Warning on lossy implicit casts. (#2367)

* Warning on bool to float conversion.

* Fix test cases.

* Improve.

* LanguageServer: don't show constant value for non constant variables.

* Fix tests.

* Fix warnings in tests.

Co-authored-by: Yong He <yhe@nvidia.com>

8 files changed, 51 insertions, 12 deletions

diff --git a/tests/diagnostics/attribute-error.slang.expected b/tests/diagnostics/attribute-error.slang.expected
index 386d08422..cde43142d 100644
--- a/tests/diagnostics/attribute-error.slang.expected
+++ b/tests/diagnostics/attribute-error.slang.expected
@@ -6,6 +6,9 @@ tests/diagnostics/attribute-error.slang(19): error 30019: expected an expression
 tests/diagnostics/attribute-error.slang(22): error 31002: attribute 'MyStruct' is not valid here
     [MyStruct(0, 10.0)] // attribute does not apply to this construct
      ^~~~~~~~
+tests/diagnostics/attribute-error.slang(24): warning 30081: implicit conversion from 'float' to 'int' is not recommended
+    [DefaultValue(2.0)] // attribute arg type mismatch
+                  ^~~
 tests/diagnostics/attribute-error.slang(24): error 39999: expression does not evaluate to a compile-time constant
     [DefaultValue(2.0)] // attribute arg type mismatch
                   ^~~
diff --git a/tests/diagnostics/bool-to-float.slang b/tests/diagnostics/bool-to-float.slang
new file mode 100644
index 000000000..087cf86b3
--- /dev/null
+++ b/tests/diagnostics/bool-to-float.slang
@@ -0,0 +1,13 @@
+// bool-to-float.slang
+
+// Diagnostic messages related to converting bool to float
+
+//DIAGNOSTIC_TEST:SIMPLE:
+
+struct Test
+{
+    void test()
+    {
+        float f = true;
+    }
+}
diff --git a/tests/diagnostics/bool-to-float.slang.expected b/tests/diagnostics/bool-to-float.slang.expected
new file mode 100644
index 000000000..e1d851163
--- /dev/null
+++ b/tests/diagnostics/bool-to-float.slang.expected
@@ -0,0 +1,8 @@
+result code = 0
+standard error = {
+tests/diagnostics/bool-to-float.slang(11): warning 30081: implicit conversion from 'bool' to 'float' is not recommended
+        float f = true;
+                  ^~~~
+}
+standard output = {
+}
diff --git a/tests/diagnostics/constexpr-error.slang b/tests/diagnostics/constexpr-error.slang
index f0de9280d..a5b98264b 100644
--- a/tests/diagnostics/constexpr-error.slang
+++ b/tests/diagnostics/constexpr-error.slang
@@ -21,7 +21,7 @@ float4 main() : SV_Target
     float4 result = 0.0f;
 
     // Okay, immediate constant
-    result += t.Sample(s, uv, uint2(0,0));
+    result += t.Sample(s, uv, int2(0,0));
 
     // Error: data passed through cbuffer isn't compile-time constant
     result += t.Sample(s, uv, offset);
@@ -32,13 +32,13 @@ float4 main() : SV_Target
     {
     	ii = 1;
     }
-    result += t.Sample(s, uv, uint2(ii));
+    result += t.Sample(s, uv, int2(ii));
 
     // Error: data computed in loop isn't compile-time constant
     // (and loop isn't unroll-able)
     for(uint jj = 0; jj < uv.y; jj++)
     {
-    	result += t.Sample(s, uv, uint2(jj));
+    	result += t.Sample(s, uv, int2(jj));
     }
 
     return result;
diff --git a/tests/diagnostics/constexpr-error.slang.expected b/tests/diagnostics/constexpr-error.slang.expected
index 4dea62ca1..a744fcafd 100644
--- a/tests/diagnostics/constexpr-error.slang.expected
+++ b/tests/diagnostics/constexpr-error.slang.expected
@@ -1,14 +1,17 @@
 result code = -1
 standard error = {
+tests/diagnostics/constexpr-error.slang(27): warning 30081: implicit conversion from 'vector<uint,2>' to 'vector<int,2>' is not recommended
+    result += t.Sample(s, uv, offset);
+                              ^~~~~~
 tests/diagnostics/constexpr-error.slang(27): error 40006: expected a compile-time constant
     result += t.Sample(s, uv, offset);
                               ^~~~~~
 tests/diagnostics/constexpr-error.slang(35): error 40006: expected a compile-time constant
-    result += t.Sample(s, uv, uint2(ii));
-                                   ^
+    result += t.Sample(s, uv, int2(ii));
+                                  ^
 tests/diagnostics/constexpr-error.slang(41): error 40006: expected a compile-time constant
-        result += t.Sample(s, uv, uint2(jj));
-                                       ^
+        result += t.Sample(s, uv, int2(jj));
+                                      ^
 }
 standard output = {
 }
diff --git a/tests/diagnostics/enum-implicit-conversion.slang.expected b/tests/diagnostics/enum-implicit-conversion.slang.expected
index 61164bbaa..4efdc9c75 100644
--- a/tests/diagnostics/enum-implicit-conversion.slang.expected
+++ b/tests/diagnostics/enum-implicit-conversion.slang.expected
@@ -1,5 +1,11 @@
 result code = -1
 standard error = {
+tests/diagnostics/enum-implicit-conversion.slang(18): warning 30081: implicit conversion from 'uint' to 'int' is not recommended
+int foo(uint x) { return x * 256 * 16; }
+                                 ^
+tests/diagnostics/enum-implicit-conversion.slang(22): warning 30081: implicit conversion from 'uint' to 'int' is not recommended
+int bar(uint  x) { return x * 256 * 256 * 16; }
+                                        ^
 tests/diagnostics/enum-implicit-conversion.slang(27): error 30019: expected an expression of type 'Color', got 'int'
     Color c = val;
               ^~~
@@ -17,6 +23,9 @@ tests/diagnostics/enum-implicit-conversion.slang(42): error 39999: ambiguous cal
                ^
 tests/diagnostics/enum-implicit-conversion.slang(18): note 39999: candidate: func foo(uint) -> int
 tests/diagnostics/enum-implicit-conversion.slang(17): note 39999: candidate: func foo(int) -> int
+tests/diagnostics/enum-implicit-conversion.slang(47): warning 30081: implicit conversion from 'uint' to 'int' is not recommended
+    return x + y + z;
+                 ^
 }
 standard output = {
 }
diff --git a/tests/diagnostics/generic-invalid-type-specialization.slang.expected b/tests/diagnostics/generic-invalid-type-specialization.slang.expected
index 3c323ef46..0fc68f6b6 100644
--- a/tests/diagnostics/generic-invalid-type-specialization.slang.expected
+++ b/tests/diagnostics/generic-invalid-type-specialization.slang.expected
@@ -1,5 +1,8 @@
 result code = -1
 standard error = {
+tests/diagnostics/generic-invalid-type-specialization.slang(14): warning 30081: implicit conversion from 'uint' to 'int' is not recommended
+    int index = dispatchThreadID.x;
+                                 ^
 tests/diagnostics/generic-invalid-type-specialization.slang(17): error 30060: expected a type, got a 'int'
     Check<2 + 2> v;
             ^
diff --git a/tests/diagnostics/local-line.slang b/tests/diagnostics/local-line.slang
index 1cdeba7e4..973c234c0 100644
--- a/tests/diagnostics/local-line.slang
+++ b/tests/diagnostics/local-line.slang
@@ -22,21 +22,21 @@ int doThing(int a, int b)
 [numthreads(4, 1, 1)]
 void computeMain(uint3 dispatchThreadID : SV_DispatchThreadID)
 {
-    int a = dispatchThreadID.x;
-    int b = dispatchThreadID.y;
-    int c = dispatchThreadID.z;
+    int a = int(dispatchThreadID.x);
+    int b = int(dispatchThreadID.y);
+    int c = int(dispatchThreadID.z);
     int d = a + b * c;
     int e = d + c / 2;
     
     for (int i = 0; i < b; ++i)
     {
-        if (e > 10 && i & 2)
+        if (e > 10 && (i & 2) != 0)
         {
             a += b; b -= c; c += c; d = d + e + a; e = a;
         }
         else
         {
-            a = e; b = c + c; d += d + __SyntaxError(); e = doThing(e, dispatchThreadID.x);
+            a = e; b = c + c; d += d + __SyntaxError(); e = doThing(e, int(dispatchThreadID.x));
             
         }
     }