Core: Add support for loading Libretro-style cht files

CHANGES

@@ -15,6 +15,7 @@ Features:
  - Switch: Option to use built-in brightness sensor for Boktai
  - Ports: Ability to enable or disable all SGB features (closes mgba.io/i/1205)
  - Ports: Ability to crop SGB borders off screen (closes mgba.io/i/1204)
+ - Cheats: Add support for loading Libretro-style cht files
 Emulation fixes:
  - GBA: All IRQs have 7 cycle delay (fixes mgba.io/i/539, mgba.io/i/1208)
  - GBA: Reset now reloads multiboot ROMs

include/mgba-util/string.h

@@ -39,6 +39,8 @@ const char* hex4(const char* line, uint8_t* out);
 
 void rtrim(char* string);
 
+ssize_t parseQuotedString(const char* unparsed, ssize_t unparsedLen, char* parsed, ssize_t parsedLen);
+
 CXX_GUARD_END
 
 #endif

include/mgba/core/cheats.h

@@ -100,6 +100,8 @@ void mCheatRemoveSet(struct mCheatDevice*, struct mCheatSet*);
 bool mCheatParseFile(struct mCheatDevice*, struct VFile*);
 bool mCheatSaveFile(struct mCheatDevice*, struct VFile*);
 
+bool mCheatParseLibretroFile(struct mCheatDevice*, struct VFile*);
+
 #if !defined(MINIMAL_CORE) || MINIMAL_CORE < 2
 void mCheatAutosave(struct mCheatDevice*);
 #endif

src/core/cheats.c

@@ -9,7 +9,8 @@
 #include <mgba-util/string.h>
 #include <mgba-util/vfs.h>
 
-#define MAX_LINE_LENGTH 128
+#define MAX_LINE_LENGTH 512
+#define MAX_CHEATS 1000
 
 const uint32_t M_CHEAT_DEVICE_ID = 0xABADC0DE;
 
@@ -191,6 +192,12 @@ bool mCheatParseFile(struct mCheatDevice* device, struct VFile* vf) {
 			break;
 		default:
 			if (!set) {
+				if (strncmp(cheat, "cheats = ", 9) == 0) {
+					// This is in libretro format, switch over to that parser
+					vf->seek(vf, 0, SEEK_SET);
+					StringListDeinit(&directives);
+					return mCheatParseLibretroFile(device, vf);
+				}
 				set = device->createSet(device, NULL);
 				set->enabled = !nextDisabled;
 				nextDisabled = false;
@@ -211,6 +218,112 @@ bool mCheatParseFile(struct mCheatDevice* device, struct VFile* vf) {
 	return true;
 }
 
+bool mCheatParseLibretroFile(struct mCheatDevice* device, struct VFile* vf) {
+	char cheat[MAX_LINE_LENGTH];
+	char parsed[MAX_LINE_LENGTH];
+	struct mCheatSet* set = NULL;
+	unsigned long i = 0;
+	bool startFound = false;
+
+	while (true) {
+		ssize_t bytesRead = vf->readline(vf, cheat, sizeof(cheat));
+		if (bytesRead == 0) {
+			break;
+		}
+		if (bytesRead < 0) {
+			return false;
+		}
+		if (cheat[0] == '\n') {
+			continue;
+		}
+		if (strncmp(cheat, "cheat", 5) != 0) {
+			return false;
+		}
+		char* underscore = strchr(&cheat[5], '_');
+		if (!underscore) {
+			if (!startFound && cheat[5] == 's') {
+				startFound = true;
+				char* eq = strchr(&cheat[6], '=');
+				if (!eq) {
+					return false;
+				}
+				++eq;
+				while (isspace((int) eq[0])) {
+					if (eq[0] == '\0') {
+						return false;
+					}
+					++eq;
+				}
+
+				char* end;
+				unsigned long nCheats = strtoul(eq, &end, 10);
+				if (end[0] != '\0' && !isspace(end[0])) {
+					return false;
+				}
+
+				if (nCheats > MAX_CHEATS) {
+					return false;
+				}
+
+				while (nCheats > mCheatSetsSize(&device->cheats)) {
+					struct mCheatSet* newSet = device->createSet(device, NULL);
+					if (!newSet) {
+						return false;
+					}
+					mCheatAddSet(device, newSet);
+				}
+				continue;
+			}
+			return false;
+		}
+		char* underscore2;
+		i = strtoul(&cheat[5], &underscore2, 10);
+		if (underscore2 != underscore) {
+			return false;
+		}
+		++underscore;
+		char* eq = strchr(underscore, '=');
+		if (!eq) {
+			return false;
+		}
+		++eq;
+		while (isspace((int) eq[0])) {
+			if (eq[0] == '\0') {
+				return false;
+			}
+			++eq;
+		}
+
+		if (i >= mCheatSetsSize(&device->cheats)) {
+			return false;
+		}
+		set = *mCheatSetsGetPointer(&device->cheats, i);
+
+		if (strncmp(underscore, "desc", 4) == 0) {
+			parseQuotedString(eq, strlen(eq), parsed, sizeof(parsed));
+			mCheatSetRename(set, parsed);
+		} else if (strncmp(underscore, "enable", 6) == 0) {
+			set->enabled = strncmp(eq, "true\n", 5) == 0;
+		} else if (strncmp(underscore, "code", 4) == 0) {
+			parseQuotedString(eq, strlen(eq), parsed, sizeof(parsed));
+			char* cur = parsed;
+			char* next;
+			while ((next = strchr(cur, '+'))) {
+				next[0] = '\0';
+				mCheatAddLine(set, cur, 0);
+				cur = &next[1];
+			}
+			mCheatAddLine(set, cur, 0);
+
+			for (++i; i < mCheatSetsSize(&device->cheats); ++i) {
+				struct mCheatSet* newSet = *mCheatSetsGetPointer(&device->cheats, i);
+				newSet->copyProperties(newSet, set);
+			}
+		}
+	}
+	return true;
+}
+
 bool mCheatSaveFile(struct mCheatDevice* device, struct VFile* vf) {
 	static const char lineStart[3] = "# ";
 	static const char lineEnd = '\n';

src/platform/qt/CheatsView.cpp

@@ -109,14 +109,14 @@ bool CheatsView::eventFilter(QObject* object, QEvent* event) {
 }
 
 void CheatsView::load() {
-	QString filename = GBAApp::app()->getOpenFileName(this, tr("Select cheats file"), tr(("Cheats file (*.cheats *.cht *.clt)")));
+	QString filename = GBAApp::app()->getOpenFileName(this, tr("Select cheats file"), tr(("Cheats file (*.cheats *.cht)")));
 	if (!filename.isEmpty()) {
 		m_model.loadFile(filename);
 	}
 }
 
 void CheatsView::save() {
-	QString filename = GBAApp::app()->getSaveFileName(this, tr("Select cheats file"), tr(("Cheats file (*.cheats *.cht *.clt)")));
+	QString filename = GBAApp::app()->getSaveFileName(this, tr("Select cheats file"), tr(("Cheats file (*.cheats)")));
 	if (!filename.isEmpty()) {
 		m_model.saveFile(filename);
 	}

src/util/string.c

@@ -1,4 +1,4 @@
-/* Copyright (c) 2013-2015 Jeffrey Pfau
+/* Copyright (c) 2013-2019 Jeffrey Pfau
  *
  * This Source Code Form is subject to the terms of the Mozilla Public
  * License, v. 2.0. If a copy of the MPL was not distributed with this
@@ -373,3 +373,64 @@ void rtrim(char* string) {
 		--end;
 	}
 }
+
+ssize_t parseQuotedString(const char* unparsed, ssize_t unparsedLen, char* parsed, ssize_t parsedLen) {
+	memset(parsed, 0, parsedLen);
+	bool escaped = false;
+	char start = '\0';
+	ssize_t len = 0;
+	ssize_t i;
+	for (i = 0; i < unparsedLen && len < parsedLen; ++i) {
+		if (i == 0) {
+			switch (unparsed[0]) {
+			case '"':
+			case '\'':
+				start = unparsed[0];
+				break;
+			default:
+				return -1;
+			}
+			continue;
+		}
+		if (escaped) {
+			switch (unparsed[i]) {
+			case 'n':
+				parsed[len] = '\n';
+				break;
+			case 'r':
+				parsed[len] = '\r';
+				break;
+			case '\\':
+				parsed[len] = '\\';
+				break;
+			case '\'':
+				parsed[len] = '\'';
+				break;
+			case '"':
+				parsed[len] = '"';
+				break;
+			default:
+				return -1;
+			}
+			escaped = false;
+			++len;
+			continue;
+		}
+		if (unparsed[i] == start) {
+			return len;
+		}
+		switch (unparsed[i]) {
+		case '\\':
+			escaped = true;
+			break;
+		case '\n':
+		case '\r':
+			return len;
+		default:
+			parsed[len] = unparsed[i];
+			++len;
+			break;
+		}
+	}
+	return -1;
+}

src/util/test/string-parser.c

@@ -0,0 +1,136 @@
+/* Copyright (c) 2013-2019 Jeffrey Pfau
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+#include "util/test/suite.h"
+
+#include <mgba-util/string.h>
+
+M_TEST_DEFINE(nullString) {
+	const char* unparsed = "";
+	char parsed[2];
+	assert_int_equal(parseQuotedString(unparsed, 1, parsed, sizeof(parsed)), -1);
+}
+
+M_TEST_DEFINE(emptyString2) {
+	const char* unparsed = "\"\"";
+	char parsed[2];
+	assert_int_equal(parseQuotedString(unparsed, strlen(unparsed) + 1, parsed, sizeof(parsed)), 0);
+}
+
+M_TEST_DEFINE(emptyString) {
+	const char* unparsed = "''";
+	char parsed[2];
+	assert_int_equal(parseQuotedString(unparsed, strlen(unparsed) + 1, parsed, sizeof(parsed)), 0);
+}
+
+M_TEST_DEFINE(plainString) {
+	const char* unparsed = "\"plain\"";
+	char parsed[32];
+	assert_int_equal(parseQuotedString(unparsed, strlen(unparsed) + 1, parsed, sizeof(parsed)), strlen("plain"));
+	assert_string_equal(parsed, "plain");
+}
+
+M_TEST_DEFINE(plainString2) {
+	const char* unparsed = "\"plain\"";
+	char parsed[32];
+	assert_int_equal(parseQuotedString(unparsed, strlen(unparsed), parsed, sizeof(parsed)), strlen("plain"));
+	assert_string_equal(parsed, "plain");
+}
+
+M_TEST_DEFINE(trailingString) {
+	const char* unparsed = "\"trailing\"T";
+	char parsed[32];
+	assert_int_equal(parseQuotedString(unparsed, strlen(unparsed) + 1, parsed, sizeof(parsed)), strlen("trailing"));
+	assert_string_equal(parsed, "trailing");
+}
+
+M_TEST_DEFINE(leadingString) {
+	const char* unparsed = "L\"leading\"";
+	char parsed[32];
+	assert_int_equal(parseQuotedString(unparsed, strlen(unparsed) + 1, parsed, sizeof(parsed)), -1);
+}
+
+M_TEST_DEFINE(backslashString) {
+	const char* unparsed = "\"back\\\\slash\"";
+	char parsed[32];
+	assert_int_equal(parseQuotedString(unparsed, strlen(unparsed) + 1, parsed, sizeof(parsed)), strlen("back\\slash"));
+	assert_string_equal(parsed, "back\\slash");
+}
+
+M_TEST_DEFINE(doubleBackslashString) {
+	const char* unparsed = "\"back\\\\\\\\slash\"";
+	char parsed[32];
+	assert_int_equal(parseQuotedString(unparsed, strlen(unparsed) + 1, parsed, sizeof(parsed)), strlen("back\\\\slash"));
+	assert_string_equal(parsed, "back\\\\slash");
+}
+
+M_TEST_DEFINE(escapeCharsString) {
+	const char* unparsed = "\"\\\"\\'\\n\\r\\\\\"";
+	char parsed[32];
+	assert_int_equal(parseQuotedString(unparsed, strlen(unparsed) + 1, parsed, sizeof(parsed)), strlen("\"'\n\r\\"));
+	assert_string_equal(parsed, "\"'\n\r\\");
+}
+
+M_TEST_DEFINE(invalidEscapeCharString) {
+	const char* unparsed = "\"\\z\"";
+	char parsed[32];
+	assert_int_equal(parseQuotedString(unparsed, strlen(unparsed) + 1, parsed, sizeof(parsed)), -1);
+}
+
+M_TEST_DEFINE(overflowString) {
+	const char* unparsed = "\"longstring\"";
+	char parsed[4];
+	assert_int_equal(parseQuotedString(unparsed, strlen(unparsed) + 1, parsed, sizeof(parsed)), -1);
+}
+
+M_TEST_DEFINE(unclosedString) {
+	const char* unparsed = "\"forever";
+	char parsed[32];
+	assert_int_equal(parseQuotedString(unparsed, strlen(unparsed) + 1, parsed, sizeof(parsed)), -1);
+}
+
+M_TEST_DEFINE(unclosedString2) {
+	const char* unparsed = "\"forever";
+	char parsed[32];
+	assert_int_equal(parseQuotedString(unparsed, 4, parsed, sizeof(parsed)), -1);
+}
+
+M_TEST_DEFINE(unclosedBackslashString) {
+	const char* unparsed = "\"backslash\\";
+	char parsed[32];
+	assert_int_equal(parseQuotedString(unparsed, strlen(unparsed), parsed, sizeof(parsed)), -1);
+}
+
+M_TEST_DEFINE(unclosedBackslashString2) {
+	const char* unparsed = "\"backslash\\";
+	char parsed[32];
+	assert_int_equal(parseQuotedString(unparsed, strlen(unparsed) + 1, parsed, sizeof(parsed)), -1);
+}
+
+M_TEST_DEFINE(highCharacterString) {
+	const char* unparsed = "\"\200\"";
+	char parsed[32];
+	assert_int_equal(parseQuotedString(unparsed, strlen(unparsed) + 1, parsed, sizeof(parsed)), 1);
+	assert_string_equal(parsed, "\200");
+}
+
+M_TEST_SUITE_DEFINE(StringParser,
+	cmocka_unit_test(nullString),
+	cmocka_unit_test(emptyString),
+	cmocka_unit_test(emptyString2),
+	cmocka_unit_test(plainString),
+	cmocka_unit_test(plainString2),
+	cmocka_unit_test(leadingString),
+	cmocka_unit_test(trailingString),
+	cmocka_unit_test(backslashString),
+	cmocka_unit_test(doubleBackslashString),
+	cmocka_unit_test(escapeCharsString),
+	cmocka_unit_test(invalidEscapeCharString),
+	cmocka_unit_test(overflowString),
+	cmocka_unit_test(unclosedString),
+	cmocka_unit_test(unclosedString2),
+	cmocka_unit_test(unclosedBackslashString),
+	cmocka_unit_test(unclosedBackslashString2),
+	cmocka_unit_test(highCharacterString))