don't use glibc-specific execinfo.h on uclibc builds

base/debug/stack_trace_posix.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "base/debug/stack_trace.h"
 
 #include <errno.h>
-#include <execinfo.h>
 #include <fcntl.h>
 #include <signal.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <sys/param.h>
 #include <sys/stat.h>
 #include <sys/types.h>
 #include <unistd.h>
 
 #include <map>
 #include <ostream>
 #include <string>
 #include <vector>
 
-#if defined(__GLIBCXX__)
+#if defined(__GLIBCXX__) && !defined(__UCLIBC__)
 #include <cxxabi.h>
+#include <execinfo.h>
 #endif
 
 #if defined(OS_MACOSX)
 #include <AvailabilityMacros.h>
 #endif
 
 #include "base/basictypes.h"
 #include "base/debug/debugger.h"
 #include "base/debug/proc_maps_linux.h"
 #include "base/logging.h"
@@ skipping 29 matching lines @@
 #if !defined(USE_SYMBOLIZE)
 // Demangles C++ symbols in the given text. Example:
 //
 // "out/Debug/base_unittests(_ZN10StackTraceC1Ev+0x20) [0x817778c]"
 // =>
 // "out/Debug/base_unittests(StackTrace::StackTrace()+0x20) [0x817778c]"
 void DemangleSymbols(std::string* text) {
   // Note: code in this function is NOT async-signal safe (std::string uses
   // malloc internally).
 
-#if defined(__GLIBCXX__)
+#if defined(__GLIBCXX__) && !defined(__UCLIBC__)
 
   std::string::size_type search_from = 0;
   while (search_from < text->size()) {
     // Look for the start of a mangled symbol, from search_from.
     std::string::size_type mangled_start =
         text->find(kMangledSymbolPrefix, search_from);
     if (mangled_start == std::string::npos) {
       break;  // Mangled symbol not found.
     }
 
@@ skipping 16 matching lines @@
       // Insert the demangled symbol.
       text->insert(mangled_start, demangled_symbol.get());
       // Next time, we'll start right after the demangled symbol we inserted.
       search_from = mangled_start + strlen(demangled_symbol.get());
     } else {
       // Failed to demangle.  Retry after the "_Z" we just found.
       search_from = mangled_start + 2;
     }
   }
 
-#endif  // defined(__GLIBCXX__)
+#endif  // defined(__GLIBCXX__) && !defined(__UCLIBC__)
 }
 #endif  // !defined(USE_SYMBOLIZE)
 
 class BacktraceOutputHandler {
  public:
   virtual void HandleOutput(const char* output) = 0;
 
  protected:
   virtual ~BacktraceOutputHandler() {}
 };
@@ skipping 38 matching lines @@
     // Subtract by one as return address of function may be in the next
     // function when a function is annotated as noreturn.
     void* address = static_cast<char*>(trace[i]) - 1;
     if (google::Symbolize(address, buf, sizeof(buf)))
       handler->HandleOutput(buf);
     else
       handler->HandleOutput("<unknown>");
 
     handler->HandleOutput("\n");
   }
-#else
+#elif defined(__GLIBCXX__) && !defined(__UCLIBC__)
   bool printed = false;
 
   // Below part is async-signal unsafe (uses malloc), so execute it only
   // when we are not executing the signal handler.
   if (in_signal_handler == 0) {
     scoped_ptr<char*, FreeDeleter>
         trace_symbols(backtrace_symbols(trace, size));
     if (trace_symbols.get()) {
       for (size_t i = 0; i < size; ++i) {
         std::string trace_symbol = trace_symbols.get()[i];
@@ skipping 550 matching lines @@
   success &= (sigaction(SIGSYS, &action, NULL) == 0);
 #endif  // !defined(OS_LINUX)
 
   return success;
 }
 
 StackTrace::StackTrace() {
   // NOTE: This code MUST be async-signal safe (it's used by in-process
   // stack dumping signal handler). NO malloc or stdio is allowed here.
 
+#if defined(__GLIBCXX__) && !defined(__UCLIBC__)
   // Though the backtrace API man page does not list any possible negative
   // return values, we take no chance.
   count_ = base::saturated_cast<size_t>(backtrace(trace_, arraysize(trace_)));
+#endif
 }
 
 void StackTrace::Print() const {
   // NOTE: This code MUST be async-signal safe (it's used by in-process
   // stack dumping signal handler). NO malloc or stdio is allowed here.
 
   PrintBacktraceOutputHandler handler;

[Mark Mentovai, 2014/04/07 20:37:12]

Do you want to wrap the implementation of Print and OutputToStream in an #ifdef
too? That will make a very clear assertion that we don’t expect any of this to
work at all with non-glibc++. It might also help strip a little extra dead code
out of non-glibc++ builds.

[Mostyn Bramley-Moore, 2014/04/07 21:00:56]

Done in patchset 2, using !uclibc checks rather than glibc checks (since I don't
want to accidentally break mac or android).

   ProcessBacktrace(trace_, count_, &handler);
 }
 
 void StackTrace::OutputToStream(std::ostream* os) const {
   StreamBacktraceOutputHandler handler(os);
   ProcessBacktrace(trace_, count_, &handler);
 }
 
 namespace internal {
 
@@ skipping 55 matching lines @@
     *ptr = *start;
     *start++ = ch;
   }
   return buf;
 }
 
 }  // namespace internal
 
 }  // namespace debug
 }  // namespace base