Cleaned up the mess that was the treatment of "below main" functions such as

'__libc_start_main', in Massif, m_debuginfo and m_stacktrace.  As part of
this, --show-below-main is now visible to tools, and Massif pays attention
to it.

Improved the description of --show-below-main=yes in the manual.

Replaced some instances of "__libc_start_main" in the test *.exp files with
"(below main)", which is what will actually be seen.  Also updated
scalar.stderr.exp*, which should make it get closer to actually passing.


git-svn-id: svn://svn.valgrind.org/valgrind/trunk@9131

coregrind/m_debuginfo/debuginfo.c

@@ -50,7 +50,7 @@
 #include "pub_core_machine.h"    // VG_PLAT_USES_PPCTOC
 #include "pub_core_xarray.h"
 #include "pub_core_oset.h"
-#include "pub_core_stacktrace.h" // VG_(get_StackTrace)
+#include "pub_core_stacktrace.h" // VG_(get_StackTrace) XXX: circular dependency
 
 #include "priv_misc.h"           /* dinfo_zalloc/free */
 #include "priv_d3basics.h"       /* ML_(pp_GX) */
@@ -1111,6 +1111,7 @@ Bool get_sym_name ( Bool demangle, Addr a, Char* buf, Int nbuf,
    if (demangle) {
       VG_(demangle) ( True/*do C++ demangle*/,
                       di->symtab[sno].name, buf, nbuf );
+
    } else {
       VG_(strncpy_safely) ( buf, di->symtab[sno].name, nbuf );
    }
@@ -1226,6 +1227,44 @@ Bool VG_(get_fnname_Z_demangle_only) ( Addr a, Char* buf, Int nbuf )
 #  undef N_TMPBUF
 }
 
+Vg_FnNameKind VG_(get_fnname_kind) ( Char* name )
+{
+   if (VG_STREQ("main", name)) {
+      return Vg_FnNameMain;
+
+   } else if (
+#if defined(VGO_linux)
+       VG_STREQ("__libc_start_main",  name) ||  // glibc glibness
+       VG_STREQ("generic_start_main", name) ||  // Yellow Dog doggedness
+#elif defined(VGO_aix5)
+       VG_STREQ("__start", name)            ||  // AIX aches
+#else
+#      error Unknown OS
+#endif
+       0) {
+      return Vg_FnNameBelowMain;
+
+   } else {
+      return Vg_FnNameNormal;
+   }
+}
+
+Vg_FnNameKind VG_(get_fnname_kind_from_IP) ( Addr ip )
+{
+   // We don't need a big buffer;  all the special names are small.
+   #define BUFLEN 50
+   Char buf[50];
+
+   // We don't demangle, because it's faster not to, and the special names
+   // we're looking for won't be demangled.
+   if (VG_(get_fnname_nodemangle) ( ip, buf, BUFLEN )) {
+      buf[BUFLEN-1] = '\0';      // paranoia
+      return VG_(get_fnname_kind)(buf);
+   } else {
+      return Vg_FnNameNormal;    // Don't know the name, treat it as normal.
+   }
+}
+
 /* Looks up data_addr in the collection of data symbols, and if found
    puts its name (or as much as will fit) into dname[0 .. n_dname-1],
    which is guaranteed to be zero terminated.  Also data_addr's offset

coregrind/m_demangle/demangle.c

@@ -29,12 +29,13 @@
 */
 
 #include "pub_core_basics.h"
+#include "pub_core_debuginfo.h"     // XXX: circular dependency
 #include "pub_core_demangle.h"
+#include "pub_core_libcassert.h"
 #include "pub_core_libcbase.h"
+#include "pub_core_libcprint.h"
 #include "pub_core_mallocfree.h"
 #include "pub_core_options.h"
-#include "pub_core_libcassert.h"
-#include "pub_core_libcprint.h"
 
 #include "vg_libciface.h"
 #include "demangle.h"
@@ -121,21 +122,24 @@ void VG_(demangle) ( Bool do_cxx_demangle,
       VG_(strncpy_safely)(result, orig, result_size);
    }
 
-   /* Do the below-main hack */
    // 13 Mar 2005: We used to check here that the demangler wasn't leaking
    // by calling the (now-removed) function VG_(is_empty_arena)().  But,
    // very rarely (ie. I've heard of it twice in 3 years), the demangler
    // does leak.  But, we can't do much about it, and it's not a disaster,
    // so we just let it slide without aborting or telling the user.
 
+   /* Do the below-main hack */
    // Finally, to reduce the endless nuisance of multiple different names 
    // for "the frame below main()" screwing up the testsuite, change all
-   // known incarnations of said into a single name, "(below main)".
-   if (0==VG_(strcmp)("__libc_start_main", result)
-       || 0==VG_(strcmp)("generic_start_main", result)
-       || 0==VG_(strcmp)("__start", result)) /* on AIX */
-      VG_(strncpy_safely)(result, "(below main)", 13);
-
+   // known incarnations of said into a single name, "(below main)", if
+   // --show-below-main=yes.
+   // XXX: this makes a circular dependency between m_demangle and
+   // m_debuginfo.
+   if ( ! VG_(clo_show_below_main) &&
+          Vg_FnNameBelowMain == VG_(get_fnname_kind)(result))
+   {
+      VG_(strncpy_safely)(result, "(below main)", result_size);
+   }
 #  undef N_ZBUF
 }
 

coregrind/m_stacktrace.c

@@ -31,7 +31,7 @@
 #include "pub_core_basics.h"
 #include "pub_core_vki.h"
 #include "pub_core_threadstate.h"
-#include "pub_core_debuginfo.h"
+#include "pub_core_debuginfo.h"     // XXX: circular dependency
 #include "pub_core_aspacemgr.h"     // For VG_(is_addressable)()
 #include "pub_core_libcbase.h"
 #include "pub_core_libcassert.h"
@@ -531,11 +531,7 @@ void VG_(get_and_pp_StackTrace) ( ThreadId tid, UInt n_ips )
 void VG_(apply_StackTrace)( void(*action)(UInt n, Addr ip),
                             StackTrace ips, UInt n_ips )
 {
-   #define MYBUF_LEN 50  // only needs to be long enough for 
-                         // the names specially tested for
-
    Bool main_done = False;
-   Char mybuf[MYBUF_LEN];     // ok to stack allocate mybuf[] -- it's tiny
    Int i = 0;
 
    vg_assert(n_ips > 0);
@@ -545,16 +541,11 @@ void VG_(apply_StackTrace)( void(*action)(UInt n, Addr ip),
       // Stop after the first appearance of "main" or one of the other names
       // (the appearance of which is a pretty good sign that we've gone past
       // main without seeing it, for whatever reason)
-      if ( ! VG_(clo_show_below_main)) {
-         VG_(get_fnname_nodemangle)( ip, mybuf, MYBUF_LEN );
-         mybuf[MYBUF_LEN-1] = 0; // paranoia
-         if ( VG_STREQ("main", mybuf)
-#             if defined(VGO_linux)
-              || VG_STREQ("__libc_start_main", mybuf)   // glibc glibness
-              || VG_STREQ("generic_start_main", mybuf)  // Yellow Dog doggedness
-#             endif
-            )
+      if ( ! VG_(clo_show_below_main) ) {
+         Vg_FnNameKind kind = VG_(get_fnname_kind_from_IP)(ip);
+         if (Vg_FnNameMain == kind || Vg_FnNameBelowMain == kind) {
             main_done = True;
+         }
       }
 
       // Act on the ip

coregrind/pub_core_demangle.h

@@ -36,7 +36,12 @@
 // Z-encoded names.
 //--------------------------------------------------------------------
 
-/* This is the main, standard demangler entry point. */
+/* This is the main, standard demangler entry point.  It does three things:
+ * (1) undoes Z-encoding;
+ * (2) undoes C++ demangling, if 'do_cxx_demangle' is True
+ * (3) converts "below main" names (eg. '__libc_start_main') to "(below
+ *     main)", if --show-below-main=no.
+ */
 
 extern 
 void VG_(demangle) ( Bool do_cxx_demangle,

coregrind/pub_core_options.h

@@ -147,8 +147,6 @@ extern Bool  VG_(clo_track_fds);
    is ignored.  Ie if a tool says no, I don't want this to run, that
    cannot be overridden from the command line. */
 extern Bool  VG_(clo_run_libc_freeres);
-/* Continue stack traces below main()?  Default: NO */
-extern Bool VG_(clo_show_below_main);
 
 /* Should we show VEX emulation warnings?  Default: NO */
 extern Bool VG_(clo_show_emwarns);

docs/xml/manual-core.xml

@@ -913,12 +913,18 @@ that can report errors, e.g. Memcheck, but not Cachegrind.</para>
     <listitem>
       <para>By default, stack traces for errors do not show any
       functions that appear beneath <function>main()</function> 
-      (or similar functions such as glibc's
-      <function>__libc_start_main()</function>, if
-      <function>main()</function> is not present in the stack trace);
-      most of the time it's uninteresting C library stuff.  If this
-      option is enabled, those entries below <function>main()</function>
-      will be shown.</para>
+      most of the time it's uninteresting C library stuff and/or
+      gobbledygook.  Alternatively, if <function>main()</function> is not
+      present in the stack trace, stack traces will not show any functions
+      below <function>main()</function>-like functions such as glibc's
+      <function>__libc_start_main()</function>).  Furthermore, if
+      <function>main()</function>-like functions are present in the trace,
+      they are normalised as "(below main)", in order to make the output
+      more deterministic.</para>
+      
+      <para>If this option is enabled, all stack trace entries will be
+      shown and <function>main()</function>-like functions will not be
+      normalised.</para>
     </listitem>
   </varlistentry>
 

include/pub_tool_debuginfo.h

@@ -74,6 +74,19 @@ extern Bool VG_(get_filename_linenum)
    entry points within it. */
 extern Bool VG_(get_fnname_if_entry) ( Addr a, Char* fnname, Int n_fnname );
 
+typedef
+   enum {
+      Vg_FnNameNormal,        // A normal function.
+      Vg_FnNameMain,          // "main"
+      Vg_FnNameBelowMain      // Something below "main", eg. __libc_start_main.
+   } Vg_FnNameKind;           //   Such names are often filtered.
+
+/* Indicates what kind of fnname it is. */
+extern Vg_FnNameKind VG_(get_fnname_kind) ( Char* name );
+
+/* Like VG_(get_fnname_kind), but takes a code address. */
+extern Vg_FnNameKind VG_(get_fnname_kind_from_IP) ( Addr ip );
+
 /* Looks up data_addr in the collection of data symbols, and if found
    puts its name (or as much as will fit) into dname[0 .. n_dname-1],
    which is guaranteed to be zero terminated.  Also data_addr's offset

include/pub_tool_options.h

@@ -119,6 +119,10 @@ extern VexControl VG_(clo_vex_control);
 /* Number of parents of a backtrace.  Default: 8.  */
 extern Int   VG_(clo_backtrace_size);
 
+/* Continue stack traces below main()?  Default: NO */
+extern Bool VG_(clo_show_below_main);
+
+
 /* Call this if a recognised option was bad for some reason.  Note:
    don't use it just because an option was unrecognised -- return
    'False' from VG_(tdict).tool_process_cmd_line_option) to indicate

massif/ms_main.c

@@ -1931,18 +1931,13 @@ static void pp_snapshot_SXPt(Int fd, SXPt* sxpt, Int depth, Char* depth_str,
       } else {
          // If it's main-or-below-main, we (if appropriate) ignore everything
          // below it by pretending it has no children.
-         // XXX: get this properly.  Also, don't hard-code "(below main)"
-         //      here -- look at the "(below main)"/"__libc_start_main" mess
-         //      (m_stacktrace.c and m_demangle.c).
-         // [Nb: Josef wants --show-below-main to work for his fn entry/exit
-         //      tracing]
-         Bool should_hide_below_main = /*!VG_(clo_show_below_main)*/True;
-         if (should_hide_below_main &&
-             VG_(get_fnname)(sxpt->Sig.ip, ip_desc, BUF_LEN) &&
-             (VG_STREQ(ip_desc, "main") || VG_STREQ(ip_desc, "(below main)")))
-         {
-            sxpt->Sig.n_children = 0;
+         if ( ! VG_(clo_show_below_main) ) {
+            Vg_FnNameKind kind = VG_(get_fnname_kind_from_IP)(sxpt->Sig.ip);
+            if (Vg_FnNameMain == kind || Vg_FnNameBelowMain == kind) {
+               sxpt->Sig.n_children = 0;
+            }
          }
+
          // We need the -1 to get the line number right, But I'm not sure why.
          ip_desc = VG_(describe_IP)(sxpt->Sig.ip-1, ip_desc, BUF_LEN);
       }

memcheck/tests/badjump.stderr.exp2

@@ -1,16 +0,0 @@
-
-Jump to the invalid address stated on the next line
-   at 0x........: ???
-   by 0x........: __libc_start_main (in /...libc...)
- Address 0x........ is not stack'd, malloc'd or (recently) free'd
-
-Process terminating with default action of signal 11 (SIGSEGV)
- Access not within mapped region at address 0x........
-   at 0x........: ???
-   by 0x........: __libc_start_main (in /...libc...)
-
-ERROR SUMMARY: 1 errors from 1 contexts (suppressed: 0 from 0)
-malloc/free: in use at exit: ... bytes in ... blocks.
-malloc/free: ... allocs, ... frees, ... bytes allocated.
-For a detailed leak analysis,  rerun with: --leak-check=yes
-For counts of detected errors, rerun with: -v

memcheck/tests/x86-linux/scalar.c

@@ -267,10 +267,8 @@ int main(void)
    GO(__NR_fcntl, "(DUPFD) 1s 0m");
    SY(__NR_fcntl, x0-1, x0+F_DUPFD, x0); FAILx(EBADF);
 
-   // For F_GETLK the 3rd arg is 'lock'
-   // on x86, this fails with EBADF.  But on amd64 in 32-bit mode
-   // it fails with EFAULT.
-   GO(__NR_fcntl, "(GETLK) 1s 0m");
+   // For F_GETLK the 3rd arg is 'lock'.  On x86, this fails w/EBADF.  But on 
+   GO(__NR_fcntl, "(GETLK) 1s 0m"); // amd64 in 32-bit mode it fails w/EFAULT.
    SY(__NR_fcntl, x0-1, x0+F_GETLK, x0); FAIL; //FAILx(EBADF);
 
    // __NR_mpx 56
@@ -976,10 +974,8 @@ int main(void)
    GO(__NR_fcntl64, "(DUPFD) 1s 0m");
    SY(__NR_fcntl64, x0-1, x0+F_DUPFD, x0); FAILx(EBADF);
 
-   // For F_GETLK the 3rd arg is 'lock'
-   // on x86, this fails with EBADF.  But on amd64 in 32-bit mode
-   // it fails with EFAULT.
-   GO(__NR_fcntl64, "(GETLK) 1s 0m");
+   // For F_GETLK the 3rd arg is 'lock'.  // On x86, this fails w/EBADF.  But on
+   GO(__NR_fcntl64, "(GETLK) 1s 0m"); // amd64 in 32-bit mode it fails w/EFAULT.
    SY(__NR_fcntl64, x0-1, x0+F_GETLK, x0); FAIL; //FAILx(EBADF);
 
    // 222

memcheck/tests/x86-linux/scalar.stderr.exp2

@@ -281,9 +281,6 @@ Syscall param mount(target) contains uninitialised byte(s)
    at 0x........: syscall (in /...libc...)
    by 0x........: main (scalar.c:124)
 
-More than 50 errors detected.  Subsequent errors
-will still be recorded, but in less detail than before.
-
 Syscall param mount(type) contains uninitialised byte(s)
    at 0x........: syscall (in /...libc...)
    by 0x........: main (scalar.c:124)
@@ -629,6 +626,9 @@ Syscall param fcntl(arg) contains uninitialised byte(s)
  55:          __NR_fcntl (GETLK) 1s 0m
 -----------------------------------------------------
 
+More than 100 errors detected.  Subsequent errors
+will still be recorded, but in less detail than before.
+
 Syscall param fcntl(fd) contains uninitialised byte(s)
    at 0x........: syscall (in /...libc...)
    by 0x........: main (scalar.c:272)
@@ -3983,6 +3983,8 @@ Syscall param mq_getsetattr(omqstat) points to unaddressable byte(s)
 WARNING: unhandled syscall: 9999
 You may be able to write your own handler.
 Read the file README_MISSING_SYSCALL_OR_IOCTL.
+Nevertheless we consider this a bug.  Please report
+it at http://valgrind.org/support/bug_reports.html.
 -----------------------------------------------------
   1:           __NR_exit 1s 0m
 -----------------------------------------------------

memcheck/tests/x86-linux/scalar_supp.stderr.exp

@@ -1,11 +1,11 @@
 Syscall param (syscallno) contains uninitialised byte(s)
    at 0x........: syscall (in /...libc...)
-   by 0x........: __libc_start_main (in /...libc...)
+   by 0x........: (below main) (in /...libc...)
 
 Syscall param write(fd) contains uninitialised byte(s)
    at 0x........: syscall (in /...libc...)
-   by 0x........: __libc_start_main (in /...libc...)
+   by 0x........: (below main) (in /...libc...)
 
 Syscall param write(count) contains uninitialised byte(s)
    at 0x........: syscall (in /...libc...)
-   by 0x........: __libc_start_main (in /...libc...)
+   by 0x........: (below main) (in /...libc...)

memcheck/tests/xml1.stderr.exp2

@@ -351,7 +351,7 @@
     <frame>
       <ip>0x........</ip>
       <obj>...</obj>
-      <fn>__libc_start_main</fn>
+      <fn>(below main)</fn>
     </frame>
   </stack>
 </error>

memcheck/tests/xml1.stderr.exp3

@@ -351,7 +351,7 @@
     <frame>
       <ip>0x........</ip>
       <obj>...</obj>
-      <fn>__libc_start_main</fn>
+      <fn>(below main)</fn>
     </frame>
   </stack>
 </error>

memcheck/tests/xml1.stderr.exp64_2

@@ -356,7 +356,7 @@
     <frame>
       <ip>0x........</ip>
       <obj>...</obj>
-      <fn>__libc_start_main</fn>
+      <fn>(below main)</fn>
     </frame>
   </stack>
 </error>

none/tests/fdleak_dup.stderr.exp2

@@ -3,7 +3,7 @@
 FILE DESCRIPTORS: 5 open at exit.
 Open file descriptor .: /dev/null
    at 0x........: dup (in /...libc...)
-   by 0x........: __libc_start_main (in /...libc...)
+   by 0x........: (below main) (in /...libc...)
 
 Open file descriptor .: /dev/null
    at 0x........: open (in /...libc...)

none/tests/fdleak_dup2.stderr.exp2

@@ -3,11 +3,11 @@
 FILE DESCRIPTORS: 6 open at exit.
 Open file descriptor .: /dev/null
    at 0x........: dup2 (in /...libc...)
-   by 0x........: __libc_start_main (in /...libc...)
+   by 0x........: (below main) (in /...libc...)
 
 Open file descriptor .: /dev/null
    at 0x........: dup2 (in /...libc...)
-   by 0x........: __libc_start_main (in /...libc...)
+   by 0x........: (below main) (in /...libc...)
 
 Open file descriptor .: /dev/null
    at 0x........: open (in /...libc...)

none/tests/fdleak_fcntl.stderr.exp2

@@ -8,7 +8,7 @@ Open file descriptor .: /dev/null
 
 Open file descriptor .: /dev/null
    at 0x........: open (in /...libc...)
-   by 0x........: __libc_start_main (in /...libc...)
+   by 0x........: (below main) (in /...libc...)
 
 Open file descriptor .: .
    <inherited from parent>

none/tests/fdleak_fcntl.stderr.exp3

@@ -8,7 +8,7 @@ Open file descriptor .: /dev/null
 
 Open file descriptor .: /dev/null
    at 0x........: open (in /...libc...)
-   by 0x........: __libc_start_main (in /...libc...)
+   by 0x........: (below main) (in /...libc...)
 
 Open file descriptor .: .
    <inherited from parent>