Add os.realpath() to resolve symbolic links on Posix systems

src/host/os_match.c

@@ -11,9 +11,6 @@
 
 #if PLATFORM_WINDOWS
 
-#define WIN32_LEAN_AND_MEAN
-#include <windows.h>
-
 typedef struct struct_MatchInfo
 {
 	HANDLE handle;

src/host/os_realpath.c

@@ -0,0 +1,37 @@
+/**
+ * \file   os_realpath.c
+ * \brief  Return the canonical absolute version of a given path.
+ * \author Copyright (c) 2014 Jason Perkins and the Premake project
+ */
+
+#include "premake.h"
+#include <stdlib.h>
+#include <string.h>
+#include <errno.h>
+
+
+int os_realpath(lua_State* L)
+{
+	char result[PATH_MAX];
+	int ok;
+
+	const char* path = luaL_checkstring(L, 1);
+
+#if PLATFORM_POSIX
+	ok = (realpath(path, result) != NULL);
+#elif PLATFORM_WINDOWS
+	ok = (_fullpath(result, path, PATH_MAX) != NULL);
+#else
+	do_getabsolute(result, path, NULL);
+	ok = 1;
+#endif
+
+	if (!ok) {
+		lua_pushnil(L);
+		lua_pushfstring(L, "unable to fetch real path of '%s', errno %d : %s", path, errno, strerror(errno));
+		return 2;
+	}
+
+	lua_pushstring(L, result);
+	return 1;
+}

src/host/path_getabsolute.c

@@ -8,7 +8,7 @@
 #include <string.h>
 
 
-static void getabsolute(char* result, const char* value, const char* relative_to)
+void do_getabsolute(char* result, const char* value, const char* relative_to)
 {
 	int i;
 	char* ch;
@@ -85,7 +85,7 @@ int path_getabsolute(lua_State* L)
 		lua_pushnil(L);
 		while (lua_next(L, 1)) {
 			const char* value = luaL_checkstring(L, -1);
-			getabsolute(buffer, value, relative_to);
+			do_getabsolute(buffer, value, relative_to);
 			lua_pop(L, 1);
 
 			lua_pushnumber(L, ++i);
@@ -96,7 +96,7 @@ int path_getabsolute(lua_State* L)
 	}
 	else {
 		const char* value = luaL_checkstring(L, 1);
-		getabsolute(buffer, value, relative_to);
+		do_getabsolute(buffer, value, relative_to);
 		lua_pushstring(L, buffer);
 		return 1;
 	}

src/host/premake.c

@@ -73,6 +73,7 @@ static const luaL_Reg os_functions[] = {
 	{ "matchstart",  os_matchstart  },
 	{ "mkdir",       os_mkdir       },
 	{ "pathsearch",  os_pathsearch  },
+	{ "realpath",    os_realpath    },
 	{ "rmdir",       os_rmdir       },
 	{ "stat",        os_stat        },
 	{ "uuid",        os_uuid        },
@@ -148,10 +149,6 @@ int premake_execute(lua_State* L, int argc, const char** argv)
  */
 int premake_locate(lua_State* L, const char* argv0)
 {
-#if !defined(PATH_MAX)
-#define PATH_MAX  (4096)
-#endif
-
 	char buffer[PATH_MAX];
 	const char* path = NULL;
 

src/host/premake.h

@@ -38,6 +38,8 @@
 #define PLATFORM_STRING   "windows"
 #endif
 
+#define PLATFORM_POSIX  (PLATFORM_LINUX || PLATFORM_BSD || PLATFORM_MACOSX || PLATFORM_SOLARIS)
+
 
 /* Pull in platform-specific headers required by built-in functions */
 #if PLATFORM_WINDOWS
@@ -48,12 +50,19 @@
 #endif
 
 
+/* Fill in any missing bits */
+#ifndef PATH_MAX
+#define PATH_MAX   (4096)
+#endif
+
+
 /* A success return code */
 #define OKAY   (0)
 
 
 /* Bootstrapping helper functions */
 unsigned long do_hash(const char* str, int seed);
+void do_getabsolute(char* result, const char* value, const char* relative_to);
 int do_getcwd(char* buffer, size_t size);
 int do_isabsolute(const char* path);
 int do_isfile(const char* filename);
@@ -87,6 +96,7 @@ int os_matchnext(lua_State* L);
 int os_matchstart(lua_State* L);
 int os_mkdir(lua_State* L);
 int os_pathsearch(lua_State* L);
+int os_realpath(lua_State* L);
 int os_rmdir(lua_State* L);
 int os_stat(lua_State* L);
 int os_uuid(lua_State* L);