COMMON: Reduce maximum Span size to 4GiB

Until C++11 (which introduces the z and t length modifiers), there
is no consistent way to print size_t and ptrdiff_t types using
printf formatting across 32-bit, LLP64, and LP64 architectures
without using a cumbersome macro to select the appropriate length
modifier for the target architecture. Since ScummVM engines
currently need to support 32-bit targets, there is no reason at
the moment to support any larger memory sizes in Span anyway.

Span error output is also updated in this commit to reflect that
index values are unsigned.

common/span.h

@@ -268,9 +268,9 @@ class SpanBase : public SafeBool<Derived<ValueType> > {
 
 public:
 	typedef ValueType value_type;
-	typedef ptrdiff_t difference_type;
-	typedef size_t index_type;
-	typedef size_t size_type;
+	typedef int32 difference_type;
+	typedef uint32 index_type;
+	typedef uint32 size_type;
 	typedef SpanInternal::SpanIterator<derived_type, true> const_iterator;
 	typedef SpanInternal::SpanIterator<derived_type, false> iterator;
 	typedef value_type *pointer;
@@ -601,11 +601,11 @@ class SpanImpl : public SpanBase<ValueType, Derived> {
 				break;
 		}
 
-		return String::format("Access violation %s %s: %ld + %ld > %ld",
+		return String::format("Access violation %s %s: %u + %d > %u",
 							  modeName,
 							  this->impl().name().c_str(),
 							  index,
-							  deltaInBytes / sizeof(value_type),
+							  deltaInBytes / (int)sizeof(value_type),
 							  size());
 	}
 
@@ -829,7 +829,7 @@ class NamedSpanImpl : public SpanImpl<ValueType, Derived> {
 		const size_type maxSizeInBytes = this->impl().byteSize();
 
 		return super_type::getValidationMessage(index, deltaInBytes, mode) +
-			String::format(" (abs: %ld + %ld > %ld)",
+			String::format(" (abs: %u + %d > %u)",
 						   this->impl().sourceByteOffset() + indexInBytes,
 						   deltaInBytes,
 						   this->impl().sourceByteOffset() + maxSizeInBytes);

test/common/span.h

@@ -640,7 +640,7 @@ class SpanTestSuite : public CxxTest::TestSuite {
 		TS_ASSERT(span.checkInvalidBounds(2, -4)); // negative overflow (-2)
 		TS_ASSERT(span.checkInvalidBounds(0, 10)); // delta positive overflow
 
-		const ptrdiff_t big = 1L << (8 * sizeof(ptrdiff_t) - 1);
+		const Common::Span<byte>::difference_type big = 1L << (8 * sizeof(Common::Span<byte>::difference_type) - 1);
 		TS_ASSERT(span.checkInvalidBounds(big, 0));
 		TS_ASSERT(span.checkInvalidBounds(0, big));
 		TS_ASSERT(span.checkInvalidBounds(big, big));
@@ -662,8 +662,8 @@ class SpanTestSuite : public CxxTest::TestSuite {
 		expected = Common::String::format("Access violation writing %s: 23 + 45 > 1", source.c_str());
 		TS_ASSERT_EQUALS(actual, expected);
 
-		actual = span.getValidationMessage(-34, -56, Common::kValidateSeek);
-		expected = Common::String::format("Access violation seeking %s: -34 + -56 > 1", source.c_str());
+		actual = span.getValidationMessage(0, -56, Common::kValidateSeek);
+		expected = Common::String::format("Access violation seeking %s: 0 + -56 > 1", source.c_str());
 		TS_ASSERT_EQUALS(actual, expected);
 	}
 
@@ -716,15 +716,15 @@ class SpanTestSuite : public CxxTest::TestSuite {
 
 		{
 			Common::NamedSpan<byte> subspan = span.subspan(2, Common::kSpanMaxSize, "new.data");
-			expected = "Access violation reading new.data: -34 + -56 > 4 (abs: -32 + -56 > 6)";
-			actual = subspan.getValidationMessage(-34, -56, Common::kValidateRead);
+			expected = "Access violation reading new.data: 0 + -56 > 4 (abs: 2 + -56 > 6)";
+			actual = subspan.getValidationMessage(0, -56, Common::kValidateRead);
 			TS_ASSERT_EQUALS(actual, expected);
 		}
 
 		{
 			Common::NamedSpan<byte> subspan = span.subspan(2, Common::kSpanMaxSize, "new.data", 0);
-			expected = "Access violation reading new.data: -34 + -56 > 4 (abs: -34 + -56 > 4)";
-			actual = subspan.getValidationMessage(-34, -56, Common::kValidateRead);
+			expected = "Access violation reading new.data: 0 + -56 > 4 (abs: 0 + -56 > 4)";
+			actual = subspan.getValidationMessage(0, -56, Common::kValidateRead);
 			TS_ASSERT_EQUALS(actual, expected);
 		}
 
@@ -754,23 +754,23 @@ class SpanTestSuite : public CxxTest::TestSuite {
 
 		{
 			Common::NamedSpan<const byte> subspan = constSpan.subspan(2, Common::kSpanMaxSize, "new.data");
-			expected = "Access violation reading new.data: -34 + -56 > 4 (abs: -32 + -56 > 6)";
-			actual = subspan.getValidationMessage(-34, -56, Common::kValidateRead);
+			expected = "Access violation reading new.data: 0 + -56 > 4 (abs: 2 + -56 > 6)";
+			actual = subspan.getValidationMessage(0, -56, Common::kValidateRead);
 			TS_ASSERT_EQUALS(actual, expected);
 		}
 
 		{
 			Common::NamedSpan<const byte> subspan = constSpan.subspan(2, Common::kSpanMaxSize, "new.data", 0);
-			expected = "Access violation reading new.data: -34 + -56 > 4 (abs: -34 + -56 > 4)";
-			actual = subspan.getValidationMessage(-34, -56, Common::kValidateRead);
+			expected = "Access violation reading new.data: 0 + -56 > 4 (abs: 0 + -56 > 4)";
+			actual = subspan.getValidationMessage(0, -56, Common::kValidateRead);
 			TS_ASSERT_EQUALS(actual, expected);
 		}
 
 		{
 			Common::NamedSpan<const byte> subspan = constSpan.subspan(2, Common::kSpanMaxSize, "new.data", 0);
 			subspan.sourceByteOffset() = 2;
-			expected = "Access violation reading new.data: -34 + -56 > 4 (abs: -32 + -56 > 6)";
-			actual = subspan.getValidationMessage(-34, -56, Common::kValidateRead);
+			expected = "Access violation reading new.data: 0 + -56 > 4 (abs: 2 + -56 > 6)";
+			actual = subspan.getValidationMessage(0, -56, Common::kValidateRead);
 			TS_ASSERT_EQUALS(actual, expected);
 		}