From 87c5cf3b48300cb046aa66bb9075c22ff4afc64a Mon Sep 17 00:00:00 2001
From: Eremey Valetov <eremey@valetov.com>
Date: Mon, 4 May 2026 16:45:20 -0400
Subject: [PATCH] Windows MSVC build: more compat-layer fixes

Round 2 of c67b631 cleanup.  After the dirent + utime fixes, the
MSVC link surface still had:

- LNK2005 'fopen already defined': dropped g_fopen so we no longer
  override the SDK's fopen.  UTF-8 paths still work on Windows 10
  with the active-codepage manifest; non-Unicode codepages will see
  ANSI translation.  This is good enough for the public release; a
  full UTF-8 fopen wrapper can be added later if needed.

- LNK2019 'unresolved S_ISDIR / S_ISREG': MSVC's <sys/stat.h> defines
  _S_IFDIR / _S_IFREG but not the POSIX S_IS* macros.  Add them in
  the unistd.h shim (which main.c already pulls).

- LNK1181 'cannot open input file m.lib': test_merkle and test_rans
  linked libm unconditionally.  Math is in the default CRT on MSVC;
  link 'm' only on non-Windows.

- 'unistd.h' not found in test_blockstore.c: it actually only needs
  getpid().  Use <process.h> + #define getpid _getpid on MSVC, keep
  <unistd.h> elsewhere.
---
 cli/CMakeLists.txt                   |  2 +-
 cli/src/compat/include/msvc/unistd.h |  8 ++++++++
 tests/CMakeLists.txt                 | 12 ++++++++++--
 tests/src/test_blockstore.c          |  5 +++++
 4 files changed, 24 insertions(+), 3 deletions(-)

diff --git a/cli/CMakeLists.txt b/cli/CMakeLists.txt
index 4f4b67c..e2ddb55 100644
--- a/cli/CMakeLists.txt
+++ b/cli/CMakeLists.txt
@@ -29,7 +29,7 @@ if(WIN32)
         NO_OLDNAMES
         g_err g_errx g_warn g_warnx g_vwarn g_vwarnx g_verr g_verrx
         g_getprogname g_setlinebuf g_fnmatch
-        g_compat__utf8_console g_compat__wpath g_fopen
+        g_compat__utf8_console g_compat__wpath
         g_access g_unlink g_chdir g_mkdir g_chmod g_utime
         g_opendir
     )
diff --git a/cli/src/compat/include/msvc/unistd.h b/cli/src/compat/include/msvc/unistd.h
index 6a8f8ee..52d380e 100644
--- a/cli/src/compat/include/msvc/unistd.h
+++ b/cli/src/compat/include/msvc/unistd.h
@@ -24,6 +24,14 @@
 #define PATH_MAX 260
 #endif
 
+#include <sys/stat.h>
+#ifndef S_ISDIR
+#define S_ISDIR(m) (((m) & _S_IFMT) == _S_IFDIR)
+#endif
+#ifndef S_ISREG
+#define S_ISREG(m) (((m) & _S_IFMT) == _S_IFREG)
+#endif
+
 /* Provided by compat_win32.c (UTF-8-aware via wide-char APIs) */
 int access(const char *path, int mode);
 int unlink(const char *path);
diff --git a/tests/CMakeLists.txt b/tests/CMakeLists.txt
index ae08797..e6bdaaf 100644
--- a/tests/CMakeLists.txt
+++ b/tests/CMakeLists.txt
@@ -52,7 +52,11 @@ target_compile_features(test_cdc PRIVATE c_std_99)
 add_test(NAME cdc COMMAND test_cdc)
 
 add_executable(test_merkle src/test_merkle.c)
-target_link_libraries(test_merkle PRIVATE uc2 m)
+if(WIN32)
+    target_link_libraries(test_merkle PRIVATE uc2)
+else()
+    target_link_libraries(test_merkle PRIVATE uc2 m)
+endif()
 target_include_directories(test_merkle PRIVATE "${PROJECT_BINARY_DIR}/lib")
 target_compile_features(test_merkle PRIVATE c_std_99)
 add_test(NAME merkle COMMAND test_merkle)
@@ -76,7 +80,11 @@ target_compile_features(test_delta PRIVATE c_std_99)
 add_test(NAME delta COMMAND test_delta)
 
 add_executable(test_rans src/test_rans.c)
-target_link_libraries(test_rans PRIVATE uc2 m)
+if(WIN32)
+    target_link_libraries(test_rans PRIVATE uc2)
+else()
+    target_link_libraries(test_rans PRIVATE uc2 m)
+endif()
 target_include_directories(test_rans PRIVATE "${PROJECT_BINARY_DIR}/lib")
 target_compile_features(test_rans PRIVATE c_std_99)
 add_test(NAME rans COMMAND test_rans)
diff --git a/tests/src/test_blockstore.c b/tests/src/test_blockstore.c
index ac875ea..6442cfd 100644
--- a/tests/src/test_blockstore.c
+++ b/tests/src/test_blockstore.c
@@ -4,7 +4,12 @@
 #include <stdlib.h>
 #include <string.h>
 #include <assert.h>
+#ifdef _MSC_VER
+#include <process.h>
+#define getpid _getpid
+#else
 #include <unistd.h>
+#endif
 #include <uc2/uc2_blockstore.h>
 #include <uc2/uc2_merkle.h>