add xmake._EXECUTABLE_PATH to fix $(xmake)

$(xmake) is set to join(_PROGRAM_DIR, 'xmake')
that is wrong when XMAKE_PROGRAM_DIR is set to
another program dir (like developing dir) with no executable

so use system-special ways to get absolution path
of executable file always

4 files changed, 65 insertions, 34 deletions

diff --git a/core/src/xmake/machine.c b/core/src/xmake/machine.c
index ccfd91254..f6818d3be 100644
--- a/core/src/xmake/machine.c
+++ b/core/src/xmake/machine.c
@@ -244,29 +244,39 @@ static tb_bool_t xm_machine_main_get_program_directory(xm_machine_impl_t* impl,
         {
             // ok
             ok = tb_true;
-            break;
+            // not break // even XMAKE_PROGRAM_DIR is set, exact path is needed
         }
 
 #if defined(TB_CONFIG_OS_WINDOWS)
         // get the executale file path as program directory
-        tb_size_t size = (tb_size_t)GetModuleFileName(tb_null, path, (DWORD)maxn);
+        tb_size_t size = (tb_size_t)GetModuleFileName(tb_null, data, (DWORD)maxn);
         tb_assert_and_check_break(size < maxn);
 
         // end
-        path[size] = '\0';
+        data[size] = '\0';
 
-        // get the directory
-        while (size-- > 0)
+        // set _EXECUTABLE_PATH
+        lua_pushstring(impl -> lua, data);
+        lua_setglobal(impl -> lua, "_EXECUTABLE_PATH");
+
+        if (!ok)
         {
-            if (path[size] == '\\') 
+            // get the directory
+            while (size-- > 0)
             {
-                path[size] = '\0';
-                break;
+                if (data[size] == '\\')
+                {
+                    data[size] = '\0';
+                    break;
+                }
             }
-        }
 
-        // ok
-        ok = tb_true;
+            // copy to path
+            tb_strcpy(path, data);
+
+            // ok
+            ok = tb_true;
+        }
 #elif defined(TB_CONFIG_OS_MACOSX)
         /*
          * _NSGetExecutablePath() copies the path of the main executable into the buffer. The bufsize parameter
@@ -279,44 +289,64 @@ static tb_bool_t xm_machine_main_get_program_directory(xm_machine_impl_t* impl,
          * needed could be more than MAXPATHLEN.
          */
         tb_uint32_t size = (tb_uint32_t)maxn;
-        if (!_NSGetExecutablePath(path, &size))
+        if (!_NSGetExecutablePath(data, &size))
         {
-            // get path size
-            size = tb_strlen(path);
+            // set _EXECUTABLE_PATH
+            lua_pushstring(impl -> lua, data);
+            lua_setglobal(impl -> lua, "_EXECUTABLE_PATH");
 
-            // get the directory
-            while (size-- > 0)
+            if (!ok)
             {
-                if (path[size] == '/') 
+                // get path size
+                size = tb_strlen(data);
+
+                // get the directory
+                while (size-- > 0)
                 {
-                    path[size] = '\0';
-                    break;
+                    if (data[size] == '/')
+                    {
+                        data[size] = '\0';
+                        break;
+                    }
                 }
-            }
 
-            // ok
-            ok = tb_true;
+                // copy to path
+                tb_strcpy(path, data);
+
+                // ok
+                ok = tb_true;
+            }
         }
 #elif defined(TB_CONFIG_OS_LINUX)
         // get the executale file path as program directory
-        ssize_t size = readlink("/proc/self/exe", path, (size_t)maxn);
+        ssize_t size = readlink("/proc/self/exe", data, (size_t)maxn);
         if (size > 0 && size < maxn)
         {
             // end
-            path[size] = '\0';
+            data[size] = '\0';
 
-            // get the directory
-            while (size-- > 0)
+            // set _EXECUTABLE_PATH
+            lua_pushstring(impl -> lua, data);
+            lua_setglobal(impl -> lua, "_EXECUTABLE_PATH");
+
+            if (!ok)
             {
-                if (path[size] == '/') 
+                // get the directory
+                while (size-- > 0)
                 {
-                    path[size] = '\0';
-                    break;
+                    if (data[size] == '/')
+                    {
+                        data[size] = '\0';
+                        break;
+                    }
                 }
-            }
 
-            // ok
-            ok = tb_true;
+                // copy to path
+                tb_strcpy(path, data);
+
+                // ok
+                ok = tb_true;
+            }
         }
 #endif
 
diff --git a/xmake/core/_xmake_main.lua b/xmake/core/_xmake_main.lua
index 1f169e4af..c454406c0 100644
--- a/xmake/core/_xmake_main.lua
+++ b/xmake/core/_xmake_main.lua
@@ -36,6 +36,7 @@ xmake._CORE_DIR         = _PROGRAM_DIR .. "/core"
 xmake._TOOLS_DIR        = _PROGRAM_DIR .. "/tools"
 xmake._TEMPLATES_DIR    = _PROGRAM_DIR .. "/templates"
 xmake._PROJECT_FILE     = "xmake.lua"
+xmake._EXECUTABLE_PATH  = _EXECUTABLE_PATH
 
 -- init package path
 package.path = xmake._CORE_DIR .. "/?.lua;" .. package.path
diff --git a/xmake/core/project/project.lua b/xmake/core/project/project.lua
index 6dff6d1a4..e68f399ca 100644
--- a/xmake/core/project/project.lua
+++ b/xmake/core/project/project.lua
@@ -320,7 +320,7 @@ function project._interpreter()
             ,   projectdir  = project.directory()
             ,   packagedir  = package.directory()
             ,   programdir  = xmake._PROGRAM_DIR
-            ,   xmake       = path.join(xmake._PROGRAM_DIR, "xmake")
+            ,   xmake       = xmake._EXECUTABLE_PATH or path.join(xmake._PROGRAM_DIR, "xmake")
             }
 
             -- map it
diff --git a/xmake/core/project/task.lua b/xmake/core/project/task.lua
index 0111dd6e9..732a33b34 100644
--- a/xmake/core/project/task.lua
+++ b/xmake/core/project/task.lua
@@ -204,7 +204,7 @@ function task._interpreter()
             ,   projectdir  = xmake._PROJECT_DIR
             ,   packagedir  = package.directory()
             ,   programdir  = xmake._PROGRAM_DIR
-            ,   xmake       = path.join(xmake._PROGRAM_DIR, "xmake")
+            ,   xmake       = xmake._EXECUTABLE_PATH or path.join(xmake._PROGRAM_DIR, "xmake")
             }
 
             -- map it