initial batch of changes to enable AIX in 32-bit and 64-bit

- Some small automake changes. Add libc++ for AIX instead of libstdc++
- Add the interface changes for AIX:User-defined malloc replacement
- Add code to avoid use of pthreads library prior to its initialization
- Some small changes to the unittest case
- Update INSTALL for AIX

[alkondratenko@gmail.com]: lower-case/de-trailing-dot for commit subject line
[alkondratenko@gmail.com]: rebase
[alkondratenko@gmail.com]: amputate unused AM_CONDITIONAL for AIX
[alkondratenko@gmail.com]: explicitly mention libc_override_aix.h in Makefile.am

INSTALL

@@ -339,6 +339,67 @@ above, by linking in libtcmalloc_minimal.
    process.  'make install' should also work.  The Makefile will limit
    itself to those libraries and binaries that work on windows.
 
+** AIX
+
+   I've tested using the IBM XL and IBM Open XL Compilers. The
+   minimum requirement for IBM XL is V16 which includes C++11
+   support. IBM XL and gcc are not ABI compatible. If you would
+   like to use the library with a gcc built executable then the
+   library must also be built with gcc. To use the library with
+   and IBM XL built binary then it follows that the library must
+   also be built with IBM XL.
+
+   Both 32-bit and 64-bit builds have been tested.
+
+   To do a 32-bit IBM XL build:
+     % ./configure CC="xlclang" CXX="xlclang++" AR="ar"
+           RANLIB="ranlib" NM="nm"
+   To do a 64-bit IBM XL build:
+     % ./configure CC="xlclang -q64" CXX="xlclang++ -q64"
+          AR="ar -X64" RANLIB="ranlib -X64" NM="nm -X64"
+
+   Add your favorite optimization levels via CFLAGS and CXXFLAGS.
+
+   If you link to the shared library but it may not work as you
+   expect. Allocations and deallocations that occur from within
+   the Standard C and C++ libraries will not be redirected the
+   tcmalloc library.
+
+   The recommended method is to use the AIX User-defined malloc
+   replacement as documented by IBM. This replaces the default
+   AIX memory subsystem with a user defined memory subsystem.
+
+   The AIX user defined memory subsystem specifies that the 32-
+   and 64- bit objects must be placed in an archive with the
+   32-bit shared object named mem32.o and the 64-bit shared
+   object named mem64.o.
+
+   It is recommended to make combined 32_64 bit archive by
+   doing a 64-bit build, then copy the shared library to mem64.o
+   add mem64.o the archive, then do a 32-bit build
+   copy the shared library to mem32.o and add it to the same
+   combined archive.
+
+   For eg) perform a 64-bit build then:
+     % cp libtcmalloc_minimal.so.4 mem64.o
+     % ar -X32_64 -r libtmalloc_minimal.a mem64.o
+
+     Followed by a 32-bit build:
+     % cp libtcmalloc_minimal.so.4 mem32.o
+     % ar -X32_64 -r libtmalloc_minimal.a mem32.o
+
+   The final archive should contain both mem32.o and mem64.o
+
+   To use the library you are expected have the library location
+   in your LIBPATH or LD_LIBRARY_PATH followed by exporting the
+   environment variable MALLOCTYPE=user:libtcmalloc_minimal.a to
+   enable the new user defined memory subsystem.
+
+   I recommend using:
+     % MALLOCTYPE=user:libtcmalloc_minimal.a <user-exectuable>
+   to minimize the impact of replacing the memory subsystem.  Once
+   the subsystem is replaced it is used for all commands issued from
+   the terminal.
 
 Basic Installation
 ==================

Makefile.am

@@ -386,6 +386,7 @@ S_TCMALLOC_MINIMAL_INCLUDES = src/common.h \
                               src/central_freelist.h \
                               src/linked_list.h \
                               src/libc_override.h \
+                              src/libc_override_aix.h \
                               src/libc_override_gcc_and_weak.h \
                               src/libc_override_glibc.h \
                               src/libc_override_osx.h \

configure.ac

@@ -428,7 +428,6 @@ else
   AC_SUBST(ac_cv_have_std_align_val_t, 0)
 fi
 
-
 AC_CACHE_CHECK([if target has _Unwind_Backtrace],
                [perftools_cv_have_unwind_backtrace],
                [AC_COMPILE_IFELSE([AC_LANG_PROGRAM(
@@ -490,6 +489,8 @@ AC_LINK_IFELSE([AC_LANG_PROGRAM([#if defined(__GNUC__) && ((__GNUC__ < 4) || (__
 #error mingw doesnt really support tls
 #elif defined(__APPLE__)
 #error OSX __thread support is known to call malloc which makes it unsafe to use from malloc replacement
+#elif defined(_AIX)
+#error AIX thread support is known to call malloc which makes it unsafe to use from malloc replacement
 #endif
 ], [static __thread int p = 0])],
                [AC_DEFINE(HAVE_TLS, 1,
@@ -594,7 +595,7 @@ AH_TOP([
 AH_VERBATIM([PTHREADS_CRASHES_IF_RUN_TOO_EARLY],
 	    [/* Mark the systems where we know it's bad if pthreads runs too
    early before main (before threads are initialized, presumably).  */
-#ifdef __FreeBSD__
+#if defined(__FreeBSD__) || defined(_AIX)
 #define PTHREADS_CRASHES_IF_RUN_TOO_EARLY 1
 #endif])
 

src/libc_override_aix.h

@@ -0,0 +1,59 @@
+// -*- Mode: C++; c-basic-offset: 2; indent-tabs-mode: nil -*-
+// Copyright (c) 2021, IBM Ltd.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// ---
+// Author: Chris Cambly <ccambly@ca.ibm.com>
+//
+// Used to override malloc routines on AIX
+
+#ifndef TCMALLOC_LIBC_OVERRIDE_AIX_INL_H_
+#define TCMALLOC_LIBC_OVERRIDE_AIX_INL_H_
+
+#ifndef _AIX
+# error libc_override_aix.h is for AIX systems only.
+#endif
+
+extern "C" {
+  // AIX user-defined malloc replacement routines
+  void* __malloc__(size_t size) __THROW               ALIAS(tc_malloc);
+  void __free__(void* ptr) __THROW                    ALIAS(tc_free);
+  void* __realloc__(void* ptr, size_t size) __THROW   ALIAS(tc_realloc);
+  void* __calloc__(size_t n, size_t size) __THROW     ALIAS(tc_calloc);
+  int __posix_memalign__(void** r, size_t a, size_t s) __THROW ALIAS(tc_posix_memalign);
+  int __mallopt__(int cmd, int value) __THROW         ALIAS(tc_mallopt);
+#ifdef HAVE_STRUCT_MALLINFO
+  struct mallinfo __mallinfo__(void) __THROW          ALIAS(tc_mallinfo);
+#endif
+  void __malloc_init__(void)               { tc_free(tc_malloc(1));}
+  void* __malloc_prefork_lock__(void)      { /* nothing to lock */ }
+  void* __malloc_postfork_unlock__(void)   { /* nothing to unlock */}
+}   // extern "C"
+
+#endif  // TCMALLOC_LIBC_OVERRIDE_AIX_INL_H_

src/libc_override_gcc_and_weak.h

@@ -235,6 +235,11 @@ extern "C" {
 #endif
 }   // extern "C"
 
+/* AIX User-defined malloc replacement interface overrides */
+#if defined(_AIX)
+#include "libc_override_aix.h"
+#endif
+
 #undef ALIAS
 
 // No need to do anything at tcmalloc-registration time: we do it all

src/maybe_threads.cc

@@ -134,7 +134,7 @@ int perftools_pthread_setspecific(pthread_key_t key, void *val) {
 static pthread_once_t pthread_once_init = PTHREAD_ONCE_INIT;
 int perftools_pthread_once(pthread_once_t *ctl,
                            void  (*init_routine) (void)) {
-#ifdef __FreeBSD__
+#if PTHREADS_CRASHES_IF_RUN_TOO_EARLY
   // On __FreeBSD__, calling pthread_once on a system that is not
   // linked with -pthread is silently a noop. :-( Luckily, we have a
   // workaround: FreeBSD exposes __isthreaded in <stdio.h>, which is
@@ -142,11 +142,17 @@ int perftools_pthread_once(pthread_once_t *ctl,
   // we can use our own separate pthreads-once mechanism, which is
   // used until __isthreaded is 1 (which will never be true if the app
   // is not linked with -pthread).
+  // On AIX __n_pthreads is -1 until pthreads has been intialized
   static bool pthread_once_ran_before_threads = false;
   if (pthread_once_ran_before_threads) {
     return 0;
   }
+ #ifdef __FreeBSD__
   if (!__isthreaded) {
+ #endif
+ #ifdef _AIX
+  if (__n_pthreads == -1) {
+ #endif
     init_routine();
     pthread_once_ran_before_threads = true;
     return 0;

src/stacktrace_powerpc-darwin-inl.h

@@ -98,7 +98,7 @@ int GET_STACK_TRACE_OR_FRAMES {
   // different asm syntax.  I don't know quite the best way to discriminate
   // systems using the old as from the new one; I've gone with __APPLE__.
   // TODO(csilvers): use autoconf instead, to look for 'as --version' == 1 or 2
-#ifdef __FreeBSD__
+#if defined(__FreeBSD__) || defined(_AIX)
   __asm__ volatile ("mr %0,1" : "=r" (sp));
 #else
   __asm__ volatile ("mr %0,r1" : "=r" (sp));

src/static_vars.cc

@@ -112,7 +112,8 @@ void Static::InitStaticVars() {
 
 void Static::InitLateMaybeRecursive() {
 #if defined(HAVE_FORK) && defined(HAVE_PTHREAD) \
-  && !defined(__APPLE__) && !defined(TCMALLOC_NO_ATFORK)
+  && !defined(__APPLE__) && !defined(TCMALLOC_NO_ATFORK) \
+  && !defined(PTHREADS_CRASHES_IF_RUN_TOO_EARLY)
   // OSX has it's own way of handling atfork in malloc (see
   // libc_override_osx.h).
   //

src/tests/tcmalloc_unittest.cc

@@ -1472,6 +1472,10 @@ static int RunAllTests(int argc, char** argv) {
 
 #endif // defined(ENABLE_ALIGNED_NEW_DELETE)
 
+// On AIX user defined malloc replacement of libc routines
+// cannot be done at link time must be done a runtime via
+// environment variable MALLOCTYPE
+#if !defined(_AIX)
     // Try strdup(), which the system allocates but we must free.  If
     // all goes well, libc will use our malloc!
     p2 = noopt(strdup("in memory of James Golick"));
@@ -1479,7 +1483,7 @@ static int RunAllTests(int argc, char** argv) {
     VerifyNewHookWasCalled();
     free(p2);
     VerifyDeleteHookWasCalled();
-
+#endif
 
     // Test mmap too: both anonymous mmap and mmap of a file
     // Note that for right now we only override mmap on linux