HLE: Revamp error handling throrough the HLE code

All service calls in the CTR OS return result codes indicating the
success or failure of the call. Previous to this commit, Citra's HLE
emulation of services and the kernel universally either ignored errors
or returned dummy -1 error codes.

This commit makes an initial effort to provide an infrastructure for
error reporting and propagation which can be use going forward to make
HLE calls accurately return errors as the original system. A few parts
of the code have been updated to use the new system where applicable.

One part of this effort is the definition of the `ResultCode` type,
which provides facilities for constructing and parsing error codes in
the structured format used by the CTR.

The `ResultVal` type builds on `ResultCode` by providing a container for
values returned by function that can report errors. It enforces that
correct error checking will be done on function returns by preventing
the use of the return value if the function returned an error code.

Currently this change is mostly internal since errors are still
suppressed on the ARM<->HLE border, as a temporary compatibility hack.
As functionality is implemented and tested this hack can be eventually
removed.

1 files changed, 18 insertions, 16 deletions

diff --git a/src/core/arm/skyeye_common/armdefs.h b/src/core/arm/skyeye_common/armdefs.h
index 6e8187c8..8343aaa0 100644
--- a/src/core/arm/skyeye_common/armdefs.h
+++ b/src/core/arm/skyeye_common/armdefs.h
@@ -799,22 +799,24 @@ pascal void SpinCursor (short increment);    /* copied from CursorCtl.h */
 #include "list.h"
 #include "tb.h"
 */
-const int EQ = 0;
-const int NE = 1;
-const int CS = 2;
-const int CC = 3;
-const int MI = 4;
-const int PL = 5;
-const int VS = 6;
-const int VC = 7;
-const int HI = 8;
-const int LS = 9;
-const int GE = 10;
-const int LT = 11;
-const int GT = 12;
-const int LE = 13;
-const int AL = 14;
-const int NV = 15;
+enum ConditionCode {
+    EQ = 0,
+    NE = 1,
+    CS = 2,
+    CC = 3,
+    MI = 4,
+    PL = 5,
+    VS = 6,
+    VC = 7,
+    HI = 8,
+    LS = 9,
+    GE = 10,
+    LT = 11,
+    GT = 12,
+    LE = 13,
+    AL = 14,
+    NV = 15,
+};
 
 #ifndef NFLAG
 #define NFLAG    state->NFlag