From 5f8faca44787cad44723c6e217de1bcbf36d3bf7 Mon Sep 17 00:00:00 2001
From: Jukka Lehtosalo <jukka.lehtosalo@iki.fi>
Date: Thu, 20 Nov 2025 13:14:35 +0000
Subject: [PATCH 1/2] [mypyc] Add primitive for librt.base64.b64decode

Forgot to add this in #20263.
---
 mypyc/lib-rt/librt_base64.c         |  5 +++--
 mypyc/lib-rt/librt_base64.h         |  5 +++--
 mypyc/primitives/misc_ops.py        | 11 +++++++++++
 mypyc/test-data/irbuild-base64.test | 19 ++++++++++++++++++-
 4 files changed, 35 insertions(+), 5 deletions(-)

diff --git a/mypyc/lib-rt/librt_base64.c b/mypyc/lib-rt/librt_base64.c
index 1720359ef9a6..9eb59d950c11 100644
--- a/mypyc/lib-rt/librt_base64.c
+++ b/mypyc/lib-rt/librt_base64.c
@@ -261,12 +261,12 @@ static PyMethodDef librt_base64_module_methods[] = {
 
 static int
 base64_abi_version(void) {
-    return 0;
+    return LIBRT_BASE64_ABI_VERSION;
 }
 
 static int
 base64_api_version(void) {
-    return 0;
+    return LIBRT_BASE64_API_VERSION;
 }
 
 static int
@@ -278,6 +278,7 @@ librt_base64_module_exec(PyObject *m)
         (void *)base64_abi_version,
         (void *)base64_api_version,
         (void *)b64encode_internal,
+        (void *)b64decode_internal,
     };
     PyObject *c_api_object = PyCapsule_New((void *)base64_api, "librt.base64._C_API", NULL);
     if (PyModule_Add(m, "_C_API", c_api_object) < 0) {
diff --git a/mypyc/lib-rt/librt_base64.h b/mypyc/lib-rt/librt_base64.h
index cc97e54155fd..177cd0c1cfef 100644
--- a/mypyc/lib-rt/librt_base64.h
+++ b/mypyc/lib-rt/librt_base64.h
@@ -13,14 +13,15 @@ import_librt_base64(void)
 #else  // MYPYC_EXPERIMENTAL
 
 #define LIBRT_BASE64_ABI_VERSION 0
-#define LIBRT_BASE64_API_VERSION 0
-#define LIBRT_BASE64_API_LEN 3
+#define LIBRT_BASE64_API_VERSION 1
+#define LIBRT_BASE64_API_LEN 4
 
 static void *LibRTBase64_API[LIBRT_BASE64_API_LEN];
 
 #define LibRTBase64_ABIVersion (*(int (*)(void)) LibRTBase64_API[0])
 #define LibRTBase64_APIVersion (*(int (*)(void)) LibRTBase64_API[1])
 #define LibRTBase64_b64encode_internal (*(PyObject* (*)(PyObject *source)) LibRTBase64_API[2])
+#define LibRTBase64_b64decode_internal (*(PyObject* (*)(PyObject *source)) LibRTBase64_API[3])
 
 static int
 import_librt_base64(void)
diff --git a/mypyc/primitives/misc_ops.py b/mypyc/primitives/misc_ops.py
index bb225a76acd8..1b4c438b58fe 100644
--- a/mypyc/primitives/misc_ops.py
+++ b/mypyc/primitives/misc_ops.py
@@ -5,6 +5,7 @@
 from mypyc.ir.ops import ERR_FALSE, ERR_MAGIC, ERR_MAGIC_OVERLAPPING, ERR_NEVER
 from mypyc.ir.rtypes import (
     KNOWN_NATIVE_TYPES,
+    RUnion,
     bit_rprimitive,
     bool_rprimitive,
     bytes_rprimitive,
@@ -475,3 +476,13 @@
     experimental=True,
     capsule="librt.base64",
 )
+
+function_op(
+    name="librt.base64.b64decode",
+    arg_types=[RUnion([bytes_rprimitive, str_rprimitive])],
+    return_type=bytes_rprimitive,
+    c_function_name="LibRTBase64_b64decode_internal",
+    error_kind=ERR_MAGIC,
+    experimental=True,
+    capsule="librt.base64",
+)
diff --git a/mypyc/test-data/irbuild-base64.test b/mypyc/test-data/irbuild-base64.test
index bc73b7e35431..4d41f2912700 100644
--- a/mypyc/test-data/irbuild-base64.test
+++ b/mypyc/test-data/irbuild-base64.test
@@ -1,14 +1,31 @@
 [case testBase64_experimental]
-from librt.base64 import b64encode
+from librt.base64 import b64encode, b64decode
 
 def enc(b: bytes) -> bytes:
     return b64encode(b)
+
+def dec_bytes(b: bytes) -> bytes:
+    return b64decode(b)
+
+def dec_str(b: str) -> bytes:
+    return b64decode(b)
 [out]
 def enc(b):
     b, r0 :: bytes
 L0:
     r0 = LibRTBase64_b64encode_internal(b)
     return r0
+def dec_bytes(b):
+    b, r0 :: bytes
+L0:
+    r0 = LibRTBase64_b64decode_internal(b)
+    return r0
+def dec_str(b):
+    b :: str
+    r0 :: bytes
+L0:
+    r0 = LibRTBase64_b64decode_internal(b)
+    return r0
 
 [case testBase64ExperimentalDisabled]
 from librt.base64 import b64encode

From f0afca6b10dcf9c0575310151caf5bf0f3289dcd Mon Sep 17 00:00:00 2001
From: Jukka Lehtosalo <jukka.lehtosalo@iki.fi>
Date: Thu, 20 Nov 2025 13:33:58 +0000
Subject: [PATCH 2/2] Fix compilation

---
 mypyc/lib-rt/librt_base64.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/mypyc/lib-rt/librt_base64.c b/mypyc/lib-rt/librt_base64.c
index 9eb59d950c11..b23be59959c5 100644
--- a/mypyc/lib-rt/librt_base64.c
+++ b/mypyc/lib-rt/librt_base64.c
@@ -259,6 +259,8 @@ static PyMethodDef librt_base64_module_methods[] = {
     {NULL, NULL, 0, NULL}
 };
 
+#ifdef MYPYC_EXPERIMENTAL
+
 static int
 base64_abi_version(void) {
     return LIBRT_BASE64_ABI_VERSION;
@@ -269,6 +271,8 @@ base64_api_version(void) {
     return LIBRT_BASE64_API_VERSION;
 }
 
+#endif
+
 static int
 librt_base64_module_exec(PyObject *m)
 {