Adding a callback mechanism to allow users of google.glog to provide

their own implementation of  OpenObjectFileContainingPcAndGetStartAddress.

GTTF: Make stack trace symbolization code recognize more symbols.
One example is __libc_start_main (easy to check), there may be more.

Include the correct elf header on OpenBSD and Android.

Fix Coverity NO_EFFECT defect. Comparing unsigned greater than or equal zero is always true.



git-svn-id: https://google-glog.googlecode.com/svn/trunk@140 eb4d4688-79bd-11dd-afb4-1d65580434c0

src/symbolize.h

@@ -60,9 +60,26 @@
 
 #ifdef HAVE_SYMBOLIZE
 
-#if defined(__ELF__)  // defined by gcc on Linux
+#if defined(__ELF__)  // defined by gcc
+#if defined(__OpenBSD__)
+#include <sys/exec_elf.h>
+#else
 #include <elf.h>
+#endif
+
+#if !defined(ANDROID)
 #include <link.h>  // For ElfW() macro.
+#endif
+
+// For systems where SIZEOF_VOID_P is not defined, determine it
+// based on __LP64__ (defined by gcc on 64-bit systems)
+#if !defined(SIZEOF_VOID_P)
+# if defined(__LP64__)
+#  define SIZEOF_VOID_P 8
+# else
+#  define SIZEOF_VOID_P 4
+# endif
+#endif
 
 // If there is no ElfW macro, let's define it by ourself.
 #ifndef ElfW
@@ -88,6 +105,10 @@ _END_GOOGLE_NAMESPACE_
 
 _START_GOOGLE_NAMESPACE_
 
+// Restrictions on the callbacks that follow:
+//  - The callbacks must not use heaps but only use stacks.
+//  - The callbacks must be async-signal-safe.
+
 // Installs a callback function, which will be called right before a symbol name
 // is printed. The callback is intended to be used for showing a file name and a
 // line number preceding a symbol name.
@@ -99,6 +120,24 @@ typedef int (*SymbolizeCallback)(int fd, void *pc, char *out, size_t out_size,
                                  uint64 relocation);
 void InstallSymbolizeCallback(SymbolizeCallback callback);
 
+// Installs a callback function, which will be called instead of
+// OpenObjectFileContainingPcAndGetStartAddress.  The callback is expected
+// to searches for the object file (from /proc/self/maps) that contains
+// the specified pc.  If found, sets |start_address| to the start address
+// of where this object file is mapped in memory, sets the module base
+// address into |base_address|, copies the object file name into
+// |out_file_name|, and attempts to open the object file.  If the object
+// file is opened successfully, returns the file descriptor.  Otherwise,
+// returns -1.  |out_file_name_size| is the size of the file name buffer
+// (including the null-terminator).
+typedef int (*SymbolizeOpenObjectFileCallback)(uint64_t pc,
+                                               uint64_t &start_address,
+                                               uint64_t &base_address,
+                                               char *out_file_name,
+                                               int out_file_name_size);
+void InstallSymbolizeOpenObjectFileCallback(
+    SymbolizeOpenObjectFileCallback callback);
+
 _END_GOOGLE_NAMESPACE_
 
 #endif