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improvements to zig build system and unwrap error safety

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* zig build system: create standard dynamic library sym links
 * unwrapping an error results in a panic message that contains
   the error name
 * rename error.SysResources to error.SystemResources
 * add std.os.symLink
 * add std.os.deleteFile
This commit is contained in:
Andrew Kelley
2017-04-17 02:58:42 -04:00
parent d16ce67106
commit 47336abae3
7 changed files with 260 additions and 89 deletions
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180
src/codegen.cpp
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@@ -255,6 +255,7 @@ void codegen_set_linker_script(CodeGen *g, const char *linker_script) {
static void render_const_val(CodeGen *g, ConstExprValue *const_val);
static void render_const_val_global(CodeGen *g, ConstExprValue *const_val, const char *name);
static LLVMValueRef gen_const_val(CodeGen *g, ConstExprValue *const_val);
static void generate_error_name_table(CodeGen *g);
static void addLLVMAttr(LLVMValueRef val, LLVMAttributeIndex attr_index, const char *attr_name) {
unsigned kind_id = LLVMGetEnumAttributeKindForName(attr_name, strlen(attr_name));
@@ -545,6 +546,34 @@ static bool ir_want_debug_safety(CodeGen *g, IrInstruction *instruction) {
return true;
}
static bool is_array_of_at_least_n_bytes(CodeGen *g, TypeTableEntry *type_entry, uint32_t n) {
if (type_entry->id != TypeTableEntryIdArray)
return false;
TypeTableEntry *child_type = type_entry->data.array.child_type;
if (child_type->id != TypeTableEntryIdInt)
return false;
if (child_type != g->builtin_types.entry_u8)
return false;
if (type_entry->data.array.len < n)
return false;
return true;
}
static uint32_t get_type_alignment(CodeGen *g, TypeTableEntry *type_entry) {
uint32_t alignment = ZigLLVMGetPrefTypeAlignment(g->target_data_ref, type_entry->type_ref);
uint32_t dbl_ptr_bytes = g->pointer_size_bytes * 2;
if (is_array_of_at_least_n_bytes(g, type_entry, dbl_ptr_bytes)) {
return (alignment < dbl_ptr_bytes) ? dbl_ptr_bytes : alignment;
} else {
return alignment;
}
}
static Buf *panic_msg_buf(PanicMsgId msg_id) {
switch (msg_id) {
case PanicMsgIdCount:
@@ -569,8 +598,6 @@ static Buf *panic_msg_buf(PanicMsgId msg_id) {
return buf_create_from_str("slice widening size mismatch");
case PanicMsgIdUnwrapMaybeFail:
return buf_create_from_str("attempt to unwrap null");
case PanicMsgIdUnwrapErrFail:
return buf_create_from_str("attempt to unwrap error");
case PanicMsgIdUnreachable:
return buf_create_from_str("reached unreachable code");
case PanicMsgIdInvalidErrorCode:
@@ -595,28 +622,128 @@ static LLVMValueRef get_panic_msg_ptr_val(CodeGen *g, PanicMsgId msg_id) {
return val->llvm_global;
}
static void gen_panic(CodeGen *g, LLVMValueRef msg_arg) {
static void gen_panic_raw(CodeGen *g, LLVMValueRef msg_ptr, LLVMValueRef msg_len) {
FnTableEntry *panic_fn = get_extern_panic_fn(g);
LLVMValueRef fn_val = fn_llvm_value(g, panic_fn);
LLVMValueRef args[] = { msg_ptr, msg_len };
ZigLLVMBuildCall(g->builder, fn_val, args, 2, panic_fn->type_entry->data.fn.calling_convention, false, "");
LLVMBuildUnreachable(g->builder);
}
static void gen_panic(CodeGen *g, LLVMValueRef msg_arg) {
TypeTableEntry *str_type = get_slice_type(g, g->builtin_types.entry_u8, true);
size_t ptr_index = str_type->data.structure.fields[slice_ptr_index].gen_index;
size_t len_index = str_type->data.structure.fields[slice_len_index].gen_index;
LLVMValueRef ptr_ptr = LLVMBuildStructGEP(g->builder, msg_arg, (unsigned)ptr_index, "");
LLVMValueRef len_ptr = LLVMBuildStructGEP(g->builder, msg_arg, (unsigned)len_index, "");
LLVMValueRef args[] = {
LLVMBuildLoad(g->builder, ptr_ptr, ""),
LLVMBuildLoad(g->builder, len_ptr, ""),
};
ZigLLVMBuildCall(g->builder, fn_val, args, 2, panic_fn->type_entry->data.fn.calling_convention, false, "");
LLVMBuildUnreachable(g->builder);
LLVMValueRef msg_ptr = LLVMBuildLoad(g->builder, ptr_ptr, "");
LLVMValueRef msg_len = LLVMBuildLoad(g->builder, len_ptr, "");
gen_panic_raw(g, msg_ptr, msg_len);
}
static void gen_debug_safety_crash(CodeGen *g, PanicMsgId msg_id) {
gen_panic(g, get_panic_msg_ptr_val(g, msg_id));
}
static LLVMValueRef get_safety_crash_err_fn(CodeGen *g) {
if (g->safety_crash_err_fn != nullptr)
return g->safety_crash_err_fn;
static const char *unwrap_err_msg_text = "attempt to unwrap error: ";
g->generate_error_name_table = true;
generate_error_name_table(g);
size_t unwrap_err_msg_text_len = strlen(unwrap_err_msg_text);
size_t err_buf_len = strlen(unwrap_err_msg_text) + g->largest_err_name_len;
LLVMValueRef *err_buf_vals = allocate<LLVMValueRef>(err_buf_len);
size_t i = 0;
for (; i < unwrap_err_msg_text_len; i += 1) {
err_buf_vals[i] = LLVMConstInt(LLVMInt8Type(), unwrap_err_msg_text[i], false);
}
for (; i < err_buf_len; i += 1) {
err_buf_vals[i] = LLVMGetUndef(LLVMInt8Type());
}
LLVMValueRef init_value = LLVMConstArray(LLVMInt8Type(), err_buf_vals, err_buf_len);
Buf *global_name = get_mangled_name(g, buf_create_from_str("__zig_panic_buf"), false);
LLVMValueRef global_value = LLVMAddGlobal(g->module, LLVMTypeOf(init_value), buf_ptr(global_name));
LLVMSetInitializer(global_value, init_value);
LLVMSetLinkage(global_value, LLVMInternalLinkage);
LLVMSetGlobalConstant(global_value, false);
LLVMSetUnnamedAddr(global_value, true);
LLVMSetAlignment(global_value, get_type_alignment(g, g->builtin_types.entry_u8));
TypeTableEntry *usize = g->builtin_types.entry_usize;
LLVMValueRef full_buf_ptr_indices[] = {
LLVMConstNull(usize->type_ref),
LLVMConstNull(usize->type_ref),
};
LLVMValueRef full_buf_ptr = LLVMConstInBoundsGEP(global_value, full_buf_ptr_indices, 2);
LLVMValueRef offset_ptr_indices[] = {
LLVMConstNull(usize->type_ref),
LLVMConstInt(usize->type_ref, unwrap_err_msg_text_len, false),
};
LLVMValueRef offset_buf_ptr = LLVMConstInBoundsGEP(global_value, offset_ptr_indices, 2);
Buf *fn_name = get_mangled_name(g, buf_create_from_str("__zig_fail_unwrap"), false);
LLVMTypeRef fn_type_ref = LLVMFunctionType(LLVMVoidType(), &g->err_tag_type->type_ref, 1, false);
LLVMValueRef fn_val = LLVMAddFunction(g->module, buf_ptr(fn_name), fn_type_ref);
addLLVMFnAttr(fn_val, "noreturn");
addLLVMFnAttr(fn_val, "cold");
LLVMSetLinkage(fn_val, LLVMInternalLinkage);
LLVMSetFunctionCallConv(fn_val, LLVMFastCallConv);
LLVMBasicBlockRef entry_block = LLVMAppendBasicBlock(fn_val, "Entry");
LLVMBasicBlockRef prev_block = LLVMGetInsertBlock(g->builder);
LLVMValueRef prev_debug_location = LLVMGetCurrentDebugLocation(g->builder);
LLVMPositionBuilderAtEnd(g->builder, entry_block);
ZigLLVMClearCurrentDebugLocation(g->builder);
LLVMValueRef err_val = LLVMGetParam(fn_val, 0);
LLVMValueRef err_table_indices[] = {
LLVMConstNull(g->builtin_types.entry_usize->type_ref),
err_val,
};
LLVMValueRef err_name_val = LLVMBuildInBoundsGEP(g->builder, g->err_name_table, err_table_indices, 2, "");
LLVMValueRef ptr_field_ptr = LLVMBuildStructGEP(g->builder, err_name_val, slice_ptr_index, "");
LLVMValueRef err_name_ptr = LLVMBuildLoad(g->builder, ptr_field_ptr, "");
LLVMValueRef len_field_ptr = LLVMBuildStructGEP(g->builder, err_name_val, slice_len_index, "");
LLVMValueRef err_name_len = LLVMBuildLoad(g->builder, len_field_ptr, "");
LLVMValueRef params[] = {
offset_buf_ptr, // dest pointer
err_name_ptr, // source pointer
err_name_len, // size bytes
LLVMConstInt(LLVMInt32Type(), 1, false), // align bytes
LLVMConstNull(LLVMInt1Type()), // is volatile
};
LLVMBuildCall(g->builder, g->memcpy_fn_val, params, 5, "");
LLVMValueRef const_prefix_len = LLVMConstInt(LLVMTypeOf(err_name_len), strlen(unwrap_err_msg_text), false);
LLVMValueRef full_buf_len = LLVMBuildNUWAdd(g->builder, const_prefix_len, err_name_len, "");
gen_panic_raw(g, full_buf_ptr, full_buf_len);
LLVMPositionBuilderAtEnd(g->builder, prev_block);
LLVMSetCurrentDebugLocation(g->builder, prev_debug_location);
g->safety_crash_err_fn = fn_val;
return fn_val;
}
static void gen_debug_safety_crash_for_err(CodeGen *g, LLVMValueRef err_val) {
LLVMValueRef safety_crash_err_fn = get_safety_crash_err_fn(g);
LLVMBuildCall(g->builder, safety_crash_err_fn, &err_val, 1, "");
LLVMBuildUnreachable(g->builder);
}
static void add_bounds_check(CodeGen *g, LLVMValueRef target_val,
LLVMIntPredicate lower_pred, LLVMValueRef lower_value,
LLVMIntPredicate upper_pred, LLVMValueRef upper_value)
@@ -790,33 +917,6 @@ static LLVMRealPredicate cmp_op_to_real_predicate(IrBinOp cmp_op) {
}
}
static bool is_array_of_at_least_n_bytes(CodeGen *g, TypeTableEntry *type_entry, uint32_t n) {
if (type_entry->id != TypeTableEntryIdArray)
return false;
TypeTableEntry *child_type = type_entry->data.array.child_type;
if (child_type->id != TypeTableEntryIdInt)
return false;
if (child_type != g->builtin_types.entry_u8)
return false;
if (type_entry->data.array.len < n)
return false;
return true;
}
static uint32_t get_type_alignment(CodeGen *g, TypeTableEntry *type_entry) {
uint32_t alignment = ZigLLVMGetPrefTypeAlignment(g->target_data_ref, type_entry->type_ref);
uint32_t dbl_ptr_bytes = g->pointer_size_bytes * 2;
if (is_array_of_at_least_n_bytes(g, type_entry, dbl_ptr_bytes)) {
return (alignment < dbl_ptr_bytes) ? dbl_ptr_bytes : alignment;
} else {
return alignment;
}
}
static LLVMValueRef gen_struct_memcpy(CodeGen *g, LLVMValueRef src, LLVMValueRef dest,
TypeTableEntry *type_entry)
{
@@ -2522,7 +2622,7 @@ static LLVMValueRef ir_render_unwrap_err_payload(CodeGen *g, IrExecutable *execu
LLVMBuildCondBr(g->builder, cond_val, ok_block, err_block);
LLVMPositionBuilderAtEnd(g->builder, err_block);
gen_debug_safety_crash(g, PanicMsgIdUnwrapErrFail);
gen_debug_safety_crash_for_err(g, err_val);
LLVMPositionBuilderAtEnd(g->builder, ok_block);
}
@@ -3384,7 +3484,7 @@ static LLVMValueRef gen_test_fn_val(CodeGen *g, FnTableEntry *fn_entry) {
}
static void generate_error_name_table(CodeGen *g) {
if (!g->generate_error_name_table || g->error_decls.length == 1) {
if (g->err_name_table != nullptr || !g->generate_error_name_table || g->error_decls.length == 1) {
return;
}
@@ -3400,6 +3500,8 @@ static void generate_error_name_table(CodeGen *g) {
assert(error_decl_node->type == NodeTypeErrorValueDecl);
Buf *name = error_decl_node->data.error_value_decl.name;
g->largest_err_name_len = max(g->largest_err_name_len, buf_len(name));
LLVMValueRef str_init = LLVMConstString(buf_ptr(name), (unsigned)buf_len(name), true);
LLVMValueRef str_global = LLVMAddGlobal(g->module, LLVMTypeOf(str_init), "");
LLVMSetInitializer(str_global, str_init);
@@ -3417,7 +3519,7 @@ static void generate_error_name_table(CodeGen *g) {
LLVMValueRef err_name_table_init = LLVMConstArray(str_type->type_ref, values, (unsigned)g->error_decls.length);
g->err_name_table = LLVMAddGlobal(g->module, LLVMTypeOf(err_name_table_init),
buf_ptr(get_mangled_name(g, buf_create_from_str("err_name_table"), false)));
buf_ptr(get_mangled_name(g, buf_create_from_str("__zig_err_name_table"), false)));
LLVMSetInitializer(g->err_name_table, err_name_table_init);
LLVMSetLinkage(g->err_name_table, LLVMPrivateLinkage);
LLVMSetGlobalConstant(g->err_name_table, true);