Revert 47789 - The newer version of tcmalloc should fix the problems with running tcmalloc under Valgrind.

Review URL: http://codereview.chromium.org/1735024

TBR=willchan,antonm
Review URL: http://codereview.chromium.org/2138002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@47909 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 74 insertions, 41 deletions

diff --git a/third_party/tcmalloc/chromium/src/stacktrace_powerpc-inl.h b/third_party/tcmalloc/chromium/src/stacktrace_powerpc-inl.h
index 9a07eea..5631e49 100644
--- a/third_party/tcmalloc/chromium/src/stacktrace_powerpc-inl.h
+++ b/third_party/tcmalloc/chromium/src/stacktrace_powerpc-inl.h
@@ -36,11 +36,6 @@
 //    http://www.linux-foundation.org/spec/ELF/ppc64/PPC-elf64abi-1.9.html#STACK
 // Linux has similar code: http://patchwork.ozlabs.org/linuxppc/patch?id=8882
 
-#ifndef BASE_STACKTRACE_POWERPC_INL_H_
-#define BASE_STACKTRACE_POWERPC_INL_H_
-// Note: this file is included into stacktrace.cc more than once.
-// Anything that should only be defined once should be here:
-
 #include <stdint.h>   // for uintptr_t
 #include <stdlib.h>   // for NULL
 #include <google/stacktrace.h>
@@ -76,23 +71,9 @@ static void **NextStackFrame(void **old_sp) {
 // This ensures that GetStackTrace stes up the Link Register properly.
 void StacktracePowerPCDummyFunction() __attribute__((noinline));
 void StacktracePowerPCDummyFunction() { __asm__ volatile(""); }
-#endif  // BASE_STACKTRACE_POWERPC_INL_H_
-
-// Note: this part of the file is included several times.
-// Do not put globals below.
 
-// The following 4 functions are generated from the code below:
-//   GetStack{Trace,Frames}()
-//   GetStack{Trace,Frames}WithContext()
-//
-// These functions take the following args:
-//   void** result: the stack-trace, as an array
-//   int* sizes: the size of each stack frame, as an array
-//               (GetStackFrames* only)
-//   int max_depth: the size of the result (and sizes) array(s)
-//   int skip_count: how many stack pointers to skip before storing in result
-//   void* ucp: a ucontext_t* (GetStack{Trace,Frames}WithContext only)
-int GET_STACK_TRACE_OR_FRAMES {
+// If you change this function, also change GetStackFrames below.
+int GetStackTrace(void** result, int max_depth, int skip_count) {
   void **sp;
   // Apple OS X uses an old version of gnu as -- both Darwin 7.9.0 (Panther)
   // and Darwin 8.8.1 (Tiger) use as 1.38.  This means we have to use a
@@ -114,29 +95,11 @@ int GET_STACK_TRACE_OR_FRAMES {
   // This routine forces the compiler (at least gcc) to push it anyway.
   StacktracePowerPCDummyFunction();
 
-#if IS_STACK_FRAMES
-  // Note we do *not* increment skip_count here for the SYSV ABI.  If
-  // we did, the list of stack frames wouldn't properly match up with
-  // the list of return addresses.  Note this means the top pc entry
-  // is probably bogus for linux/ppc (and other SYSV-ABI systems).
-#else
   // The LR save area is used by the callee, so the top entry is bogus.
   skip_count++;
-#endif
 
   int n = 0;
   while (sp && n < max_depth) {
-#if IS_STACK_FRAMES
-    // The GetStackFrames routine is called when we are in some
-    // informational context (the failure signal handler for example).
-    // Use the non-strict unwinding rules to produce a stack trace
-    // that is as complete as possible (even if it contains a few bogus
-    // entries in some rare cases).
-    void **next_sp = NextStackFrame<false>(sp);
-#else
-    void **next_sp = NextStackFrame<true>(sp);
-#endif
-
     if (skip_count > 0) {
       skip_count--;
     } else {
@@ -157,15 +120,85 @@ int GET_STACK_TRACE_OR_FRAMES {
 #else
 #error Need to specify the PPC ABI for your archiecture.
 #endif
+    }
+    // Use strict unwinding rules.
+    sp = NextStackFrame<true>(sp);
+  }
+  return n;
+}
+
+// If you change this function, also change GetStackTrace above:
+//
+// This GetStackFrames routine shares a lot of code with GetStackTrace
+// above. This code could have been refactored into a common routine,
+// and then both GetStackTrace/GetStackFrames could call that routine.
+// There are two problems with that:
+//
+// (1) The performance of the refactored-code suffers substantially - the
+//     refactored needs to be able to record the stack trace when called
+//     from GetStackTrace, and both the stack trace and stack frame sizes,
+//     when called from GetStackFrames - this introduces enough new
+//     conditionals that GetStackTrace performance can degrade by as much
+//     as 50%.
+//
+// (2) Whether the refactored routine gets inlined into GetStackTrace and
+//     GetStackFrames depends on the compiler, and we can't guarantee the
+//     behavior either-way, even with "__attribute__ ((always_inline))"
+//     or "__attribute__ ((noinline))". But we need this guarantee or the
+//     frame counts may be off by one.
+//
+// Both (1) and (2) can be addressed without this code duplication, by
+// clever use of template functions, and by defining GetStackTrace and
+// GetStackFrames as macros that expand to these template functions.
+// However, this approach comes with its own set of problems - namely,
+// macros and  preprocessor trouble - for example,  if GetStackTrace
+// and/or GetStackFrames is ever defined as a member functions in some
+// class, we are in trouble.
+int GetStackFrames(void** pcs, int *sizes, int max_depth, int skip_count) {
+  void **sp;
+#ifdef __APPLE__
+  __asm__ volatile ("mr %0,r1" : "=r" (sp));
+#else
+  __asm__ volatile ("mr %0,1" : "=r" (sp));
+#endif
 
-#if IS_STACK_FRAME
+  StacktracePowerPCDummyFunction();
+  // Note we do *not* increment skip_count here for the SYSV ABI.  If
+  // we did, the list of stack frames wouldn't properly match up with
+  // the list of return addresses.  Note this means the top pc entry
+  // is probably bogus for linux/ppc (and other SYSV-ABI systems).
+
+  int n = 0;
+  while (sp && n < max_depth) {
+    // The GetStackFrames routine is called when we are in some
+    // informational context (the failure signal handler for example).
+    // Use the non-strict unwinding rules to produce a stack trace
+    // that is as complete as possible (even if it contains a few bogus
+    // entries in some rare cases).
+    void **next_sp = NextStackFrame<false>(sp);
+    if (skip_count > 0) {
+      skip_count--;
+    } else {
+#if defined(_CALL_AIX) || defined(_CALL_DARWIN)
+      pcs[n++] = *(sp+2);
+#elif defined(_CALL_SYSV)
+      pcs[n++] = *(sp+1);
+#elif defined(__APPLE__) || (defined(__linux) && defined(__PPC64__))
+      // This check is in case the compiler doesn't define _CALL_AIX/etc.
+      pcs[n++] = *(sp+2);
+#elif defined(__linux)
+      // This check is in case the compiler doesn't define _CALL_SYSV.
+      pcs[n++] = *(sp+1);
+#else
+#error Need to specify the PPC ABI for your archiecture.
+#endif
       if (next_sp > sp) {
         sizes[n] = (uintptr_t)next_sp - (uintptr_t)sp;
       } else {
         // A frame-size of 0 is used to indicate unknown frame size.
         sizes[n] = 0;
       }
-#endif
+      n++;
     }
     sp = next_sp;
   }