feat: make userspace StatusCodes positive; print status text along with code in shell exec; make init return BadInvocation on faulty launch

programs/include/montauk/statuscodes.h

@@ -6,29 +6,83 @@
 
 #pragma once
 
-// Userspace mirror of kernel/src/Common/StatusCodes.hpp. Also usable from C
-// (the libc includes it), where the enumerators are unqualified.
+// Userspace status codes.
+// Analogous to kernel/src/Common/StatusCodes.hpp, but positive numbers are used.
 #ifdef __cplusplus
 namespace montauk {
 #endif
 
-enum StatusCodes {
+typedef enum {
     Success = 0,
-    GenericFailure = -1,
-    PermissionDenied = -2,
-    CapabilityDenied = -3,
-    SystemIntegrityError = -4,
-    BadPointer = -5,
-    InvalidArgument = -6,
-    UnsupportedOp = -7,
-    NoDevice = -8,
-    IoFailure = -9,
-    BadInvocation = -10,
-    NoSuchPath = -11,
-    Busy = -12,
-    BufferTooSmall = -13,
-    OutOfMemory = -14
-};
+    GenericFailure = 1,
+    PermissionDenied = 2,
+    CapabilityDenied = 3,
+    SystemIntegrityError = 4,
+    BadPointer = 5,
+    InvalidArgument = 6,
+    UnsupportedOp = 7,
+    NoDevice = 8,
+    IoFailure = 9,
+    BadInvocation = 10,
+    NoSuchPath = 11,
+    Busy = 12,
+    BufferTooSmall = 13,
+    OutOfMemory = 14
+} StatusCodes;
+
+inline const char* GetStatusText(StatusCodes statusCode) {
+    const char* statusText[] = {
+        "Success", // 0
+        "Generic failure", // 1
+        "Permission denied", // 2
+        "Capability denied", // 3
+        "System integrity error", // 4
+        "Bad pointer", // 5
+        "Invalid argument", // 6
+        "Unsupported operation", // 7
+        "No device", // 8
+        "I/O failure", // 9
+        "Bad invocation", // 10
+        "No such path", // 11
+        "Busy", // 12
+        "Buffer too small", // 13
+        "Out of memory", // 14
+    };
+
+    if (statusCode > 0 && statusCode <= 14) {
+        return statusText[statusCode];
+    } else {
+        return "Unknown error";
+    }
+}
+
+inline const char* GetStatusExplanationText(StatusCodes statusCode) {
+    const char* explanationText[] = {
+        nullptr, // 0
+        nullptr, // 1
+        nullptr, // 2
+        nullptr, // 3
+        "The path is protected by the system and can't be modified.", // 4
+        nullptr, // 5
+        nullptr, // 6
+        nullptr, // 7
+        nullptr, // 8
+        nullptr, // 9
+        nullptr, // 10
+        nullptr, // 11
+        nullptr, // 12
+        "The buffer supplied by the caller is too small.", // 13
+        nullptr, // 14
+    };
+
+    if (statusCode > 0 && statusCode <= 14) {
+        if (explanationText[statusCode] != nullptr) {
+            return explanationText[statusCode];
+        }
+    }
+
+    return GetStatusText(statusCode);
+}
 
 #ifdef __cplusplus
 }