[lldb] Improve error message when --func-regex parameter for the brea…

lldb/source/Commands/CommandObjectBreakpoint.cpp

@@ -620,7 +620,7 @@ class CommandObjectBreakpointSet : public CommandObjectParsed {
       RegularExpression regexp(m_options.m_func_regexp);
       if (llvm::Error err = regexp.GetError()) {
         result.AppendErrorWithFormat(
-            "Function name regular expression could not be compiled: \"%s\"",
+            "Function name regular expression could not be compiled: %s",
             llvm::toString(std::move(err)).c_str());
         result.SetStatus(eReturnStatusFailed);
         return false;

lldb/source/Utility/RegularExpression.cpp

@@ -35,7 +35,7 @@ llvm::StringRef RegularExpression::GetText() const { return m_regex_text; }
 llvm::Error RegularExpression::GetError() const {
   std::string error;
   if (!m_regex.isValid(error))
-    return llvm::make_error<llvm::StringError>(llvm::inconvertibleErrorCode(),
-                                               error);
+    return llvm::make_error<llvm::StringError>(error,
+                                               llvm::inconvertibleErrorCode());
   return llvm::Error::success();
 }

lldb/test/API/commands/breakpoint/set/func-regex/TestBreakpointRegexError.py

@@ -0,0 +1,14 @@
+import lldb
+from lldbsuite.test.decorators import *
+from lldbsuite.test.lldbtest import *
+from lldbsuite.test import lldbutil
+
+class TestCase(TestBase):
+
+    mydir = TestBase.compute_mydir(__file__)
+
+    @no_debug_info_test
+    def test_error(self):
+        self.expect("breakpoint set --func-regex (", error=True,
+                    substrs=["error: Function name regular expression could " +
+                             "not be compiled: parentheses not balanced"])