[Tooling] JSONCompilationDatabase::loadFromBuffer retains the buffer, copy it.

This function doesn't seem to be used in-tree outside tests.
However clangd wants to use it soon, and having the CDB be self-contained seems
reasonable.

Differential Revision: https://reviews.llvm.org/D92646

1 files changed, 3 insertions, 1 deletions

diff --git a/clang/unittests/Tooling/CompilationDatabaseTest.cpp b/clang/unittests/Tooling/CompilationDatabaseTest.cpp
index 9e23428..168a1d6 100644
--- a/clang/unittests/Tooling/CompilationDatabaseTest.cpp
+++ b/clang/unittests/Tooling/CompilationDatabaseTest.cpp
@@ -172,13 +172,15 @@ TEST(JSONCompilationDatabase, GetAllCompileCommands) {
 }
 
 static CompileCommand findCompileArgsInJsonDatabase(StringRef FileName,
-                                                    StringRef JSONDatabase,
+                                                    std::string JSONDatabase,
                                                     std::string &ErrorMessage) {
   std::unique_ptr<CompilationDatabase> Database(
       JSONCompilationDatabase::loadFromBuffer(JSONDatabase, ErrorMessage,
                                               JSONCommandLineSyntax::Gnu));
   if (!Database)
     return CompileCommand();
+  // Overwrite the string to verify we're not reading from it later.
+  JSONDatabase.assign(JSONDatabase.size(), '*');
   std::vector<CompileCommand> Commands = Database->getCompileCommands(FileName);
   EXPECT_LE(Commands.size(), 1u);
   if (Commands.empty())