Show a better message if the game crashes

src/main.c

@@ -78,13 +78,17 @@ static uint16 g_gamepad_last_cmd[kGamepadBtn_Count];
 extern Snes *g_snes;
 
 void NORETURN Die(const char *error) {
-#if defined(NDEBUG) && defined(_WIN32)
   SDL_ShowSimpleMessageBox(SDL_MESSAGEBOX_ERROR, kWindowTitle, error, NULL);
-#endif
   fprintf(stderr, "Error: %s\n", error);
   exit(1);
 }
 
+void Warning(const char *error) {
+  SDL_ShowSimpleMessageBox(SDL_MESSAGEBOX_WARNING, kWindowTitle, error, NULL);
+  fprintf(stderr, "Warning: %s\n", error);
+}
+
+
 void ChangeWindowScale(int scale_step) {
   if ((SDL_GetWindowFlags(g_window) & (SDL_WINDOW_FULLSCREEN_DESKTOP | SDL_WINDOW_FULLSCREEN | SDL_WINDOW_MINIMIZED | SDL_WINDOW_MAXIMIZED)) != 0)
     return;

src/snes/cart.c

@@ -3,8 +3,7 @@
 #include <string.h>
 #include <stdint.h>
 #include <stdbool.h>
-#include <assert.h>
+#include "../types.h"
-
 #include "cart.h"
 #include "snes.h"
 
@@ -72,6 +71,8 @@ void cart_write(Cart* cart, uint8_t bank, uint16_t adr, uint8_t val) {
   }
 }
 
+void DumpCpuHistory();
+
 static uint8_t cart_readLorom(Cart* cart, uint8_t bank, uint16_t adr) {
   if(((bank >= 0x70 && bank < 0x7e) || bank >= 0xf0) && adr < 0x8000 && cart->ramSize > 0) {
     // banks 70-7e and f0-ff, adr 0000-7fff
@@ -82,7 +83,9 @@ static uint8_t cart_readLorom(Cart* cart, uint8_t bank, uint16_t adr) {
     // adr 8000-ffff in all banks or all addresses in banks 40-7f and c0-ff
     return cart->rom[((bank << 15) | (adr & 0x7fff)) & (cart->romSize - 1)];
   }
-  assert(0);
+  printf("While trying to read from 0x%x\n", bank << 16 | adr);
+  DumpCpuHistory();
+  Die("The game crashed in cart_readLorom");
   return cart->snes->openBus;
 }
 

src/snes/cpu.c

@@ -727,6 +727,12 @@ uint32_t pc_hist[8], pc_hist_ctr;
 
 uint32_t pc_bp = 0;
 
+void DumpCpuHistory() {
+  for (int i = 0; i < 8; i++) {
+    printf("PC history: 0x%x\n", pc_hist[(pc_hist_ctr + i) & 7]);
+  }
+}
+
 static void cpu_doOpcode(Cpu* cpu, uint8_t opcode) {
   uint32 cur_pc = ((cpu->k << 16) | cpu->pc - 1);
   pc_hist[pc_hist_ctr] = cur_pc;
@@ -1344,9 +1350,7 @@ restart:
       uint8_t new_k = cpu_readOpcode(cpu);
       if (new_k == 0x80 && value == 0x8573) {
         printf("Current PC = 0x%x\n", cpu->k << 16 | cpu->pc);
-        for (int i = 0; i < 8; i++) {
+        DumpCpuHistory();
-          printf("PC history: 0x%x\n", pc_hist[(pc_hist_ctr + i) & 7]);
-        }
         Die("The game has crashed!\n");
       }
       cpu->k = new_k;

src/types.h

@@ -70,6 +70,7 @@ static FORCEINLINE uint UintMax(uint a, uint b) { return a > b ? a : b; }
 static inline uint16 swap16(uint16 v) { return (v << 8) | (v >> 8); }
 
 void NORETURN Die(const char *error);
+void Warning(const char *error);
 
 // compile time assertion
 #define __CASSERT_N0__(l) COMPILE_TIME_ASSERT_ ## l