std::string allocating getcwd

hecl/include/HECL/HECL.hpp

@@ -194,6 +194,54 @@ static inline SystemChar* Getcwd(SystemChar* buf, int maxlen)
 #endif
 }
 
+static SystemString GetcwdStr()
+{
+    /* http://stackoverflow.com/a/2869667 */
+    const size_t ChunkSize=255;
+    const int MaxChunks=10240; // 2550 KiBs of current path are more than enough
+
+    SystemChar stackBuffer[ChunkSize]; // Stack buffer for the "normal" case
+    if (Getcwd(stackBuffer, sizeof(stackBuffer)) != nullptr)
+        return stackBuffer;
+    if (errno != ERANGE)
+    {
+        // It's not ERANGE, so we don't know how to handle it
+        LogModule.report(LogVisor::FatalError, "Cannot determine the current path.");
+        // Of course you may choose a different error reporting method
+    }
+    // Ok, the stack buffer isn't long enough; fallback to heap allocation
+    for (int chunks=2 ; chunks<MaxChunks ; chunks++)
+    {
+        // With boost use scoped_ptr; in C++0x, use unique_ptr
+        // If you want to be less C++ but more efficient you may want to use realloc
+        std::unique_ptr<SystemChar[]> cwd(new SystemChar[ChunkSize*chunks]);
+        if (Getcwd(cwd.get(), ChunkSize*chunks) != nullptr)
+            return cwd.get();
+        if (errno != ERANGE)
+        {
+            // It's not ERANGE, so we don't know how to handle it
+            LogModule.report(LogVisor::FatalError, "Cannot determine the current path.");
+            // Of course you may choose a different error reporting method
+        }
+    }
+    LogModule.report(LogVisor::FatalError, "Cannot determine the current path; the path is apparently unreasonably long");
+    return SystemString();
+}
+
+static inline bool IsAbsolute(const SystemString& path)
+{
+#if WIN32
+    if (path.size() && (path[0] == _S('\\') || path[0] == _S('/')))
+        return true;
+    if (path.size() >= 2 && iswalpha(path[0]) && path[1] == _S(':'))
+        return true;
+#else
+    if (path.size() && path[0] == _S('/'))
+        return true;
+#endif
+    return false;
+}
+
 enum class FileLockType
 {
     None = 0,

hecl/lib/ProjectPath.cpp

@@ -8,20 +8,6 @@ static const SystemRegex regGLOB(_S("\\*"), SystemRegex::ECMAScript|SystemRegex:
 static const SystemRegex regPATHCOMP(_S("[/\\\\]*([^/\\\\]+)"), SystemRegex::ECMAScript|SystemRegex::optimize);
 static const SystemRegex regDRIVELETTER(_S("^([^/]*)/"), SystemRegex::ECMAScript|SystemRegex::optimize);
 
-static bool IsAbsolute(const SystemString& path)
-{
-#if WIN32
-    if (path.size() && (path[0] == _S('\\') || path[0] == _S('/')))
-        return true;
-    if (path.size() >= 2 && iswalpha(path[0]) && path[1] == _S(':'))
-        return true;
-#else
-    if (path[0] == _S('/'))
-        return true;
-#endif
-    return false;
-}
-
 static SystemString CanonRelPath(const SystemString& path)
 {
     /* Tokenize Path */