From bdf954f3095ef4c85402b47af99ec22e87f2a024 Mon Sep 17 00:00:00 2001
From: Juan Miguel Carceller <jmcarcell@users.noreply.github.com>
Date: Thu, 8 Oct 2026 07:52:29 +0200
Subject: [PATCH] [cppjit] Declare code through TCling::Declare [ROOT-patch]

Cpp::Declare keeps class autoloading and autoparsing on, so including a
header whose dictionary is autoloaded from its rootmap can parse it twice.
Use gInterpreter.Declare in cppdef, include and c_include, as cppyy did.
---
 python/cppjit/__init__.py | 17 +++++++------
 test/CMakeLists.txt       |  1 +
 test/test_root_declare.py | 52 +++++++++++++++++++++++++++++++++++++++
 3 files changed, 62 insertions(+), 8 deletions(-)
 create mode 100644 test/test_root_declare.py

diff --git a/python/cppjit/__init__.py b/python/cppjit/__init__.py
index 3d0282af..8b8f3a8d 100644
--- a/python/cppjit/__init__.py
+++ b/python/cppjit/__init__.py
@@ -241,8 +241,10 @@ def _interpreter_lock():
 def cppdef(src, verbose=True):
     """Declare C++ source <src> to Cling."""
     with _stderr_capture() as err, _interpreter_lock():
-        errcode = gbl.Cpp.Declare(src, not verbose)
-    if not errcode == 0 or err.err:
+        ok = gbl.gInterpreter.Declare(src)
+    if not verbose:
+        err.err = ""
+    if not ok or err.err:
         if "warning" in err.err.lower() and "error" not in err.err.lower():
             warnings.warn(err.err, SyntaxWarning)
             return True
@@ -326,8 +328,8 @@ def load_library(name):
 def include(header):
     """Load (and JIT) header file <header> into Cling."""
     with _stderr_capture() as err, _interpreter_lock():
-        errcode = gbl.Cpp.Declare('#include "%s"' % header, False)
-    if not errcode == 0:
+        ok = gbl.gInterpreter.Declare('#include "%s"' % header)
+    if not ok:
         raise ImportError('Failed to load header file "%s"%s' % (header, err.err))
     return True
 
@@ -335,14 +337,13 @@ def include(header):
 def c_include(header):
     """Load (and JIT) header file <header> into Cling."""
     with _stderr_capture() as err, _interpreter_lock():
-        errcode = gbl.Cpp.Declare(
+        ok = gbl.gInterpreter.Declare(
             """extern "C" {
                                     #include "%s"
                                     }"""
-            % header,
-            False,
+            % header
         )
-    if not errcode == 0:
+    if not ok:
         raise ImportError('Failed to load header file "%s"%s' % (header, err.err))
     return True
 
diff --git a/test/CMakeLists.txt b/test/CMakeLists.txt
index 482c2abb..b0ea1e2b 100644
--- a/test/CMakeLists.txt
+++ b/test/CMakeLists.txt
@@ -124,4 +124,5 @@ CPPJIT_ADD_PYTEST(test_eigen)
 CPPJIT_ADD_PYTEST(test_leakcheck)
 CPPJIT_ADD_PYTEST(test_numba)
 CPPJIT_ADD_PYTEST(test_regression)
+CPPJIT_ADD_PYTEST(test_root_declare)
 CPPJIT_ADD_PYTEST(test_root_interpreter_lock)
diff --git a/test/test_root_declare.py b/test/test_root_declare.py
new file mode 100644
index 00000000..7a843385
--- /dev/null
+++ b/test/test_root_declare.py
@@ -0,0 +1,52 @@
+import os
+import subprocess
+
+from pytest import mark
+from support import IS_WINDOWS
+
+
+class TestROOTDECLARE:
+    @mark.skipif(IS_WINDOWS, reason="builds a dictionary with rootcling")
+    def test01_include_header_of_autoloaded_dictionary(self, tmp_path):
+        """include a #pragma once header whose dictionary its rootmap autoloads"""
+
+        import cppjit
+
+        name = "pragma_once_dict"
+        header, linkdef = name + ".h", name + "LinkDef.h"
+        rootmap, lib = name + ".rootmap", "lib%s.so" % name
+        (tmp_path / header).write_text(
+            "#pragma once\n"
+            "namespace %s { struct Thing { int value() const { return 42; } }; }\n"
+            % name
+        )
+        (tmp_path / linkdef).write_text(
+            "#ifdef __CLING__\n#pragma link C++ class %s::Thing+;\n#endif\n" % name
+        )
+
+        bindir = cppjit.gbl.TROOT.GetBinDir().Data()
+        rootcling = os.path.join(bindir, "rootcling")
+        root_config = os.path.join(bindir, "root-config")
+        subprocess.check_call(
+            [rootcling, "-f", "dict.cxx", "-rmf", rootmap, "-rml", lib]
+            + ["-I" + str(tmp_path), header, linkdef],
+            cwd=tmp_path,
+        )
+        cxx = subprocess.check_output([root_config, "--cxx"], text=True).split()
+        flags = subprocess.check_output(
+            [root_config, "--cflags", "--libs"], text=True
+        ).split()
+        subprocess.check_call(
+            cxx
+            + ["-shared", "-fPIC", "-o", lib, "dict.cxx", "-I" + str(tmp_path)]
+            + flags,
+            cwd=tmp_path,
+        )
+
+        cppjit.add_include_path(str(tmp_path))
+        cppjit.add_library_path(str(tmp_path))
+        cppjit.gbl.gInterpreter.LoadLibraryMap(str(tmp_path / rootmap))
+
+        cppjit.include(header)
+
+        assert cppjit.gbl.pragma_once_dict.Thing().value() == 42