vkd3d-shader: Add a compile option to control whether implicit truncation warnings are printed.

d3dcompiler and d3dx9 versions before 42 don't emit this error; this will be
necessary to emulate that behaviour.

Other warnings exist that are introduced in different d3dcompiler versions,
although there are not very many distinct HLSL warnings to begin with.

We could of course group all these together under a single compiler option, but
I find that using separate top-level options is unilaterally friendlier to an
API consumer, and simpler to implement as well. It also in some sense maps
conceptually to e.g. "-Wno-implicit-conversion".

include/vkd3d_shader.h

@@ -310,6 +310,17 @@ enum vkd3d_shader_compile_option_name
      * \since 1.12
      */
     VKD3D_SHADER_COMPILE_OPTION_CHILD_EFFECT = 0x0000000b,
+    /**
+     * If \a value is nonzero, emit a compile warning warn when vectors or
+     * matrices are truncated in an implicit conversion.
+     * If warnings are disabled, this option has no effect.
+     * This option has no effects for targets other than HLSL.
+     *
+     * The default value is nonzero, i.e. enable implicit truncation warnings.
+     *
+     * \since 1.12
+     */
+    VKD3D_SHADER_COMPILE_OPTION_WARN_IMPLICIT_TRUNCATION = 0x0000000c,
 
     VKD3D_FORCE_32_BIT_ENUM(VKD3D_SHADER_COMPILE_OPTION_NAME),
 };

libs/vkd3d-shader/hlsl.c

@@ -3593,24 +3593,35 @@ static bool hlsl_ctx_init(struct hlsl_ctx *ctx, const struct vkd3d_shader_compil
         return false;
     ctx->cur_buffer = ctx->globals_buffer;
 
+    ctx->warn_implicit_truncation = true;
+
     for (i = 0; i < compile_info->option_count; ++i)
     {
         const struct vkd3d_shader_compile_option *option = &compile_info->options[i];
 
-        if (option->name == VKD3D_SHADER_COMPILE_OPTION_PACK_MATRIX_ORDER)
+        switch (option->name)
         {
+            case VKD3D_SHADER_COMPILE_OPTION_PACK_MATRIX_ORDER:
                 if (option->value == VKD3D_SHADER_COMPILE_OPTION_PACK_MATRIX_ROW_MAJOR)
                     ctx->matrix_majority = HLSL_MODIFIER_ROW_MAJOR;
                 else if (option->value == VKD3D_SHADER_COMPILE_OPTION_PACK_MATRIX_COLUMN_MAJOR)
                     ctx->matrix_majority = HLSL_MODIFIER_COLUMN_MAJOR;
-        }
-        else if (option->name == VKD3D_SHADER_COMPILE_OPTION_BACKWARD_COMPATIBILITY)
-        {
+                break;
+
+            case VKD3D_SHADER_COMPILE_OPTION_BACKWARD_COMPATIBILITY:
                 ctx->semantic_compat_mapping = option->value & VKD3D_SHADER_COMPILE_OPTION_BACKCOMPAT_MAP_SEMANTIC_NAMES;
-        }
-        else if (option->name == VKD3D_SHADER_COMPILE_OPTION_CHILD_EFFECT)
-        {
-            ctx->child_effect = !!option->value;
+                break;
+
+            case VKD3D_SHADER_COMPILE_OPTION_CHILD_EFFECT:
+                ctx->child_effect = option->value;
+                break;
+
+            case VKD3D_SHADER_COMPILE_OPTION_WARN_IMPLICIT_TRUNCATION:
+                ctx->warn_implicit_truncation = option->value;
+                break;
+
+            default:
+                break;
         }
     }
 

libs/vkd3d-shader/hlsl.h

@@ -925,6 +925,7 @@ struct hlsl_ctx
 
     bool semantic_compat_mapping;
     bool child_effect;
+    bool warn_implicit_truncation;
 };
 
 struct hlsl_resource_load_params

libs/vkd3d-shader/hlsl.y

@@ -413,7 +413,7 @@ static struct hlsl_ir_node *add_implicit_conversion(struct hlsl_ctx *ctx, struct
         return NULL;
     }
 
-    if (dst_type->dimx * dst_type->dimy < src_type->dimx * src_type->dimy)
+    if (dst_type->dimx * dst_type->dimy < src_type->dimx * src_type->dimy && ctx->warn_implicit_truncation)
         hlsl_warning(ctx, loc, VKD3D_SHADER_WARNING_HLSL_IMPLICIT_TRUNCATION, "Implicit truncation of %s type.",
                 src_type->class == HLSL_CLASS_VECTOR ? "vector" : "matrix");
 

tests/vkd3d_shader_api.c

@@ -1642,6 +1642,57 @@ static void test_emit_signature(void)
     }
 }
 
+static void test_warning_options(void)
+{
+    struct vkd3d_shader_hlsl_source_info hlsl_info = {.type = VKD3D_SHADER_STRUCTURE_TYPE_HLSL_SOURCE_INFO};
+    struct vkd3d_shader_compile_info info = {.type = VKD3D_SHADER_STRUCTURE_TYPE_COMPILE_INFO};
+    struct vkd3d_shader_compile_option options[1];
+    struct vkd3d_shader_code d3dbc;
+    char *messages;
+    int rc;
+
+    static const char ps_source[] =
+        "float4 main(uniform float4 u) : color\n"
+        "{\n"
+        "    float3 x = u;\n"
+        "    return 0;\n"
+        "}\n";
+
+    hlsl_info.profile = "ps_2_0";
+
+    info.next = &hlsl_info;
+    info.source.code = ps_source;
+    info.source.size = ARRAY_SIZE(ps_source);
+    info.source_type = VKD3D_SHADER_SOURCE_HLSL;
+    info.target_type = VKD3D_SHADER_TARGET_D3D_BYTECODE;
+    info.log_level = VKD3D_SHADER_LOG_INFO;
+
+    rc = vkd3d_shader_compile(&info, &d3dbc, &messages);
+    ok(rc == VKD3D_OK, "Got rc %d.\n", rc);
+    ok(messages, "Expected messages.\n");
+    vkd3d_shader_free_shader_code(&d3dbc);
+    vkd3d_shader_free_messages(messages);
+
+    info.options = options;
+    info.option_count = ARRAY_SIZE(options);
+    options[0].name = VKD3D_SHADER_COMPILE_OPTION_WARN_IMPLICIT_TRUNCATION;
+    options[0].value = 0;
+
+    rc = vkd3d_shader_compile(&info, &d3dbc, &messages);
+    ok(rc == VKD3D_OK, "Got rc %d.\n", rc);
+    ok(!messages, "Expected no messages.\n");
+    vkd3d_shader_free_shader_code(&d3dbc);
+    vkd3d_shader_free_messages(messages);
+
+    options[0].value = 1;
+
+    rc = vkd3d_shader_compile(&info, &d3dbc, &messages);
+    ok(rc == VKD3D_OK, "Got rc %d.\n", rc);
+    ok(messages, "Expected messages.\n");
+    vkd3d_shader_free_shader_code(&d3dbc);
+    vkd3d_shader_free_messages(messages);
+}
+
 START_TEST(vkd3d_shader_api)
 {
     setlocale(LC_ALL, "");
@@ -1656,4 +1707,5 @@ START_TEST(vkd3d_shader_api)
     run_test(test_build_varying_map);
     run_test(test_scan_combined_resource_samplers);
     run_test(test_emit_signature);
+    run_test(test_warning_options);
 }