commit 50cbbaa935e92dc570fc899a17669cd6782b09cd
Author: Siddhesh Poyarekar <siddhesh@redhat.com>
Date:   Mon Dec 29 17:40:47 2014 +0530

    Use posix-conf-vars.list to generate spec array
    
    This patch adds support to generate the spec array in getconf from the
    conf.list.  The generated code is mostly unchanged.  the only changes
    are due to the change in layout of the spec and val arrays in the ELF.
    
    The val array can also be auto-generated from posix-conf-vars.list
    once the remaining macros are added to it.
    
            * posix/posix-conf-vars.list (SPEC:XBS5): Add sysconf prefix.
            * posix/confstr.c: Define NEED_SPEC_ARRAY to 0.
            * posix/posix-envs.def: Likewise.
            * sysdeps/posix/sysconf.c: Likewise.
            * posix/getconf.c: Define NEED_SPEC_ARRAY to 1.
            (specs): Remove array.
            * scripts/gen-posix-conf-vars.awk: Support generation of specs
            array.

diff --git a/posix/confstr.c b/posix/confstr.c
index 5b03986a3678e007..0233ea94707ee627 100644
--- a/posix/confstr.c
+++ b/posix/confstr.c
@@ -21,6 +21,8 @@
 #include <string.h>
 #include <confstr.h>
 #include "../version.h"
+
+#define NEED_SPEC_ARRAY 0
 #include <posix-conf-vars.h>
 
 /* If BUF is not NULL and LEN > 0, fill in at most LEN - 1 bytes
diff --git a/posix/getconf.c b/posix/getconf.c
index 9cb8f29be28466ff..bd844dead16e9400 100644
--- a/posix/getconf.c
+++ b/posix/getconf.c
@@ -26,6 +26,9 @@
 #include "../version.h"
 #define PACKAGE _libc_intl_domainname
 
+#define NEED_SPEC_ARRAY 1
+#include <posix-conf-vars.h>
+
 struct conf
   {
     const char *name;
@@ -1008,23 +1011,6 @@ static const struct conf vars[] =
   };
 
 
-static const struct { const char *name; int num; } specs[] =
-  {
-    { "XBS5_ILP32_OFF32", _SC_XBS5_ILP32_OFF32 },
-    { "XBS5_ILP32_OFFBIG", _SC_XBS5_ILP32_OFFBIG },
-    { "XBS5_LP64_OFF64", _SC_XBS5_LP64_OFF64 },
-    { "XBS5_LPBIG_OFFBIG", _SC_XBS5_LPBIG_OFFBIG },
-    { "POSIX_V6_ILP32_OFF32", _SC_V6_ILP32_OFF32 },
-    { "POSIX_V6_ILP32_OFFBIG", _SC_V6_ILP32_OFFBIG },
-    { "POSIX_V6_LP64_OFF64", _SC_V6_LP64_OFF64 },
-    { "POSIX_V6_LPBIG_OFFBIG", _SC_V6_LPBIG_OFFBIG },
-    { "POSIX_V7_ILP32_OFF32", _SC_V7_ILP32_OFF32 },
-    { "POSIX_V7_ILP32_OFFBIG", _SC_V7_ILP32_OFFBIG },
-    { "POSIX_V7_LP64_OFF64", _SC_V7_LP64_OFF64 },
-    { "POSIX_V7_LPBIG_OFFBIG", _SC_V7_LPBIG_OFFBIG },
-  };
-static const int nspecs = sizeof (specs) / sizeof (specs[0]);
-
 extern const char *__progname;
 
 
diff --git a/posix/posix-conf-vars.list b/posix/posix-conf-vars.list
index 3e7e7cdaa9c46c85..601bc2fd33f72f27 100644
--- a/posix/posix-conf-vars.list
+++ b/posix/posix-conf-vars.list
@@ -1,7 +1,8 @@
 # Configuration variables identified by getconf.  The heading of each section
-# is of the format TYPE PREFIX with the opening curly brace on the same line.
-# TYPE can either be SYSCONF, PATHCONF, CONFSTR or SPEC.  Variable names are
-# put one on each line with a curly brace on its own line ending the section.
+# is of the format TYPE PREFIX SC_PREFIX with the opening curly brace on the
+# same line.  TYPE can either be SYSCONF, PATHCONF, CONFSTR or SPEC.  In the
+# absence of SC_PREFIX, _SC is used as the SC_PREFIX.  Variable names are put
+# one on each line with a curly brace on its own line ending the section.
 
 SPEC POSIX {
   V6_ILP32_OFF32
@@ -104,7 +105,7 @@ SYSCONF POSIX {
   RAW_SOCKETS
 }
 
-SPEC XBS5 {
+SPEC XBS5 _SC_XBS5 {
   ILP32_OFF32
   ILP32_OFFBIG
   LP64_OFF64
diff --git a/posix/posix-envs.def b/posix/posix-envs.def
index e820e6dbe3fa3b61..428dbc23ceb7f64c 100644
--- a/posix/posix-envs.def
+++ b/posix/posix-envs.def
@@ -42,6 +42,7 @@
    defined.  These are called with arguments V5, V6, V7 before and
    after the relevant groups of environments.  */
 
+#define NEED_SPEC_ARRAY 0
 #include <posix-conf-vars.h>
 
 START_ENV_GROUP (V7)
diff --git a/scripts/gen-posix-conf-vars.awk b/scripts/gen-posix-conf-vars.awk
index 16e20fc1007bd2f5..0eca55d536bd7f70 100644
--- a/scripts/gen-posix-conf-vars.awk
+++ b/scripts/gen-posix-conf-vars.awk
@@ -15,12 +15,19 @@ $1 ~ /^#/ || $0 ~ /^\s*$/ {
 $NF == "{" {
   type = $1
   prefix = $2
+
+  if (NF == 4)
+    sc_prefix = $3
+  else
+    sc_prefix = "_SC"
+
   next
 }
 
 $1 == "}" {
   prefix = ""
   type = ""
+  sc_prefix = ""
   next
 }
 
@@ -35,6 +42,7 @@ $1 == "}" {
   # CONFSTR: A configuration string
   # SYSCONF: A numeric value
   # SPEC: A specification
+  sc_prefixes[prefix][$1] = sc_prefix
   conf[prefix][$1] = type
 }
 
@@ -56,6 +64,26 @@ END {
 	printf "# endif\n"
       }
       printf "#endif\n\n"
+
+      # Build a name -> sysconf number associative array to print a C array at
+      # the end.
+      if (conf[p][c] == "SPEC") {
+	name = sprintf ("%s_%s", p, c)
+	num = sprintf ("%s_%s", sc_prefixes[p][c], c)
+	spec[name] = num
+      }
     }
   }
+
+  # Print the specification array.  Define the macro NEED_SPEC_ARRAY before
+  # including posix-conf-vars.h to make it available in the compilation unit.
+  print "#if NEED_SPEC_ARRAY"
+  print "static const struct { const char *name; int num; } specs[] ="
+  print "  {"
+  for (s in spec) {
+    printf "    { \"%s\", %s },\n", s, spec[s]
+  }
+  print "  };"
+  print "static const int nspecs = sizeof (specs) / sizeof (specs[0]);"
+  print "#endif"
 }
diff --git a/sysdeps/posix/sysconf.c b/sysdeps/posix/sysconf.c
index 1e9d4e099e94981c..88aa151422dc56f9 100644
--- a/sysdeps/posix/sysconf.c
+++ b/sysdeps/posix/sysconf.c
@@ -31,9 +31,9 @@
 #include <sys/types.h>
 #include <regex.h>
 
+#define NEED_SPEC_ARRAY 0
 #include <posix-conf-vars.h>
 
-
 #define NEED_CHECK_SPEC \
   (!defined _XBS5_ILP32_OFF32 || !defined _XBS5_ILP32_OFFBIG \
    || !defined _XBS5_LP64_OFF64 || !defined _XBS5_LPBIG_OFFBIG \