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Goober5000andClaude Opus 4.8 bed228d264 avoid undefined behavior from UNREACHABLE on reachable code paths (#7555)
* avoid undefined behavior from UNREACHABLE on reachable code paths

UNREACHABLE expands to __assume(false) / __builtin_unreachable() in
release builds, which is undefined behavior if the code is ever actually
reached. Many UNREACHABLE sites only guard against unexpected-but-
possible runtime states (values from tables, mission/save files, network
packets, scripting, or user input), so reaching them should degrade
gracefully rather than invoke UB.

Replace UNREACHABLE with Assertion(false, ...) at all such sites. It
still pops an error in debug builds, but in release it is a harmless
no-op that simply falls through to the following code. Sites that are
genuinely unreachable by local invariants (e.g. a switch over a bounded
random number) are left as UNREACHABLE.

A few converted sites had no safe fall-through -- an uninitialized read,
null dereference, or null call would have followed -- so they also get a
minimal recovery: initialize the value, guard the dereference, return
early, or skip the offending item.

Where the converted site was a simple guard of the form
    if (x) { Assertion(false, ...); return; }
hoist the check onto the invariant instead:
    Assertion(!x, ...);
    if (x) { return; }
This states the expectation directly and shows the offending value in
the debug popup, while keeping the same graceful runtime degradation.

Co-Authored-By: Claude Opus 4.8 (1M context) <[email protected]>

* addendum

After consultation with Lafiel, use UNREACHABLE in situations that are effectively impossible even if not provably impossible.  UNREACHABLE = "this shouldn't ever happen"; Assertion = "if this ever happens, it's a coding error".  Also fix a few other sites and change a couple to Warnings.

---------

Co-authored-by: Claude Opus 4.8 (1M context) <[email protected]>
2026-07-09 11:20:25 +09:00

600 lines
23 KiB
C++

/*
* Copyright (C) Volition, Inc. 1999. All rights reserved.
*
* All source code herein is the property of Volition, Inc. You may not sell
* or otherwise commercially exploit the source or things you created based on the
* source.
*
*/
#include "globalincs/systemvars.h"
#include "debugconsole/console.h"
#include "globalincs/pstypes.h"
#include "graphics/2d.h"
#include "nebula/neb.h"
#include "options/Option.h"
fix Missiontime;
fix Frametime;
int Framecount=0;
int Game_mode;
int Game_restoring = 0; // If set, this means we are restoring data from disk
int Viewer_mode; // Viewer's mode, see VM_xxxx flags.
//CUTSCENE STUFF
//Cutscene flags
int Cutscene_bar_flags = CUB_NONE;
//Time for gradual change in seconds
float Cutscene_delta_time = 1.0f;
//How far along a change is (0 to 1)
float Cutscene_bars_progress = 1.0f;
// The detail level. Anything below zero draws simple models earlier than it
// should. Anything above zero draws higher detail models longer than it should.
// -2=lowest
// -1=low
// 0=normal (medium)
// 1=high
// 2=extra high
int Game_detail_level = 0;
uint Game_detail_flags = DETAIL_DEFAULT; // see systemvars.h for explanation
angles Viewer_slew_angles; // Angles of viewer relative to forward.
vei Viewer_external_info; // Viewer angles to ship in external view.
vci Viewer_chase_info; // View chase camera information
vec3d leaning_position;
int Is_standalone;
int Interface_last_tick = -1; // last timer tick on flip
#ifndef NDEBUG
// for debugging, used to print the currently processing filename on the loading screen
char Processing_filename[MAX_PATH_LEN];
#endif
// override states to skip rendering of certain elements, but without disabling them completely
bool Envmap_override = false;
bool Glowpoint_override = false;
bool Glowpoint_use_depth_buffer = true;
bool PostProcessing_override = false;
bool Shadow_override = false;
bool Trail_render_override = false;
// Values used for noise for thruster animations
float Noise[NOISE_NUM_FRAMES] = {
0.468225f,
0.168765f,
0.318945f,
0.292866f,
0.553357f,
0.468225f,
0.180456f,
0.418465f,
0.489958f,
1.000000f,
0.468225f,
0.599820f,
0.664718f,
0.294215f,
0.000000f
};
// Variables for the loading callback hooks
static int cf_timestamp = -1;
static void (*cf_callback)(int count) = NULL;
static int cf_in_callback = 0;
static int cb_counter = 0;
static int cb_last_counter = 0;
static int cb_delta_step = -1;
// Call this with the name of a function. That function will
// then get called around 10x per second. The callback function
// gets passed a 'count' which is how many times game_busy has
// been called since the callback was set. It gets called
// one last time with count=-1 when you turn off the callback
// by calling game_busy_callback(NULL). Game_busy_callback
// returns the current count, so you can tell how many times
// game_busy got called.
int game_busy_callback( void (*callback)(int count), int delta_step )
{
if ( !callback ) {
// Call it once more to finalize things
cf_in_callback++;
(*cf_callback)(-1);
cf_in_callback--;
cf_timestamp = -1;
cf_callback = NULL;
} else {
cb_counter = 0;
cb_last_counter = 0;
cb_delta_step = delta_step;
cf_timestamp = timer_get_milliseconds()+(1000/10);
cf_callback = callback;
// Call it once
cf_in_callback++;
(*cf_callback)(0); // pass 0 first time!
cf_in_callback--;
}
return cb_counter;
}
// Call whenever loading to display cursor
void game_busy(const char *filename)
{
if ( cf_in_callback != 0 ) return; // don't call callback if we're already in it.
if ( cf_timestamp < 0 ) return;
if ( !cf_callback ) return;
cb_counter++;
// mprintf(( "CB_COUNTER=%d\n", cb_counter ));
#ifndef NDEBUG
if (filename != NULL)
strcpy_s(Processing_filename, filename);
#endif
int t1 = timer_get_milliseconds();
if ( (t1 > cf_timestamp) || ((cb_counter > cb_last_counter+155) && (cb_delta_step > 0)) ) {
cb_last_counter = cb_counter;
cf_in_callback++;
(*cf_callback)(cb_counter);
cf_in_callback--;
cf_timestamp = t1 + (1000/10);
}
}
static_assert(MAX_DETAIL_VALUE == 4, "MAX_DETAIL_VALUE is assumed to be 4 in SystemVars.cpp");
static_assert(static_cast<int>(DefaultDetailPreset::Num_detail_presets) == 4, "Code in ManagePilot assumes Num_detail_presets = 4");
// Detail preset stuff
detail_levels Detail_defaults[static_cast<int>(DefaultDetailPreset::Num_detail_presets)] = {
{
DefaultDetailPreset::Low, // setting
// ================== Analogs ==================
0, // nebula_detail; // 0=lowest detail, MAX_DETAIL_VALUE=highest detail
0, // detail_distance; // 0=lowest MAX_DETAIL_VALUE=highest
0, // hardware_textures; // 0=max culling, MAX_DETAIL_VALUE=no culling
0, // num_small_debris; // 0=min number, MAX_DETAIL_VALUE=max number
0, // num_particles; // 0=min number, MAX_DETAIL_VALUE=max number
0, // num_stars; // 0=min number, MAX_DETAIL_VALUE=max number
0, // shield_effects; // 0=min, MAX_DETAIL_VALUE=max
2, // lighting; // 0=min, MAX_DETAIL_VALUE=max
// ================== Booleans ==================
false, // targetview_model; // false=off, true=on
false, // planets_suns; // false=off, true=on
false, // weapon_extras // false=off, true=on
},
{
DefaultDetailPreset::Medium, // setting
// ================== Analogs ==================
2, // nebula_detail; // 0=lowest detail, MAX_DETAIL_VALUE=highest detail
2, // detail_distance; // 0=lowest MAX_DETAIL_VALUE=highest
2, // hardware_textures; // 0=max culling, MAX_DETAIL_VALUE=no culling
2, // num_small_debris; // 0=min number, MAX_DETAIL_VALUE=max number
2, // num_particles; // 0=min number, MAX_DETAIL_VALUE=max number
2, // num_stars; // 0=min number, MAX_DETAIL_VALUE=max number
2, // shield_effects; // 0=min, MAX_DETAIL_VALUE=max
3, // lighting; // 0=min, MAX_DETAIL_VALUE=max
// ================== Booleans ==================
true, // targetview_model; // false=off, true=on
true, // planets_suns; // false=off, true=on
true, // weapon_extras // false=off, true=on
},
{
DefaultDetailPreset::High, // setting
// ================== Analogs ==================
2, // nebula_detail; // 0=lowest detail, MAX_DETAIL_VALUE=highest detail
2, // detail_distance; // 0=lowest MAX_DETAIL_VALUE=highest
3, // hardware_textures; // 0=max culling, MAX_DETAIL_VALUE=no culling
3, // num_small_debris; // 0=min number, MAX_DETAIL_VALUE=max number
3, // num_particles; // 0=min number, MAX_DETAIL_VALUE=max number
4, // num_stars; // 0=min number, MAX_DETAIL_VALUE=max number
3, // shield_effects; // 0=min, MAX_DETAIL_VALUE=max
4, // lighting; // 0=min, MAX_DETAIL_VALUE=max
// ================== Booleans ==================
true, // targetview_model; // false=off, true=on
true, // planets_suns; // false=off, true=on
true, // weapon_extras // false=off, true=on
},
{
DefaultDetailPreset::VeryHigh, // setting
// ================== Analogs ==================
4, // nebula_detail; // 0=lowest detail, MAX_DETAIL_VALUE=highest detail
4, // detail_distance; // 0=lowest MAX_DETAIL_VALUE=highest
4, // hardware_textures; // 0=max culling, MAX_DETAIL_VALUE=no culling
4, // num_small_debris; // 0=min number, MAX_DETAIL_VALUE=max number
4, // num_particles; // 0=min number, MAX_DETAIL_VALUE=max number
4, // num_stars; // 0=min number, MAX_DETAIL_VALUE=max number
4, // shield_effects; // 0=min, MAX_DETAIL_VALUE=max
4, // lighting; // 0=min, MAX_DETAIL_VALUE=max
// ================== Booleans ==================
true, // targetview_model; // false=off, true=on
true, // planets_suns; // false=off, true=on
true, // weapon_extras // false=off, true=on
},
};
// Global used to access detail presets in game and libs
detail_levels Detail = Detail_defaults[static_cast<int>(DefaultDetailPreset::Num_detail_presets) - 1];
const SCP_vector<std::pair<int, std::pair<const char*, int>>> DetailLevelValues = {{ 0, {"Minimum", 1680}},
{ 1, {"Low", 1160}},
{ 2, {"Medium", 1161}},
{ 3, {"High", 1162}},
{ 4, {"Ultra", 1721}}};
static void parse_model_detail_func()
{
constexpr int num_detail_presets = static_cast<int>(DefaultDetailPreset::Num_detail_presets);
int value[num_detail_presets];
stuff_int_list(value, num_detail_presets, ParseLookupType::RAW_INTEGER_TYPE);
for (int i = 0; i < num_detail_presets; i++) {
if (value[i] < 0 || value[i] > MAX_DETAIL_VALUE) {
error_display(0, "%i is an invalid detail level value!", value[i]);
} else {
change_default_detail_level(static_cast<DefaultDetailPreset>(i), DetailSetting::DetailDistance, value[i]);
}
}
}
// coverity[GLOBAL_INIT_ORDER] -- safe; OptionBuilder::finish() uses Meyers singleton
const auto ModelDetailOption __UNUSED = options::OptionBuilder<int>("Graphics.Detail",
std::pair<const char*, int>{"Model Detail", 1739},
std::pair<const char*, int>{"Detail level of models", 1740})
.importance(8)
.category(std::make_pair("Graphics", 1825))
.values(DetailLevelValues)
.default_func([](){return Detail.detail_distance;})
.change_listener([](int val, bool) {
Detail.detail_distance = val;
return true;
})
.flags({options::OptionFlags::RetailBuiltinOption})
.parser(parse_model_detail_func)
.finish();
static void parse_texture_detail_func()
{
constexpr int num_detail_presets = static_cast<int>(DefaultDetailPreset::Num_detail_presets);
int value[num_detail_presets];
stuff_int_list(value, num_detail_presets, ParseLookupType::RAW_INTEGER_TYPE);
for (int i = 0; i < num_detail_presets; i++) {
if (value[i] < 0 || value[i] > MAX_DETAIL_VALUE) {
error_display(0, "%i is an invalid detail level value!", value[i]);
} else {
change_default_detail_level(static_cast<DefaultDetailPreset>(i), DetailSetting::HardwareTextures, value[i]);
}
}
}
// coverity[GLOBAL_INIT_ORDER] -- safe; OptionBuilder::finish() uses Meyers singleton
const auto TexturesOption __UNUSED = options::OptionBuilder<int>("Graphics.Texture",
std::pair<const char*, int>{"3D Hardware Textures", 1362},
std::pair<const char*, int>{"Level of detail of textures", 1720})
.importance(6)
.category(std::make_pair("Graphics", 1825))
.values(DetailLevelValues)
.default_func([](){return Detail.hardware_textures;})
.change_listener([](int val, bool) {
Detail.hardware_textures = val;
return true;
})
.flags({options::OptionFlags::RetailBuiltinOption})
.parser(parse_texture_detail_func)
.finish();
static void parse_particles_detail_func()
{
constexpr int num_detail_presets = static_cast<int>(DefaultDetailPreset::Num_detail_presets);
int value[num_detail_presets];
stuff_int_list(value, num_detail_presets, ParseLookupType::RAW_INTEGER_TYPE);
for (int i = 0; i < num_detail_presets; i++) {
if (value[i] < 0 || value[i] > MAX_DETAIL_VALUE) {
error_display(0, "%i is an invalid detail level value!", value[i]);
} else {
change_default_detail_level(static_cast<DefaultDetailPreset>(i), DetailSetting::NumParticles, value[i]);
}
}
}
// coverity[GLOBAL_INIT_ORDER] -- safe; OptionBuilder::finish() uses Meyers singleton
const auto ParticlesOption __UNUSED = options::OptionBuilder<int>("Graphics.Particles",
std::pair<const char*, int>{"Particles", 1363},
std::pair<const char*, int>{"Level of detail for particles", 1717})
.importance(5)
.category(std::make_pair("Graphics", 1825))
.values(DetailLevelValues)
.default_func([](){return Detail.num_particles;})
.change_listener([](int val, bool) {
Detail.num_particles = val;
return true;
})
.flags({options::OptionFlags::RetailBuiltinOption})
.parser(parse_particles_detail_func)
.finish();
static void parse_debris_detail_func()
{
constexpr int num_detail_presets = static_cast<int>(DefaultDetailPreset::Num_detail_presets);
int value[num_detail_presets];
stuff_int_list(value, num_detail_presets, ParseLookupType::RAW_INTEGER_TYPE);
for (int i = 0; i < num_detail_presets; i++) {
if (value[i] < 0 || value[i] > MAX_DETAIL_VALUE) {
error_display(0, "%i is an invalid detail level value!", value[i]);
} else {
change_default_detail_level(static_cast<DefaultDetailPreset>(i), DetailSetting::NumSmallDebris, value[i]);
}
}
}
// coverity[GLOBAL_INIT_ORDER] -- safe; OptionBuilder::finish() uses Meyers singleton
const auto SmallDebrisOption __UNUSED = options::OptionBuilder<int>("Graphics.SmallDebris",
std::pair<const char*, int>{"Impact Effects", 1364},
std::pair<const char*, int>{"Level of detail of impact effects", 1743})
.category(std::make_pair("Graphics", 1825))
.values(DetailLevelValues)
.default_func([](){return Detail.num_small_debris;})
.importance(4)
.change_listener([](int val,bool) {
Detail.num_small_debris = val;
return true;
})
.flags({options::OptionFlags::RetailBuiltinOption})
.parser(parse_debris_detail_func)
.finish();
static void parse_shield_detail_func()
{
constexpr int num_detail_presets = static_cast<int>(DefaultDetailPreset::Num_detail_presets);
int value[num_detail_presets];
stuff_int_list(value, num_detail_presets, ParseLookupType::RAW_INTEGER_TYPE);
for (int i = 0; i < num_detail_presets; i++) {
if (value[i] < 0 || value[i] > MAX_DETAIL_VALUE) {
error_display(0, "%i is an invalid detail level value!", value[i]);
} else {
change_default_detail_level(static_cast<DefaultDetailPreset>(i), DetailSetting::ShieldEffects, value[i]);
}
}
}
// coverity[GLOBAL_INIT_ORDER] -- safe; OptionBuilder::finish() uses Meyers singleton
const auto ShieldEffectsOption __UNUSED = options::OptionBuilder<int>("Graphics.ShieldEffects",
std::pair<const char*, int>{"Shield Hit Effects", 1718},
std::pair<const char*, int>{"Level of detail of shield impacts", 1719})
.importance(3)
.category(std::make_pair("Graphics", 1825))
.values(DetailLevelValues)
.default_func([](){return Detail.shield_effects;})
.change_listener([](int val, bool) {
Detail.shield_effects = val;
return true;
})
.flags({options::OptionFlags::RetailBuiltinOption})
.parser(parse_shield_detail_func)
.finish();
static void parse_stars_detail_func()
{
constexpr int num_detail_presets = static_cast<int>(DefaultDetailPreset::Num_detail_presets);
int value[num_detail_presets];
stuff_int_list(value, num_detail_presets, ParseLookupType::RAW_INTEGER_TYPE);
for (int i = 0; i < num_detail_presets; i++) {
if (value[i] < 0 || value[i] > MAX_DETAIL_VALUE) {
error_display(0, "%i is an invalid detail level value!", value[i]);
} else {
change_default_detail_level(static_cast<DefaultDetailPreset>(i), DetailSetting::NumStars, value[i]);
}
}
}
// coverity[GLOBAL_INIT_ORDER] -- safe; OptionBuilder::finish() uses Meyers singleton
const auto StarsOption __UNUSED = options::OptionBuilder<int>("Graphics.Stars",
std::pair<const char*, int>{"Stars", 1366},
std::pair<const char*, int>{"Number of stars in the mission", 1698})
.importance(2)
.category(std::make_pair("Graphics", 1825))
.values(DetailLevelValues)
.default_func([](){return Detail.num_stars;})
.change_listener([](int val, bool) {
Detail.num_stars = val;
return true;
})
.flags({options::OptionFlags::RetailBuiltinOption})
.parser(parse_stars_detail_func)
.finish();
// Call this with:
// 0 - lowest
// Num_detail_presets - highest
// To set the parameters in Detail to some set of defaults
void detail_level_set(DefaultDetailPreset preset)
{
if (preset == DefaultDetailPreset::Custom) {
Detail.setting = DefaultDetailPreset::Custom;
return;
}
Detail = Detail_defaults[static_cast<int>(preset)];
}
// Change detail values 0 - MAX_DETAIL_VALUE
void change_default_detail_level(DefaultDetailPreset preset, DetailSetting selection, int value)
{
// Use a switch statement for more readable access to the struct members
switch (selection) {
case DetailSetting::NebulaDetail:
Detail_defaults[static_cast<int>(preset)].nebula_detail = value;
break;
case DetailSetting::DetailDistance:
Detail_defaults[static_cast<int>(preset)].detail_distance = value;
break;
case DetailSetting::HardwareTextures:
Detail_defaults[static_cast<int>(preset)].hardware_textures = value;
break;
case DetailSetting::NumSmallDebris:
Detail_defaults[static_cast<int>(preset)].num_small_debris = value;
break;
case DetailSetting::NumParticles:
Detail_defaults[static_cast<int>(preset)].num_particles = value;
break;
case DetailSetting::NumStars:
Detail_defaults[static_cast<int>(preset)].num_stars = value;
break;
case DetailSetting::ShieldEffects:
Detail_defaults[static_cast<int>(preset)].shield_effects = value;
break;
case DetailSetting::Lighting:
Detail_defaults[static_cast<int>(preset)].lighting = value;
break;
default:
UNREACHABLE("Invalid detail selection %d. Get a coder!", static_cast<int>(selection));
}
}
// Change detail values bool overload
void change_default_detail_level(DefaultDetailPreset preset, DetailSetting selection, bool value)
{
// Use a switch statement for more readable access to the struct members
switch (selection) {
case DetailSetting::TargetViewModel:
Detail_defaults[static_cast<int>(preset)].targetview_model = value;
break;
case DetailSetting::PlanetsSuns:
Detail_defaults[static_cast<int>(preset)].planets_suns = value;
break;
case DetailSetting::WeaponExtras:
Detail_defaults[static_cast<int>(preset)].weapon_extras = value;
break;
default:
UNREACHABLE("Invalid detail selection %d. Get a coder!", static_cast<int>(selection));
}
}
// Returns the current detail preset or -1 if custom.
DefaultDetailPreset current_detail_preset()
{
// return Detail.setting;
int i;
for (i = 0; i < static_cast<int>(DefaultDetailPreset::Num_detail_presets); i++) {
if ( memcmp( &Detail, &Detail_defaults[i], sizeof(detail_levels) )==0 ) {
return static_cast<DefaultDetailPreset>(i);
}
}
return DefaultDetailPreset::Custom;
}
#ifndef NDEBUG
DCF(detail_level,"Change the detail level")
{
int value;
if (dc_optional_string_either("help", "--help")) {
dc_printf( "Usage: detail_level [n]\n");
dc_printf("[n] -- is detail level.\n");
dc_printf("\t0 is 'normal' detail,\n");
dc_printf("\tnegative values are lower, and\n");
dc_printf("\tpositive values are higher.\n\n");
dc_printf("No parameter resets it to default.\n");
return;
}
if (dc_optional_string_either("status", "--status") || dc_optional_string_either("?", "--?")) {
dc_printf("Detail level set to %d\n", Game_detail_level);
return;
}
if (dc_maybe_stuff_int(&value)) {
Game_detail_level = value;
dc_printf("Detail level set to %i\n", Game_detail_level);
} else {
Game_detail_level = 0;
dc_printf("Detail level reset\n");
}
}
DCF(detail, "Turns on/off parts of the game for speed testing" )
{
int value;
if (dc_optional_string_either("help", "--help")) {
dc_printf( "Usage: detail [n]\n");
dc_printf("[n] is detail bit to toggle:\n" );
dc_printf( " 1: draw the stars\n" );
dc_printf( " 2: draw the nebulas\n" );
dc_printf( " 4: draw the motion debris\n" );
dc_printf( " 8: draw planets\n" );
dc_printf( " 16: draw models not as blobs\n" );
dc_printf( " 32: draw lasers not as pixels\n" );
dc_printf( " 64: clear screen background after each frame\n" );
dc_printf( " 128: draw hud stuff\n" );
dc_printf( " 256: draw fireballs\n" );
dc_printf( " 512: do collision detection\n\n" );
dc_printf("No argument will toggle between highest/lowest detail settings\n");
return;
}
if (dc_optional_string_either("status", "--status") || dc_optional_string_either("?", "--?")) {
dc_printf("Detail flags set to 0x%08x\n", Game_detail_flags);
dc_printf( " 1: draw the stars: %s\n", ((Game_detail_flags & 1) ? "on" : "off"));
dc_printf( " 2: draw the nebulas: %s\n", ((Game_detail_flags & 2)?"on" : "off"));
dc_printf( " 4: draw the motion debris: %s\n", ((Game_detail_flags & 4) ? "on" : "off"));
dc_printf( " 8: draw planets: %s\n", ((Game_detail_flags & 8) ? "on" : "off"));
dc_printf( " 16: draw models not as blobs: %s\n", ((Game_detail_flags & 16) ? "on" : "off"));
dc_printf( " 32: draw lasers not as pixels: %s\n", ((Game_detail_flags & 32) ? "on" : "off"));
dc_printf( " 64: clear screen background after each frame: %s\n", ((Game_detail_flags & 64) ? "on" : "off"));
dc_printf( " 128: draw hud stuff: %s\n", ((Game_detail_flags & 128) ? "on" : "off"));
dc_printf( " 256: draw fireballs: %s\n", ((Game_detail_flags & 256) ? "on" : "off"));
dc_printf( " 512: do collision detection: %s\n", ((Game_detail_flags & 512) ? "on" : "off"));
return;
}
if (dc_maybe_stuff_int(&value)) {
Game_detail_flags ^= value;
} else {
if (Game_detail_flags == DETAIL_DEFAULT) {
Game_detail_flags = DETAIL_FLAG_CLEAR;
dc_printf( "Detail flags set lowest (except has screen clear)\n" );
} else {
Game_detail_flags = DETAIL_DEFAULT;
dc_printf( "Detail flags set highest\n" );
}
}
}
#endif