disallow C pointers to non-C-ABI-compatible element types

See #1059

1 files changed, 4 insertions, 0 deletions

diff --git a/src/ir.cpp b/src/ir.cpp
index 1f0edc910d..64e08ef7ea 100644
--- a/src/ir.cpp
+++ b/src/ir.cpp
@@ -21145,6 +21145,10 @@ static IrInstruction *ir_analyze_instruction_ptr_type(IrAnalyze *ira, IrInstruct
     } else if (child_type->id == ZigTypeIdOpaque && instruction->ptr_len == PtrLenUnknown) {
         ir_add_error(ira, &instruction->base, buf_sprintf("unknown-length pointer to opaque"));
         return ira->codegen->invalid_instruction;
+    } else if (instruction->ptr_len == PtrLenC && !type_allowed_in_extern(ira->codegen, child_type)) {
+        ir_add_error(ira, &instruction->base,
+            buf_sprintf("C pointers cannot point to non-C-ABI-compatible type '%s'", buf_ptr(&child_type->name)));
+        return ira->codegen->invalid_instruction;
     }
 
     uint32_t align_bytes;