IO: Resolve IO DLL paths from environment variables (#119)

## Summary

Adds a unified mechanism for locating third-party IO DLLs through environment
variables, on top of the existing per-game `[xxxio] path=` INI setting.

## Changes

For each IO DLL, the path is resolved in this order:

1. The section-specific INI value, e.g. `[mai2io] path=`.
2. The section-specific environment variable, e.g. `SEGATOOLS_MAI2IO_PATH`.
3. `SEGATOOLS_IO_ROOT` joined with the default IO DLL filename, e.g.
   `%SEGATOOLS_IO_ROOT%\mai2io.dll`.
4. Empty path, which keeps the built-in IO implementation (unchanged default).

INI and environment-variable paths are run through Windows environment-variable
expansion, so values such as `%SEGATOOLS_IO_ROOT%\mai2io.dll` are valid in the
INI directly.

Reviewed-on: https://gitea.tendokyu.moe/TeamTofuShop/segatools/pulls/119
Co-authored-by: グローランプ <130208311+Gl0w1amp@users.noreply.github.com>
Co-committed-by: グローランプ <130208311+Gl0w1amp@users.noreply.github.com>

common/board/config.c

@@ -11,6 +11,7 @@
 #include "board/vfd.h"
 
 #include "util/dprintf.h"
+#include "util/io-path.h"
 
 // Check windows
 #if _WIN32 || _WIN64
@@ -44,24 +45,26 @@ static void aime_dll_config_load(struct aime_dll_config *cfg, const wchar_t *fil
             // Always empty, due to amdaemon being 64 bit in 32 bit mode
             memset(cfg->path, 0, sizeof(cfg->path));
         #elif defined(ENV64BIT)
-            GetPrivateProfileStringW(
-                    L"aimeio",
-                    L"path",
-                    L"",
+            io_path_config_load(
                     cfg->path,
                     _countof(cfg->path),
+                    L"aimeio",
+                    L"path",
+                    L"SEGATOOLS_AIMEIO_PATH",
+                    L"aimeio.dll",
                     filename);
         #else
             #error "Unknown environment"
         #endif
     } else {
-        GetPrivateProfileStringW(
-            L"aimeio",
-            L"path",
-            L"",
-            cfg->path,
-            _countof(cfg->path),
-            filename);
+        io_path_config_load(
+                cfg->path,
+                _countof(cfg->path),
+                L"aimeio",
+                L"path",
+                L"SEGATOOLS_AIMEIO_PATH",
+                L"aimeio.dll",
+                filename);
     }
 }
 

common/hooklib/config.c

@@ -9,6 +9,7 @@
 #include "hooklib/dvd.h"
 #include "hooklib/y3.h"
 #include "hooklib/y3-dll.h"
+#include "util/io-path.h"
 
 void dvd_config_load(struct dvd_config *cfg, const wchar_t *filename)
 {
@@ -158,12 +159,13 @@ void y3_dll_config_load(
     assert(cfg != NULL);
     assert(filename != NULL);
 
-    GetPrivateProfileStringW(
-            L"y3io",
-            L"path",
-            L"",
+    io_path_config_load(
             cfg->path,
             _countof(cfg->path),
+            L"y3io",
+            L"path",
+            L"SEGATOOLS_Y3IO_PATH",
+            L"y3io.dll",
             filename);
 }
 
@@ -243,4 +245,4 @@ void y3_config_load(
             filename);
 
     wcstombs(cfg->target_code_printer, tmpstr, sizeof(cfg->target_code_printer) - 1);
-}
+}

common/util/io-path.c

@@ -0,0 +1,203 @@
+#include <windows.h>
+
+#include <assert.h>
+#include <stdbool.h>
+#include <stddef.h>
+#include <stdlib.h>
+#include <string.h>
+#include <wchar.h>
+
+#include "util/dprintf.h"
+#include "util/io-path.h"
+
+static bool io_path_expand(
+        wchar_t *out,
+        size_t out_count,
+        const wchar_t *path,
+        const wchar_t *source);
+static bool io_path_from_root(
+        wchar_t *out,
+        size_t out_count,
+        const wchar_t *root_filename);
+static bool io_path_is_separator(wchar_t ch);
+
+bool io_path_config_load(
+        wchar_t *out,
+        size_t out_count,
+        const wchar_t *section,
+        const wchar_t *key,
+        const wchar_t *env_name,
+        const wchar_t *root_filename,
+        const wchar_t *filename)
+{
+    wchar_t path[MAX_PATH];
+    DWORD count;
+
+    assert(out != NULL);
+    assert(out_count > 0);
+    assert(section != NULL);
+    assert(key != NULL);
+    assert(filename != NULL);
+
+    out[0] = L'\0';
+
+    count = GetPrivateProfileStringW(
+            section,
+            key,
+            L"",
+            path,
+            _countof(path),
+            filename);
+
+    if (count >= _countof(path) - 1 && path[0] != L'\0') {
+        dprintf("IO path: INI value [%S] %S may be truncated "
+                "(exceeds %d characters)\n",
+                section,
+                key,
+                (int) _countof(path) - 1);
+    }
+
+    if (path[0] != L'\0') {
+        return io_path_expand(out, out_count, path, key);
+    }
+
+    if (env_name != NULL) {
+        count = GetEnvironmentVariableW(env_name, path, _countof(path));
+
+        if (count >= _countof(path)) {
+            dprintf("IO path: Environment variable too long: %S\n", env_name);
+
+            return false;
+        }
+
+        if (count != 0 && path[0] != L'\0') {
+            return io_path_expand(out, out_count, path, env_name);
+        }
+    }
+
+    return io_path_from_root(out, out_count, root_filename);
+}
+
+static bool io_path_expand(
+        wchar_t *out,
+        size_t out_count,
+        const wchar_t *path,
+        const wchar_t *source)
+{
+    DWORD expanded;
+
+    assert(out != NULL);
+    assert(out_count > 0);
+    assert(path != NULL);
+    assert(source != NULL);
+
+    expanded = ExpandEnvironmentStringsW(path, out, (DWORD) out_count);
+
+    if (expanded == 0) {
+        dprintf("IO path: Failed to expand path from %S: %lx\n",
+                source,
+                GetLastError());
+        out[0] = L'\0';
+
+        return false;
+    }
+
+    if (expanded > out_count) {
+        dprintf("IO path: Expanded path from %S is too long: %S\n",
+                source,
+                path);
+        out[0] = L'\0';
+
+        return false;
+    }
+
+    return true;
+}
+
+static bool io_path_from_root(
+        wchar_t *out,
+        size_t out_count,
+        const wchar_t *root_filename)
+{
+    wchar_t root[MAX_PATH];
+    wchar_t expanded_root[MAX_PATH];
+    size_t root_len;
+    size_t file_len;
+    DWORD count;
+
+    assert(out != NULL);
+    assert(out_count > 0);
+
+    if (root_filename == NULL || root_filename[0] == L'\0') {
+        return false;
+    }
+
+    count = GetEnvironmentVariableW(
+            L"SEGATOOLS_IO_ROOT",
+            root,
+            _countof(root));
+
+    if (count >= _countof(root)) {
+        dprintf("IO path: SEGATOOLS_IO_ROOT is too long\n");
+
+        return false;
+    }
+
+    if (count == 0 || root[0] == L'\0') {
+        return false;
+    }
+
+    if (!io_path_expand(
+            expanded_root,
+            _countof(expanded_root),
+            root,
+            L"SEGATOOLS_IO_ROOT")) {
+        return false;
+    }
+
+    root_len = wcslen(expanded_root);
+    file_len = wcslen(root_filename);
+
+    if (root_len == 0) {
+        return false;
+    }
+
+    if (root_len + file_len + 2 > out_count) {
+        dprintf("IO path: SEGATOOLS_IO_ROOT path is too long: %S\\%S\n",
+                expanded_root,
+                root_filename);
+
+        return false;
+    }
+
+    wcscpy_s(out, out_count, expanded_root);
+
+    if (!io_path_is_separator(out[root_len - 1])) {
+        out[root_len++] = L'\\';
+        out[root_len] = L'\0';
+    }
+
+    wcscat_s(out, out_count, root_filename);
+
+    /* The SEGATOOLS_IO_ROOT fallback is broadcast to every hook at once, so a
+       single global setting is shared by games that may not each ship an IO
+       DLL in that directory. Unlike an explicit INI/env path (direct user
+       intent, allowed to fail loudly at load time), a synthesized root path
+       that does not exist should quietly fall back to the built-in IO
+       implementation instead of aborting hook startup. */
+    if (GetFileAttributesW(out) == INVALID_FILE_ATTRIBUTES) {
+        dprintf("IO path: SEGATOOLS_IO_ROOT DLL not found, "
+                "using built-in IO: %S\n",
+                out);
+        out[0] = L'\0';
+
+        return false;
+    }
+
+    return true;
+}
+
+static bool io_path_is_separator(wchar_t ch)
+{
+    return ch == L'\\' || ch == L'/';
+}

common/util/io-path.h

@@ -0,0 +1,15 @@
+#pragma once
+
+#include <windows.h>
+
+#include <stdbool.h>
+#include <stddef.h>
+
+bool io_path_config_load(
+        wchar_t *out,
+        size_t out_count,
+        const wchar_t *section,
+        const wchar_t *key,
+        const wchar_t *env_name,
+        const wchar_t *root_filename,
+        const wchar_t *filename);

common/util/meson.build

@@ -21,6 +21,8 @@ util_lib = static_library(
         'fg-detect.h',
         'get_function_ordinal.c',
         'get_function_ordinal.h',
+        'io-path.c',
+        'io-path.h',
         'lib.c',
         'lib.h',
         'slurp.c',

dist/apm3/segatools.ini

@@ -133,11 +133,15 @@ enable=1
 [aimeio]
 ; To use a custom card reader IO DLL enter its path here.
 ; Leave empty if you want to use Segatools built-in keyboard input.
+; If empty, SEGATOOLS_AIMEIO_PATH is used if set, followed by
+; SEGATOOLS_IO_ROOT\aimeio.dll.
 path=
 
 [apm3io]
 ; To use a custom APM3 IO DLL enter its path here.
 ; Leave empty if you want to use Segatools built-in gamepad input.
+; If empty, SEGATOOLS_APM3IO_PATH is used if set, followed by
+; SEGATOOLS_IO_ROOT\apm3io.dll.
 path=
 
 ; -----------------------------------------------------------------------------

dist/carol/segatools.ini

@@ -97,6 +97,8 @@ dpiAware=1
 [aimeio]
 ; To use a custom card reader IO DLL enter its path here.
 ; Leave empty if you want to use Segatools built-in keyboard input.
+; If empty, SEGATOOLS_AIMEIO_PATH is used if set, followed by
+; SEGATOOLS_IO_ROOT\aimeio.dll.
 path=
 
 ; -----------------------------------------------------------------------------

dist/chuni/segatools.ini

@@ -136,11 +136,15 @@ controllerLedOutputOpeNITHM=0
 [aimeio]
 ; To use a custom card reader IO DLL enter its path here.
 ; Leave empty if you want to use Segatools built-in keyboard input.
+; If empty, SEGATOOLS_AIMEIO_PATH is used if set, followed by
+; SEGATOOLS_IO_ROOT\aimeio.dll.
 path=
 
 [chuniio]
 ; To use a custom Chunithm IO DLL enter its path here.
 ; Leave empty if you want to use Segatools built-in keyboard input.
+; If empty, SEGATOOLS_CHUNIIO_PATH is used if set, followed by
+; SEGATOOLS_IO_ROOT\chuniio.dll.
 path=
 
 ; -----------------------------------------------------------------------------

dist/chusan/segatools.ini

@@ -162,15 +162,20 @@ controllerLedOutputOpeNITHM=0
 [aimeio]
 ; To use a custom card reader IO DLL (x64) enter its path here.
 ; Leave empty if you want to use Segatools built-in keyboard input.
+; If empty, SEGATOOLS_AIMEIO_PATH is used if set, followed by
+; SEGATOOLS_IO_ROOT\aimeio.dll.
 path=
 
 [chuniio]
 ; Uncomment this if you have custom chuniio implementation comprised of a single 32bit DLL.
 ; (will use chu2to3 engine internally)
+; If empty, SEGATOOLS_CHUNIIO_PATH can provide this path.
 ;path=
 
 ; Uncomment both of these if you have custom chuniio implementation comprised of two DLLs.
 ; x86 chuniio to path32, x64 to path64. Both are necessary.
+; If empty, SEGATOOLS_CHUNIIO_PATH32 and SEGATOOLS_CHUNIIO_PATH64 are used if set.
+; Otherwise SEGATOOLS_IO_ROOT\chuniio_x86.dll and SEGATOOLS_IO_ROOT\chuniio_x64.dll are used.
 ;path32=
 ;path64=
 

dist/cm/segatools.ini

@@ -103,6 +103,8 @@ printerOutPath="DEVICE\print"
 [aimeio]
 ; To use a custom card reader IO DLL enter its path here.
 ; Leave empty if you want to use Segatools built-in keyboard input.
+; If empty, SEGATOOLS_AIMEIO_PATH is used if set, followed by
+; SEGATOOLS_IO_ROOT\aimeio.dll.
 path=
 
 ; -----------------------------------------------------------------------------

dist/cxb/segatools.ini

@@ -108,11 +108,15 @@ dpiAware=1
 [aimeio]
 ; To use a custom card reader IO DLL enter its path here.
 ; Leave empty if you want to use Segatools built-in keyboard input.
+; If empty, SEGATOOLS_AIMEIO_PATH is used if set, followed by
+; SEGATOOLS_IO_ROOT\aimeio.dll.
 path=
 
 [cxbio]
 ; To use a custom crossbeats REV. DLL enter its path here.
 ; Leave empty if you want to use Segatools built-in keyboard input.
+; If empty, SEGATOOLS_CXBIO_PATH is used if set, followed by
+; SEGATOOLS_IO_ROOT\cxbio.dll.
 path=
 
 ; -----------------------------------------------------------------------------

dist/diva/segatools.ini

@@ -98,11 +98,15 @@ dpiAware=1
 [aimeio]
 ; To use a custom card reader IO DLL enter its path here.
 ; Leave empty if you want to use Segatools built-in keyboard input.
+; If empty, SEGATOOLS_AIMEIO_PATH is used if set, followed by
+; SEGATOOLS_IO_ROOT\aimeio.dll.
 path=
 
 [divaio]
 ; To use a custom Project DIVA Arcade IO DLL enter its path here.
 ; Leave empty if you want to use Segatools built-in gamepad/wheel input.
+; If empty, SEGATOOLS_DIVAIO_PATH is used if set, followed by
+; SEGATOOLS_IO_ROOT\divaio.dll.
 path=
 
 ; -----------------------------------------------------------------------------

dist/ekt/segatools_satellite.ini

@@ -114,16 +114,22 @@ enable=1
 [aimeio]
 ; To use a custom card reader IO DLL enter its path here.
 ; Leave empty if you want to use Segatools built-in keyboard input.
+; If empty, SEGATOOLS_AIMEIO_PATH is used if set, followed by
+; SEGATOOLS_IO_ROOT\aimeio.dll.
 path=
 
 [ektio]
 ; To use a custom Eiketsu Taisen IO DLL enter its path here.
 ; Leave empty if you want to use Segatools built-in keyboard/gamepad input.
+; If empty, SEGATOOLS_EKTIO_PATH is used if set, followed by
+; SEGATOOLS_IO_ROOT\ektio.dll.
 path=
 
 [y3io]
 ; To use a custom Y3 IO DLL enter its path here.
 ; Leave empty if you want to use ... TBA ...
+; If empty, SEGATOOLS_Y3IO_PATH is used if set, followed by
+; SEGATOOLS_IO_ROOT\y3io.dll.
 path=
 
 ; -----------------------------------------------------------------------------

dist/ekt/segatools_terminal.ini

@@ -101,11 +101,15 @@ enable=1
 [aimeio]
 ; To use a custom card reader IO DLL enter its path here.
 ; Leave empty if you want to use Segatools built-in keyboard input.
+; If empty, SEGATOOLS_AIMEIO_PATH is used if set, followed by
+; SEGATOOLS_IO_ROOT\aimeio.dll.
 path=
 
 [ektio]
 ; To use a custom Eiketsu Taisen IO DLL enter its path here.
 ; Leave empty if you want to use Segatools built-in keyboard/gamepad input.
+; If empty, SEGATOOLS_EKTIO_PATH is used if set, followed by
+; SEGATOOLS_IO_ROOT\ektio.dll.
 path=
 
 ; -----------------------------------------------------------------------------

dist/fgo/segatools.ini

@@ -134,11 +134,15 @@ rotate180=1
 [aimeio]
 ; To use a custom card reader IO DLL enter its path here.
 ; Leave empty if you want to use Segatools built-in keyboard input.
+; If empty, SEGATOOLS_AIMEIO_PATH is used if set, followed by
+; SEGATOOLS_IO_ROOT\aimeio.dll.
 path=
 
 [fgoio]
 ; To use a custom Fate/Grand Order Arcade IO DLL enter its path here.
 ; Leave empty if you want to use Segatools built-in gamepad input.
+; If empty, SEGATOOLS_FGOIO_PATH is used if set, followed by
+; SEGATOOLS_IO_ROOT\fgoio.dll.
 path=
 
 ; -----------------------------------------------------------------------------

dist/idac/segatools.ini

@@ -125,11 +125,15 @@ enable=1
 [aimeio]
 ; To use a custom card reader IO DLL enter its path here.
 ; Leave empty if you want to use Segatools built-in keyboard input.
+; If empty, SEGATOOLS_AIMEIO_PATH is used if set, followed by
+; SEGATOOLS_IO_ROOT\aimeio.dll.
 path=
 
 [idacio]
 ; To use a custom Initial D THE ARCADE IO DLL enter its path here.
 ; Leave empty if you want to use Segatools built-in gamepad/wheel input.
+; If empty, SEGATOOLS_IDACIO_PATH is used if set, followed by
+; SEGATOOLS_IO_ROOT\idacio.dll.
 path=
 
 ; -----------------------------------------------------------------------------

dist/idz/segatools.ini

@@ -125,11 +125,15 @@ dpiAware=1
 [aimeio]
 ; To use a custom card reader IO DLL enter its path here.
 ; Leave empty if you want to use Segatools built-in keyboard input.
+; If empty, SEGATOOLS_AIMEIO_PATH is used if set, followed by
+; SEGATOOLS_IO_ROOT\aimeio.dll.
 path=
 
 [idzio]
 ; To use a custom Initial D Zero IO DLL enter its path here.
 ; Leave empty if you want to use Segatools built-in gamepad/wheel input.
+; If empty, SEGATOOLS_IDZIO_PATH is used if set, followed by
+; SEGATOOLS_IO_ROOT\idzio.dll.
 path=
 
 ; -----------------------------------------------------------------------------

dist/kemono/segatools.ini

@@ -123,11 +123,15 @@ enable=1
 [aimeio]
 ; To use a custom card reader IO DLL enter its path here.
 ; Leave empty if you want to use Segatools built-in keyboard input.
+; If empty, SEGATOOLS_AIMEIO_PATH is used if set, followed by
+; SEGATOOLS_IO_ROOT\aimeio.dll.
 path=
 
 [kemonoio]
 ; To use a custom Kemono IO DLL enter its path here.
 ; Leave empty if you want to use Segatools built-in keyboard input.
+; If empty, SEGATOOLS_KEMONOIO_PATH is used if set, followed by
+; SEGATOOLS_IO_ROOT\kemonoio.dll.
 path=
 
 ; -----------------------------------------------------------------------------

dist/mai2/segatools.ini

@@ -112,11 +112,15 @@ targetAssembly=
 [aimeio]
 ; To use a custom card reader IO DLL enter its path here.
 ; Leave empty if you want to use Segatools built-in keyboard input.
+; If empty, SEGATOOLS_AIMEIO_PATH is used if set, followed by
+; SEGATOOLS_IO_ROOT\aimeio.dll.
 path=
 
 [mai2io]
 ; To use a custom maimai DX IO DLL enter its path here.
 ; Leave empty if you want to use Segatools built-in keyboard input.
+; If empty, SEGATOOLS_MAI2IO_PATH is used if set, followed by
+; SEGATOOLS_IO_ROOT\mai2io.dll.
 path=
 
 ; -----------------------------------------------------------------------------

dist/mercury/segatools.ini

@@ -109,11 +109,15 @@ enable=1
 [aimeio]
 ; To use a custom card reader IO DLL enter its path here.
 ; Leave empty if you want to use Segatools built-in keyboard input.
+; If empty, SEGATOOLS_AIMEIO_PATH is used if set, followed by
+; SEGATOOLS_IO_ROOT\aimeio.dll.
 path=
 
 [mercuryio]
 ; To use a custom WACCA IO DLL enter its path here.
 ; Leave empty if you want to use Segatools built-in keyboard input.
+; If empty, SEGATOOLS_MERCURYIO_PATH is used if set, followed by
+; SEGATOOLS_IO_ROOT\mercuryio.dll.
 path=
 
 ; -----------------------------------------------------------------------------

dist/mu3/segatools.ini

@@ -153,11 +153,15 @@ controllerLedOutputSerial=0
 [aimeio]
 ; To use a custom card reader IO DLL enter its path here.
 ; Leave empty if you want to use Segatools built-in keyboard input.
+; If empty, SEGATOOLS_AIMEIO_PATH is used if set, followed by
+; SEGATOOLS_IO_ROOT\aimeio.dll.
 path=
 
 [mu3io]
 ; To use a custom O.N.G.E.K.I. IO DLL enter its path here.
 ; Leave empty if you want to use Segatools built-in keyboard/gamepad input.
+; If empty, SEGATOOLS_MU3IO_PATH is used if set, followed by
+; SEGATOOLS_IO_ROOT\mu3io.dll.
 path=
 
 ; -----------------------------------------------------------------------------

dist/sekito/segatools_satellite.ini

@@ -138,16 +138,22 @@ enable=1
 [aimeio]
 ; To use a custom card reader IO DLL enter its path here.
 ; Leave empty if you want to use Segatools built-in keyboard input.
+; If empty, SEGATOOLS_AIMEIO_PATH is used if set, followed by
+; SEGATOOLS_IO_ROOT\aimeio.dll.
 path=
 
 [sekitoio]
 ; To use a custom Eiketsu Taisen IO DLL enter its path here.
 ; Leave empty if you want to use Segatools built-in keyboard/gamepad input.
+; If empty, SEGATOOLS_SEKITOIO_PATH is used if set, followed by
+; SEGATOOLS_IO_ROOT\sekitoio.dll.
 path=
 
 [y3io]
 ; To use a custom Y3 IO DLL enter its path here.
 ; Leave empty if you want to use ... TBA ...
+; If empty, SEGATOOLS_Y3IO_PATH is used if set, followed by
+; SEGATOOLS_IO_ROOT\y3io.dll.
 path=
 
 ; -----------------------------------------------------------------------------

dist/sekito/segatools_terminal.ini

@@ -123,11 +123,15 @@ enable=1
 [aimeio]
 ; To use a custom card reader IO DLL enter its path here.
 ; Leave empty if you want to use Segatools built-in keyboard input.
+; If empty, SEGATOOLS_AIMEIO_PATH is used if set, followed by
+; SEGATOOLS_IO_ROOT\aimeio.dll.
 path=
 
 [sekitoio]
 ; To use a custom Eiketsu Taisen IO DLL enter its path here.
 ; Leave empty if you want to use Segatools built-in keyboard/gamepad input.
+; If empty, SEGATOOLS_SEKITOIO_PATH is used if set, followed by
+; SEGATOOLS_IO_ROOT\sekitoio.dll.
 path=
 
 ; -----------------------------------------------------------------------------

dist/swdc/segatools.ini

@@ -92,11 +92,15 @@ enable=1
 [aimeio]
 ; To use a custom card reader IO DLL enter its path here.
 ; Leave empty if you want to use Segatools built-in keyboard input.
+; If empty, SEGATOOLS_AIMEIO_PATH is used if set, followed by
+; SEGATOOLS_IO_ROOT\aimeio.dll.
 path=
 
 [swdcio]
 ; To use a custom SEGA World Drivers Championship DLL enter its path here.
 ; Leave empty if you want to use Segatools built-in gamepad/wheel input.
+; If empty, SEGATOOLS_SWDCIO_PATH is used if set, followed by
+; SEGATOOLS_IO_ROOT\swdcio.dll.
 path=
 
 ; -----------------------------------------------------------------------------

dist/tokyo/segatools.ini

@@ -106,6 +106,8 @@ enable=1
 ; To use a custom Mario & Sonic at the Tokyo 2020 Olympics Arcade IO DLL enter 
 ; its path here. Leave empty if you want to use Segatools built-in keyboard/
 ; gamepad input.
+; If empty, SEGATOOLS_TOKYOIO_PATH is used if set, followed by
+; SEGATOOLS_IO_ROOT\tokyoio.dll.
 path=
 
 ; -----------------------------------------------------------------------------

doc/config/common.md

@@ -17,6 +17,61 @@ Then you can copy `segatools.ini` to `another_config.ini` but with different dns
 set SEGATOOLS_CONFIG_PATH=.\another_config.ini
 ```
 
+## IO DLL path resolution
+
+Custom IO DLL paths are resolved in this order:
+
+1. The section-specific INI value, such as `[mai2io] path=`.
+2. The section-specific environment variable, such as `SEGATOOLS_MAI2IO_PATH`.
+3. `SEGATOOLS_IO_ROOT` joined with the default IO DLL filename, such as
+   `%SEGATOOLS_IO_ROOT%\mai2io.dll`.
+4. Empty path, which keeps the built-in IO implementation.
+
+INI paths and environment-variable paths support Windows environment variable
+expansion, so an INI entry like this is valid:
+
+```ini
+[mai2io]
+path=%SEGATOOLS_IO_ROOT%\mai2io.dll
+```
+
+Supported IO environment variables:
+
+| INI section | Direct environment variable | `SEGATOOLS_IO_ROOT` filename |
+| --- | --- | --- |
+| `[aimeio]` | `SEGATOOLS_AIMEIO_PATH` | `aimeio.dll` |
+| `[apm3io]` | `SEGATOOLS_APM3IO_PATH` | `apm3io.dll` |
+| `[carolio]` | `SEGATOOLS_CAROLIO_PATH` | `carolio.dll` |
+| `[chuniio]` | `SEGATOOLS_CHUNIIO_PATH` | `chuniio.dll` \* |
+| `[cmio]` | `SEGATOOLS_CMIO_PATH` | `cmio.dll` |
+| `[cxbio]` | `SEGATOOLS_CXBIO_PATH` | `cxbio.dll` |
+| `[divaio]` | `SEGATOOLS_DIVAIO_PATH` | `divaio.dll` |
+| `[ektio]` | `SEGATOOLS_EKTIO_PATH` | `ektio.dll` |
+| `[fgoio]` | `SEGATOOLS_FGOIO_PATH` | `fgoio.dll` |
+| `[idacio]` | `SEGATOOLS_IDACIO_PATH` | `idacio.dll` |
+| `[idzio]` | `SEGATOOLS_IDZIO_PATH` | `idzio.dll` |
+| `[kemonoio]` | `SEGATOOLS_KEMONOIO_PATH` | `kemonoio.dll` |
+| `[mai2io]` | `SEGATOOLS_MAI2IO_PATH` | `mai2io.dll` |
+| `[mercuryio]` | `SEGATOOLS_MERCURYIO_PATH` | `mercuryio.dll` |
+| `[mu3io]` | `SEGATOOLS_MU3IO_PATH` | `mu3io.dll` |
+| `[sekitoio]` | `SEGATOOLS_SEKITOIO_PATH` | `sekitoio.dll` |
+| `[swdcio]` | `SEGATOOLS_SWDCIO_PATH` | `swdcio.dll` |
+| `[tokyoio]` | `SEGATOOLS_TOKYOIO_PATH` | `tokyoio.dll` |
+| `[y3io]` | `SEGATOOLS_Y3IO_PATH` | `y3io.dll` |
+
+\* The `%SEGATOOLS_IO_ROOT%\chuniio.dll` fallback applies to the
+single-32-bit-DLL Chunithm hook (`chunihook`) only. Chunithm NEW and later
+(`chusanhook`) resolve the single-DLL `[chuniio] path=` / `SEGATOOLS_CHUNIIO_PATH`
+from the INI value or environment variable only, with no `SEGATOOLS_IO_ROOT`
+default; those builds use the `path32`/`path64` mechanism below for their
+`SEGATOOLS_IO_ROOT` defaults.
+
+For Chunithm NEW and later hooks that use separate 32-bit and 64-bit IO DLLs,
+`[chuniio] path32=` maps to `SEGATOOLS_CHUNIIO_PATH32` and
+`[chuniio] path64=` maps to `SEGATOOLS_CHUNIIO_PATH64`. When only
+`SEGATOOLS_IO_ROOT` is set, these hooks look for `chuniio_x86.dll` and
+`chuniio_x64.dll`.
+
 ## `[aimeio]`
 
 Controls the card reader driver.
@@ -25,6 +80,8 @@ Controls the card reader driver.
 
 Specify a path for a third-party card reader driver DLL. Default is empty
 (use built-in emulation based on text files and keyboard input).
+If empty, `SEGATOOLS_AIMEIO_PATH` is used if set, followed by
+`%SEGATOOLS_IO_ROOT%\aimeio.dll`.
 
 In previous versions of Segatools this was accomplished by replacing the
 AIMEIO.DLL file that came with Segatools. Segatools no longer ships with a
@@ -812,4 +869,4 @@ This is a file that will be set to the content of what would be written to the `
 
 This allows whatever executed the game process to react what should happen next (System Test Mode selected, network delivery completed, ...) without requiring admin permissions. 
 
-The file is deleted on startup of segatools.
+The file is deleted on startup of segatools.

games/apm3hook/config.c

@@ -10,6 +10,7 @@
 #include "apm3hook/config.h"
 
 #include "platform/config.h"
+#include "util/io-path.h"
 
 void apm3_dll_config_load(
         struct apm3_dll_config *cfg,
@@ -18,12 +19,13 @@ void apm3_dll_config_load(
     assert(cfg != NULL);
     assert(filename != NULL);
 
-    GetPrivateProfileStringW(
-            L"apm3io",
-            L"path",
-            L"",
+    io_path_config_load(
             cfg->path,
             _countof(cfg->path),
+            L"apm3io",
+            L"path",
+            L"SEGATOOLS_APM3IO_PATH",
+            L"apm3io.dll",
             filename);
 }
 

games/carolhook/config.c

@@ -13,6 +13,7 @@
 
 #include "platform/config.h"
 #include "platform/platform.h"
+#include "util/io-path.h"
 
 void carol_dll_config_load(
         struct carol_dll_config *cfg,
@@ -21,12 +22,13 @@ void carol_dll_config_load(
     assert(cfg != NULL);
     assert(filename != NULL);
 
-    GetPrivateProfileStringW(
-            L"carolio",
-            L"path",
-            L"",
+    io_path_config_load(
             cfg->path,
             _countof(cfg->path),
+            L"carolio",
+            L"path",
+            L"SEGATOOLS_CAROLIO_PATH",
+            L"carolio.dll",
             filename);
 }
 

games/chunihook/config.c

@@ -19,6 +19,7 @@
 
 #include "platform/config.h"
 #include "platform/platform.h"
+#include "util/io-path.h"
 
 void chuni_dll_config_load(
         struct chuni_dll_config *cfg,
@@ -27,12 +28,13 @@ void chuni_dll_config_load(
     assert(cfg != NULL);
     assert(filename != NULL);
 
-    GetPrivateProfileStringW(
-            L"chuniio",
-            L"path",
-            L"",
+    io_path_config_load(
             cfg->path,
             _countof(cfg->path),
+            L"chuniio",
+            L"path",
+            L"SEGATOOLS_CHUNIIO_PATH",
+            L"chuniio.dll",
             filename);
 }
 

games/chusanhook/config.c

@@ -12,6 +12,7 @@
 #include "platform/config.h"
 
 #include "chusanhook/config.h"
+#include "util/io-path.h"
 
 // Check windows
 #if _WIN32 || _WIN64
@@ -42,32 +43,34 @@ void chuni_dll_config_load(
     // path32 for 32bit, path64 for 64bit
     // path for 32bit only dlls (internal chu2to3 engine)
 
-    GetPrivateProfileStringW(
-            L"chuniio",
-            L"path",
-            L"",
+    if (io_path_config_load(
             cfg->path,
             _countof(cfg->path),
-            filename);
-    if (cfg->path[0] != L'\0') {
+            L"chuniio",
+            L"path",
+            L"SEGATOOLS_CHUNIIO_PATH",
+            NULL,
+            filename)) {
         cfg->chu2to3 = 1;
     } else {
         cfg->chu2to3 = 0;
     #if defined(ENV32BIT)	
-			GetPrivateProfileStringW(
-					L"chuniio",
-					L"path32",
-					L"",
-					cfg->path,
-					_countof(cfg->path),
-					filename);
+            io_path_config_load(
+                    cfg->path,
+                    _countof(cfg->path),
+                    L"chuniio",
+                    L"path32",
+                    L"SEGATOOLS_CHUNIIO_PATH32",
+                    L"chuniio_x86.dll",
+                    filename);
     #elif defined(ENV64BIT)
-        GetPrivateProfileStringW(
-                L"chuniio",
-                L"path64",
-                L"",
+        io_path_config_load(
                 cfg->path,
                 _countof(cfg->path),
+                L"chuniio",
+                L"path64",
+                L"SEGATOOLS_CHUNIIO_PATH64",
+                L"chuniio_x64.dll",
                 filename);
     #else
         #error "Unknown environment"

games/cmhook/config.c

@@ -10,6 +10,7 @@
 #include "cmhook/config.h"
 
 #include "platform/config.h"
+#include "util/io-path.h"
 
 void cm_dll_config_load(
         struct cm_dll_config *cfg,
@@ -18,12 +19,13 @@ void cm_dll_config_load(
     assert(cfg != NULL);
     assert(filename != NULL);
 
-    GetPrivateProfileStringW(
-            L"cmio",
-            L"path",
-            L"",
+    io_path_config_load(
             cfg->path,
             _countof(cfg->path),
+            L"cmio",
+            L"path",
+            L"SEGATOOLS_CMIO_PATH",
+            L"cmio.dll",
             filename);
 }
 

games/cxbhook/config.c

@@ -19,6 +19,7 @@
 
 #include "platform/config.h"
 #include "platform/platform.h"
+#include "util/io-path.h"
 
 void cxb_dll_config_load(
         struct cxb_dll_config *cfg,
@@ -27,12 +28,13 @@ void cxb_dll_config_load(
     assert(cfg != NULL);
     assert(filename != NULL);
 
-    GetPrivateProfileStringW(
-            L"cxbio",
-            L"path",
-            L"",
+    io_path_config_load(
             cfg->path,
             _countof(cfg->path),
+            L"cxbio",
+            L"path",
+            L"SEGATOOLS_CXBIO_PATH",
+            L"cxbio.dll",
             filename);
 }
 
@@ -69,4 +71,4 @@ void cxb_hook_config_load(
     cxb_dll_config_load(&cfg->dll, filename);
     revio_config_load(&cfg->revio, filename);
     led_config_load(&cfg->led, filename);
-}
+}

games/divahook/config.c

@@ -15,6 +15,7 @@
 
 #include "platform/config.h"
 #include "platform/platform.h"
+#include "util/io-path.h"
 
 void diva_dll_config_load(
         struct diva_dll_config *cfg,
@@ -23,12 +24,13 @@ void diva_dll_config_load(
     assert(cfg != NULL);
     assert(filename != NULL);
 
-    GetPrivateProfileStringW(
-            L"divaio",
-            L"path",
-            L"",
+    io_path_config_load(
             cfg->path,
             _countof(cfg->path),
+            L"divaio",
+            L"path",
+            L"SEGATOOLS_DIVAIO_PATH",
+            L"divaio.dll",
             filename);
 }
 

games/ekthook/config.c

@@ -11,6 +11,7 @@
 #include "hooklib/config.h"
 
 #include "platform/config.h"
+#include "util/io-path.h"
 
 void led15093_config_load(struct led15093_config *cfg, const wchar_t *filename)
 {
@@ -80,12 +81,13 @@ void ekt_dll_config_load(
     assert(cfg != NULL);
     assert(filename != NULL);
 
-    GetPrivateProfileStringW(
-            L"ektio",
-            L"path",
-            L"",
+    io_path_config_load(
             cfg->path,
             _countof(cfg->path),
+            L"ektio",
+            L"path",
+            L"SEGATOOLS_EKTIO_PATH",
+            L"ektio.dll",
             filename);
 }
 

games/fgohook/config.c

@@ -10,6 +10,7 @@
 #include "fgohook/config.h"
 
 #include "platform/config.h"
+#include "util/io-path.h"
 
 void fgo_dll_config_load(
         struct fgo_dll_config *cfg,
@@ -18,12 +19,13 @@ void fgo_dll_config_load(
     assert(cfg != NULL);
     assert(filename != NULL);
 
-    GetPrivateProfileStringW(
-            L"fgoio",
-            L"path",
-            L"",
+    io_path_config_load(
             cfg->path,
             _countof(cfg->path),
+            L"fgoio",
+            L"path",
+            L"SEGATOOLS_FGOIO_PATH",
+            L"fgoio.dll",
             filename);
 }
 

games/idachook/config.c

@@ -13,6 +13,7 @@
 
 #include "platform/config.h"
 #include "platform/platform.h"
+#include "util/io-path.h"
 
 
 void led15070_config_load(struct led15070_config *cfg, const wchar_t *filename)
@@ -59,12 +60,13 @@ void idac_dll_config_load(
     assert(cfg != NULL);
     assert(filename != NULL);
 
-    GetPrivateProfileStringW(
-            L"idacio",
-            L"path",
-            L"",
+    io_path_config_load(
             cfg->path,
             _countof(cfg->path),
+            L"idacio",
+            L"path",
+            L"SEGATOOLS_IDACIO_PATH",
+            L"idacio.dll",
             filename);
 }
 

games/idzhook/config.c

@@ -18,6 +18,7 @@
 
 #include "platform/config.h"
 #include "platform/platform.h"
+#include "util/io-path.h"
 
 void led15070_config_load(struct led15070_config *cfg, const wchar_t *filename)
 {
@@ -63,12 +64,13 @@ void idz_dll_config_load(
     assert(cfg != NULL);
     assert(filename != NULL);
 
-    GetPrivateProfileStringW(
-            L"idzio",
-            L"path",
-            L"",
+    io_path_config_load(
             cfg->path,
             _countof(cfg->path),
+            L"idzio",
+            L"path",
+            L"SEGATOOLS_IDZIO_PATH",
+            L"idzio.dll",
             filename);
 }
 

games/kemonohook/config.c

@@ -12,6 +12,7 @@
 #include "kemonohook/config.h"
 
 #include "platform/config.h"
+#include "util/io-path.h"
 
 // Check windows
 #if _WIN32 || _WIN64
@@ -41,12 +42,13 @@ void kemono_dll_config_load(
         // Always empty, due to amdaemon being 64 bit in 32 bit mode
         memset(cfg->path, 0, sizeof(cfg->path));
     #elif defined(ENV64BIT)
-        GetPrivateProfileStringW(
-                L"kemonoio",
-                L"path",
-                L"",
+        io_path_config_load(
                 cfg->path,
                 _countof(cfg->path),
+                L"kemonoio",
+                L"path",
+                L"SEGATOOLS_KEMONOIO_PATH",
+                L"kemonoio.dll",
                 filename);
     #else
         #error "Unknown environment"

games/mai2hook/config.c

@@ -10,6 +10,7 @@
 #include "mai2hook/config.h"
 
 #include "platform/config.h"
+#include "util/io-path.h"
 
 void mai2_dll_config_load(
     struct mai2_dll_config *cfg,
@@ -18,12 +19,13 @@ void mai2_dll_config_load(
     assert(cfg != NULL);
     assert(filename != NULL);
 
-    GetPrivateProfileStringW(
-        L"mai2io",
-        L"path",
-        L"",
+    io_path_config_load(
         cfg->path,
         _countof(cfg->path),
+        L"mai2io",
+        L"path",
+        L"SEGATOOLS_MAI2IO_PATH",
+        L"mai2io.dll",
         filename);
 }
 

games/mercuryhook/config.c

@@ -11,6 +11,7 @@
 #include "mercuryhook/config.h"
 
 #include "platform/config.h"
+#include "util/io-path.h"
 
 void mercury_dll_config_load(
         struct mercury_dll_config *cfg,
@@ -19,12 +20,13 @@ void mercury_dll_config_load(
     assert(cfg != NULL);
     assert(filename != NULL);
 
-    GetPrivateProfileStringW(
-            L"mercuryio",
-            L"path",
-            L"",
+    io_path_config_load(
             cfg->path,
             _countof(cfg->path),
+            L"mercuryio",
+            L"path",
+            L"SEGATOOLS_MERCURYIO_PATH",
+            L"mercuryio.dll",
             filename);
 }
 

games/mu3hook/config.c

@@ -12,6 +12,7 @@
 #include "mu3hook/config.h"
 
 #include "platform/config.h"
+#include "util/io-path.h"
 
 void mu3_dll_config_load(
         struct mu3_dll_config *cfg,
@@ -20,12 +21,13 @@ void mu3_dll_config_load(
     assert(cfg != NULL);
     assert(filename != NULL);
 
-    GetPrivateProfileStringW(
-            L"mu3io",
-            L"path",
-            L"",
+    io_path_config_load(
             cfg->path,
             _countof(cfg->path),
+            L"mu3io",
+            L"path",
+            L"SEGATOOLS_MU3IO_PATH",
+            L"mu3io.dll",
             filename);
 }
 

games/sekitohook/config.c

@@ -12,6 +12,7 @@
 #include "hooklib/config.h"
 
 #include "platform/config.h"
+#include "util/io-path.h"
 
 void led15093_config_load(struct led15093_config *cfg, const wchar_t *filename)
 {
@@ -81,12 +82,13 @@ void sekito_dll_config_load(
     assert(cfg != NULL);
     assert(filename != NULL);
 
-    GetPrivateProfileStringW(
-            L"sekitoio",
-            L"path",
-            L"",
+    io_path_config_load(
             cfg->path,
             _countof(cfg->path),
+            L"sekitoio",
+            L"path",
+            L"SEGATOOLS_SEKITOIO_PATH",
+            L"sekitoio.dll",
             filename);
 }
 

games/swdchook/config.c

@@ -13,6 +13,7 @@
 
 #include "platform/config.h"
 #include "platform/platform.h"
+#include "util/io-path.h"
 
 
 void led15070_config_load(struct led15070_config *cfg, const wchar_t *filename)
@@ -59,12 +60,13 @@ void swdc_dll_config_load(
     assert(cfg != NULL);
     assert(filename != NULL);
 
-    GetPrivateProfileStringW(
-            L"swdcio",
-            L"path",
-            L"",
+    io_path_config_load(
             cfg->path,
             _countof(cfg->path),
+            L"swdcio",
+            L"path",
+            L"SEGATOOLS_SWDCIO_PATH",
+            L"swdcio.dll",
             filename);
 }
 

games/tokyohook/config.c

@@ -12,6 +12,7 @@
 #include "platform/config.h"
 
 #include "tokyohook/config.h"
+#include "util/io-path.h"
 
 void tokyo_dll_config_load(
     struct tokyo_dll_config *cfg,
@@ -19,12 +20,13 @@ void tokyo_dll_config_load(
     assert(cfg != NULL);
     assert(filename != NULL);
 
-    GetPrivateProfileStringW(
-        L"tokyoio",
-        L"path",
-        L"",
+    io_path_config_load(
         cfg->path,
         _countof(cfg->path),
+        L"tokyoio",
+        L"path",
+        L"SEGATOOLS_TOKYOIO_PATH",
+        L"tokyoio.dll",
         filename);
 }