We use cookies to distinguish you from other users and to provide you with a better experience on our websites. Close this message to accept cookies or find out how to manage your cookie settings.
We use cookies to distinguish you from other users and to provide you with a better experience on our websites. Close this message to accept cookies or find out how to manage your cookie settings.
Published online by Cambridge University Press: 05 June 2012
de-bug: to eliminate errors in or malfunctions of
Webster's DictionaryChapters 2–11 have described the fundamental components of a good compiler: a front end, which does lexical analysis, parsing, construction of abstract syntax, type-checking, and translation to intermediate code; and a back end, which does instruction selection, dataflow analysis, and register allocation.
What lessons have we learned? I hope that the reader has learned about the algorithms used in different components of a compiler and the interfaces used to connect the components. But the author has also learned quite a bit from the exercise.
My goal was to describe a good compiler that is, to use Einstein's phrase, “as simple as possible – but no simpler.” I will now discuss the thorny issues that arose in designing Tiger and its compiler.
Nested functions. Tiger has nested functions, requiring somemechanism (such as static links) for implementing access to nonlocal variables. But many programming languages in widespread use -C, C++, Java – do not have nested functions or static links. The Tiger compiler would become simpler without nested functions, for then variables would not escape, and the FindEscape phase would be unnecessary. But there are two reasons for explaining how to compile nonlocal variables. First, there are programming languages where nested functions are extremely useful – these are the functional languages described in Chapter 15. And second, escaping variables and the mechanisms necessary to handle them are also found in languages where addresses can be taken (such as C) or with call-by-reference (such as C++).
To save this book to your Kindle, first ensure [email protected] is added to your Approved Personal Document E-mail List under your Personal Document Settings on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part of your Kindle email address below. Find out more about saving to your Kindle.
Note you can select to save to either the @free.kindle.com or @kindle.com variations. ‘@free.kindle.com’ emails are free but can only be saved to your device when it is connected to wi-fi. ‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.
Find out more about the Kindle Personal Document Service.
To save content items to your account, please confirm that you agree to abide by our usage policies. If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account. Find out more about saving content to Dropbox.
To save content items to your account, please confirm that you agree to abide by our usage policies. If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account. Find out more about saving content to Google Drive.
