langref: docs for invalid error set cast and incorrect pointer alignment

also add detection of incorrect pointer alignment at compile-time
of pointers that were constructed with `@intToPtr`.

1 files changed, 9 insertions, 0 deletions

diff --git a/src/ir.cpp b/src/ir.cpp
index 5e4c847e14..dcd39ccfe5 100644
--- a/src/ir.cpp
+++ b/src/ir.cpp
@@ -19370,6 +19370,15 @@ static IrInstruction *ir_align_cast(IrAnalyze *ira, IrInstruction *target, uint3
         if (!val)
             return ira->codegen->invalid_instruction;
 
+        if (val->data.x_ptr.special == ConstPtrSpecialHardCodedAddr &&
+            val->data.x_ptr.data.hard_coded_addr.addr % align_bytes != 0)
+        {
+            ir_add_error(ira, target,
+                    buf_sprintf("pointer address 0x%lx is not aligned to %" PRIu32 " bytes",
+                        val->data.x_ptr.data.hard_coded_addr.addr, align_bytes));
+            return ira->codegen->invalid_instruction;
+        }
+
         IrInstruction *result = ir_create_const(&ira->new_irb, target->scope, target->source_node, result_type);
         copy_const_val(&result->value, val, false);
         result->value.type = result_type;