From 85bc088441bcf4047ee9bdcfa22e5448f445a565 Mon Sep 17 00:00:00 2001
From: "Ralf W. Grosse-Kunstleve" <rwgk@google.com>
Date: Thu, 7 Jul 2022 17:51:44 -0700
Subject: [PATCH 1/2] Report `C++ Info:` via `pytest_report_header()` (#4046)

* Report `C++ Info:` from `pytest_configure()`

* Use pytest_report_header() as suggested by @skylion007
---
 include/pybind11/detail/common.h |  1 +
 tests/conftest.py                | 15 ++++++++++++++-
 tests/pybind11_tests.cpp         | 25 +++++++++++++++++++++++++
 3 files changed, 40 insertions(+), 1 deletion(-)

diff --git a/include/pybind11/detail/common.h b/include/pybind11/detail/common.h
index 9355ecfda..e52507a9e 100644
--- a/include/pybind11/detail/common.h
+++ b/include/pybind11/detail/common.h
@@ -38,6 +38,7 @@
 #            define PYBIND11_CPP17
 #            if __cplusplus >= 202002L
 #                define PYBIND11_CPP20
+// Please update tests/pybind11_tests.cpp `cpp_std()` when adding a macro here.
 #            endif
 #        endif
 #    endif
diff --git a/tests/conftest.py b/tests/conftest.py
index e72ec0ef8..02ce263af 100644
--- a/tests/conftest.py
+++ b/tests/conftest.py
@@ -13,7 +13,7 @@ import textwrap
 import pytest
 
 # Early diagnostic for failed imports
-import pybind11_tests  # noqa: F401
+import pybind11_tests
 
 _long_marker = re.compile(r"([0-9])L")
 _hexadecimal = re.compile(r"0x[0-9a-fA-F]+")
@@ -198,3 +198,16 @@ def gc_collect():
 def pytest_configure():
     pytest.suppress = suppress
     pytest.gc_collect = gc_collect
+
+
+def pytest_report_header(config):
+    del config  # Unused.
+    assert (
+        pybind11_tests.compiler_info is not None
+    ), "Please update pybind11_tests.cpp if this assert fails."
+    return (
+        "C++ Info:"
+        f" {pybind11_tests.compiler_info}"
+        f" {pybind11_tests.cpp_std}"
+        f" {pybind11_tests.PYBIND11_INTERNALS_ID}"
+    )
diff --git a/tests/pybind11_tests.cpp b/tests/pybind11_tests.cpp
index 3c0469915..aa3095594 100644
--- a/tests/pybind11_tests.cpp
+++ b/tests/pybind11_tests.cpp
@@ -62,9 +62,34 @@ void bind_ConstructorStats(py::module_ &m) {
         });
 }
 
+const char *cpp_std() {
+    return
+#if defined(PYBIND11_CPP20)
+        "C++20";
+#elif defined(PYBIND11_CPP17)
+        "C++17";
+#elif defined(PYBIND11_CPP14)
+        "C++14";
+#else
+        "C++11";
+#endif
+}
+
 PYBIND11_MODULE(pybind11_tests, m) {
     m.doc() = "pybind11 test module";
 
+    // Intentionally kept minimal to not create a maintenance chore
+    // ("just enough" to be conclusive).
+#if defined(_MSC_FULL_VER)
+    m.attr("compiler_info") = "MSVC " PYBIND11_TOSTRING(_MSC_FULL_VER);
+#elif defined(__VERSION__)
+    m.attr("compiler_info") = __VERSION__;
+#else
+    m.attr("compiler_info") = py::none();
+#endif
+    m.attr("cpp_std") = cpp_std();
+    m.attr("PYBIND11_INTERNALS_ID") = PYBIND11_INTERNALS_ID;
+
     bind_ConstructorStats(m);
 
 #if defined(PYBIND11_DETAILED_ERROR_MESSAGES)

From 432bc5cfb5c696044e93dfc78b2fa822dfd1dc4e Mon Sep 17 00:00:00 2001
From: "Ralf W. Grosse-Kunstleve" <rwgk@google.com>
Date: Thu, 7 Jul 2022 19:08:10 -0700
Subject: [PATCH 2/2] Add `std::string clean_type_id(const char *typeid_name)`
 overload (in namespace detail). (#4049)

Very minor refactoring to ease development and debugging.

Having to declare a local `std::string` has bugged me many times. Nice to get this little nuisance out of the way.

Extracted from PR #4022, where it is used like this:

```
    std::fprintf(stdout,
                 "\nTYPE_CASTER_ODR_GUARD_IMPL %s %s\n",
                 clean_type_id(intrinsic_type_info.name()).c_str(),
                 source_file_line_from_sloc.c_str());
```
---
 include/pybind11/detail/typeid.h | 12 +++++++++---
 1 file changed, 9 insertions(+), 3 deletions(-)

diff --git a/include/pybind11/detail/typeid.h b/include/pybind11/detail/typeid.h
index 8d99fc028..a67b52135 100644
--- a/include/pybind11/detail/typeid.h
+++ b/include/pybind11/detail/typeid.h
@@ -20,6 +20,7 @@
 
 PYBIND11_NAMESPACE_BEGIN(PYBIND11_NAMESPACE)
 PYBIND11_NAMESPACE_BEGIN(detail)
+
 /// Erase all occurrences of a substring
 inline void erase_all(std::string &string, const std::string &search) {
     for (size_t pos = 0;;) {
@@ -46,14 +47,19 @@ PYBIND11_NOINLINE void clean_type_id(std::string &name) {
 #endif
     detail::erase_all(name, "pybind11::");
 }
+
+inline std::string clean_type_id(const char *typeid_name) {
+    std::string name(typeid_name);
+    detail::clean_type_id(name);
+    return name;
+}
+
 PYBIND11_NAMESPACE_END(detail)
 
 /// Return a string representation of a C++ type
 template <typename T>
 static std::string type_id() {
-    std::string name(typeid(T).name());
-    detail::clean_type_id(name);
-    return name;
+    return detail::clean_type_id(typeid(T).name());
 }
 
 PYBIND11_NAMESPACE_END(PYBIND11_NAMESPACE)