Add 'json4cpp/' from commit '9a737481aed085fd289f82dff1fa8c3c66627a7e'

git-subtree-dir: json4cpp
git-subtree-mainline: 292baed7ac0cf84263263966ed32ed113cae857f
git-subtree-split: 9a737481aed085fd289f82dff1fa8c3c66627a7e

1 files changed, 35 insertions, 0 deletions

diff --git a/json4cpp/tools/gdb_pretty_printer/nlohmann-json.py b/json4cpp/tools/gdb_pretty_printer/nlohmann-json.py
new file mode 100644
index 0000000000..2c120befd9
--- /dev/null
+++ b/json4cpp/tools/gdb_pretty_printer/nlohmann-json.py
@@ -0,0 +1,35 @@
+import gdb
+import re
+
+ns_pattern = re.compile(r'nlohmann(::json_abi(?P<tags>\w*)(_v(?P<v_major>\d+)_(?P<v_minor>\d+)_(?P<v_patch>\d+))?)?::(?P<name>.+)')
+class JsonValuePrinter:
+    "Print a json-value"
+
+    def __init__(self, val):
+        self.val = val
+
+    def to_string(self):
+        if self.val.type.strip_typedefs().code == gdb.TYPE_CODE_FLT:
+            return ("%.6f" % float(self.val)).rstrip("0")
+        return self.val
+
+def json_lookup_function(val):
+    if m := ns_pattern.fullmatch(str(val.type.strip_typedefs().name)):
+        name = m.group('name')
+        if name and name.startswith('basic_json<') and name.endswith('>'):
+            m_data = val['m_data']
+            m_type = m_data['m_type']
+            m = ns_pattern.fullmatch(str(m_type))
+            t = m.group('name')
+            prefix = 'detail::value_t::'
+            if t and t.startswith(prefix):
+                try:
+                    union_val = m_data['m_value'][t.replace(prefix, '', 1)]
+                    if union_val.type.code == gdb.TYPE_CODE_PTR:
+                        return gdb.default_visualizer(union_val.dereference())
+                    else:
+                        return JsonValuePrinter(union_val)
+                except Exception:
+                    return JsonValuePrinter(m_type)
+
+gdb.pretty_printers.append(json_lookup_function)