Move path.normalize() to native code for performance

src/base/path.lua

@@ -185,29 +185,6 @@
 	end
 
 
---
--- Remove any extraneous weirdness from a path, such as double slashes or
--- leading single dots.
---
--- @param p
---    The path to normalize.
--- @return
---    A path known weirdnesses removed.
---
-
-	function path.normalize(p)
-		-- trim off any leading "./" sequences
-		while p:startswith("./") do
-			p = p:sub(3)
-		end
-
-		-- remove any "//" sequences from path concatenation
-		p = p:gsub("//", "/")
-
-		return p
-	end
-
-
 --
 -- Takes a path which is relative to one location and makes it relative
 -- to another location instead.

src/host/path_getrelative.c

@@ -8,45 +8,6 @@
 #include <string.h>
 
 
-static void normalize(char* buffer, const char* path)
-{
-	char* src;
-	char* dst;
-	char last;
-
-	strcpy(buffer, path);
-	do_translate(buffer, '/');
-
-	/* remove any duplicate slashes within the path */
-	src = buffer;
-	dst = buffer;
-	last = '\0';
-
-	while (*src != '\0') {
-		/* if I don't have consecutive slashes, keep the char */
-		if (*src != '/' || last != '/') {
-			*(dst++) = *src;
-		}
-
-		/* Allow double-slash at the start of the string, so absolute
-		 * UNC paths can be expressed, but nowhere else */
-		if (src != buffer) {
-			last = (*src);
-		}
-
-		/* check the next one */
-		++src;
-	}
-
-    /* remove any trailing slashes */
-    for (--src; src > buffer && *src == '/'; --src) {
-         *src = '\0';
-    }
-
-	*dst = '\0';
-}
-
-
 int path_getrelative(lua_State* L)
 {
 	int i, last, count;
@@ -57,8 +18,8 @@ int path_getrelative(lua_State* L)
 	const char* p2 = luaL_checkstring(L, 2);
 
 	/* normalize the paths */
-	normalize(src, p1);
-	normalize(dst, p2);
+	do_normalize(L, src, p1);
+	do_normalize(L, dst, p2);
 
 	/* same directory? */
 	if (strcmp(src, dst) == 0) {

src/host/path_normalize.c

@@ -0,0 +1,77 @@
+/**
+ * \file   path_normalize.c
+ * \brief  Removes any weirdness from a file system path string.
+ * \author Copyright (c) 2013 Jason Perkins and the Premake project
+ */
+
+#include "premake.h"
+#include <string.h>
+
+
+int path_normalize(lua_State* L)
+{
+	char buffer[0x4000];
+	char* src;
+	char* dst;
+	char last;
+
+	const char* path = luaL_checkstring(L, 1);
+	strcpy(buffer, path);
+
+	src = buffer;
+	dst = buffer;
+	last = '\0';
+
+	while (*src != '\0') {
+		char ch = (*src);
+
+		/* make sure we're using '/' for all separators */
+		if (ch == '\\') {
+			ch = '/';
+		}
+
+		/* add to the result, filtering out duplicate slashes */
+		if (ch != '/' || last != '/') {
+			*(dst++) = ch;
+		}
+
+		/* ...except at the start of a string, for UNC paths */
+		if (src != buffer) {
+			last = (*src);
+		}
+
+		++src;
+	}
+
+	/* remove any trailing slashes */
+    for (--src; src > buffer && *src == '/'; --src) {
+         *src = '\0';
+    }
+
+    /* remove any leading "./" sequences */
+    src = buffer;
+    while (strncmp(src, "./", 2) == 0) {
+    	src += 2;
+    }
+
+	*dst = '\0';
+	lua_pushstring(L, src);
+	return 1;
+}
+
+
+/* Call the scripted path.normalize(), to allow for overrides */
+void do_normalize(lua_State* L, char* buffer, const char* path)
+{
+	int top = lua_gettop(L);
+
+	lua_getglobal(L, "path");
+	lua_getfield(L, -1, "normalize");
+	lua_pushstring(L, path);
+	lua_call(L, 1, 1);
+
+	path = luaL_checkstring(L, -1);
+	strcpy(buffer, path);
+
+	lua_settop(L, top);
+}

src/host/premake.c

@@ -41,6 +41,7 @@ static const luaL_Reg path_functions[] = {
 	{ "getrelative", path_getrelative },
 	{ "isabsolute",  path_isabsolute },
 	{ "join", path_join },
+	{ "normalize", path_normalize },
 	{ "translate", path_translate },
 	{ NULL, NULL }
 };

src/host/premake.h

@@ -57,6 +57,7 @@ unsigned long do_hash(const char* str, int seed);
 int do_getcwd(char* buffer, size_t size);
 int do_isabsolute(const char* path);
 int do_isfile(const char* filename);
+void do_normalize(lua_State* L, char* buffer, const char* path);
 void do_translate(char* value, const char sep);
 
 
@@ -65,6 +66,7 @@ int path_getabsolute(lua_State* L);
 int path_getrelative(lua_State* L);
 int path_isabsolute(lua_State* L);
 int path_join(lua_State* L);
+int path_normalize(lua_State* L);
 int path_translate(lua_State* L);
 int os_chdir(lua_State* L);
 int os_copyfile(lua_State* L);