Add warning on some cases of integer literal coercion

Fix misisng warnings on:

int x3 = 18446744073709551615;
int x4 = 0xFFFFFFFFFFFFFFFF;

Add test cases for the integer literal coercion

Author: zlatinski

source/slang/slang-parser.cpp

@@ -6897,7 +6897,7 @@ static IntegerLiteralValue _fixIntegerLiteral(
         // If the masked value is 0 or equal to the mask, we 'assume' no information is
         // lost
         // This allows for example -1u, to give 0xffffffff
-        // It also means 0xfffffffffffffffffu will give 0xffffffff, without a warning.
+        // It also means 0xffffffffffffffffu will give 0xffffffff, without a warning.
         if ((!(maskedValue == 0 || maskedValue == mask)) && sink && token)
         {
             // Output a warning that number has been altered
@@ -6954,8 +6954,11 @@ static BaseType _determineNonSuffixedIntegerLiteralType(
     {
         baseType = BaseType::UInt64;
 
-        if (isDecimalBase)
+        // Emit warning if the value is too large for signed 64-bit, regardless of base
+        // This fixes the inconsistency between decimal and hex literals
+        if (sink && token)
         {
+
             // There is an edge case here where 9223372036854775808 or INT64_MAX + 1
             // brings us here, but the complete literal is -9223372036854775808 or INT64_MIN and is
             // valid. Unfortunately because the lexer handles the negative(-) part of the literal

tests/diagnostics/integer-literal-warnings.slang

@@ -0,0 +1,24 @@
+//TEST:SIMPLE(filecheck=CHECK): -target dxbc-assembly
+
+// Test that UINT64_MAX literals produce appropriate warnings
+// This test verifies the fix from commit 0a3c1c8dbd6aa9501ea94a8de69d1a5967034b2c
+// which ensures literals equivalent to UINT64_MAX produce appropriate warnings
+
+void main()
+{
+    // Decimal form of UINT64_MAX
+    // CHECK: warning 39999: integer literal is too large to be represented in a signed integer type, interpreting as unsigned
+    uint64_t a = 18446744073709551615;
+    
+    // Hex form of UINT64_MAX
+    // CHECK: warning 39999: integer literal is too large to be represented in a signed integer type, interpreting as unsigned
+    uint64_t b = 0xFFFFFFFFFFFFFFFF;
+    
+    // Assigning UINT64_MAX to int - should also warn about size
+    // CHECK: warning 39999: integer literal is too large to be represented in a signed integer type, interpreting as unsigned
+    int c = 18446744073709551615;
+    
+    // Also hex form to int
+    // CHECK: warning 39999: integer literal is too large to be represented in a signed integer type, interpreting as unsigned
+    int d = 0xFFFFFFFFFFFFFFFF;
+} 

tests/slang-extension/atomic-int64-byte-address-buffer.slang

@@ -32,6 +32,6 @@ void computeMain(int3 dispatchThreadID : SV_DispatchThreadID)
     // Bit logical
     outputBuffer.InterlockedOrU64((idx << 3), (uint64_t(2) << 32) | (tid << 4));
     outputBuffer.InterlockedXorU64((idx << 3), tid << 8);
-    outputBuffer.InterlockedAndU64((idx << 3), (uint64_t(tid | 2) << 32) |  0xffffffffffffffff);
+    outputBuffer.InterlockedAndU64((idx << 3), (uint64_t(tid | 2) << 32) |  0xffffffffffffffffULL);
 }