selection of default architecture changed from system to current process (new function detect_process_arch added)

src/copapy/_basic_types.py

@@ -1,7 +1,6 @@
 import pkgutil
 from typing import Any, TypeVar, overload, TypeAlias, Generic, cast
-from ._stencils import stencil_database
-import platform
+from ._stencils import stencil_database, detect_process_arch
 import copapy as cp
 
 NumLike: TypeAlias = 'variable[int] | variable[float] | variable[bool] | int | float | bool'
@@ -12,17 +11,25 @@ unibool: TypeAlias = 'variable[bool] | bool'
 TCPNum = TypeVar("TCPNum", bound='variable[Any]')
 TNum = TypeVar("TNum", int, bool, float)
 
+stencil_cache: dict[tuple[str, str], stencil_database] = {}
+
 
 def get_var_name(var: Any, scope: dict[str, Any] = globals()) -> list[str]:
     return [name for name, value in scope.items() if value is var]
 
 
 def stencil_db_from_package(arch: str = 'native', optimization: str = 'O3') -> stencil_database:
+    global stencil_cache
+    ci = (arch, optimization)
+    if ci in stencil_cache:
+        return stencil_cache[ci]  # return cached stencil db
     if arch == 'native':
-        arch = platform.machine()
+        arch = detect_process_arch()
     stencil_data = pkgutil.get_data(__name__, f"obj/stencils_{arch}_{optimization}.o")
     assert stencil_data, f"stencils_{arch}_{optimization} not found"
-    return stencil_database(stencil_data)
+    sdb = stencil_database(stencil_data)
+    stencil_cache[ci] = sdb
+    return sdb
 
 
 generic_sdb = stencil_db_from_package()

src/copapy/_stencils.py

@@ -2,6 +2,8 @@ from dataclasses import dataclass
 from pelfy import open_elf_file, elf_file, elf_symbol
 from typing import Generator, Literal, Iterable
 import pelfy
+import struct
+import platform
 
 ByteOrder = Literal['little', 'big']
 
@@ -37,6 +39,28 @@ class patch_entry:
     patch_type: int
 
 
+def detect_process_arch() -> str:
+    bits = struct.calcsize("P") * 8
+    arch = platform.machine().lower()
+
+    if arch in ('amd64', 'x86_64'):
+        arch_family = 'x86_64' if bits == 64 else 'x86'
+    elif arch in ('i386', 'i686', 'x86'):
+        arch_family = 'x86'
+    elif arch in ('arm64', 'aarch64'):
+        arch_family = 'arm64'
+    elif 'arm' in arch:
+        arch_family = 'arm'
+    elif 'mips' in arch:
+        arch_family = 'mips64' if bits == 64 else 'mips'
+    elif 'riscv' in arch:
+        arch_family = 'riscv64' if bits == 64 else 'riscv'
+    else:
+        raise NotImplementedError(f"Platform {arch} with {bits} bits is not supported.")
+
+    return arch_family
+
+
 def get_return_function_type(symbol: elf_symbol) -> str:
     if symbol.relocations:
         result_func = symbol.relocations[-1].symbol
@@ -275,6 +299,10 @@ class stencil_database():
     def get_section_size(self, index: int) -> int:
         """Returns the size of a section specified by index."""
         return self.elf.sections[index].fields['sh_size']
+    
+    def get_section_alignment(self, index: int) -> int:
+        """Returns the required alignment of a section specified by index."""
+        return self.elf.sections[index].fields['sh_addralign']
 
     def get_section_data(self, index: int) -> bytes:
         """Returns the data of a section specified by index."""