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e1b5b0b60ceaad4d44240e69072b15c2bac03122
c3c/src/compiler/llvm_codegen_stmt.c
Christoffer Lerno e1b5b0b60c Implement static finalize / initialize. Version bump.
2022-09-28 17:18:20 +02:00

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// Copyright (c) 2019 Christoffer Lerno. All rights reserved.
// Use of this source code is governed by the GNU LGPLv3.0 license
// a copy of which can be found in the LICENSE file.
#include "llvm_codegen_internal.h"
static void llvm_emit_switch_body(GenContext *c, BEValue *switch_value, Ast *switch_ast);
// Emit a regular compound statement.
void llvm_emit_compound_stmt(GenContext *c, Ast *ast)
{
assert(ast->ast_kind == AST_COMPOUND_STMT);
// Push the lexical scope if debug.
if (llvm_use_debug(c))
{
llvm_debug_push_lexical_scope(c, ast->span);
}
// Emit the statement chain
llvm_emit_statement_chain(c, ast->compound_stmt.first_stmt);
if (llvm_use_debug(c))
{
llvm_debug_scope_pop(c);
}
}
/**
* This emits a local declaration.
*/
void llvm_emit_local_decl(GenContext *c, Decl *decl, BEValue *value)
{
// 1. Get the declaration and the LLVM type.
Type *var_type = type_lowering(type_no_optional(decl->type));
LLVMTypeRef alloc_type = llvm_get_type(c, var_type);
// 2. In the case we have a static variable,
// then we essentially treat this as a global.
if (decl->var.is_static)
{
// In defers we might already have generated this variable.
if (decl->backend_ref)
{
llvm_value_set_decl(c, value, decl);
return;
}
void *builder = c->builder;
c->builder = c->global_builder;
decl->backend_ref = llvm_add_global(c, "tempglobal", var_type, decl->alignment);
if (IS_OPTIONAL(decl))
{
scratch_buffer_clear();
scratch_buffer_append(decl->extname);
scratch_buffer_append("$f");
decl->var.failable_ref = llvm_add_global(c, scratch_buffer_to_string(), type_anyerr, 0);
}
llvm_emit_global_variable_init(c, decl);
c->builder = builder;
llvm_value_set_decl(c, value, decl);
return;
}
assert(!decl->backend_ref);
llvm_emit_local_var_alloca(c, decl);
Expr *init = decl->var.init_expr;
bool is_failable = IS_OPTIONAL(decl);
if (is_failable)
{
scratch_buffer_clear();
scratch_buffer_append(decl->name);
scratch_buffer_append(".f");
decl->var.failable_ref = llvm_emit_alloca_aligned(c, type_anyerr, scratch_buffer_to_string());
// Only clear out the result if the assignment isn't a failable.
}
if (init)
{
llvm_value_set_decl_address(c, value, decl);
value->kind = BE_ADDRESS;
BEValue res = llvm_emit_assign_expr(c, value, decl->var.init_expr, decl->var.failable_ref);
if (!is_failable) *value = res;
}
else if (decl->var.no_init)
{
llvm_value_set(value, LLVMGetUndef(alloc_type), decl->type);
if (decl->var.failable_ref)
{
llvm_store_to_ptr_raw(c, decl->var.failable_ref, llvm_get_undef(c, type_anyerr), type_anyerr);
}
}
else
{
if (decl->var.failable_ref)
{
llvm_store_to_ptr_zero(c, decl->var.failable_ref, type_anyerr);
}
Type *type = type_lowering(decl->type);
// Normal case, zero init.
if (type_is_builtin(type->type_kind) || type->type_kind == TYPE_POINTER)
{
LLVMValueRef zero = llvm_get_zero(c, var_type);
llvm_value_set(value, zero, type);
llvm_store_decl(c, decl, value);
}
else
{
llvm_value_set_decl_address(c, value, decl);
value->kind = BE_ADDRESS;
llvm_store_zero(c, value);
llvm_value_set(value, llvm_get_zero(c, type), type);
}
}
}
void llvm_emit_decl_expr_list_ignore_result(GenContext *context, Expr *expr)
{
assert(expr->expr_kind == EXPR_COND);
VECEACH(expr->cond_expr, i)
{
BEValue value;
llvm_emit_expr(context, &value, expr->cond_expr[i]);
}
}
void llvm_emit_decl_expr_list(GenContext *context, BEValue *be_value, Expr *expr, bool bool_cast)
{
assert(expr->expr_kind == EXPR_COND);
ByteSize size = vec_size(expr->cond_expr);
ByteSize last_index = size - 1;
for (ByteSize i = 0; i < last_index; i++)
{
BEValue value;
llvm_emit_expr(context, &value, expr->cond_expr[i]);
}
Expr *last = expr->cond_expr[last_index];
Type *type = last->type;
llvm_emit_expr(context, be_value, last);
if (last->expr_kind == EXPR_DECL)
{
type = last->decl_expr->var.type_info->type;
LLVMValueRef decl_value = llvm_get_ref(context, last->decl_expr);
if (bool_cast && last->decl_expr->var.unwrap)
{
llvm_value_set_bool(be_value, LLVMConstInt(context->bool_type, 1, false));
return;
}
llvm_value_set_address_abi_aligned(be_value, decl_value, type);
}
if (bool_cast)
{
type = type_lowering(type);
if (type->type_kind != TYPE_BOOL)
{
CastKind cast = cast_to_bool_kind(type);
llvm_emit_cast(context, cast, last, be_value, type, type_bool);
}
}
}
void llvm_emit_jmp(GenContext *context, LLVMBasicBlockRef block)
{
llvm_emit_br(context, block);
LLVMBasicBlockRef post_jump_block = llvm_basic_block_new(context, "jmp");
llvm_emit_block(context, post_jump_block);
}
static inline void llvm_emit_return(GenContext *c, Ast *ast)
{
PUSH_OPT();
Expr *expr = ast->return_stmt.expr;
if (expr && expr->expr_kind == EXPR_FAILABLE)
{
BEValue be_value;
llvm_emit_expr(c, &be_value, expr->inner_expr);
llvm_emit_statement_chain(c, ast->return_stmt.cleanup);
llvm_emit_return_abi(c, NULL, &be_value);
return;
}
LLVMBasicBlockRef error_return_block = NULL;
LLVMValueRef error_out = NULL;
if (c->cur_func.prototype && type_is_optional(c->cur_func.prototype->rtype))
{
error_return_block = llvm_basic_block_new(c, "err_retblock");
error_out = llvm_emit_alloca_aligned(c, type_anyerr, "reterr");
c->opt_var = error_out;
c->catch_block = error_return_block;
}
bool has_return_value = ast->return_stmt.expr != NULL;
BEValue return_value = { 0 };
if (has_return_value)
{
llvm_emit_expr(c, &return_value, ast->return_stmt.expr);
llvm_value_fold_optional(c, &return_value);
c->retval = return_value;
}
POP_OPT();
llvm_emit_statement_chain(c, ast->return_stmt.cleanup);
// Are we in an expression block?
if (!has_return_value)
{
llvm_emit_return_implicit(c);
}
else
{
llvm_emit_return_abi(c, &return_value, NULL);
}
c->current_block = NULL;
if (error_return_block && LLVMGetFirstUse(LLVMBasicBlockAsValue(error_return_block)))
{
llvm_emit_block(c, error_return_block);
BEValue value;
llvm_value_set_address_abi_aligned(&value, error_out, type_anyerr);
llvm_emit_return_abi(c, NULL, &value);
c->current_block = NULL;
}
LLVMBasicBlockRef post_ret_block = llvm_basic_block_new(c, "postreturn");
llvm_emit_block(c, post_ret_block);
}
static inline void llvm_emit_block_exit_return(GenContext *c, Ast *ast)
{
PUSH_OPT();
LLVMBasicBlockRef error_return_block = NULL;
LLVMValueRef error_out = NULL;
BlockExit *exit = *ast->return_stmt.block_exit_ref;
c->opt_var = exit->block_error_var;
c->catch_block = exit->block_failable_exit;
LLVMBasicBlockRef err_cleanup_block = NULL;
Expr *ret_expr = ast->return_stmt.expr;
BEValue return_value = { 0 };
if (ret_expr)
{
if (ast->return_stmt.cleanup && IS_OPTIONAL(ret_expr))
{
assert(c->catch_block);
err_cleanup_block = llvm_basic_block_new(c, "opt_block_cleanup");
c->catch_block = err_cleanup_block;
}
llvm_emit_expr(c, &return_value, ast->return_stmt.expr);
llvm_value_fold_optional(c, &return_value);
}
POP_OPT();
llvm_emit_statement_chain(c, ast->return_stmt.cleanup);
if (exit->block_return_out && return_value.value)
{
llvm_store_to_ptr_aligned(c, exit->block_return_out, &return_value, type_alloca_alignment(return_value.type));
}
if (err_cleanup_block)
{
llvm_emit_br(c, exit->block_return_exit);
llvm_emit_block(c, err_cleanup_block);
llvm_emit_statement_chain(c, ast->return_stmt.cleanup);
llvm_emit_jmp(c, exit->block_failable_exit);
}
else
{
llvm_emit_jmp(c, exit->block_return_exit);
}
}
/**
* Emit if (...) { ... } else { ... }
*
* This code is slightly optimized to omit branches when not needed. This is something LLVM
* will optimize as well, but it is convenient to make the code slightly smaller for LLVM to work with:
* 1. If the "then" branch is empty, replace it with "exit".
* 2. If the "else" branch is empty or missing, replace if with "exit".
* 3. If both "else" and "then" branches are empty, replace it with just the condition and remove the "exit"
*/
void llvm_emit_if(GenContext *c, Ast *ast)
{
// We need at least the exit block and the "then" block.
LLVMBasicBlockRef exit_block = llvm_basic_block_new(c, "if.exit");
LLVMBasicBlockRef then_block = exit_block;
LLVMBasicBlockRef else_block = exit_block;
Ast *then_body = astptr(ast->if_stmt.then_body);
// Only generate a target if
if (ast_is_not_empty(then_body))
{
then_block = llvm_basic_block_new(c, "if.then");
}
// We have an optional else block.
AstId else_id = ast->if_stmt.else_body;
Ast *else_body = else_id ? astptr(else_id) : NULL;
if (ast_is_not_empty(else_body))
{
else_block = llvm_basic_block_new(c, "if.else");
}
Expr *cond = exprptr(ast->if_stmt.cond);
ast->if_stmt.codegen.break_block = exit_block;
// Output boolean value and switch.
Decl *label = ast->if_stmt.flow.label;
if (label)
{
label->label.break_target = exit_block;
}
BEValue be_value = { 0 };
bool exit_in_use = true;
if (then_body->ast_kind == AST_IF_CATCH_SWITCH_STMT)
{
llvm_emit_decl_expr_list(c, &be_value, cond, false);
llvm_value_rvalue(c, &be_value);
BEValue comp;
llvm_emit_int_comp_zero(c, &comp, &be_value, BINARYOP_NE);
llvm_emit_cond_br(c, &comp, then_block, else_block);
llvm_emit_br(c, then_block);
llvm_emit_block(c, then_block);
llvm_emit_switch_body(c, &be_value, then_body);
llvm_emit_br(c, exit_block);
goto EMIT_ELSE;
}
llvm_emit_decl_expr_list(c, &be_value, cond, true);
llvm_value_rvalue(c, &be_value);
assert(llvm_value_is_bool(&be_value));
if (llvm_value_is_const(&be_value) && then_block != else_block)
{
if (LLVMConstIntGetZExtValue(be_value.value))
{
llvm_emit_br(c, then_block);
else_block = exit_block;
}
else
{
llvm_emit_br(c, else_block);
then_block = exit_block;
}
}
else
{
if (then_block != else_block)
{
llvm_emit_cond_br(c, &be_value, then_block, else_block);
}
else
{
exit_in_use = LLVMGetFirstUse(LLVMBasicBlockAsValue(exit_block)) != NULL;
if (exit_in_use) llvm_emit_br(c, exit_block);
}
}
// Emit the 'then' code.
if (then_block != exit_block)
{
llvm_emit_block(c, then_block);
llvm_emit_stmt(c, then_body);
// Jump to exit.
llvm_emit_br(c, exit_block);
}
EMIT_ELSE:
// Emit the 'else' branch if present.
if (else_block != exit_block)
{
llvm_emit_block(c, else_block);
llvm_emit_stmt(c, else_body);
llvm_emit_br(c, exit_block);
}
// And now we just emit the exit block.
if (exit_in_use)
{
llvm_emit_block(c, exit_block);
}
}
typedef enum
{
LOOP_NORMAL,
LOOP_INFINITE,
LOOP_NONE
} LoopType;
static inline LoopType loop_type_for_cond(Expr *cond, bool do_while)
{
if (!cond)
{
// We may have do-while (0)
if (do_while) return LOOP_NONE;
// OR we have for (int x;;x++)
return LOOP_INFINITE;
}
// Fold simple conds
if (cond->expr_kind == EXPR_COND && vec_size(cond->cond_expr) == 1)
{
cond = cond->cond_expr[0];
}
// Do we have a constant cond?
if (cond->expr_kind == EXPR_CONST)
{
assert(cond->const_expr.const_kind == CONST_BOOL);
// The result is either infinite or no loop
return cond->const_expr.b ? LOOP_INFINITE : LOOP_NONE;
}
// Otherwise we have a normal loop.
return LOOP_NORMAL;
}
void llvm_emit_for_stmt(GenContext *c, Ast *ast)
{
// First, emit all inits.
BEValue value;
if (ast->for_stmt.init) llvm_emit_expr(c, &value, exprptr(ast->for_stmt.init));
bool no_exit = ast->for_stmt.flow.no_exit;
ExprId incr = ast->for_stmt.incr;
LLVMBasicBlockRef inc_block = incr ? llvm_basic_block_new(c, "loop.inc") : NULL;
Ast *body = astptr(ast->for_stmt.body);
LLVMBasicBlockRef body_block = ast_is_not_empty(body) ? llvm_basic_block_new(c, "loop.body") : NULL;
LLVMBasicBlockRef cond_block = NULL;
// Skipping first cond? This is do-while semantics
bool skip_first = ast->for_stmt.flow.skip_first;
ExprId cond_id = ast->for_stmt.cond;
Expr *cond = cond_id ? exprptr(cond_id) : NULL;
LoopType loop = loop_type_for_cond(cond, skip_first);
// This is the starting block to loop back to, and may either be cond, body or inc
LLVMBasicBlockRef loop_start_block = body_block ? body_block : inc_block;
// We only emit a cond block if we have a normal loop.
if (loop == LOOP_NORMAL)
{
cond_block = llvm_basic_block_new(c, "loop.cond");
loop_start_block = cond_block;
}
// In the case that *none* of the blocks exist.
if (!inc_block && !body_block && !cond_block)
{
if (loop == LOOP_INFINITE)
{
SourceSpan loc = ast->span;
File *file = source_file_by_id(loc.file_id);
llvm_emit_panic(c, "Infinite loop found", file->name, c->cur_func.name, loc.row ? loc.row : 1);
LLVMBuildUnreachable(c->builder);
LLVMBasicBlockRef block = llvm_basic_block_new(c, "unreachable_block");
c->current_block = NULL;
c->current_block_is_target = false;
llvm_emit_block(c, block);
return;
}
return;
}
assert(loop_start_block != NULL);
LLVMBasicBlockRef exit_block = llvm_basic_block_new(c, "loop.exit");
// Break is simple it always jumps out.
// For continue:
// 1. If there is inc, jump to the condition
// 2. If this is not looping, jump to the exit, otherwise go to cond/body depending on what the start is.
LLVMBasicBlockRef continue_block = inc_block;
if (!continue_block)
{
continue_block = loop == LOOP_NONE ? exit_block : loop_start_block;
}
ast->for_stmt.codegen.continue_block = continue_block;
ast->for_stmt.codegen.exit_block = exit_block;
// We have a normal loop, so we emit a cond.
if (loop == LOOP_NORMAL)
{
// Emit a jump for do-while semantics, to skip the initial cond.
if (skip_first)
{
LLVMBasicBlockRef do_while_start = body_block ? body_block : inc_block;
// Only jump if we have a body / inc
// if the case is do {} while (...) then we basically can treat this as while (...) {}
llvm_emit_br(c, do_while_start ? do_while_start : cond_block);
}
else
{
llvm_emit_br(c, cond_block);
}
// Emit the block
llvm_emit_block(c, cond_block);
BEValue be_value;
assert(cond);
if (cond->expr_kind == EXPR_COND)
{
llvm_emit_decl_expr_list(c, &be_value, cond, true);
}
else
{
llvm_emit_expr(c, &be_value, cond);
}
llvm_value_rvalue(c, &be_value);
assert(llvm_value_is_bool(&be_value));
// If we have a body, conditionally jump to it.
LLVMBasicBlockRef cond_success = body_block ? body_block : inc_block;
// If there is a while (...) { } we need to set the success to this block
if (!cond_success) cond_success = cond_block;
// Otherwise jump to inc or cond depending on what's available.
llvm_emit_cond_br(c, &be_value, cond_success, exit_block);
}
// The optional cond is emitted, so emit the body
if (body_block)
{
// If we have LOOP_NONE, then we don't need a new block here
// since we will just exit. That leaves the infinite loop.
switch (loop)
{
case LOOP_NORMAL:
// If we have LOOP_NORMAL, we already emitted a br to the body.
// so emit the block
llvm_emit_block(c, body_block);
break;
case LOOP_INFINITE:
// In this case we have no cond, so we need to emit the br and
// then the block
llvm_emit_br(c, body_block);
llvm_emit_block(c, body_block);
case LOOP_NONE:
// If there is no loop, then we will just fall through and the
// block is needed.
body_block = NULL;
break;
}
// Now emit the body
llvm_emit_stmt(c, body);
// Did we have a jump to inc yet?
if (inc_block && !llvm_basic_block_is_unused(inc_block))
{
// If so we emit the jump to the inc block.
llvm_emit_br(c, inc_block);
}
else
{
inc_block = NULL;
}
}
if (incr)
{
// We might have neither body nor cond
// In that case we do a jump from the init.
if (loop_start_block == inc_block)
{
llvm_emit_br(c, inc_block);
}
if (inc_block)
{
// Emit the block if it exists.
// The inc block might also be the end of the body block.
llvm_emit_block(c, inc_block);
}
BEValue dummy;
llvm_emit_expr(c, &dummy, incr ? exprptr(incr) : NULL);
}
// Loop back.
if (loop != LOOP_NONE)
{
llvm_emit_br(c, loop_start_block);
}
else
{
// If the exit block is unused, just skip it.
if (llvm_basic_block_is_unused(exit_block)) return;
llvm_emit_br(c, exit_block);
}
// And insert exit block
llvm_emit_block(c, exit_block);
}
static void llvm_emit_switch_body_if_chain(GenContext *c,
Ast **cases,
Ast *default_case,
BEValue *switch_value,
LLVMBasicBlockRef exit_block)
{
LLVMBasicBlockRef next = NULL;
VECEACH(cases, i)
{
Ast *case_stmt = cases[i];
LLVMBasicBlockRef block = case_stmt->case_stmt.backend_block;
if (case_stmt == default_case) continue;
BEValue be_value;
llvm_emit_expr(c, &be_value, case_stmt->case_stmt.expr);
llvm_value_rvalue(c, &be_value);
BEValue equals;
Expr *to_expr = case_stmt->case_stmt.to_expr;
if (to_expr)
{
BEValue to_value;
llvm_emit_expr(c, &to_value, to_expr);
llvm_value_rvalue(c, &to_value);
BEValue le;
llvm_emit_comp(c, &le, &be_value, switch_value, BINARYOP_LE);
BEValue ge;
llvm_emit_comp(c, &ge, &to_value, switch_value, BINARYOP_GE);
llvm_value_set_bool(&equals, llvm_emit_and(c, &le, &ge));
}
else
{
llvm_emit_comp(c, &equals, &be_value, switch_value, BINARYOP_EQ);
}
next = llvm_basic_block_new(c, "next_if");
llvm_emit_cond_br(c, &equals, block, next);
if (case_stmt->case_stmt.body)
{
llvm_emit_block(c, block);
c->current_block_is_target = true;
llvm_emit_stmt(c, case_stmt->case_stmt.body);
llvm_emit_br(c, exit_block);
}
llvm_emit_block(c, next);
}
if (default_case && default_case->case_stmt.body)
{
llvm_emit_br(c, default_case->case_stmt.backend_block);
llvm_emit_block(c, default_case->case_stmt.backend_block);
c->current_block_is_target = true;
llvm_emit_stmt(c, default_case->case_stmt.body);
llvm_emit_br(c, exit_block);
}
else
{
llvm_emit_br(c, exit_block);
}
llvm_emit_block(c, exit_block);
return;
}
static void llvm_emit_switch_jump_table(GenContext *c,
Ast **cases,
Ast *default_case,
BEValue *switch_value,
LLVMBasicBlockRef exit_block)
{
#ifdef jump_table_done
c->current_block = NULL;
unsigned case_count = vec_size(cases);
Int min = { .type = TYPE_VOID };
Int max = { .type = TYPE_VOID };
for (unsigned i = 0; i < case_count; i++)
{
Ast *case_ast = cases[i];
Expr *from = case_ast->case_stmt.expr;
Expr *to = case_ast->case_stmt.to_expr;
assert(type_is_integer(from->type) && from->expr_kind == EXPR_CONST);
Int value = from->const_expr.ixx;
Int to_value = to ? to->const_expr.ixx : value;
if (min.type == TYPE_VOID)
{
min = value;
max = to_value;
}
else if (int_comp(value, min, BINARYOP_LT))
{
min = value;
}
else if (int_comp(to_value, max, BINARYOP_GT))
{
max = to_value;
}
}
switch_value->value = LLVMBuildSub(c->builder, switch_value->value, llvm_const_int(c, switch_value->type, min.i.low), "");
max = int_sub(max, min);
Type *create_array = type_get_array(type_voidptr, max.i.low);
LLVMTypeRef llvm_array_type = llvm_get_type(c, create_array);
AlignSize alignment = type_alloca_alignment(switch_value->type);
LLVMValueRef array_ref = llvm_emit_alloca(c, llvm_array_type, alignment, "");
BEValue array_value;
llvm_value_set_address(&array_value, array_ref, create_array);
for (int i = 0; i < max.i.low; i++)
{
AlignSize align;
LLVMValueRef ptr = llvm_emit_array_gep_raw(c, array_ref, llvm_array_type, i, alignment, &align);
}
for (unsigned i = 0; i < case_count; i++)
{
Ast *case_stmt = cases[i];
LLVMBasicBlockRef block = case_stmt->case_stmt.backend_block;
if (case_stmt != default_case)
{
LLVMValueRef case_value;
BEValue be_value;
llvm_emit_expr(c, &be_value, case_stmt->case_stmt.expr);
llvm_value_rvalue(c, &be_value);
case_value = be_value.value;
}
// Skip fallthroughs.
if (!case_stmt->case_stmt.body) continue;
llvm_emit_block(c, block);
// IMPORTANT!
c->current_block_is_target = true;
llvm_emit_stmt(c, case_stmt->case_stmt.body);
llvm_emit_br(c, exit_block);
}
llvm_emit_block(c, exit_block);
#endif
}
static void llvm_emit_switch_body(GenContext *c, BEValue *switch_value, Ast *switch_ast)
{
bool is_if_chain = switch_ast->switch_stmt.flow.if_chain;
Type *switch_type = switch_ast->ast_kind == AST_IF_CATCH_SWITCH_STMT ? type_lowering(type_anyerr) : exprptr(switch_ast->switch_stmt.cond)->type;
Ast **cases = switch_ast->switch_stmt.cases;
ArraySize case_count = vec_size(cases);
if (!case_count)
{
// No body or default is empty, just exit after the value.
return;
}
Ast *default_case = NULL;
for (unsigned i = 0; i < case_count; i++)
{
Ast *case_stmt = cases[i];
if (!case_stmt->case_stmt.expr)
{
if (case_stmt->case_stmt.body)
{
case_stmt->case_stmt.backend_block = llvm_basic_block_new(c, "switch.default");
}
default_case = case_stmt;
}
else if (case_stmt->case_stmt.body)
{
case_stmt->case_stmt.backend_block = llvm_basic_block_new(c, "switch.case");
}
}
LLVMBasicBlockRef exit_block = llvm_basic_block_new(c, "switch.exit");
LLVMBasicBlockRef switch_block = llvm_basic_block_new(c, "switch.entry");
switch_ast->switch_stmt.codegen.retry_block = switch_block;
switch_ast->switch_stmt.codegen.exit_block = exit_block;
// We will now treat the fallthrough cases:
// switch (i)
// {
// case 1:
// case 2:
// do_something();
// default:
// }
LLVMBasicBlockRef next_block = exit_block;
for (unsigned i = case_count; i > 0; i--)
{
Ast *case_stmt = cases[i - 1];
if (case_stmt->case_stmt.backend_block)
{
next_block = case_stmt->case_stmt.backend_block;
continue;
}
case_stmt->case_stmt.backend_block = next_block;
}
BEValue switch_var;
llvm_value_set_address_abi_aligned(&switch_var, llvm_emit_alloca_aligned(c, switch_type, "switch"), switch_type);
switch_ast->switch_stmt.codegen.retry_var = &switch_var;
llvm_store(c, &switch_var, switch_value);
llvm_emit_br(c, switch_block);
llvm_emit_block(c, switch_block);
BEValue switch_current_val = switch_var;
llvm_value_rvalue(c, &switch_current_val);
if (is_if_chain)
{
llvm_emit_switch_body_if_chain(c, cases, default_case, &switch_current_val, exit_block);
return;
}
c->current_block = NULL;
LLVMValueRef switch_stmt = LLVMBuildSwitch(c->builder, switch_current_val.value, default_case ? default_case->case_stmt.backend_block : exit_block, case_count);
for (unsigned i = 0; i < case_count; i++)
{
Ast *case_stmt = cases[i];
LLVMBasicBlockRef block = case_stmt->case_stmt.backend_block;
if (case_stmt != default_case)
{
LLVMValueRef case_value;
BEValue be_value;
Expr *from = case_stmt->case_stmt.expr;
assert(from->expr_kind == EXPR_CONST);
llvm_emit_expr(c, &be_value, case_stmt->case_stmt.expr);
llvm_value_rvalue(c, &be_value);
case_value = be_value.value;
LLVMAddCase(switch_stmt, case_value, block);
Expr *to_expr =case_stmt->case_stmt.to_expr;
if (to_expr)
{
BEValue to_value;
llvm_emit_expr(c, &to_value, to_expr);
llvm_value_rvalue(c, &to_value);
LLVMValueRef to = to_value.value;
assert(LLVMIsAConstant(to));
LLVMValueRef one = llvm_const_int(c, to_value.type, 1);
while (LLVMConstIntGetZExtValue(LLVMBuildICmp(c->builder, LLVMIntEQ, to, case_value, "")) != 1)
{
case_value = LLVMBuildAdd(c->builder, case_value, one, "");
LLVMAddCase(switch_stmt, case_value, block);
}
}
}
// Skip fallthroughs.
if (!case_stmt->case_stmt.body) continue;
llvm_emit_block(c, block);
// IMPORTANT!
c->current_block_is_target = true;
llvm_emit_stmt(c, case_stmt->case_stmt.body);
llvm_emit_br(c, exit_block);
}
llvm_emit_block(c, exit_block);
}
void gencontext_emit_switch(GenContext *context, Ast *ast)
{
BEValue switch_value;
llvm_emit_decl_expr_list(context, &switch_value, exprptr(ast->switch_stmt.cond), false);
llvm_emit_switch_body(context, &switch_value, ast);
}
void llvm_emit_break(GenContext *c, Ast *ast)
{
llvm_emit_statement_chain(c, ast->contbreak_stmt.defers);
Ast *jump_target = astptr(ast->contbreak_stmt.ast);
LLVMBasicBlockRef jump;
switch (jump_target->ast_kind)
{
case AST_IF_STMT:
jump = jump_target->if_stmt.codegen.break_block;
break;
case AST_FOR_STMT:
jump = jump_target->for_stmt.codegen.exit_block;
break;
case AST_IF_CATCH_SWITCH_STMT:
case AST_SWITCH_STMT:
jump = jump_target->switch_stmt.codegen.exit_block;
break;
case AST_FOREACH_STMT:
default:
UNREACHABLE
}
llvm_emit_jmp(c, jump);
}
void llvm_emit_continue(GenContext *c, Ast *ast)
{
llvm_emit_statement_chain(c, ast->contbreak_stmt.defers);
Ast *jump_target = astptr(ast->contbreak_stmt.ast);
LLVMBasicBlockRef jump;
switch (jump_target->ast_kind)
{
case AST_IF_STMT:
case AST_SWITCH_STMT:
case AST_FOREACH_STMT:
UNREACHABLE
break;
case AST_FOR_STMT:
jump = jump_target->for_stmt.codegen.continue_block;
break;
default:
UNREACHABLE
}
llvm_emit_jmp(c, jump);
}
void gencontext_emit_next_stmt(GenContext *context, Ast *ast)
{
Ast *jump_target = astptr(ast->nextcase_stmt.case_switch_stmt);
if (jump_target->ast_kind != AST_SWITCH_STMT)
{
llvm_emit_statement_chain(context, ast->nextcase_stmt.defer_id);
llvm_emit_jmp(context, jump_target->case_stmt.backend_block);
return;
}
BEValue be_value;
llvm_emit_expr(context, &be_value, ast->nextcase_stmt.switch_expr);
llvm_store(context, jump_target->switch_stmt.codegen.retry_var, &be_value);
llvm_emit_statement_chain(context, ast->nextcase_stmt.defer_id);
llvm_emit_jmp(context, jump_target->switch_stmt.codegen.retry_block);
}
static inline void llvm_emit_assume(GenContext *c, Expr *expr)
{
// 1. Convert x > 0 && y > 2 => llvm.assume(x > 0) + llvm.assume(y > 2)
if (expr->expr_kind == EXPR_BINARY && expr->binary_expr.operator == BINARYOP_AND)
{
llvm_emit_assume(c, exprptr(expr->binary_expr.left));
llvm_emit_assume(c, exprptr(expr->binary_expr.right));
return;
}
// 2. Convert !(x > 0 || y > 2) => llvm.assume(!(x > 0)) + llvm.assume(!(y > 2))
if (expr->expr_kind == EXPR_UNARY && expr->unary_expr.operator == UNARYOP_NOT)
{
Expr *inner = expr->unary_expr.expr;
if (inner->expr_kind == EXPR_BINARY && inner->binary_expr.operator == BINARYOP_OR)
{
Expr *left = exprptr(inner->binary_expr.left);
Expr *right = exprptr(inner->binary_expr.right);
expr->unary_expr.expr = left;
llvm_emit_assume(c, expr);
expr->unary_expr.expr = right;
llvm_emit_assume(c, expr);
return;
}
}
// 3. Check if pure, if so we emit the assume.
if (expr_is_pure(expr))
{
BEValue value;
llvm_emit_expr(c, &value, expr);
llvm_value_rvalue(c, &value);
assert(value.kind == BE_BOOLEAN);
EMIT_LOC(c, expr);
llvm_emit_call_intrinsic(c, intrinsic_id.assume, NULL, 0, &(value.value), 1);
}
}
static inline void llvm_emit_assert_stmt(GenContext *c, Ast *ast)
{
ExprId exprid = ast->assert_stmt.expr;
Expr *assert_expr = exprptr(exprid);
if (active_target.feature.safe_mode)
{
BEValue value;
llvm_emit_expr(c, &value, assert_expr);
llvm_value_rvalue(c, &value);
LLVMBasicBlockRef on_fail = llvm_basic_block_new(c, "assert_fail");
LLVMBasicBlockRef on_ok = llvm_basic_block_new(c, "assert_ok");
assert(value.kind == BE_BOOLEAN);
llvm_emit_cond_br(c, &value, on_ok, on_fail);
llvm_emit_block(c, on_fail);
SourceSpan loc = assert_expr->span;
const char *error;
if (ast->assert_stmt.message)
{
error = exprptr(ast->assert_stmt.message)->const_expr.string.chars;
}
else
{
error = "Assert violation";
}
File *file = source_file_by_id(loc.file_id);
llvm_emit_panic(c, error, file->name, c->cur_func.name, loc.row ? loc.row : 1);
llvm_emit_br(c, on_ok);
llvm_emit_block(c, on_ok);
}
llvm_emit_assume(c, exprptr(ast->assert_stmt.expr));
}
static inline void add_target_clobbers_to_buffer(GenContext *c)
{
switch (platform_target.arch)
{
case ARCH_TYPE_X86_64:
case ARCH_TYPE_X86:
scratch_buffer_append("~{dirflag},~{fpsr},~{flags}");
break;
case ARCH_TYPE_MIPS:
case ARCH_TYPE_MIPS64:
case ARCH_TYPE_MIPS64EL:
case ARCH_TYPE_MIPSEL:
// Currently Clang does this
scratch_buffer_append("~{$1}");
break;
default:
// In Clang no other platform has automatic clobbers
break;
}
}
static void codegen_append_constraints(ClobberList *clobber_list, const char *str)
{
char *string = clobber_list->string;
unsigned len = clobber_list->constraint_len;
while (*str)
{
if (len > 1022) error_exit("Constraint list exceeded max length.");
string[len++] = *(str++);
}
clobber_list->constraint_len = len;
}
static void codegen_new_constraint(ClobberList *clobber_list)
{
if (clobber_list->constraint_len) codegen_append_constraints(clobber_list, ",");
}
static inline void llvm_emit_asm_block_stmt(GenContext *c, Ast *ast)
{
const char *data;
scratch_buffer_clear();
add_target_clobbers_to_buffer(c);
char *clobbers = scratch_buffer_copy();
ClobberList clobber_list = { .constraint_len = 0 };
LLVMTypeRef param_types[512];
LLVMTypeRef pointer_type[512];
LLVMValueRef args[512];
LLVMTypeRef result_types[512];
Decl *result_decls[512];
unsigned result_count = 0;
unsigned param_count = 0;
AsmInlineBlock *block = ast->asm_block_stmt.block;
if (ast->asm_block_stmt.is_string)
{
data = exprptr(ast->asm_block_stmt.asm_string)->const_expr.string.chars;
}
else
{
data = codegen_create_asm(ast);
clobbers = clobber_list.string;
FOREACH_BEGIN(ExprAsmArg * var, block->output_vars)
codegen_new_constraint(&clobber_list);
if (var->kind == ASM_ARG_MEMVAR)
{
if (var->ident.early_clobber)
{
codegen_append_constraints(&clobber_list, "=*&m");
}
else
{
codegen_append_constraints(&clobber_list, "=*m");
}
BEValue value;
llvm_value_set_decl(c, &value, var->ident.ident_decl);
llvm_value_addr(c, &value);
value.kind = BE_VALUE;
pointer_type[param_count] = llvm_get_type(c, value.type);
value.type = type_get_ptr(value.type);
llvm_value_rvalue(c, &value);
param_types[param_count] = LLVMTypeOf(value.value);
args[param_count++] = value.value;
continue;
}
assert(var->kind == ASM_ARG_REGVAR);
if (var->ident.early_clobber)
{
codegen_append_constraints(&clobber_list, "=&r");
}
else
{
codegen_append_constraints(&clobber_list, "=r");
}
Decl *decl = result_decls[result_count] = var->ident.ident_decl;
result_types[result_count++] = llvm_get_type(c, decl->type);
FOREACH_END();
FOREACH_BEGIN(ExprAsmArg * val, block->input)
BEValue value;
codegen_new_constraint(&clobber_list);
pointer_type[param_count] = NULL;
switch (val->kind)
{
case ASM_ARG_MEMVAR:
llvm_value_set_decl(c, &value, val->ident.ident_decl);
llvm_value_addr(c, &value);
value.kind = BE_VALUE;
pointer_type[param_count] = llvm_get_type(c, value.type);
value.type = type_get_ptr(value.type);
assert(!val->ident.copy_output);
codegen_append_constraints(&clobber_list, "*m");
break;
case ASM_ARG_REGVAR:
llvm_value_set_decl(c, &value, val->ident.ident_decl);
if (val->ident.copy_output)
{
char buf[10];
sprintf(buf, "%d", val->index);
codegen_append_constraints(&clobber_list, buf);
}
else
{
codegen_append_constraints(&clobber_list, "r");
}
break;
case ASM_ARG_VALUE:
llvm_emit_exprid(c, &value, val->expr_id);
codegen_append_constraints(&clobber_list, "r");
break;
default:
TODO
}
llvm_value_rvalue(c, &value);
param_types[param_count] = LLVMTypeOf(value.value);
args[param_count++] = value.value;
FOREACH_END();
for (int i = 0; i < CLOBBER_FLAG_ELEMENTS; i++)
{
uint64_t clobber_mask = block->clobbers.mask[i];
if (!clobber_mask) continue;
uint64_t mask = 1;
for (int j = 0; j < 64; j++)
{
if (mask & clobber_mask)
{
unsigned clobber_index = i * 64 + j;
codegen_new_constraint(&clobber_list);
codegen_append_constraints(&clobber_list, "~{");
codegen_append_constraints(&clobber_list, asm_clobber_by_index(clobber_index));
codegen_append_constraints(&clobber_list, "}");
}
mask <<= 1;
}
}
if (asm_target.extra_clobbers)
{
codegen_new_constraint(&clobber_list);
codegen_append_constraints(&clobber_list, asm_target.extra_clobbers);
}
}
DEBUG_LOG("Asm: %s (%s)", data, clobbers);
LLVMTypeRef result_type;
if (result_count)
{
result_type = result_count == 1 ? result_types[0] : LLVMStructTypeInContext(c->context, result_types, result_count, false);
}
else
{
result_type = llvm_get_type(c, type_void);
}
LLVMTypeRef asm_fn_type = LLVMFunctionType(result_type, param_types, param_count, 0);
LLVMValueRef asm_fn = LLVMGetInlineAsm(asm_fn_type,
(char*)data,
strlen(data),
clobbers,
strlen(clobbers),
ast->asm_block_stmt.is_volatile,
true,
ast->asm_block_stmt.is_string ? LLVMInlineAsmDialectIntel : LLVMInlineAsmDialectATT,
/* can throw */ false
);
LLVMValueRef res = LLVMBuildCall2(c->builder, asm_fn_type, asm_fn, args, param_count, "");
#if LLVM_VERSION_MAJOR > 13
for (unsigned i = 0; i < param_count; i++)
{
if (pointer_type[i])
{
llvm_attribute_add_call_type(c, res, attribute_id.elementtype, i + 1, pointer_type[i]);
}
}
#else
(void)pointer_type;
#endif
if (!result_count) return;
if (result_count == 1)
{
Decl *decl = block->output_vars[0]->ident.ident_decl;
llvm_store_decl_raw(c, decl, res);
return;
}
for (unsigned i = 0; i < result_count; i++)
{
Decl *decl = result_decls[i];
LLVMValueRef res_val = LLVMBuildExtractValue(c->builder, res, i, "");
llvm_store_decl_raw(c, decl, res_val);
}
}
void gencontext_emit_expr_stmt(GenContext *c, Ast *ast)
{
BEValue value;
if (IS_OPTIONAL(ast->expr_stmt))
{
PUSH_OPT();
LLVMBasicBlockRef discard_fail = llvm_basic_block_new(c, "voiderr");
c->catch_block = discard_fail;
c->opt_var = NULL;
llvm_emit_expr(c, &value, ast->expr_stmt);
llvm_value_fold_optional(c, &value);
EMIT_LOC(c, ast);
llvm_emit_br(c, discard_fail);
llvm_emit_block(c, discard_fail);
POP_OPT();
return;
}
llvm_emit_expr(c, &value, ast->expr_stmt);
}
LLVMValueRef llvm_emit_zstring(GenContext *c, const char *str)
{
return llvm_emit_zstring_named(c, str, ".zstr");
}
LLVMValueRef llvm_emit_zstring_named(GenContext *c, const char *str, const char *extname)
{
LLVMTypeRef char_type = llvm_get_type(c, type_char);
unsigned len = (unsigned)strlen(str);
LLVMTypeRef char_array_type = LLVMArrayType(char_type, len + 1);
LLVMValueRef global_string = llvm_add_global_raw(c, extname, char_array_type, 0);
llvm_set_internal_linkage(global_string);
LLVMSetGlobalConstant(global_string, 1);
LLVMSetInitializer(global_string, llvm_get_zstring(c, str, len));
AlignSize alignment;
LLVMValueRef string = llvm_emit_array_gep_raw(c, global_string, char_array_type, 0, 1, &alignment);
return llvm_emit_bitcast_ptr(c, string, type_char);
}
void llvm_emit_panic(GenContext *c, const char *message, const char *file, const char *func, unsigned line)
{
if (c->debug.stack_slot_row)
{
llvm_store_to_ptr_raw_aligned(c,
c->debug.stack_slot_row,
llvm_const_int(c, type_uint, line),
type_abi_alignment(type_uint));
}
Decl *panicfn = c->panicfn;
if (!panicfn)
{
llvm_emit_call_intrinsic(c, intrinsic_id.trap, NULL, 0, NULL, 0);
return;
}
LLVMValueRef args[4] = {
llvm_emit_zstring(c, message),
llvm_emit_zstring(c, file),
func ? llvm_emit_zstring(c, func) : llvm_get_zero(c, type_get_ptr(type_char)),
llvm_const_int(c, type_uint, line)
};
LLVMBuildCall2(c->builder, llvm_get_type(c, panicfn->type), llvm_get_ref(c, panicfn), args, 4, "");
}
void llvm_emit_panic_if_true(GenContext *c, BEValue *value, const char *panic_name, SourceSpan loc)
{
if (llvm_is_const(value->value))
{
assert(!LLVMConstIntGetZExtValue(value->value) && "Unexpected bounds check failed.");
return;
}
LLVMBasicBlockRef panic_block = llvm_basic_block_new(c, "panic");
LLVMBasicBlockRef ok_block = llvm_basic_block_new(c, "checkok");
assert(llvm_value_is_bool(value));
llvm_emit_cond_br(c, value, panic_block, ok_block);
llvm_emit_block(c, panic_block);
File *file = source_file_by_id(loc.file_id);
llvm_emit_panic(c, panic_name, file->name, c->cur_func.name, loc.row);
llvm_emit_br(c, ok_block);
llvm_emit_block(c, ok_block);
}
void llvm_emit_panic_on_true(GenContext *c, LLVMValueRef value, const char *panic_name, SourceSpan loc)
{
File *file = source_file_by_id(loc.file_id);
LLVMBasicBlockRef panic_block = llvm_basic_block_new(c, "panic");
LLVMBasicBlockRef ok_block = llvm_basic_block_new(c, "checkok");
BEValue be_value;
llvm_value_set_bool(&be_value, value);
llvm_emit_cond_br(c, &be_value, panic_block, ok_block);
llvm_emit_block(c, panic_block);
llvm_emit_panic(c, panic_name, file->name, c->cur_func.name, loc.row ? loc.row : 1);
llvm_emit_br(c, ok_block);
llvm_emit_block(c, ok_block);
}
void llvm_emit_stmt(GenContext *c, Ast *ast)
{
EMIT_LOC(c, ast);
assert(!c->catch_block && "Did not expect a catch block here.");
switch (ast->ast_kind)
{
case AST_POISONED:
case AST_IF_CATCH_SWITCH_STMT:
case AST_FOREACH_STMT:
case AST_DOC_STMT:
case AST_ASM_STMT:
UNREACHABLE
case AST_EXPR_STMT:
gencontext_emit_expr_stmt(c, ast);
break;
case AST_DECLARE_STMT:
{
BEValue value;
llvm_emit_local_decl(c, ast->declare_stmt, &value);
break;
}
case AST_BREAK_STMT:
llvm_emit_break(c, ast);
break;
case AST_CONTINUE_STMT:
llvm_emit_continue(c, ast);
break;
case AST_IF_STMT:
llvm_emit_if(c, ast);
break;
case AST_RETURN_STMT:
llvm_emit_return(c, ast);
break;
case AST_BLOCK_EXIT_STMT:
llvm_emit_block_exit_return(c, ast);
break;
case AST_COMPOUND_STMT:
llvm_emit_compound_stmt(c, ast);
break;
case AST_FOR_STMT:
llvm_emit_for_stmt(c, ast);
break;
case AST_NEXT_STMT:
gencontext_emit_next_stmt(c, ast);
break;
case AST_DEFER_STMT:
case AST_NOP_STMT:
break;
case AST_ASM_BLOCK_STMT:
llvm_emit_asm_block_stmt(c, ast);
break;
case AST_ASSERT_STMT:
llvm_emit_assert_stmt(c, ast);
break;
case AST_CT_ASSERT:
case AST_CT_IF_STMT:
case AST_CT_ELSE_STMT:
case AST_CT_FOR_STMT:
case AST_CT_SWITCH_STMT:
case AST_CASE_STMT:
case AST_DEFAULT_STMT:
case AST_CT_FOREACH_STMT:
UNREACHABLE
case AST_SWITCH_STMT:
gencontext_emit_switch(c, ast);
break;
}
}
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