From fec4555476e38d2eeb1dfb02572404b243acd0b2 Mon Sep 17 00:00:00 2001
From: Andrew Kelley <andrew@ziglang.org>
Date: Sun, 10 Mar 2019 18:02:59 -0400
Subject: [PATCH] fix inconsistent type information of optional C pointers

solves an assertion failure in LLVM
---
 src/analyze.cpp | 10 +++-------
 src/analyze.hpp |  1 -
 src/codegen.cpp | 12 ++++++------
 3 files changed, 9 insertions(+), 14 deletions(-)

diff --git a/src/analyze.cpp b/src/analyze.cpp
index 6cbcc311efd3..79a723b2e5e0 100644
--- a/src/analyze.cpp
+++ b/src/analyze.cpp
@@ -601,7 +601,7 @@ ZigType *get_optional_type(CodeGen *g, ZigType *child_type) {
         if (child_type->zero_bits) {
             entry->type_ref = LLVMInt1Type();
             entry->di_type = g->builtin_types.entry_bool->di_type;
-        } else if (type_is_non_optional_pointer(child_type) || child_type->id == ZigTypeIdErrorSet) {
+        } else if (type_is_nonnull_ptr(child_type) || child_type->id == ZigTypeIdErrorSet) {
             assert(child_type->di_type);
             // this is an optimization but also is necessary for calling C
             // functions where all pointers are maybe pointers
@@ -4145,11 +4145,7 @@ ZigType *get_codegen_ptr_type(ZigType *type) {
 }
 
 bool type_is_nonnull_ptr(ZigType *type) {
-    return type_is_non_optional_pointer(type) && !ptr_allows_addr_zero(type);
-}
-
-bool type_is_non_optional_pointer(ZigType *type) {
-    return get_codegen_ptr_type(type) == type;
+    return get_codegen_ptr_type(type) == type && !ptr_allows_addr_zero(type);
 }
 
 uint32_t get_ptr_align(CodeGen *g, ZigType *type) {
@@ -4667,7 +4663,7 @@ bool handle_is_ptr(ZigType *type_entry) {
              return type_has_bits(type_entry->data.error_union.payload_type);
         case ZigTypeIdOptional:
              return type_has_bits(type_entry->data.maybe.child_type) &&
-                    !type_is_non_optional_pointer(type_entry->data.maybe.child_type) &&
+                    !type_is_nonnull_ptr(type_entry->data.maybe.child_type) &&
                     type_entry->data.maybe.child_type->id != ZigTypeIdErrorSet;
         case ZigTypeIdUnion:
              assert(type_entry->data.unionation.zero_bits_known);
diff --git a/src/analyze.hpp b/src/analyze.hpp
index 22e44ebd3ff9..3b4f6b711845 100644
--- a/src/analyze.hpp
+++ b/src/analyze.hpp
@@ -60,7 +60,6 @@ ZigVar *find_variable(CodeGen *g, Scope *orig_context, Buf *name, ScopeFnDef **c
 Tld *find_decl(CodeGen *g, Scope *scope, Buf *name);
 Tld *find_container_decl(CodeGen *g, ScopeDecls *decls_scope, Buf *name);
 void resolve_top_level_decl(CodeGen *g, Tld *tld, AstNode *source_node);
-bool type_is_non_optional_pointer(ZigType *type);
 
 ZigType *get_src_ptr_type(ZigType *type);
 ZigType *get_codegen_ptr_type(ZigType *type);
diff --git a/src/codegen.cpp b/src/codegen.cpp
index 719eead7f2ab..71f9f0217b39 100644
--- a/src/codegen.cpp
+++ b/src/codegen.cpp
@@ -3948,10 +3948,10 @@ static LLVMValueRef ir_render_asm(CodeGen *g, IrExecutable *executable, IrInstru
 static LLVMValueRef gen_non_null_bit(CodeGen *g, ZigType *maybe_type, LLVMValueRef maybe_handle) {
     assert(maybe_type->id == ZigTypeIdOptional);
     ZigType *child_type = maybe_type->data.maybe.child_type;
-    if (child_type->zero_bits) {
+    if (!type_has_bits(child_type)) {
         return maybe_handle;
     } else {
-        bool is_scalar = type_is_non_optional_pointer(child_type) || child_type->id == ZigTypeIdErrorSet;
+        bool is_scalar = !handle_is_ptr(maybe_type);
         if (is_scalar) {
             return LLVMBuildICmp(g->builder, LLVMIntNE, maybe_handle, LLVMConstNull(maybe_type->type_ref), "");
         } else {
@@ -3991,7 +3991,7 @@ static LLVMValueRef ir_render_optional_unwrap_ptr(CodeGen *g, IrExecutable *exec
     if (child_type->zero_bits) {
         return nullptr;
     } else {
-        bool is_scalar = type_is_non_optional_pointer(child_type) || child_type->id == ZigTypeIdErrorSet;
+        bool is_scalar = !handle_is_ptr(maybe_type);
         if (is_scalar) {
             return maybe_ptr;
         } else {
@@ -4854,7 +4854,7 @@ static LLVMValueRef ir_render_maybe_wrap(CodeGen *g, IrExecutable *executable, I
     }
 
     LLVMValueRef payload_val = ir_llvm_value(g, instruction->value);
-    if (type_is_non_optional_pointer(child_type) || child_type->id == ZigTypeIdErrorSet) {
+    if (!handle_is_ptr(wanted_type)) {
         return payload_val;
     }
 
@@ -8690,10 +8690,10 @@ static void get_c_type(CodeGen *g, GenH *gen_h, ZigType *type_entry, Buf *out_bu
         case ZigTypeIdOptional:
             {
                 ZigType *child_type = type_entry->data.maybe.child_type;
-                if (child_type->zero_bits) {
+                if (!type_has_bits(child_type)) {
                     buf_init_from_str(out_buf, "bool");
                     return;
-                } else if (type_is_non_optional_pointer(child_type)) {
+                } else if (type_is_nonnull_ptr(child_type)) {
                     return get_c_type(g, gen_h, child_type, out_buf);
                 } else {
                     zig_unreachable();