pythongh-141341: Rename COMPILER macro to _Py_COMPILER on Windows (python#141342)

Author: vstinner

Misc/NEWS.d/next/C_API/2025-11-10-11-26-26.gh-issue-141341.OsO6-y.rst

@@ -0,0 +1,2 @@
+On Windows, rename the ``COMPILER`` macro to ``_Py_COMPILER`` to avoid name
+conflicts. Patch by Victor Stinner.

PC/pyconfig.h

@@ -118,7 +118,7 @@ WIN32 is still required for the locale module.
 /* Microsoft C defines _MSC_VER, as does clang-cl.exe */
 #ifdef _MSC_VER
 
-/* We want COMPILER to expand to a string containing _MSC_VER's *value*.
+/* We want _Py_COMPILER to expand to a string containing _MSC_VER's *value*.
  * This is horridly tricky, because the stringization operator only works
  * on macro arguments, and doesn't evaluate macros passed *as* arguments.
  */
@@ -148,7 +148,7 @@ WIN32 is still required for the locale module.
 #define MS_WIN64
 #endif
 
-/* set the COMPILER and support tier
+/* set the _Py_COMPILER and support tier
  *
  * win_amd64 MSVC (x86_64-pc-windows-msvc): 1
  * win32 MSVC (i686-pc-windows-msvc): 1
@@ -158,22 +158,22 @@ WIN32 is still required for the locale module.
 #ifdef MS_WIN64
 #if defined(_M_X64) || defined(_M_AMD64)
 #if defined(__clang__)
-#define COMPILER ("[Clang " __clang_version__ "] 64 bit (AMD64) with MSC v." _Py_STRINGIZE(_MSC_VER) " CRT]")
+#define _Py_COMPILER ("[Clang " __clang_version__ "] 64 bit (AMD64) with MSC v." _Py_STRINGIZE(_MSC_VER) " CRT]")
 #define PY_SUPPORT_TIER 0
 #elif defined(__INTEL_COMPILER)
-#define COMPILER ("[ICC v." _Py_STRINGIZE(__INTEL_COMPILER) " 64 bit (amd64) with MSC v." _Py_STRINGIZE(_MSC_VER) " CRT]")
+#define _Py_COMPILER ("[ICC v." _Py_STRINGIZE(__INTEL_COMPILER) " 64 bit (amd64) with MSC v." _Py_STRINGIZE(_MSC_VER) " CRT]")
 #define PY_SUPPORT_TIER 0
 #else
-#define COMPILER _Py_PASTE_VERSION("64 bit (AMD64)")
+#define _Py_COMPILER _Py_PASTE_VERSION("64 bit (AMD64)")
 #define PY_SUPPORT_TIER 1
 #endif /* __clang__ */
 #define PYD_PLATFORM_TAG "win_amd64"
 #elif defined(_M_ARM64)
-#define COMPILER _Py_PASTE_VERSION("64 bit (ARM64)")
+#define _Py_COMPILER _Py_PASTE_VERSION("64 bit (ARM64)")
 #define PY_SUPPORT_TIER 3
 #define PYD_PLATFORM_TAG "win_arm64"
 #else
-#define COMPILER _Py_PASTE_VERSION("64 bit (Unknown)")
+#define _Py_COMPILER _Py_PASTE_VERSION("64 bit (Unknown)")
 #define PY_SUPPORT_TIER 0
 #endif
 #endif /* MS_WIN64 */
@@ -220,22 +220,22 @@ typedef _W64 int Py_ssize_t;
 #if defined(MS_WIN32) && !defined(MS_WIN64)
 #if defined(_M_IX86)
 #if defined(__clang__)
-#define COMPILER ("[Clang " __clang_version__ "] 32 bit (Intel) with MSC v." _Py_STRINGIZE(_MSC_VER) " CRT]")
+#define _Py_COMPILER ("[Clang " __clang_version__ "] 32 bit (Intel) with MSC v." _Py_STRINGIZE(_MSC_VER) " CRT]")
 #define PY_SUPPORT_TIER 0
 #elif defined(__INTEL_COMPILER)
-#define COMPILER ("[ICC v." _Py_STRINGIZE(__INTEL_COMPILER) " 32 bit (Intel) with MSC v." _Py_STRINGIZE(_MSC_VER) " CRT]")
+#define _Py_COMPILER ("[ICC v." _Py_STRINGIZE(__INTEL_COMPILER) " 32 bit (Intel) with MSC v." _Py_STRINGIZE(_MSC_VER) " CRT]")
 #define PY_SUPPORT_TIER 0
 #else
-#define COMPILER _Py_PASTE_VERSION("32 bit (Intel)")
+#define _Py_COMPILER _Py_PASTE_VERSION("32 bit (Intel)")
 #define PY_SUPPORT_TIER 1
 #endif /* __clang__ */
 #define PYD_PLATFORM_TAG "win32"
 #elif defined(_M_ARM)
-#define COMPILER _Py_PASTE_VERSION("32 bit (ARM)")
+#define _Py_COMPILER _Py_PASTE_VERSION("32 bit (ARM)")
 #define PYD_PLATFORM_TAG "win_arm32"
 #define PY_SUPPORT_TIER 0
 #else
-#define COMPILER _Py_PASTE_VERSION("32 bit (Unknown)")
+#define _Py_COMPILER _Py_PASTE_VERSION("32 bit (Unknown)")
 #define PY_SUPPORT_TIER 0
 #endif
 #endif /* MS_WIN32 && !MS_WIN64 */
@@ -273,7 +273,7 @@ typedef int pid_t;
 #warning "Please use an up-to-date version of gcc! (>2.91 recommended)"
 #endif
 
-#define COMPILER "[gcc]"
+#define _Py_COMPILER "[gcc]"
 #define PY_LONG_LONG long long
 #define PY_LLONG_MIN LLONG_MIN
 #define PY_LLONG_MAX LLONG_MAX
@@ -286,7 +286,7 @@ typedef int pid_t;
 /* XXX These defines are likely incomplete, but should be easy to fix.
    They should be complete enough to build extension modules. */
 
-#define COMPILER "[lcc-win32]"
+#define _Py_COMPILER "[lcc-win32]"
 typedef int pid_t;
 /* __declspec() is supported here too - do nothing to get the defaults */
 

Python/getcompiler.c

@@ -3,6 +3,10 @@
 
 #include "Python.h"
 
+#ifdef _Py_COMPILER
+#  define COMPILER _Py_COMPILER
+#endif
+
 #ifndef COMPILER
 
 // Note the __clang__ conditional has to come before the __GNUC__ one because