[clang-diff] Move the JSON export function to clang-diff

Reviewers: arphaman

Subscribers: klimek

Differential Revision: https://reviews.llvm.org/D36178

llvm-svn: 311199

1 files changed, 64 insertions, 1 deletions

diff --git a/clang/tools/clang-diff/ClangDiff.cpp b/clang/tools/clang-diff/ClangDiff.cpp
index ea721836885..aec2b0f9b3a 100644
--- a/clang/tools/clang-diff/ClangDiff.cpp
+++ b/clang/tools/clang-diff/ClangDiff.cpp
@@ -94,6 +94,65 @@ getAST(const std::unique_ptr<CompilationDatabase> &CommonCompilations,
   return std::move(ASTs[0]);
 }
 
+static char hexdigit(int N) { return N &= 0xf, N + (N < 10 ? '0' : 'a' - 10); }
+
+static void printJsonString(raw_ostream &OS, const StringRef Str) {
+  for (char C : Str) {
+    switch (C) {
+    case '"':
+      OS << R"(\")";
+      break;
+    case '\\':
+      OS << R"(\\)";
+      break;
+    case '\n':
+      OS << R"(\n)";
+      break;
+    case '\t':
+      OS << R"(\t)";
+      break;
+    default:
+      if ('\x00' <= C && C <= '\x1f') {
+        OS << R"(\u00)" << hexdigit(C >> 4) << hexdigit(C);
+      } else {
+        OS << C;
+      }
+    }
+  }
+}
+
+static void printNodeAttributes(raw_ostream &OS, diff::SyntaxTree &Tree,
+                                diff::NodeId Id) {
+  const diff::Node &N = Tree.getNode(Id);
+  OS << R"("id":)" << int(Id);
+  OS << R"(,"type":")" << N.getTypeLabel() << '"';
+  auto Offsets = Tree.getSourceRangeOffsets(N);
+  OS << R"(,"begin":)" << Offsets.first;
+  OS << R"(,"end":)" << Offsets.second;
+  std::string Value = Tree.getNodeValue(N.ASTNode);
+  if (!Value.empty()) {
+    OS << R"(,"value":")";
+    printJsonString(OS, Value);
+    OS << '"';
+  }
+}
+
+static void printNodeAsJson(raw_ostream &OS, diff::SyntaxTree &Tree,
+                            diff::NodeId Id) {
+  const diff::Node &N = Tree.getNode(Id);
+  OS << "{";
+  printNodeAttributes(OS, Tree, Id);
+  OS << R"(,"children":[)";
+  if (N.Children.size() > 0) {
+    printNodeAsJson(OS, Tree, N.Children[0]);
+    for (size_t I = 1, E = N.Children.size(); I < E; ++I) {
+      OS << ",";
+      printNodeAsJson(OS, Tree, N.Children[I]);
+    }
+  }
+  OS << "]}";
+}
+
 int main(int argc, const char **argv) {
   std::string ErrorMessage;
   std::unique_ptr<CompilationDatabase> CommonCompilations =
@@ -117,7 +176,11 @@ int main(int argc, const char **argv) {
     if (!AST)
       return 1;
     diff::SyntaxTree Tree(AST->getASTContext());
-    Tree.printAsJson(llvm::outs());
+    llvm::outs() << R"({"filename":")";
+    printJsonString(llvm::outs(), SourcePath);
+    llvm::outs() << R"(","root":)";
+    printNodeAsJson(llvm::outs(), Tree, Tree.getRootId());
+    llvm::outs() << "}\n";
     return 0;
   }