Check for undefined %id in spirv_asm block. (#5966)

1 files changed, 62 insertions, 0 deletions

diff --git a/source/slang/slang-check-expr.cpp b/source/slang/slang-check-expr.cpp
index 7cb0ede2d..83b668a33 100644
--- a/source/slang/slang-check-expr.cpp
+++ b/source/slang/slang-check-expr.cpp
@@ -5311,6 +5311,10 @@ Expr* SemanticsExprVisitor::visitSPIRVAsmExpr(SPIRVAsmExpr* expr)
     // We will iterate over all the operands in all the insts and check
     // them
     bool failed = false;
+
+    // Track %id's that have been defined in this asm block.
+    HashSet<Name*> definedIds;
+
     for (auto& inst : expr->insts)
     {
         // It's not automatically a failure to not have info, we just won't
@@ -5327,6 +5331,52 @@ Expr* SemanticsExprVisitor::visitSPIRVAsmExpr(SPIRVAsmExpr* expr)
                 0);
             continue;
         }
+        int resultIdIndex = -1;
+        if (opInfo)
+        {
+            resultIdIndex = opInfo->resultIdIndex;
+        }
+        else if (inst.opcode.flavor == SPIRVAsmOperand::TruncateMarker)
+        {
+            // If this is __truncate, register the result id in the third operand.
+            resultIdIndex = 1;
+        }
+        else
+        {
+            // If there is no opInfo, just register all Ids as defined.
+            for (auto& operand : inst.operands)
+            {
+                if (operand.flavor == SPIRVAsmOperand::Id)
+                {
+                    definedIds.add(operand.token.getName());
+                }
+            }
+        }
+
+        // Register result ID.
+        if (resultIdIndex != -1)
+        {
+            if (inst.operands.getCount() <= resultIdIndex)
+            {
+                failed = true;
+                getSink()->diagnose(
+                    inst.opcode.token,
+                    Diagnostics::spirvInstructionWithNotEnoughOperands,
+                    inst.opcode.token);
+                continue;
+            }
+            auto& resultIdOperand = inst.operands[resultIdIndex];
+
+            if (!definedIds.add(resultIdOperand.token.getName()))
+            {
+                failed = true;
+                getSink()->diagnose(
+                    inst.opcode.token,
+                    Diagnostics::spirvIdRedefinition,
+                    inst.opcode.token);
+                continue;
+            }
+        }
 
         const bool isLast = &inst == &expr->insts.getLast();
         for (Index operandIndex = 0; operandIndex < inst.operands.getCount(); ++operandIndex)
@@ -5438,6 +5488,18 @@ Expr* SemanticsExprVisitor::visitSPIRVAsmExpr(SPIRVAsmExpr* expr)
                     }
                     operand.knownValue = builtinVarKind.value();
                 }
+                else if (operand.flavor == SPIRVAsmOperand::Id)
+                {
+                    if (!definedIds.contains(operand.token.getName()))
+                    {
+                        failed = true;
+                        getSink()->diagnose(
+                            operand.token,
+                            Diagnostics::spirvUndefinedId,
+                            operand.token);
+                        return;
+                    }
+                }
                 if (operand.bitwiseOrWith.getCount() &&
                     operand.flavor != SPIRVAsmOperand::Literal &&
                     operand.flavor != SPIRVAsmOperand::NamedValue)