code review 88190043: liblink, cmd/ld: reenable nosplit checking and test

include/link.h

 // Derived from Inferno utils/6l/l.h and related files.
 // http://code.google.com/p/inferno-os/source/browse/utils/6l/l.h
 //
 //      Copyright © 1994-1999 Lucent Technologies Inc.  All rights reserved.
 //      Portions Copyright © 1995-1997 C H Forsyth (forsyth@terzarima.net)
 //      Portions Copyright © 1997-1999 Vita Nuova Limited
 //      Portions Copyright © 2000-2007 Vita Nuova Holdings Limited (www.vitanuova.com)
 //      Portions Copyright © 2004,2006 Bruce Ellis
 //      Portions Copyright © 2005-2007 C H Forsyth (forsyth@terzarima.net)
 //      Revisions Copyright © 2000-2007 Lucent Technologies Inc. and others
@@ skipping 106 matching lines @@
 // prevent incompatible type signatures between liblink and 8l on Plan 9
 #pragma incomplete struct Section
 
 struct  LSym
 {
         char*   name;
         char*   extname;        // name used in external object files
         short   type;
         short   version;
         uchar   dupok;
+        uchar   external;
+        uchar   nosplit;
         uchar   reachable;
         uchar   cgoexport;
         uchar   special;
         uchar   stkcheck;
         uchar   hide;
         uchar   leaf;   // arm only
         uchar   fnptr;  // arm only
         uchar   seenglobl;
         uchar   onlist; // on the textp or datap lists
         int16   symid;  // for writing .5/.6/.8 files
@@ skipping 85 matching lines @@
         SSUB = 1<<8,    /* sub-symbol, linked from parent via ->sub list */
         SMASK = SSUB - 1,
         SHIDDEN = 1<<9, // hidden or local symbol
 };
 
 // Reloc.type
 enum
 {
         R_ADDR = 1,
         R_SIZE,
-        R_CALL,
+        R_CALL, // relocation for direct call

[iant, 2014/04/16 21:29:09]

The way this is used in the machine-independent code suggests that this comment
should "relocation for direct PC-relative call".

[rsc, 2014/04/16 22:59:16]

Thanks. Changed, and changed ARM to use R_CALLARM.

+        R_CALLIND, // marker for indirect call (no actual relocating necessary)
         R_CONST,
         R_PCREL,
         R_TLS,
         R_TLS_LE, // TLS local exec offset from TLS segment register
         R_TLS_IE, // TLS initial exec offset from TLS base pointer
         R_GOTOFF,
         R_PLT0,
         R_PLT1,
         R_PLT2,
 };
@@ skipping 358 matching lines @@
 
 #pragma varargck        type    "A"     int
 #pragma varargck        type    "D"     Addr*
 #pragma varargck        type    "lD"    Addr*
 #pragma varargck        type    "P"     Prog*
 #pragma varargck        type    "R"     int
 
 // TODO(ality): remove this workaround.
 //   It's here because Pconv in liblink/list?.c references %L.
 #pragma varargck        type    "L"     int32