[PATCH] Cygwin: Use two pass parse for tlsoffsets generation.

[Takashi Yano <takashi.yano@nifty.ne.jp>]

- The commit "Cygwin: fix new sigfe.o generation in optimized case"
  fixed the wrong tlsoffsets generation by adding -O0 to compile
  options. Current gentls_offsets expects entry of "start_offset"
  is the first entry in the assembler code. However, without -O0,
  entry of "start_offset" goes to the last entry for some reason.
  Currently, -O0 can prevents assembler code from reversing the
  order of the entry, however, there is no guarantee will retain
  the order of the entries in the future.

  This patch make gentls_offsets parse the assembler code in the
  two pass to omit -O0 option dependency.
---
 winsup/cygwin/gentls_offsets | 27 ++++++++++++++++++++++-----
 1 file changed, 22 insertions(+), 5 deletions(-)

diff --git a/winsup/cygwin/gentls_offsets b/winsup/cygwin/gentls_offsets
index d76562c05..111e6aa78 100755
--- a/winsup/cygwin/gentls_offsets
+++ b/winsup/cygwin/gentls_offsets
@@ -43,7 +43,7 @@ gawk '
   }
 ' | \
 # Now run the compiler to generate an assembler file.
-${CXXCOMPILE} -x c++ -g0 -O0 -S - -o - | \
+${CXXCOMPILE} -x c++ -g0 -S - -o ${output_file}.s && \
 # The assembler file consists of lines like these:
 #
 #   __CYGTLS__foo
@@ -52,10 +52,25 @@ ${CXXCOMPILE} -x c++ -g0 -O0 -S - -o - | \
 #       .align 4
 #
 # From this info, generate the tlsoffsets file.
-gawk '\
+start_offset=$(gawk '\
+  BEGIN {
+    varname=""
+  }
+  /^__CYGTLS__/ {
+    varname = gensub (/__CYGTLS__(\w+):/, "\\1", "g");
+  }
+  /\s*\.long\s+/ {
+    if (length (varname) > 0) {
+      if (varname == "start_offset") {
+	print $2;
+      }
+      varname = "";
+    }
+  }
+' ${output_file}.s) && \
+gawk -v start_offset="$start_offset" '\
   BEGIN {
     varname=""
-    start_offset = 0
   }
   /^__CYGTLS__/ {
     varname = gensub (/__CYGTLS__(\w+):/, "\\1", "g");
@@ -70,7 +85,6 @@ gawk '\
   /\s*\.long\s+/ {
     if (length (varname) > 0) {
       if (varname == "start_offset") {
-      	start_offset = $2;
 	printf (".equ _cygtls.%s, -%u\n", varname, start_offset);
       } else {
       	value = $2;
@@ -80,4 +94,7 @@ gawk '\
       varname = "";
     }
   }
-' > "${output_file}"
+' ${output_file}.s > "${output_file}"
+ret=$?
+rm -f ${output_file}.s
+exit $ret
-- 
2.36.1