diff options
Diffstat (limited to 'src/stacktrace.cc')
| -rw-r--r-- | src/stacktrace.cc | 78 |
1 files changed, 49 insertions, 29 deletions
diff --git a/src/stacktrace.cc b/src/stacktrace.cc index da20659..f236798 100644 --- a/src/stacktrace.cc +++ b/src/stacktrace.cc @@ -30,38 +30,58 @@ // --- // Author: Sanjay Ghemawat // -// Produce stack trace +// Produce stack trace. +// +// There are three different ways we can try to get the stack trace: +// +// 1) Our hand-coded stack-unwinder. This depends on a certain stack +// layout, which is used by gcc (and those systems using a +// gcc-compatible ABI) on x86 systems, at least since gcc 2.95. +// It uses the frame pointer to do its work. +// +// 2) The libunwind library. This is still in development, and as a +// separate library adds a new dependency, abut doesn't need a frame +// pointer. It also doesn't call malloc. +// +// 3) The gdb unwinder -- also the one used by the c++ exception code. +// It's obviously well-tested, but has a fatal flaw: it can call +// malloc() from the unwinder. This is a problem because we're +// trying to use the unwinder to instrument malloc(). +// +// Note: if you add a new implementation here, make sure it works +// correctly when GetStackTrace() is called with max_depth == 0. +// Some code may do that. #include "config.h" -#include <stdlib.h> -#include "google/stacktrace.h" - -#undef IMPLEMENTED_STACK_TRACE -// Linux/x86 implementation (requires the binary to be compiled with -// frame pointers) -#if defined(__i386__) && defined(__linux) && !defined(NO_FRAME_POINTER) -#define IMPLEMENTED_STACK_TRACE -#include "stacktrace_x86-inl.h" -#endif - -#if !defined(IMPLEMENTED_STACK_TRACE) && defined(__x86_64__) && HAVE_LIBUNWIND_H -#define IMPLEMENTED_STACK_TRACE -#define UNW_LOCAL_ONLY -#include "stacktrace_libunwind-inl.h" -#endif +// First, the i386 case. +#if defined(__i386__) && __GNUC__ >= 2 +# if !defined(NO_FRAME_POINTER) +# include "stacktrace_x86-inl.h" +# else +# include "stacktrace_generic-inl.h" +# endif -#if !defined(IMPLEMENTED_STACK_TRACE) && defined(__x86_64__) && HAVE_UNWIND_H -// This implementation suffers from deadlocks. Don't enable it. -#define IMPLEMENTED_STACK_TRACE -#include "stacktrace_x86_64-inl.h" -#endif - -#if !defined(IMPLEMENTED_STACK_TRACE) && !defined(__x86_64__) && HAVE_EXECINFO_H -#define IMPLEMENTED_STACK_TRACE -#include "stacktrace_generic-inl.h" -#endif +// Now, the x86_64 case. +#elif defined(__x86_64__) && __GNUC__ >= 2 +# if !defined(NO_FRAME_POINTER) +# include "stacktrace_x86-inl.h" +# elif defined(HAVE_LIBUNWIND_H) // a proxy for having libunwind installed +# define UNW_LOCAL_ONLY +# include "stacktrace_libunwind-inl.h" +# elif 0 + // This is the unwinder used by gdb, which can call malloc (see above). + // We keep this code around, so we can test cases where libunwind + // doesn't work, but there's no way to enable it except for manually + // editing this file (by replacing this "elif 0" with "elif 1", e.g.). +# include "stacktrace_x86_64-inl.h" +# elif defined(__linux) +# error Cannnot calculate stack trace: need either libunwind or frame-pointers (see INSTALL file) +# else +# error Cannnot calculate stack trace: need libunwind (see INSTALL file) +# endif -#ifndef IMPLEMENTED_STACK_TRACE -#error Cannot calculate stack trace: will need to write for your environment +// OK, those are all the processors we know how to deal with. +#else +# error Cannot calculate stack trace: will need to write for your environment #endif |