Method primPostLoop

cmd/ll2go/primitive.go:299–333

primPostLoop merges the basic blocks of the given post_loop-primitive into a corresponding conceputal basic block for the primitive.

(condBlock, exitBlock *basicBlock)

// primPostLoop merges the basic blocks of the given post_loop-primitive into a
// corresponding conceputal basic block for the primitive.
func (d *decompiler) primPostLoop(condBlock, exitBlock *basicBlock) (*basicBlock, error) {
	// Handle terminators.
	condTerm, ok := condBlock.Term.(*ir.TermCondBr)
	if !ok {
		return nil, errors.Errorf("invalid cond terminator type; expected *ir.TermCondBr, got %T", condBlock.Term)
	}
	cond := d.value(condTerm.Cond)
	cond = &ast.UnaryExpr{
		Op: token.NOT,
		X:  cond,
	}
	// TODO: Figure out a clean way to check if the exit basic block is the true
	// branch or the false branch. If exit is the true branch, negate the
	// condition.
	block := &basicBlock{BasicBlock: &ir.BasicBlock{}}
	block.Term = exitBlock.Term
	// Handle instructions.
	body := &ast.BlockStmt{
		List: d.stmts(condBlock),
	}
	breakStmt := &ast.BranchStmt{Tok: token.BREAK}
	ifBreakStmt := &ast.IfStmt{
		Cond: cond,
		Body: &ast.BlockStmt{
			List: []ast.Stmt{breakStmt},
		},
	}
	body.List = append(body.List, ifBreakStmt)
	forStmt := &ast.ForStmt{
		Body: body,
	}
	block.stmts = append(block.stmts, forStmt)
	block.stmts = append(block.stmts, d.stmts(exitBlock)...)
	return block, nil
}

// primSeq merges the basic blocks of the given seq-primitive into a
// corresponding conceputal basic block for the primitive.