Apply noreturn attribute where applicable (#1532)

include/attributes.h

@@ -0,0 +1,12 @@
+#ifndef ATTRIBUTES_H
+#define ATTRIBUTES_H
+
+#ifndef __GNUC__
+#define __attribute__(x)
+#endif
+
+#define UNUSED      __attribute__((unused))
+#define FALLTHROUGH __attribute__((fallthrough))
+#define NORETURN    __attribute__((noreturn))
+
+#endif

include/fault.h

@@ -42,8 +42,8 @@ void Fault_Init(void);
 
 // Fatal Errors
 
-void Fault_AddHungupAndCrashImpl(const char* exp1, const char* exp2);
+NORETURN void Fault_AddHungupAndCrashImpl(const char* exp1, const char* exp2);
-void Fault_AddHungupAndCrash(const char* file, s32 line);
+NORETURN void Fault_AddHungupAndCrash(const char* file, s32 line);
 
 // Client Registration
 

include/functions.h

@@ -30,13 +30,13 @@ void Locale_ResetRegion(void);
 u32 func_80001F48(void);
 u32 func_80001F8C(void);
 u32 Locale_IsRegionNative(void);
-void __assert(const char* exp, const char* file, s32 line);
+NORETURN void __assert(const char* exp, const char* file, s32 line);
 void isPrintfInit(void);
 void osSyncPrintfUnused(const char* fmt, ...);
 void osSyncPrintf(const char* fmt, ...);
 void rmonPrintf(const char* fmt, ...);
 void* is_proutSyncPrintf(void* arg, const char* str, u32 count);
-void func_80002384(const char* exp, const char* file, u32 line);
+NORETURN void func_80002384(const char* exp, const char* file, u32 line);
 OSPiHandle* osDriveRomInit(void);
 void Mio0_Decompress(Yaz0Header* hdr, u8* dst);
 void StackCheck_Init(StackEntry* entry, void* stackBottom, void* stackTop, u32 initValue, s32 minSpace,
@@ -1476,7 +1476,7 @@ u64* SysUcode_GetUCodeBoot(void);
 size_t SysUcode_GetUCodeBootSize(void);
 u64* SysUcode_GetUCode(void);
 u64* SysUcode_GetUCodeData(void);
-void func_800D31A0(void);
+NORETURN void func_800D31A0(void);
 void func_800D31F0(void);
 void func_800D3210(void);
 void DebugArena_CheckPointer(void* ptr, u32 size, const char* name, const char* action);

include/macros.h

@@ -1,19 +1,12 @@
 #ifndef MACROS_H
 #define MACROS_H
 
-#ifndef __GNUC__
-#define __attribute__(x)
-#endif
-
 #ifndef AVOID_UB
 #define BAD_RETURN(type) type
 #else
 #define BAD_RETURN(type) void
 #endif
 
-#define UNUSED __attribute__((unused))
-#define FALLTHROUGH __attribute__((fallthrough))
-
 #define ARRAY_COUNT(arr) (s32)(sizeof(arr) / sizeof(arr[0]))
 #define ARRAY_COUNTU(arr) (u32)(sizeof(arr) / sizeof(arr[0]))
 

include/z64.h

@@ -3,6 +3,7 @@
 
 #include "ultra64.h"
 #include "ultra64/gs2dex.h"
+#include "attributes.h"
 #include "z64save.h"
 #include "z64light.h"
 #include "z64bgcheck.h"

src/boot/assert.c

@@ -1,6 +1,6 @@
 #include "global.h"
 
-void __assert(const char* exp, const char* file, s32 line) {
+NORETURN void __assert(const char* exp, const char* file, s32 line) {
     char msg[256];
 
     osSyncPrintf("Assertion failed: %s, file %s, line %d, thread %d\n", exp, file, line, osGetThreadId(NULL));

src/boot/is_debug.c

@@ -86,7 +86,7 @@ void* is_proutSyncPrintf(void* arg, const char* str, u32 count) {
     return (void*)1;
 }
 
-void func_80002384(const char* exp, const char* file, u32 line) {
+NORETURN void func_80002384(const char* exp, const char* file, u32 line) {
     osSyncPrintf("File:%s Line:%d  %s \n", file, line, exp);
     while (true) {
         ;

src/boot/z_std_dma.c

@@ -231,7 +231,7 @@ void DmaMgr_DmaFromDriveRom(void* ram, uintptr_t rom, size_t size) {
  *
  * This function does not return.
  */
-void DmaMgr_Error(DmaRequest* req, const char* file, const char* errorName, const char* errorDesc) {
+NORETURN void DmaMgr_Error(DmaRequest* req, const char* file, const char* errorName, const char* errorDesc) {
     uintptr_t vrom = req->vromAddr;
     void* ram = req->dramAddr;
     size_t size = req->size;

src/code/code_800D31A0.c

@@ -3,7 +3,7 @@
 
 u32 gIsCtrlr2Valid = false;
 
-void func_800D31A0(void) {
+NORETURN void func_800D31A0(void) {
     osSyncPrintf(VT_FGCOL(RED) "\n**** Freeze!! ****\n" VT_RST);
     while (true) {
         Sleep_Msec(1000);

src/code/fault.c

@@ -1304,19 +1304,25 @@ void Fault_HungupFaultClient(const char* exp1, const char* exp2) {
  * error occurs. The parameters specify two messages detailing the error, one
  * or both may be NULL.
  */
-void Fault_AddHungupAndCrashImpl(const char* exp1, const char* exp2) {
+NORETURN void Fault_AddHungupAndCrashImpl(const char* exp1, const char* exp2) {
     FaultClient client;
     s32 pad;
 
     Fault_AddClient(&client, Fault_HungupFaultClient, (void*)exp1, (void*)exp2);
     *(u32*)0x11111111 = 0; // trigger an exception via unaligned memory access
+
+    // Since the above line triggers an exception and transfers execution to the fault handler
+    // this function does not return and the rest of the function is unreachable.
+#ifdef __GNUC__
+    __builtin_unreachable();
+#endif
 }
 
 /**
  * Like `Fault_AddHungupAndCrashImpl`, however provides a fixed message containing
  * filename and line number
  */
-void Fault_AddHungupAndCrash(const char* file, s32 line) {
+NORETURN void Fault_AddHungupAndCrash(const char* file, s32 line) {
     char msg[256];
 
     sprintf(msg, "HungUp %s:%d", file, line);