127 .Sh SHADOW COMPILATION
 128 If
 129 .Fl -shadow
 130 compilers are specified
 131 .Nm cw
 132 will invoke shadow compiler, with the outputs modified (as well as any
 133 translation for compiler style) as follows:
 134 .Bl -enum
 135 .It
 136 If none of
 137 .Fl c ,
 138 .Fl E ,
 139 .Fl P ,
 140 or
 141 .Fl S
 142 appears in the argument list (that is, linking is attempted), the shadow
 143 compilers will not be invoked.
 144 This is because the objects built with that compiler which would be linked
 145 have been previously discarded.
 146 .It
 147 If an option of the form
 148 .Fl o Ar filename
 149 was provided, it will be replaced by two options of the form
 150 .Fl o Ar tempfile
 151 .It
 152 If the option
 153 .Fl o
 154 was not provided,
 155 .Fl o Ar tempfile
 156 will be added to the end of the argument list used to invoke
 157 the shadow compilers.
 158 .El
 159 When shadow compilation is in effect,
 160 .Nm cw
 161 writes to standard error each compiler's standard error output following its
 162 argument list.
 163 Messages from the compilers will not be interleaved.
 164 If
 165 .Nm cw
 166 is used to invoke the preprocessor and no output location is specified,
 167 .Nm cw
 168 will write to standard output the primary compiler's standard output, and the
 169 secondary compiler's standard output will be discarded.

 127 .Sh SHADOW COMPILATION
 128 If
 129 .Fl -shadow
 130 compilers are specified
 131 .Nm cw
 132 will invoke shadow compiler, with the outputs modified (as well as any
 133 translation for compiler style) as follows:
 134 .Bl -enum
 135 .It
 136 If none of
 137 .Fl c ,
 138 .Fl E ,
 139 .Fl P ,
 140 or
 141 .Fl S
 142 appears in the argument list (that is, linking is attempted), the shadow
 143 compilers will not be invoked.
 144 This is because the objects built with that compiler which would be linked
 145 have been previously discarded.
 146 .It
 147 If the
 148 .Fl o Ar filename
 149 option was provided, with or without a separating space, it will be replaced with
 150 .Fl o Ar tempfile
 151 .It
 152 If the option
 153 .Fl o
 154 was not provided,
 155 .Fl o Ar tempfile
 156 will be added to the end of the argument list used to invoke
 157 the shadow compilers.
 158 .El
 159 When shadow compilation is in effect,
 160 .Nm cw
 161 writes to standard error each compiler's standard error output following its
 162 argument list.
 163 Messages from the compilers will not be interleaved.
 164 If
 165 .Nm cw
 166 is used to invoke the preprocessor and no output location is specified,
 167 .Nm cw
 168 will write to standard output the primary compiler's standard output, and the
 169 secondary compiler's standard output will be discarded.