writer/hlsl: Do not emit `(void) call_expr;`

Just emit `call_expr;` instead.

Fixed: tint:1259
Change-Id: I84a2976d82f891e9263f3e11e5774fcb01ea09bd
Reviewed-on: https://dawn-review.googlesource.com/c/tint/+/67381
Reviewed-by: Corentin Wallez <cwallez@chromium.org>
Kokoro: Kokoro <noreply+kokoro@google.com>
Commit-Queue: Ben Clayton <bclayton@google.com>

docs/origin-trial-changes.md

@@ -21,6 +21,7 @@
 ### Fixes
 
 * Swizzling of `vec3` types in `storage` and `uniform` buffers has been fixed for Metal 1.x. [tint:1249](https://crbug.com/tint/1249)
+* Calling a function that returns an unused value no longer produces an FXC compilation error. [tint:1259](https://crbug.com/tint/1259)
 
 ## Changes for M95
 

src/writer/hlsl/generator_impl.cc

@@ -2907,9 +2907,6 @@ bool GeneratorImpl::EmitStatement(const ast::Statement* stmt) {
   }
   if (auto* c = stmt->As<ast::CallStatement>()) {
     auto out = line();
-    if (!TypeOf(c->expr)->Is<sem::Void>()) {
-      out << "(void) ";
-    }
     if (!EmitCall(out, c->expr)) {
       return false;
     }

src/writer/hlsl/generator_impl_intrinsic_test.cc

@@ -317,7 +317,7 @@ modf_result tint_modf(float param_0) {
 
 [numthreads(1, 1, 1)]
 void test_function() {
-  (void) tint_modf(1.0f);
+  tint_modf(1.0f);
   return;
 }
 )");
@@ -343,7 +343,7 @@ modf_result_vec3 tint_modf(float3 param_0) {
 
 [numthreads(1, 1, 1)]
 void test_function() {
-  (void) tint_modf(float3(0.0f, 0.0f, 0.0f));
+  tint_modf(float3(0.0f, 0.0f, 0.0f));
   return;
 }
 )");
@@ -369,7 +369,7 @@ frexp_result tint_frexp(float param_0) {
 
 [numthreads(1, 1, 1)]
 void test_function() {
-  (void) tint_frexp(1.0f);
+  tint_frexp(1.0f);
   return;
 }
 )");
@@ -395,7 +395,7 @@ frexp_result_vec3 tint_frexp(float3 param_0) {
 
 [numthreads(1, 1, 1)]
 void test_function() {
-  (void) tint_frexp(float3(0.0f, 0.0f, 0.0f));
+  tint_frexp(float3(0.0f, 0.0f, 0.0f));
   return;
 }
 )");
@@ -418,7 +418,7 @@ TEST_F(HlslGeneratorImplTest_Intrinsic, IsNormal_Scalar) {
 [numthreads(1, 1, 1)]
 void test_function() {
   float val = 0.0f;
-  (void) tint_isNormal(val);
+  tint_isNormal(val);
   return;
 }
 )");
@@ -441,7 +441,7 @@ TEST_F(HlslGeneratorImplTest_Intrinsic, IsNormal_Vector) {
 [numthreads(1, 1, 1)]
 void test_function() {
   float3 val = float3(0.0f, 0.0f, 0.0f);
-  (void) tint_isNormal(val);
+  tint_isNormal(val);
   return;
 }
 )");
@@ -463,7 +463,7 @@ static float4 p1 = float4(0.0f, 0.0f, 0.0f, 0.0f);
 
 [numthreads(1, 1, 1)]
 void test_function() {
-  (void) tint_pack4x8snorm(p1);
+  tint_pack4x8snorm(p1);
   return;
 }
 )");
@@ -485,7 +485,7 @@ static float4 p1 = float4(0.0f, 0.0f, 0.0f, 0.0f);
 
 [numthreads(1, 1, 1)]
 void test_function() {
-  (void) tint_pack4x8unorm(p1);
+  tint_pack4x8unorm(p1);
   return;
 }
 )");
@@ -507,7 +507,7 @@ static float2 p1 = float2(0.0f, 0.0f);
 
 [numthreads(1, 1, 1)]
 void test_function() {
-  (void) tint_pack2x16snorm(p1);
+  tint_pack2x16snorm(p1);
   return;
 }
 )");
@@ -529,7 +529,7 @@ static float2 p1 = float2(0.0f, 0.0f);
 
 [numthreads(1, 1, 1)]
 void test_function() {
-  (void) tint_pack2x16unorm(p1);
+  tint_pack2x16unorm(p1);
   return;
 }
 )");
@@ -551,7 +551,7 @@ static float2 p1 = float2(0.0f, 0.0f);
 
 [numthreads(1, 1, 1)]
 void test_function() {
-  (void) tint_pack2x16float(p1);
+  tint_pack2x16float(p1);
   return;
 }
 )");
@@ -574,7 +574,7 @@ static uint p1 = 0u;
 
 [numthreads(1, 1, 1)]
 void test_function() {
-  (void) tint_unpack4x8snorm(p1);
+  tint_unpack4x8snorm(p1);
   return;
 }
 )");
@@ -597,7 +597,7 @@ static uint p1 = 0u;
 
 [numthreads(1, 1, 1)]
 void test_function() {
-  (void) tint_unpack4x8unorm(p1);
+  tint_unpack4x8unorm(p1);
   return;
 }
 )");
@@ -620,7 +620,7 @@ static uint p1 = 0u;
 
 [numthreads(1, 1, 1)]
 void test_function() {
-  (void) tint_unpack2x16snorm(p1);
+  tint_unpack2x16snorm(p1);
   return;
 }
 )");
@@ -643,7 +643,7 @@ static uint p1 = 0u;
 
 [numthreads(1, 1, 1)]
 void test_function() {
-  (void) tint_unpack2x16unorm(p1);
+  tint_unpack2x16unorm(p1);
   return;
 }
 )");
@@ -665,7 +665,7 @@ static uint p1 = 0u;
 
 [numthreads(1, 1, 1)]
 void test_function() {
-  (void) tint_unpack2x16float(p1);
+  tint_unpack2x16float(p1);
   return;
 }
 )");

test/intrinsics/repeated_use.wgsl.expected.hlsl

@@ -24,17 +24,17 @@ bool tint_isNormal_3(float param_0) {
 
 [numthreads(1, 1, 1)]
 void main() {
-  (void) tint_isNormal(float4(0.0f, 0.0f, 0.0f, 0.0f));
+  tint_isNormal(float4(0.0f, 0.0f, 0.0f, 0.0f));
-  (void) tint_isNormal(float4((1.0f).xxxx));
+  tint_isNormal(float4((1.0f).xxxx));
-  (void) tint_isNormal(float4(1.0f, 2.0f, 3.0f, 4.0f));
+  tint_isNormal(float4(1.0f, 2.0f, 3.0f, 4.0f));
-  (void) tint_isNormal_1(float3(0.0f, 0.0f, 0.0f));
+  tint_isNormal_1(float3(0.0f, 0.0f, 0.0f));
-  (void) tint_isNormal_1(float3((1.0f).xxx));
+  tint_isNormal_1(float3((1.0f).xxx));
-  (void) tint_isNormal_1(float3(1.0f, 2.0f, 3.0f));
+  tint_isNormal_1(float3(1.0f, 2.0f, 3.0f));
-  (void) tint_isNormal_2(float2(0.0f, 0.0f));
+  tint_isNormal_2(float2(0.0f, 0.0f));
-  (void) tint_isNormal_2(float2((1.0f).xx));
+  tint_isNormal_2(float2((1.0f).xx));
-  (void) tint_isNormal_2(float2(1.0f, 2.0f));
+  tint_isNormal_2(float2(1.0f, 2.0f));
-  (void) tint_isNormal_3(1.0f);
+  tint_isNormal_3(1.0f);
-  (void) tint_isNormal_3(2.0f);
+  tint_isNormal_3(2.0f);
-  (void) tint_isNormal_3(3.0f);
+  tint_isNormal_3(3.0f);
   return;
 }

test/statements/assign/phony/call.wgsl.expected.hlsl

@@ -4,6 +4,6 @@ int f(int a, int b, int c) {
 
 [numthreads(1, 1, 1)]
 void main() {
-  (void) f(1, 2, 3);
+  f(1, 2, 3);
   return;
 }