Modernize C++ usage (#144)

* Stratosphere: Use modern C++ idioms in some places

* algorithms like std::for_each are used instead of raw loops

* Stratosphere: Replace more raw loops with algorithms

* Stratosphere: Add a utility predicate function to test for equality with a reference element

This can be used to rewrite some common raw loops using algorithms instead

* fs.mitm: Use variant

* fs.mitm: Use enum class

* fs.mitm: Turn RomFSSourceInfo::Cleanup into a destructor

This obsoletes the need for a custom deleter in other places

* fs.mitm: Use enum class some more

* fs.mitm: Use unique_ptr

* fs.mitm: Simplify initialization

* Stratosphere: Simplify initialization

* fs.mitm: Use unique_ptr (fix memory leak along the way)

The previous code was using "delete" rather than "delete[]"

* fs.mitm: Use vector::emplace_back rather than push_back

emplace_back constructs elements in-place, hence avoiding a redundant element copy.

* Stratosphere: Replace more raw loops with algorithms

* Stratosphere: Use unique_ptr

* fs.mitm: Replace more raw loops with algorithms

* Stratosphere: Prefer move-construction over copy-construction when moving sink parameters around

stratosphere/loader/source/ldr_launch_queue.cpp

@@ -1,9 +1,11 @@
 #include <switch.h>
 #include <algorithm>
+#include <array>
 #include <cstdio>
 #include "ldr_launch_queue.hpp"
+#include "meta_tools.hpp"
 
-static LaunchQueue::LaunchItem g_launch_queue[LAUNCH_QUEUE_SIZE] = {0};
+static std::array<LaunchQueue::LaunchItem, LAUNCH_QUEUE_SIZE> g_launch_queue = {0};
 
 Result LaunchQueue::add(u64 tid, const char *args, u64 arg_size) {
     if(arg_size > LAUNCH_QUEUE_ARG_SIZE_MAX) {
@@ -45,12 +47,11 @@ Result LaunchQueue::add_item(const LaunchItem *item) {
 }
 
 int LaunchQueue::get_index(u64 tid) {
-    for(unsigned int i = 0; i < LAUNCH_QUEUE_SIZE; i++) {
-        if(g_launch_queue[i].tid == tid) {
-            return i;
-        }
+    auto it = std::find_if(g_launch_queue.begin(), g_launch_queue.end(), member_equals_fn(&LaunchQueue::LaunchItem::tid, tid));
+    if (it == g_launch_queue.end()) {
+        return LAUNCH_QUEUE_FULL;
     }
-    return LAUNCH_QUEUE_FULL;
+    return std::distance(g_launch_queue.begin(), it);
 }
 
 int LaunchQueue::get_free_index(u64 tid) {
@@ -74,8 +75,8 @@ void LaunchQueue::clear() {
 
 
 LaunchQueue::LaunchItem *LaunchQueue::get_item(u64 tid) {
-    int idx;
-    if ((idx = get_index(tid)) == LAUNCH_QUEUE_FULL) {
+    int idx = get_index(tid);
+    if (idx == LAUNCH_QUEUE_FULL) {
         return NULL;
     }
     return &g_launch_queue[idx];

stratosphere/loader/source/ldr_main.cpp

@@ -93,7 +93,7 @@ int main(int argc, char **argv)
     consoleDebugInit(debugDevice_SVC);
         
     /* TODO: What's a good timeout value to use here? */
-    WaitableManager *server_manager = new WaitableManager(U64_MAX);
+    auto server_manager = std::make_unique<WaitableManager>(U64_MAX);
     
     /* Add services to manager. */
     server_manager->add_waitable(new ServiceServer<ProcessManagerService>("ldr:pm", 1));
@@ -107,8 +107,6 @@ int main(int argc, char **argv)
     /* Loop forever, servicing our services. */
     server_manager->process();
     
-    /* Cleanup. */
-    delete server_manager;
 	return 0;
 }
 

stratosphere/loader/source/ldr_nro.cpp

@@ -1,6 +1,7 @@
 #include <switch.h>
 #include <algorithm>
 #include <cstdio>
+#include <functional>
 #include <cstring>
 #include "sha256.h"
 #include "ldr_nro.hpp"
@@ -37,12 +38,7 @@ Result NroUtils::LoadNro(Registration::Process *target_proc, Handle process_h, u
     u8 nro_hash[0x20];
     SHA256_CTX sha_ctx;
     /* Ensure there is an available NRO slot. */
-    for (i = 0; i < NRO_INFO_MAX; i++) {
-        if (!target_proc->nro_infos[i].in_use) {
-            break;
-        }
-    }
-    if (i >= NRO_INFO_MAX) {
+    if (std::all_of(target_proc->nro_infos.begin(), target_proc->nro_infos.end(), std::mem_fn(&Registration::NroInfo::in_use))) {
         return 0x6E09;
     }
     for (i = 0; i < 0x200; i++) {
@@ -118,4 +114,4 @@ LOAD_NRO_END:
         mcm_bss.Close();
     }
     return 0x0;
-}
+}

stratosphere/loader/source/ldr_registration.cpp

@@ -2,6 +2,7 @@
 #include <algorithm>
 #include <cstdio>
 #include <cstring>
+#include <functional>
 #include "ldr_registration.hpp"
 #include "ldr_nro.hpp"
 
@@ -9,12 +10,11 @@ static Registration::List g_registration_list = {0};
 static u64 g_num_registered = 1;
 
 Registration::Process *Registration::GetFreeProcess() {
-    for (unsigned int i = 0; i < REGISTRATION_LIST_MAX; i++) {
-        if (!g_registration_list.processes[i].in_use) {
-            return &g_registration_list.processes[i];
-        }
+    auto process_it = std::find_if_not(g_registration_list.processes.begin(), g_registration_list.processes.end(), std::mem_fn(&Registration::Process::in_use));
+    if (process_it == g_registration_list.processes.end()) {
+        return nullptr;
     }
-    return NULL;
+    return &*process_it;
 }
 
 Registration::Process *Registration::GetProcess(u64 index) {
@@ -98,15 +98,13 @@ void Registration::AddNsoInfo(u64 index, u64 base_address, u64 size, const unsig
     if (target_process == NULL) {
         return;
     }
-    
-    for (unsigned int i = 0; i < NSO_INFO_MAX; i++) {
-        if (!target_process->nso_infos[i].in_use) {
-            target_process->nso_infos[i].info.base_address = base_address;
-            target_process->nso_infos[i].info.size = size;
-            std::copy(build_id, build_id + sizeof(target_process->nso_infos[i].info.build_id), target_process->nso_infos[i].info.build_id);
-            target_process->nso_infos[i].in_use = true;
-            return;
-        }
+
+    auto nso_info_it = std::find_if_not(target_process->nso_infos.begin(), target_process->nso_infos.end(), std::mem_fn(&Registration::NsoInfoHolder::in_use));
+    if (nso_info_it != target_process->nso_infos.end()) {
+        nso_info_it->info.base_address = base_address;
+        nso_info_it->info.size = size;
+        std::copy(build_id, build_id + sizeof(nso_info_it->info.build_id), nso_info_it->info.build_id);
+        nso_info_it->in_use = true;
     }
 }
 
@@ -130,13 +128,12 @@ Result Registration::AddNrrInfo(u64 index, MappedCodeMemory *nrr_info) {
         return 0x7009;
     }
     
-    for (unsigned int i = 0; i < NRR_INFO_MAX; i++) {
-        if (!target_process->nrr_infos[i].IsActive()) {
-            target_process->nrr_infos[i] = *nrr_info;
-            return 0;
-        }
+    auto nrr_info_it = std::find_if_not(target_process->nrr_infos.begin(), target_process->nrr_infos.end(), std::mem_fn(&MappedCodeMemory::IsActive));
+    if (nrr_info_it == target_process->nrr_infos.end()) {
+        return 0x7009;
     }
-    return 0x7009;
+    *nrr_info_it = *nrr_info;
+    return 0;
 }
 
 Result Registration::RemoveNrrInfo(u64 index, u64 base_address) {
@@ -193,7 +190,7 @@ bool Registration::IsNroAlreadyLoaded(u64 index, u8 *build_id) {
     }
     
     for (unsigned int i = 0; i < NRO_INFO_MAX; i++) {
-        if (target_process->nro_infos[i].in_use && std::memcmp(target_process->nro_infos[i].build_id, build_id, 0x20) == 0) {
+        if (target_process->nro_infos[i].in_use && std::equal(build_id, build_id + 0x20, target_process->nro_infos[i].build_id)) {
             return true;
         }
     }
@@ -207,20 +204,18 @@ void Registration::AddNroToProcess(u64 index, MappedCodeMemory *nro, MappedCodeM
         return;
     }
     
-    for (unsigned int i = 0; i < NRO_INFO_MAX; i++) {
-        if (!target_process->nro_infos[i].in_use) {
-            target_process->nro_infos[i].base_address = nro->code_memory_address;
-            target_process->nro_infos[i].nro_heap_address = nro->base_address;
-            target_process->nro_infos[i].nro_heap_size = nro->size;
-            target_process->nro_infos[i].bss_heap_address = bss->base_address;
-            target_process->nro_infos[i].bss_heap_size = bss->size;
-            target_process->nro_infos[i].text_size = text_size;
-            target_process->nro_infos[i].ro_size = ro_size;
-            target_process->nro_infos[i].rw_size = rw_size;
-            std::copy(build_id, build_id + sizeof(target_process->nro_infos[i].build_id), target_process->nro_infos[i].build_id);
-            target_process->nro_infos[i].in_use = true;
-            break;
-        }
+    auto nro_info_it = std::find_if_not(target_process->nro_infos.begin(), target_process->nro_infos.end(), std::mem_fn(&Registration::NroInfo::in_use));
+    if (nro_info_it != target_process->nro_infos.end()) {
+        nro_info_it->base_address = nro->code_memory_address;
+        nro_info_it->nro_heap_address = nro->base_address;
+        nro_info_it->nro_heap_size = nro->size;
+        nro_info_it->bss_heap_address = bss->base_address;
+        nro_info_it->bss_heap_size = bss->size;
+        nro_info_it->text_size = text_size;
+        nro_info_it->ro_size = ro_size;
+        nro_info_it->rw_size = rw_size;
+        std::copy(build_id, build_id + sizeof(nro_info_it->build_id), nro_info_it->build_id);
+        nro_info_it->in_use = true;
     }
 }
 
@@ -254,11 +249,9 @@ Result Registration::GetNsoInfosForProcessId(Registration::NsoInfo *out, u32 max
     }
     u32 cur = 0;
     
-    if (max_out > 0) {
-        for (unsigned int i = 0; i < NSO_INFO_MAX && cur < max_out; i++) {
-            if (target_process->nso_infos[i].in_use) {
-                out[cur++] = target_process->nso_infos[i].info;
-            }
+    for (unsigned int i = 0; i < NSO_INFO_MAX && cur < max_out; i++) {
+        if (target_process->nso_infos[i].in_use) {
+            out[cur++] = target_process->nso_infos[i].info;
         }
     }
     

stratosphere/loader/source/ldr_registration.hpp

@@ -1,5 +1,6 @@
 #pragma once
 #include <switch.h>
+#include <array>
 
 #include "ldr_map.hpp"
 
@@ -48,14 +49,14 @@ class Registration {
             u64 process_id;
             u64 title_id;
             Registration::TidSid tid_sid;
-            Registration::NsoInfoHolder nso_infos[NSO_INFO_MAX];
-            Registration::NroInfo nro_infos[NRO_INFO_MAX];
-            MappedCodeMemory nrr_infos[NRR_INFO_MAX];
+            std::array<Registration::NsoInfoHolder, NSO_INFO_MAX> nso_infos;
+            std::array<Registration::NroInfo, NRO_INFO_MAX> nro_infos;
+            std::array<MappedCodeMemory, NRR_INFO_MAX> nrr_infos;
             void *owner_ro_service;
         };
         
         struct List {
-            Registration::Process processes[REGISTRATION_LIST_MAX];
+            std::array<Registration::Process, REGISTRATION_LIST_MAX> processes;
             u64 num_processes;
         };