[LLDB][DataFormatter] Add support for std::__map_const_iterator

[Michael137]

Summary

This patch adds support for formatting std::map::const_iterator.
It's just a matter of adding const_ to the existing regex.

Testing

• Added test case to existing API tests

[aprantl]

lldb/test/API/functionalities/data-formatter/data-formatter-stl/libcxx/map/main.cpp

30

I know this is just a test, but maybe add a \n at the end?

[Michael137]

• Add newline to flush printf buffer

lldb/source/Plugins/Language/CPlusPlus/CPlusPlusLanguage.cpp

AddCXXSynthetic(
       "std::vector iterator synthetic children",
       ConstString("^std::__[[:alnum:]]+::__wrap_iter<.+>$"), stl_synth_flags,
       true);
 
   AddCXXSynthetic(
       cpp_category_sp,
       lldb_private::formatters::LibCxxMapIteratorSyntheticFrontEndCreator,
       "std::map iterator synthetic children",
-      ConstString("^std::__[[:alnum:]]+::__map_iterator<.+>$"), stl_synth_flags,
+      ConstString("^std::__[[:alnum:]]+::__map_(const_)?iterator<.+>$"), stl_synth_flags,
       true);
 
   AddCXXSynthetic(
       cpp_category_sp,
       lldb_private::formatters::
           LibCxxUnorderedMapIteratorSyntheticFrontEndCreator,
       "std::unordered_map iterator synthetic children",
       ConstString("^std::__[[:alnum:]]+::__hash_map_(const_)?iterator<.+>$"),

lldb/test/API/functionalities/data-formatter/data-formatter-stl/libcxx/map/TestDataFormatterLibccMap.py

def test_with_run_command(self):
         # check access-by-index
         self.expect("frame variable ii[0]",
                     substrs=['first = 0',
                              'second = 0'])
         self.expect("frame variable ii[3]",
                     substrs=['first =',
                              'second ='])
 
+        # (Non-)const key/val iterators
+        self.expect_expr("it", result_children=[
+            ValueCheck(name="first", value="0"),
+            ValueCheck(name="second", value="0")
+        ])
+        self.expect_expr("const_it", result_children=[
+            ValueCheck(name="first", value="0"),
+            ValueCheck(name="second", value="0")
+        ])
+
         # check that MightHaveChildren() gets it right
         self.assertTrue(
             self.frame().FindVariable("ii").MightHaveChildren(),
             "ii.MightHaveChildren() says False for non empty!")
 
         # check that the expression parser does not make use of
         # synthetic children instead of running code
         # TOT clang has a fix for this, which makes the expression command here succeed

lldb/test/API/functionalities/data-formatter/data-formatter-stl/libcxx/map/main.cpp

 }
 
 int main()
 {
     intint_map ii;
     
     ii[0] = 0; // Set break point at this line.
     ii[1] = 1;
-  thefoo_rw(1);  // Set break point at this line.
+
+    intint_map::iterator it = ii.begin();
+    intint_map::const_iterator const_it = ii.cbegin();
+    std::printf("%d %d", it->second, const_it->second);
+
+    thefoo_rw(1); // Set break point at this line.
     ii[2] = 0;
     ii[3] = 1;
   thefoo_rw(1);  // Set break point at this line.
   ii[4] = 0;
     ii[5] = 1;
     ii[6] = 0;
     ii[7] = 1;
     thefoo_rw(1);  // Set break point at this line.