winsup/cygwin/scripts/gentls_offsets

   1 #!/usr/bin/env bash
   2 #set -x
   3 input_file=$1
   4 output_file=$2
   5 tmp_file=/tmp/${output_file}.$$
   6
   7 trap "rm -f ${tmp_file}" 0 1 2 15
   8
   9 # Preprocess cygtls.h and filter out only the member lines from
  10 # class _cygtls to generate an input file for the cross compiler
  11 # to generate the member offsets for tlsoffsets-$(target_cpu).h.
  12 ${CXXCOMPILE} -E -P "${input_file}" 2> /dev/null | \
  13 gawk '
  14   BEGIN {
  15     # marker is used to split out the member lines from class _cygtls
  16     marker=0;
  17     # Prepare the input file for the subsequent compiler run.
  18     # Prepend value of __CYGTLS_PADSIZE__ so we can compute the offsets
  19     # up and down at the same time
  20     print "#include \"winsup.h\"";
  21     print "#include \"cygtls.h\"";
  22     print "extern \"C\" const uint32_t __CYGTLS__start_offset = __CYGTLS_PADSIZE__;";
  23   }
  24   /^class _cygtls$/ {
  25     # Ok, bump marker, next we are expecting a "public:" line
  26     marker=1;
  27   }
  28   /^public:/ {
  29     # We are only interested in the lines between the first (marker == 2)
  30     # and the second (marker == 3) "public:" line in class _cygtls.  These
  31     # are where the members are defined.
  32     if (marker > 0) ++marker;
  33     if (marker > 2) exit;
  34   }
  35   {
  36     if (marker == 2 && $1 != "public:") {
  37       # Filter out function names
  38       $0 = gensub (/\(\*(\w+)\)\s*\([^\)]*\)/, "\\1", "g");
  39       # Filter out leading asterisk
  40       $NF = gensub (/^\**(\w+)/, "\\1", "g", $NF);
  41       # Filter out trailing array expression
  42       $NF = gensub (/(\w+)\s*\[[^\]]*\]/, "\\1", "g", $NF);
  43       $NF = gensub (/(\w+);/, "\\1", "g", $NF);
  44       print "extern \"C\" const uint32_t __CYGTLS__" $NF " = offsetof (class _cygtls, " $NF ");";
  45     }
  46   }
  47 ' | \
  48 # Now run the compiler to generate an assembler file.
  49 ${CXXCOMPILE} -x c++ -g0 -S - -o ${tmp_file} && \
  50 # The assembler file consists of lines like these:
  51 #
  52 #   __CYGTLS__foo
  53 #       .long 42
  54 #       .globl __CYGTLS__foo
  55 #       .align 4
  56 #
  57 # From this info, generate the tlsoffsets file.
  58 start_offset=$(gawk '\
  59   BEGIN {
  60     varname=""
  61   }
  62   /^__CYGTLS__/ {
  63     varname = gensub (/__CYGTLS__(\w+):/, "\\1", "g");
  64   }
  65   /\s*\.long\s+/ {
  66     if (length (varname) > 0) {
  67       if (varname == "start_offset") {
  68         print $2;
  69       }
  70       varname = "";
  71     }
  72   }
  73 ' ${tmp_file}) && \
  74 gawk -v start_offset="$start_offset" '\
  75   BEGIN {
  76     varname=""
  77   }
  78   /^__CYGTLS__/ {
  79     varname = gensub (/__CYGTLS__(\w+):/, "\\1", "g");
  80   }
  81   /\s*\.space\s*4/ {
  82     if (length (varname) > 0) {
  83       printf (".equ _cygtls.%s, %d\n", varname, -start_offset);
  84       printf (".equ _cygtls.%s_p, 0\n", varname);
  85       varname = "";
  86     }
  87   }
  88   /\s*\.long\s+/ {
  89     if (length (varname) > 0) {
  90       if (varname == "start_offset") {
  91         printf (".equ _cygtls.%s, -%u\n", varname, start_offset);
  92       } else {
  93         value = $2;
  94         printf (".equ _cygtls.%s, %d\n", varname, value - start_offset);
  95         printf (".equ _cygtls.%s_p, %d\n", varname, value);
  96       }
  97       varname = "";
  98     }
  99   }
 100 ' ${tmp_file} > "${output_file}"
 101 # Check if the `context' member is 16 bytes aligned.  Delete output_file
 102 # and bail out with error if not.
 103 MOD=$(awk '/_cygtls.context_p/{ print $3 % 16; }' "${output_file}")
 104 if [ $MOD -ne 0 ]
 105 then
 106   echo "Error: _cygtls.context member is not 16 bytes aligned!"
 107   rm "${output_file}"
 108   exit 1
 109 fi