llvm::StringRef Code) {
diff --git a/clang/unittests/Format/FormatTestSelective.cpp b/clang/unittests/Format/FormatTestSelective.cpp
index c4286d4297d..2bc60fd1e0d 100644
--- a/clang/unittests/Format/FormatTestSelective.cpp
+++ b/clang/unittests/Format/FormatTestSelective.cpp
@@ -28,10 +28,10 @@ protected:
     tooling::Replacements Replaces =
         reformat(Style, Code, Ranges, "<stdin>", &IncompleteFormat);
     EXPECT_FALSE(IncompleteFormat) << Code << "\n\n";
-    std::string Result = applyAllReplacements(Code, Replaces);
-    EXPECT_NE("", Result);
-    DEBUG(llvm::errs() << "\n" << Result << "\n\n");
-    return Result;
+    auto Result = applyAllReplacements(Code, Replaces);
+    EXPECT_TRUE(static_cast<bool>(Result));
+    DEBUG(llvm::errs() << "\n" << *Result << "\n\n");
+    return *Result;
   }
 
   FormatStyle Style = getLLVMStyle();
diff --git a/clang/unittests/Format/SortImportsTestJS.cpp b/clang/unittests/Format/SortImportsTestJS.cpp
index e6b5273f7b1..77c37e337dd 100644
--- a/clang/unittests/Format/SortImportsTestJS.cpp
+++ b/clang/unittests/Format/SortImportsTestJS.cpp
@@ -25,10 +25,13 @@ protected:
     if (Length == 0U)
       Length = Code.size() - Offset;
     std::vector<tooling::Range> Ranges(1, tooling::Range(Offset, Length));
-    std::string Sorted =
+    auto Sorted =
         applyAllReplacements(Code, sortIncludes(Style, Code, Ranges, FileName));
-    return applyAllReplacements(Sorted,
-                                reformat(Style, Sorted, Ranges, FileName));
+    EXPECT_TRUE(static_cast<bool>(Sorted));
+    auto Formatted = applyAllReplacements(
+        *Sorted, reformat(Style, *Sorted, Ranges, FileName));
+    EXPECT_TRUE(static_cast<bool>(Formatted));
+    return *Formatted;
   }
 
   void verifySort(llvm::StringRef Expected, llvm::StringRef Code,
diff --git a/clang/unittests/Format/SortIncludesTest.cpp b/clang/unittests/Format/SortIncludesTest.cpp
index c8a43fc6240..13a1b9adeee 100644
--- a/clang/unittests/Format/SortIncludesTest.cpp
+++ b/clang/unittests/Format/SortIncludesTest.cpp
@@ -26,10 +26,13 @@ protected:
 
   std::string sort(StringRef Code, StringRef FileName = "input.cpp") {
     auto Ranges = GetCodeRange(Code);
-    std::string Sorted =
+    auto Sorted =
         applyAllReplacements(Code, sortIncludes(Style, Code, Ranges, FileName));
-    return applyAllReplacements(Sorted,
-                                reformat(Style, Sorted, Ranges, FileName));
+    EXPECT_TRUE(static_cast<bool>(Sorted));
+    auto Result = applyAllReplacements(
+        *Sorted, reformat(Style, *Sorted, Ranges, FileName));
+    EXPECT_TRUE(static_cast<bool>(Result));
+    return *Result;
   }
 
   unsigned newCursor(llvm::StringRef Code, unsigned Cursor) {
diff --git a/clang/unittests/Tooling/RefactoringTest.cpp b/clang/unittests/Tooling/RefactoringTest.cpp
index fbf54134a7c..df96bb159de 100644
--- a/clang/unittests/Tooling/RefactoringTest.cpp
+++ b/clang/unittests/Tooling/RefactoringTest.cpp
@@ -640,27 +640,32 @@ protected:
                            StringRef Result, const Replacements &First,
                            const Replacements &Second) {
     // These are mainly to verify the test itself and make it easier to read.
-    std::string AfterFirst = applyAllReplacements(Code, First);
-    std::string InSequenceRewrite = applyAllReplacements(AfterFirst, Second);
-    EXPECT_EQ(Intermediate, AfterFirst);
-    EXPECT_EQ(Result, InSequenceRewrite);
+    auto AfterFirst = applyAllReplacements(Code, First);
+    EXPECT_TRUE(static_cast<bool>(AfterFirst));
+    auto InSequenceRewrite = applyAllReplacements(*AfterFirst, Second);
+    EXPECT_TRUE(static_cast<bool>(InSequenceRewrite));
+    EXPECT_EQ(Intermediate, *AfterFirst);
+    EXPECT_EQ(Result, *InSequenceRewrite);
 
     tooling::Replacements Merged = mergeReplacements(First, Second);
-    std::string MergedRewrite = applyAllReplacements(Code, Merged);
-    EXPECT_EQ(InSequenceRewrite, MergedRewrite);
-    if (InSequenceRewrite != MergedRewrite)
+    auto MergedRewrite = applyAllReplacements(Code, Merged);
+    EXPECT_TRUE(static_cast<bool>(MergedRewrite));
+    EXPECT_EQ(*InSequenceRewrite, *MergedRewrite);
+    if (*InSequenceRewrite != *MergedRewrite)
       for (tooling::Replacement M : Merged)
         llvm::errs() << M.getOffset() << " " << M.getLength() << " "
                      << M.getReplacementText() << "\n";
   }
   void mergeAndTestRewrite(StringRef Code, const Replacements &First,
                            const Replacements &Second) {
-    std::string InSequenceRewrite =
-        applyAllReplacements(applyAllReplacements(Code, First), Second);
+    auto AfterFirst = applyAllReplacements(Code, First);
+    EXPECT_TRUE(static_cast<bool>(AfterFirst));
+    auto InSequenceRewrite = applyAllReplacements(*AfterFirst, Second);
     tooling::Replacements Merged = mergeReplacements(First, Second);
-    std::string MergedRewrite = applyAllReplacements(Code, Merged);
-    EXPECT_EQ(InSequenceRewrite, MergedRewrite);
-    if (InSequenceRewrite != MergedRewrite)
+    auto MergedRewrite = applyAllReplacements(Code, Merged);
+    EXPECT_TRUE(static_cast<bool>(MergedRewrite));
+    EXPECT_EQ(*InSequenceRewrite, *MergedRewrite);
+    if (*InSequenceRewrite != *MergedRewrite)
       for (tooling::Replacement M : Merged)
         llvm::errs() << M.getOffset() << " " << M.getLength() << " "
                      << M.getReplacementText() << "\n";
diff --git a/clang/unittests/Tooling/RewriterTest.cpp b/clang/unittests/Tooling/RewriterTest.cpp
index 93f69eb9fa0..e8afedb0117 100644
--- a/clang/unittests/Tooling/RewriterTest.cpp
+++ b/clang/unittests/Tooling/RewriterTest.cpp
@@ -41,8 +41,9 @@ TEST(Rewriter, AdjacentInsertAndDelete) {
   Replacements Replaces;
   Replaces.insert(Replacement("<file>", 6, 6, ""));
   Replaces.insert(Replacement("<file>", 6, 0, "replaced\n"));
-  EXPECT_EQ("line1\nreplaced\nline3\nline4",
-            applyAllReplacements("line1\nline2\nline3\nline4", Replaces));
+  auto Rewritten = applyAllReplacements("line1\nline2\nline3\nline4", Replaces);
+  EXPECT_TRUE(static_cast<bool>(Rewritten));
+  EXPECT_EQ("line1\nreplaced\nline3\nline4", *Rewritten);
 }
 
 } // end namespace