[PATCH v16 7/8] vkd3d-shader/hlsl: Add a pass to validate switch cases blocks.

[Nikolay Sivov]

From: Nikolay Sivov

Signed-off-by: Nikolay Sivov 
---
 libs/vkd3d-shader/hlsl_codegen.c | 39 ++++++++++++++++++++++++++++++++
 tests/hlsl/switch.shader_test    |  2 +-
 2 files changed, 40 insertions(+), 1 deletion(-)

diff --git a/libs/vkd3d-shader/hlsl_codegen.c b/libs/vkd3d-shader/hlsl_codegen.c
index fef871e3..534d5e92 100644
--- a/libs/vkd3d-shader/hlsl_codegen.c
+++ b/libs/vkd3d-shader/hlsl_codegen.c
@@ -2167,6 +2167,44 @@ static bool remove_trivial_conditional_branches(struct hlsl_ctx *ctx, struct hls
     return true;
 }

+static bool validate_switch_cases(struct hlsl_ctx *ctx, struct hlsl_ir_node *instr, void *context)
+{
+    struct hlsl_ir_switch_case *c;
+    bool terminal_break = false;
+    struct hlsl_ir_node *node;
+    struct hlsl_ir_jump *jump;
+    struct hlsl_ir_switch *s;
+
+    if (instr->type != HLSL_IR_SWITCH)
+        return false;
+    s = hlsl_ir_switch(instr);
+
+    LIST_FOR_EACH_ENTRY(c, &s->cases, struct hlsl_ir_switch_case, entry)
+    {
+        if (list_empty(&c->body.instrs))
+            continue;
+
+        terminal_break = false;
+        node = LIST_ENTRY(list_tail(&c->body.instrs), struct hlsl_ir_node, entry);
+        if (node->type == HLSL_IR_JUMP)
+        {
+            jump = hlsl_ir_jump(node);
+            terminal_break = jump->type == HLSL_IR_JUMP_BREAK;
+        }
+
+        if (!terminal_break)
+            break;
+    }
+
+    if (!terminal_break)
+    {
+        hlsl_error(ctx, &instr->loc, VKD3D_SHADER_ERROR_HLSL_INVALID_SYNTAX,
+                "Fallthrough is only allowed for empty switch cases.");
+    }
+
+    return true;
+}
+
 static bool lower_nonconstant_vector_derefs(struct hlsl_ctx *ctx, struct hlsl_ir_node *instr, struct hlsl_block *block)
 {
     struct hlsl_ir_node *idx;
@@ -4627,6 +4665,7 @@ int hlsl_emit_bytecode(struct hlsl_ctx *ctx, struct hlsl_ir_function_decl *entry
     }
     while (progress);
     remove_unreachable_code(ctx, body);
+    hlsl_transform_ir(ctx, validate_switch_cases, body, NULL);

lower_ir(ctx, lower_nonconstant_vector_derefs, body);
     lower_ir(ctx, lower_casts_to_bool, body);
diff --git a/tests/hlsl/switch.shader_test b/tests/hlsl/switch.shader_test
index 999158c1..02e499c9 100644
--- a/tests/hlsl/switch.shader_test
+++ b/tests/hlsl/switch.shader_test
@@ -183,7 +183,7 @@ float4 main() : sv_target
 }

% unterminated cases
-[pixel shader fail todo]
+[pixel shader fail]
 uint4 v;

float4 main() : sv_target