Fix -Wsign-conversion on GCC 8 (fixes #1715)

CHANGELOG.md

@@ -6,6 +6,7 @@ HEAD
 
 * Fix `call of overloaded 'String(const char*, int)' is ambiguous`
 * Fix `JsonString` operator `==` and `!=` for non-zero-terminated string
+* Fix `-Wsign-conversion` on GCC 8 (issue #1715)
 
 v6.19.2 (2022-02-14)
 -------

extras/CompileOptions.cmake

@@ -18,6 +18,7 @@ if(CMAKE_CXX_COMPILER_ID MATCHES "(GNU|Clang)")
 		-Wparentheses
 		-Wredundant-decls
 		-Wshadow
+		-Wsign-conversion
 		-Wsign-promo
 		-Wstrict-aliasing
 		-Wundef

extras/tests/JsonArray/add.cpp

@@ -40,7 +40,7 @@ TEST_CASE("JsonArray::add()") {
 
 #ifdef HAS_VARIABLE_LENGTH_ARRAY
   SECTION("vla") {
-    int i = 16;
+    size_t i = 16;
     char vla[i];
     strcpy(vla, "world");
 

extras/tests/JsonArray/subscript.cpp

@@ -135,7 +135,7 @@ TEST_CASE("JsonArray::operator[]") {
 
 #ifdef HAS_VARIABLE_LENGTH_ARRAY
   SECTION("set(VLA)") {
-    int i = 16;
+    size_t i = 16;
     char vla[i];
     strcpy(vla, "world");
 
@@ -146,7 +146,7 @@ TEST_CASE("JsonArray::operator[]") {
   }
 
   SECTION("operator=(VLA)") {
-    int i = 16;
+    size_t i = 16;
     char vla[i];
     strcpy(vla, "world");
 

extras/tests/JsonDeserializer/filter.cpp

@@ -708,7 +708,7 @@ TEST_CASE("Overloads") {
 
 #ifdef HAS_VARIABLE_LENGTH_ARRAY
   SECTION("char[n], Filter") {
-    int i = 4;
+    size_t i = 4;
     char vla[i];
     strcpy(vla, "{}");
     deserializeJson(doc, vla, Filter(filter));
@@ -736,7 +736,7 @@ TEST_CASE("Overloads") {
 
 #ifdef HAS_VARIABLE_LENGTH_ARRAY
   SECTION("char[n], Filter, NestingLimit") {
-    int i = 4;
+    size_t i = 4;
     char vla[i];
     strcpy(vla, "{}");
     deserializeJson(doc, vla, Filter(filter), NestingLimit(5));
@@ -764,7 +764,7 @@ TEST_CASE("Overloads") {
 
 #ifdef HAS_VARIABLE_LENGTH_ARRAY
   SECTION("char[n], NestingLimit, Filter") {
-    int i = 4;
+    size_t i = 4;
     char vla[i];
     strcpy(vla, "{}");
     deserializeJson(doc, vla, NestingLimit(5), Filter(filter));

extras/tests/JsonDeserializer/input_types.cpp

@@ -121,7 +121,7 @@ TEST_CASE("deserializeJson(std::istream&)") {
 
 #ifdef HAS_VARIABLE_LENGTH_ARRAY
 TEST_CASE("deserializeJson(VLA)") {
-  int i = 9;
+  size_t i = 9;
   char vla[i];
   strcpy(vla, "{\"a\":42}");
 

extras/tests/JsonDocument/ElementProxy.cpp

@@ -131,7 +131,7 @@ TEST_CASE("ElementProxy::remove()") {
     ep["a"] = 1;
     ep["b"] = 2;
 
-    int i = 4;
+    size_t i = 4;
     char vla[i];
     strcpy(vla, "b");
     ep.remove(vla);

extras/tests/JsonDocument/MemberProxy.cpp

@@ -171,7 +171,7 @@ TEST_CASE("MemberProxy::remove()") {
     mp["a"] = 1;
     mp["b"] = 2;
 
-    int i = 4;
+    size_t i = 4;
     char vla[i];
     strcpy(vla, "b");
     mp.remove(vla);

extras/tests/JsonDocument/remove.cpp

@@ -41,7 +41,7 @@ TEST_CASE("JsonDocument::remove()") {
     doc["a"] = 1;
     doc["b"] = 2;
 
-    int i = 4;
+    size_t i = 4;
     char vla[i];
     strcpy(vla, "b");
     doc.remove(vla);

extras/tests/JsonObject/containsKey.cpp

@@ -29,7 +29,7 @@ TEST_CASE("JsonObject::containsKey()") {
 
 #ifdef HAS_VARIABLE_LENGTH_ARRAY
   SECTION("key is a VLA") {
-    int i = 16;
+    size_t i = 16;
     char vla[i];
     strcpy(vla, "hello");
 

extras/tests/JsonObject/createNestedArray.cpp

@@ -16,7 +16,7 @@ TEST_CASE("JsonObject::createNestedArray()") {
 
 #ifdef HAS_VARIABLE_LENGTH_ARRAY
   SECTION("key is a VLA") {
-    int i = 16;
+    size_t i = 16;
     char vla[i];
     strcpy(vla, "hello");
 

extras/tests/JsonObject/createNestedObject.cpp

@@ -15,7 +15,7 @@ TEST_CASE("JsonObject::createNestedObject()") {
 
 #ifdef HAS_VARIABLE_LENGTH_ARRAY
   SECTION("key is a VLA") {
-    int i = 16;
+    size_t i = 16;
     char vla[i];
     strcpy(vla, "hello");
 

extras/tests/JsonObject/remove.cpp

@@ -60,7 +60,7 @@ TEST_CASE("JsonObject::remove()") {
 
 #ifdef HAS_VARIABLE_LENGTH_ARRAY
   SECTION("key is a vla") {
-    int i = 16;
+    size_t i = 16;
     char vla[i];
     strcpy(vla, "b");
     obj.remove(vla);

extras/tests/JsonObject/subscript.cpp

@@ -172,7 +172,7 @@ TEST_CASE("JsonObject::operator[]") {
 #if defined(HAS_VARIABLE_LENGTH_ARRAY) && \
     !defined(SUBSCRIPT_CONFLICTS_WITH_BUILTIN_OPERATOR)
   SECTION("obj[VLA] = str") {
-    int i = 16;
+    size_t i = 16;
     char vla[i];
     strcpy(vla, "hello");
 
@@ -182,7 +182,7 @@ TEST_CASE("JsonObject::operator[]") {
   }
 
   SECTION("obj[str] = VLA") {  // issue #416
-    int i = 32;
+    size_t i = 32;
     char vla[i];
     strcpy(vla, "world");
 
@@ -192,7 +192,7 @@ TEST_CASE("JsonObject::operator[]") {
   }
 
   SECTION("obj.set(VLA, str)") {
-    int i = 16;
+    size_t i = 16;
     char vla[i];
     strcpy(vla, "hello");
 
@@ -202,7 +202,7 @@ TEST_CASE("JsonObject::operator[]") {
   }
 
   SECTION("obj.set(str, VLA)") {
-    int i = 32;
+    size_t i = 32;
     char vla[i];
     strcpy(vla, "world");
 
@@ -212,7 +212,7 @@ TEST_CASE("JsonObject::operator[]") {
   }
 
   SECTION("obj[VLA]") {
-    int i = 16;
+    size_t i = 16;
     char vla[i];
     strcpy(vla, "hello");
 

extras/tests/JsonVariant/set.cpp

@@ -71,7 +71,7 @@ TEST_CASE("JsonVariant::set() when there is enough memory") {
 
 #ifdef HAS_VARIABLE_LENGTH_ARRAY
   SECTION("VLA") {
-    int n = 16;
+    size_t n = 16;
     char str[n];
 
     strcpy(str, "hello");

extras/tests/JsonVariant/subscript.cpp

@@ -108,7 +108,7 @@ TEST_CASE("JsonVariant::operator[]") {
 #if defined(HAS_VARIABLE_LENGTH_ARRAY) && \
     !defined(SUBSCRIPT_CONFLICTS_WITH_BUILTIN_OPERATOR)
   SECTION("key is a VLA") {
-    int i = 16;
+    size_t i = 16;
     char vla[i];
     strcpy(vla, "hello");
 
@@ -119,7 +119,7 @@ TEST_CASE("JsonVariant::operator[]") {
   }
 
   SECTION("key is a VLA, const JsonVariant") {
-    int i = 16;
+    size_t i = 16;
     char vla[i];
     strcpy(vla, "hello");
 

extras/tests/MsgPackDeserializer/filter.cpp

@@ -1068,7 +1068,7 @@ TEST_CASE("Overloads") {
 
 #ifdef HAS_VARIABLE_LENGTH_ARRAY
   SECTION("char[n], Filter") {
-    int i = 4;
+    size_t i = 4;
     char vla[i];
     strcpy(vla, "{}");
     deserializeMsgPack(doc, vla, Filter(filter));
@@ -1096,7 +1096,7 @@ TEST_CASE("Overloads") {
 
 #ifdef HAS_VARIABLE_LENGTH_ARRAY
   SECTION("char[n], Filter, NestingLimit") {
-    int i = 4;
+    size_t i = 4;
     char vla[i];
     strcpy(vla, "{}");
     deserializeMsgPack(doc, vla, Filter(filter), NestingLimit(5));
@@ -1124,7 +1124,7 @@ TEST_CASE("Overloads") {
 
 #ifdef HAS_VARIABLE_LENGTH_ARRAY
   SECTION("char[n], NestingLimit, Filter") {
-    int i = 4;
+    size_t i = 4;
     char vla[i];
     strcpy(vla, "{}");
     deserializeMsgPack(doc, vla, NestingLimit(5), Filter(filter));

extras/tests/MsgPackDeserializer/input_types.cpp

@@ -72,7 +72,7 @@ TEST_CASE("deserializeMsgPack(std::istream&)") {
 
 #ifdef HAS_VARIABLE_LENGTH_ARRAY
 TEST_CASE("deserializeMsgPack(VLA)") {
-  int i = 16;
+  size_t i = 16;
   char vla[i];
   memcpy(vla, "\xDE\x00\x01\xA5Hello\xA5world", 15);
 

src/ArduinoJson/MsgPack/MsgPackDeserializer.hpp

@@ -481,7 +481,7 @@ class MsgPackDeserializer {
     T size;
     if (!readInteger(size))
       return false;
-    return skipBytes(size + 1);
+    return skipBytes(size + 1U);
   }
 
   MemoryPool *_pool;

src/ArduinoJson/Strings/Adapters/RamString.hpp

@@ -106,13 +106,13 @@ inline SizedRamString adaptString(const char* s, size_t n) {
   return SizedRamString(s, n);
 }
 
-template <int N>
+template <size_t N>
 struct IsString<char[N]> : true_type {};
 
-template <int N>
+template <size_t N>
 struct IsString<const char[N]> : true_type {};
 
-template <int N>
+template <size_t N>
 inline SizedRamString adaptString(char s[N]) {
   return SizedRamString(s, strlen(s));
 }