1#!/usr/bin/env awk
2
3
4function shift( array, \
5                junk, elm0, l )
6{
7  elm0 = array[0]
8  for ( l = 0; l < asorti( array, junk ) - 1; l++ )
9    array[l] = array[l+1];
10  delete array[l]
11  return elm0
12}
13
14
15function init_cpp_src_line()
16{
17  logical_line = ""
18  delete break_pos
19}
20
21
22function shift_valid_bp( array, \
23                         junk, elm )
24{
25  elm = -1
26
27  if ( 0 < asorti( array, junk ) )
28    do {
29      elm = shift( array )
30    } while ( 0 > elm );
31
32  return elm
33}
34
35
36function check_cpp_src_line_break_pos( \
37                                       i, junk )
38{
39  printf( "break_pos:" )
40  for ( i = 0; i < asorti( break_pos, junk ); i++ )
41    printf( " %d", break_pos[i] );
42  printf( "\n" )
43}
44
45
46function check_cpp_src_line()
47{
48  printf( "logical_line[%s]\n", logical_line )
49  check_cpp_src_line_break_pos()
50}
51
52
53function append_line( phys_line, \
54                      filt_line, bp_len )
55{
56  filt_line = phys_line
57  sub( /\\$/, " ", filt_line )
58  logical_line    = logical_line filt_line
59  bp_len = asorti( break_pos, junk )
60  break_pos[bp_len] = length( logical_line ) - 1
61}
62
63
64function print_line( \
65                     c0, c1, i, junk, part_str )
66{
67  c0 = 0
68
69  while( asorti( break_pos, junk ) > 1 )
70  {
71    if ( ( c1 = shift_valid_bp( break_pos ) ) < 1 )
72    {
73      part_str = substr( logical_line, c0 + 1 )
74      printf( "%s\n", part_str )
75      return
76    }
77
78    part_str = substr( logical_line, c0 + 1, c1 - c0 + 1 )
79    gsub( / $/, "\\", part_str )
80    printf( "%s\n", part_str )
81    c0 = c1 + 1
82  }
83
84  part_str = substr( logical_line, c0 + 1 )
85  printf( "%s\n", part_str )
86}
87
88
89function shrink_spaces( pos, \
90                        tail, removed_length, k )
91{
92  tail = substr( logical_line, pos )
93  sub( /^[ \t]+/, " ", tail )
94  removed_length = length( logical_line ) - pos - length( tail ) + 1
95  logical_line = substr( logical_line, 0, pos - 1 ) tail
96
97
98  for ( k = 0; k < asorti( break_pos, junk ); k++ )
99    if ( ( pos + removed_length ) <= break_pos[k] )
100      break_pos[k] = break_pos[k] - removed_length;
101    else if ( pos <= break_pos[k] )
102      break_pos[k] = -1;
103
104  return removed_length
105}
106
107
108function shrink_spaces_to_linebreak( pos, \
109                                     junk, part_str, removed_length, i )
110{
111  for ( i = 0; i < asorti( break_pos, junk ) && break_pos[i] < pos ; i++ )
112    ;
113
114  if ( break_pos[i] < 1 )
115    return;
116
117  part_str = substr( logical_line, pos, break_pos[i] - pos + 1 )
118  sub( /^[ \t]+/, " ", part_str )
119  removed_length = ( break_pos[i] - pos + 1 ) - length( part_str )
120
121  tail = substr( logical_line, pos + removed_length )
122  logical_line = substr( logical_line, 0, pos - 1 ) tail
123
124  for ( ; i < asorti( break_pos, junk ); i++ )
125    break_pos[i] -= removed_length;
126
127  return removed_length
128}
129
130
131function delete_linebreaks_in_2nd_token( \
132                                           tail, paren_depth, junk, i, j, k, l )
133{
134  if ( logical_line ~ /^[ \t]*#[ \t]*define[ \t]+[0-9A-Za-z_]+\(/ )
135  {
136    tail = logical_line
137    sub( /^[ \t]*#[ \t]*define[ \t]+[0-9A-Za-z_]+/, "", tail )
138
139    paren_depth = 0
140    l = 0
141    i = length( logical_line ) - length( tail ) + 1 # seek to the 1st op paren
142    j = i
143    do {
144      if ( substr( logical_line, j, 2 ) ~ /[ \t][ \t]/ )
145        l = shrink_spaces( j );
146      else if ( substr( logical_line, j, 1 ) == "(" )
147        paren_depth += 1;
148      else if ( substr( logical_line, j, 1 ) == ")" )
149        paren_depth -= 1;
150      j += 1
151    } while ( j < length( logical_line ) && paren_depth != 0 )
152
153    for ( k = 0; k < asorti( break_pos, junk ); k++ )
154      if ( i <= break_pos[k] && break_pos[k] < j )
155        break_pos[k] = -1;
156
157    if ( l > 0 )
158      shrink_spaces_to_linebreak( j );
159  }
160}
161
162
163BEGIN{
164  init_cpp_src_line()
165}
166{
167  append_line( $0 )
168  if ( $0 !~ /\\$/ )
169  {
170    delete_linebreaks_in_2nd_token()
171    print_line()
172    init_cpp_src_line()
173  }
174}
175END{
176  if ( 0 < length( logical_line ) )
177  {
178    delete_linebreaks_in_2nd_token()
179    print_line()
180  }
181}
182