From 26a0ee4af3f8ed033fa55b786372b0917fd36be8 Mon Sep 17 00:00:00 2001
From: fincs <fincs@devkitpro.org>
Date: Sun, 20 Oct 2019 02:47:37 +0200
Subject: [PATCH] fsdev/romfsdev: Reduce TLS usage by sharing the path buffer

---
 nx/source/runtime/devices/fs_dev.c    | 28 +++++++++++++--------------
 nx/source/runtime/devices/path_buf.c  |  3 +++
 nx/source/runtime/devices/path_buf.h  |  4 ++++
 nx/source/runtime/devices/romfs_dev.c | 14 +++++++-------
 4 files changed, 28 insertions(+), 21 deletions(-)
 create mode 100644 nx/source/runtime/devices/path_buf.c
 create mode 100644 nx/source/runtime/devices/path_buf.h

diff --git a/nx/source/runtime/devices/fs_dev.c b/nx/source/runtime/devices/fs_dev.c
index 2036b886..e1bac69a 100644
--- a/nx/source/runtime/devices/fs_dev.c
+++ b/nx/source/runtime/devices/fs_dev.c
@@ -14,6 +14,7 @@
 #include "services/fs.h"
 #include "services/time.h"
 
+#include "path_buf.h"
 
 /*! @internal
  *
@@ -109,7 +110,6 @@ static fsdev_fsdevice fsdev_fsdevices[32];
 /*! @endcond */
 
 static char     __cwd[PATH_MAX+1] = "/";
-static __thread char     __fixedpath[PATH_MAX+1];
 
 __attribute__((weak)) u32 __nx_fsdev_direntry_cache_size = 32;
 
@@ -202,17 +202,17 @@ fsdev_fixpath(struct _reent *r,
   } while(code != 0);
 
   if(path[0] == '/')
-    strncpy(__fixedpath, path, PATH_MAX);
+    strncpy(__nx_dev_path_buf, path, PATH_MAX);
   else
   {
-    strncpy(__fixedpath, __cwd, PATH_MAX);
-    __fixedpath[PATH_MAX] = '\0';
-    strncat(__fixedpath, path, PATH_MAX - strlen(__cwd));
+    strncpy(__nx_dev_path_buf, __cwd, PATH_MAX);
+    __nx_dev_path_buf[PATH_MAX] = '\0';
+    strncat(__nx_dev_path_buf, path, PATH_MAX - strlen(__cwd));
   }
 
-  if(__fixedpath[PATH_MAX] != 0)
+  if(__nx_dev_path_buf[PATH_MAX] != 0)
   {
-    __fixedpath[PATH_MAX] = 0;
+    __nx_dev_path_buf[PATH_MAX] = 0;
     r->_errno = ENAMETOOLONG;
     return NULL;
   }
@@ -236,7 +236,7 @@ fsdev_fixpath(struct _reent *r,
     }
   }
 
-  return __fixedpath;
+  return __nx_dev_path_buf;
 }
 
 static int
@@ -248,7 +248,7 @@ fsdev_getfspath(struct _reent *r,
   if(fsdev_fixpath(r, path, device) == NULL)
     return -1;
 
-  memcpy(outpath, __fixedpath,FS_MAX_PATH-1);
+  memcpy(outpath, __nx_dev_path_buf,FS_MAX_PATH-1);
   outpath[FS_MAX_PATH-1] = '\0';
 
   return 0;
@@ -462,15 +462,15 @@ Result fsdevMountSdmc(void)
       {
         if(FindDevice(__system_argv[0]) == dev)
         {
-          strncpy(__fixedpath,__system_argv[0],PATH_MAX);
-          if(__fixedpath[PATH_MAX] != 0)
+          strncpy(__nx_dev_path_buf,__system_argv[0],PATH_MAX);
+          if(__nx_dev_path_buf[PATH_MAX] != 0)
           {
-            __fixedpath[PATH_MAX] = 0;
+            __nx_dev_path_buf[PATH_MAX] = 0;
           }
           else
           {
             char *last_slash = NULL;
-            p = __fixedpath;
+            p = __nx_dev_path_buf;
             do
             {
               units = decode_utf8(&code, (const uint8_t*)p);
@@ -489,7 +489,7 @@ Result fsdevMountSdmc(void)
             if(last_slash != NULL)
             {
               last_slash[0] = 0;
-              chdir(__fixedpath);
+              chdir(__nx_dev_path_buf);
             }
           }
         }
diff --git a/nx/source/runtime/devices/path_buf.c b/nx/source/runtime/devices/path_buf.c
new file mode 100644
index 00000000..b03dbb53
--- /dev/null
+++ b/nx/source/runtime/devices/path_buf.c
@@ -0,0 +1,3 @@
+#include "path_buf.h"
+
+char __thread __nx_dev_path_buf[PATH_MAX+1];
diff --git a/nx/source/runtime/devices/path_buf.h b/nx/source/runtime/devices/path_buf.h
new file mode 100644
index 00000000..dcf0b1eb
--- /dev/null
+++ b/nx/source/runtime/devices/path_buf.h
@@ -0,0 +1,4 @@
+#pragma once
+#include <limits.h>
+
+extern char __thread __nx_dev_path_buf[PATH_MAX+1];
diff --git a/nx/source/runtime/devices/romfs_dev.c b/nx/source/runtime/devices/romfs_dev.c
index 459f6f63..43b74510 100644
--- a/nx/source/runtime/devices/romfs_dev.c
+++ b/nx/source/runtime/devices/romfs_dev.c
@@ -15,6 +15,8 @@
 #include "runtime/env.h"
 #include "nro.h"
 
+#include "path_buf.h"
+
 typedef enum {
     RomfsSource_FsFile,
     RomfsSource_FsStorage,
@@ -40,8 +42,6 @@ typedef struct romfs_mount
 extern int __system_argc;
 extern char** __system_argv;
 
-static char __thread __component[PATH_MAX+1];
-
 #define romFS_root(m)   ((romfs_dir*)(m)->dirTable)
 #define romFS_dir(m,x)  ((romfs_dir*) ((u8*)(m)->dirTable  + (x)))
 #define romFS_file(m,x) ((romfs_file*)((u8*)(m)->fileTable + (x)))
@@ -233,10 +233,10 @@ Result romfsMount(const char *name)
             filename += 5;
         else if (strncmp(filename, "nxlink:/", 8) == 0)
         {
-            strncpy(__component, "/switch",     PATH_MAX);
-            strncat(__component, filename+7, PATH_MAX);
-            __component[PATH_MAX] = 0;
-            filename = __component;
+            strncpy(__nx_dev_path_buf, "/switch",  PATH_MAX);
+            strncat(__nx_dev_path_buf, filename+7, PATH_MAX);
+            __nx_dev_path_buf[PATH_MAX] = 0;
+            filename = __nx_dev_path_buf;
         }
         else
         {
@@ -501,7 +501,7 @@ static int navigateToDir(romfs_mount *mount, romfs_dir** ppDir, const char** pPa
     while (**pPath)
     {
         char* slashPos = strchr(*pPath, '/');
-        char* component = __component;
+        char* component = __nx_dev_path_buf;
 
         if (slashPos)
         {