I wanna know what type of parser is used in the gcc and turbo c++ compilers. whether a top-down or bottom-up parser is used..... ?
stevanity 4 Posting Whiz in Training
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Jump to Postparsers start at the top of the program (line 1) and work themselves down. The bottom up approach would be a little like you trying to read a book backwards.
Jump to PostI wanna know what type of parser is used in the gcc and turbo c++ compilers. whether a top-down or bottom-up parser is used..... ?
GCC uses a hand written recursive descent parser (ie. it's top-down). I wouldn't be surprised if Turbo C++ worked the same way, though it might …
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Ancient Dragon 5,243 Achieved Level 70 Team Colleague Featured Poster
parsers start at the top of the program (line 1) and work themselves down. The bottom up approach would be a little like you trying to read a book backwards.
stevanity 4 Posting Whiz in Training
Sorry...Top-down and bottom up parsing is not about the line where parsing starts..
Narue 5,707 Bad Cop Team Colleague
I wanna know what type of parser is used in the gcc and turbo c++ compilers. whether a top-down or bottom-up parser is used..... ?
GCC uses a hand written recursive descent parser (ie. it's top-down). I wouldn't be surprised if Turbo C++ worked the same way, though it might use one of the parser generators rather than a hand written approach.
mike_2000_17 2,669 21st Century Viking Team Colleague Featured Poster
With compilers in general, we often talk about the front-end and the back-end. The front-end is the program that parses the source code, verifies all the grammar and syntax rules, and basically produces a translation of it in some intermediate language (not human-readable but readable for the back-end). The back-end takes the intermediate source code and performs most of the optimizations and then compiles to native machine code. So, the back-end is usually common to an entire compiler suite (like GCC, ICC, Clang, etc.), and then there is one specific front-end for each programming language supported by the compiler suite.
Examples:
- Borland's Delphi and C++Builder compilers share the same back-end (meaning you can also link C++ object files ".obj" with Delphi compiled units ".dcu" together).
- All GCC compilers (C, C++, Objective-C, Ada, Fortran, Java, etc.) share the same back-end, but with different front-ends.
A prominent back-end is LLVM which is used by the Clang front-ends and other compilers.
Prominent front-ends are those of EDG, which are used by Intel and Comeau.
Whatever front-end, parsing the C++ language is not an easy task, because its grammar is complex and context-dependent. Recursive descent parsers are used with plenty of modifications to really get reliable and accurate parsing. There are also tools for generating parsers, including YACC and Boost.Spirit.
stevanity 4 Posting Whiz in Training
GCC uses a hand written recursive descent parser (ie. it's top-down). I wouldn't be surprised if Turbo C++ worked the same way, though it might use one of the parser generators rather than a hand written approach.
Thanks a lot!! That was very helpful... :)
And thanks to everyone who replied :)
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