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Re^2: C parsing questions

by Nkuvu (Priest)
on Nov 29, 2005 at 00:22 UTC ( [id://512444]=note: print w/replies, xml ) Need Help??


in reply to Re: C parsing questions
in thread C parsing questions

I really like this approach, thanks for suggesting it. I've had to go in and modify some Python scripts to match changes in the source code, and it's usually quite a pain to find out where things are being set/called/parsed/whatever. Anything I can do to make it easier will definitely be appreciated by non-Perl programmers.

Of course since it's Monday (that's my excuse and I'm sticking to it) I still feel like I'm writing very messy code. Any suggestions on the added sub would be appreciated.

Also note that the header files are auto-generated by a tool we're using, so the format of the struct definitions is always the same. And my subroutine takes this into account -- it fails horribly with comments in the code, but works just fine for the "live" code.

use strict; use warnings; use Data::Dumper; my %default_values = ( 'float' => 0, 'int' => 3, # Unique value for visibility durin +g testing 'bool' => 'false' ); my %structs; parse_struct_definitions(); print Dumper(%structs); sub parse_struct_definitions { # Reads the typedef struct lines in the __DATA__ section to popula +te the # %structs hash. Created for simple updates to the defined struct +ures # (simply copy and paste from the header files into the DATA secti +on # below) local $/ = 'typedef struct {'; while (my $line = <DATA>) { chomp $line; next if $line !~ /\w/; # For me to parse out the data more easily: $line =~ s/\n/ /g; $line =~ s/\s+/ /g; # Break the line into members and the struct name my ($member_string, $name) = $line =~ /([^\}]+)\s*\}\s*(.+)/; my @members = split ';', $member_string; $name =~ tr/; //d; foreach my $member (@members) { next if $member !~ /\w/; my ($type, $member_name) = split " ", $member; push @{$structs{$name}}, [ $type, $member_name, $default_v +alues{$type} ]; } } } # end of parse_struct_definitions __DATA__ typedef struct { float one; float two; int three; bool potato; } struct_name; typedef struct { float one; /* 0.0 */ float two; /* 0.0 */ int three; /* 0 */ bool potato; /* false */ } struct_name_with_comments;

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Re^3: C parsing questions
by GrandFather (Saint) on Nov 29, 2005 at 00:38 UTC

    If you change your data to:

    typedef struct { float one; float two; int three; bool potato; } struct_name; typedef struct { float one; /* 1.1 */ float two; /* 2.2 */ int three; /* 3 */ bool potato; /* true */ } struct_name_with_comments;

    You get the following (wrapped to compress):

    $VAR1 = 'struct_name_with_comments'; $VAR2 = [ ['float', 'one', 0], ['/*', '1.1', undef], ['/*', '2.2', undef], ['/*', '3', undef], ['/*', 'true', undef] ]; $VAR3 = 'struct_name'; $VAR4 = [ ['float','one',0], ['float', 'two', 0], ['int', 'three', 3], ['bool', 'potato', 'false'] ];

    There appear to be bugs :).

    Given you are $line =~ s/\n/ /g; and $line =~ s/\s+/ /g; you could just $line =~ s/[\n\s]+/ /g;.

    <>.The use of $/ is nice. Good to see someone remembering it's there.


    DWIM is Perl's answer to Gödel
      There appear to be bugs :).
      Um, yeah, I mentioned as much. Last (non-code) paragraph from my previous post:
      ...the format of the struct definitions is always the same. And my subroutine takes this into account -- it fails horribly with comments in the code, but works just fine for the "live" code.

      I originally had only one of the s/// operations, then was playing around with another -- now that you point out the combination of the two it's very obvious. Doh.

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