Index: lib/sanitizer_common/CMakeLists.txt
===================================================================
--- lib/sanitizer_common/CMakeLists.txt
+++ lib/sanitizer_common/CMakeLists.txt
@@ -31,6 +31,7 @@
   sanitizer_stoptheworld_mac.cc
   sanitizer_suppressions.cc
   sanitizer_symbolizer.cc
+  sanitizer_symbolizer_fuchsia.cc
   sanitizer_symbolizer_libbacktrace.cc
   sanitizer_symbolizer_mac.cc
   sanitizer_symbolizer_win.cc
Index: lib/sanitizer_common/sanitizer_fuchsia.h
===================================================================
--- lib/sanitizer_common/sanitizer_fuchsia.h
+++ lib/sanitizer_common/sanitizer_fuchsia.h
@@ -22,6 +22,12 @@
 
 namespace __sanitizer {
 
+struct DataInfo;
+
+void RenderStackFrame(InternalScopedString *buffer,
+                      unsigned int frame_no, uptr pc);
+void RenderDataInfo(InternalScopedString *buffer, const DataInfo *DI);
+
 extern uptr MainThreadStackBase, MainThreadStackSize;
 extern sanitizer_shadow_bounds_t ShadowBounds;
 
Index: lib/sanitizer_common/sanitizer_stacktrace_printer.cc
===================================================================
--- lib/sanitizer_common/sanitizer_stacktrace_printer.cc
+++ lib/sanitizer_common/sanitizer_stacktrace_printer.cc
@@ -13,6 +13,7 @@
 
 #include "sanitizer_stacktrace_printer.h"
 #include "sanitizer_file.h"
+#include "sanitizer_fuchsia.h"
 
 namespace __sanitizer {
 
@@ -30,6 +31,11 @@
 void RenderFrame(InternalScopedString *buffer, const char *format, int frame_no,
                  const AddressInfo &info, bool vs_style,
                  const char *strip_path_prefix, const char *strip_func_prefix) {
+#if SANITIZER_FUCHSIA
+  // Fuchsia uses its own bespoke format to enable offline symbolization.
+  // It doesn't support the stack_trace_format flag at all.
+  RenderStackFrame(buffer, frame_no, info.address);
+#else
   if (0 == internal_strcmp(format, "DEFAULT"))
     format = kDefaultFormat;
   for (const char *p = format; *p != '\0'; p++) {
@@ -116,10 +122,16 @@
       Die();
     }
   }
+#endif
 }
 
 void RenderData(InternalScopedString *buffer, const char *format,
                 const DataInfo *DI, const char *strip_path_prefix) {
+#if SANITIZER_FUCHSIA
+  // Fuchsia uses its own bespoke format to enable offline symbolization.
+  // It ignores the format argument to __sanitizer_symbolize_global.
+  RenderDataInfo(buffer, DI);
+#else
   for (const char *p = format; *p != '\0'; p++) {
     if (*p != '%') {
       buffer->append("%c", *p);
@@ -145,6 +157,7 @@
         Die();
     }
   }
+#endif
 }
 
 void RenderSourceLocation(InternalScopedString *buffer, const char *file,
Index: lib/sanitizer_common/sanitizer_symbolizer_fuchsia.cc
===================================================================
--- /dev/null
+++ lib/sanitizer_common/sanitizer_symbolizer_fuchsia.cc
@@ -0,0 +1,111 @@
+//===-- sanitizer_symbolizer_fuchsia.cc -----------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file is shared between various sanitizers' runtime libraries.
+//
+// Implementation of Fuchsia-specific symbolizer.
+//===----------------------------------------------------------------------===//
+
+#include "sanitizer_platform.h"
+#if SANITIZER_FUCHSIA
+
+#include "sanitizer_fuchsia.h"
+#include "sanitizer_symbolizer.h"
+
+namespace __sanitizer {
+
+// For Fuchsia we don't do any actual symbolization per se.
+// Instead, we emit text containing raw addresses and raw linkage
+// symbol names, embedded in Fuchsia's symbolization markup format.
+// Fuchsia's logging infrastructure emits enough information about
+// process memory layout that a post-processing filter can do the
+// symbolization and pretty-print the markup.
+// TODO(mcgrathr): URL to markup format document
+
+// This is used by UBSan for type names, and by ASan for global variable names.
+constexpr const char *kFormatDemangle = "{{{symbol:%s}}}";
+constexpr uptr kFormatDemangleMax = 1024;  // Arbitrary.
+
+// Function name or equivalent from PC location.
+constexpr const char *kFormatFunction = "{{{pc:%p}}}";
+constexpr uptr kFormatFunctionMax = 64; // More than big enough for 64-bit hex.
+
+// Global variable name or equivalent from data memory address.
+constexpr const char *kFormatData = "{{{data:%p}}}";
+
+// One frame in a backtrace (printed on a line by itself).
+constexpr const char *kFormatFrame = "{{{bt:%u:%p}}}";
+
+// Just a trivial singleton.  It could be static if the generic
+// Symbolizer class supported linker initialization.
+Symbolizer *Symbolizer::GetOrInit() {
+  SpinMutexLock l(&init_mu_);
+  if (!symbolizer_) {
+    symbolizer_ = new(symbolizer_allocator_) Symbolizer({});
+    CHECK(symbolizer_);
+  }
+  return symbolizer_;
+}
+
+// Nothing to do.
+void Symbolizer::LateInitialize() { }
+
+// This is used by UBSan for type names, and by ASan for global variable names.
+// It's expected to return a static buffer that will be reused on each call.
+const char *Symbolizer::Demangle(const char *name) {
+  static char buffer[kFormatDemangleMax];
+  internal_snprintf(buffer, sizeof(buffer), kFormatDemangle, name);
+  return buffer;
+}
+
+// This is used mostly for suppression matching.  Making it work
+// would enable "interceptor_via_lib" suppressions.  It's also used
+// once in UBSan to say "in module ..." in a message that also
+// includes an address in the module, so post-processing can already
+// pretty-print that so as to indicate the module.
+bool Symbolizer::GetModuleNameAndOffsetForPC(uptr pc, const char **module_name,
+                                             uptr *module_address) {
+  return false;
+}
+
+// This is used in some places for suppression checking, which we
+// don't really support for Fuchsia.  It's also used in UBSan to
+// identify a PC location to a function name, so we always fill in
+// the function member with a string containing markup around the PC
+// value.
+// TODO(mcgrathr): Under SANITIZER_GO, it's currently used by TSan
+// to render stack frames, but that should be changed to use
+// RenderStackFrame.
+SymbolizedStack *Symbolizer::SymbolizePC(uptr addr) {
+  SymbolizedStack *s = SymbolizedStack::New(addr);
+  char buffer[kFormatFunctionMax];
+  internal_snprintf(buffer, sizeof(buffer), kFormatFunction, addr);
+  s->info.function = internal_strdup(buffer);
+  return s;
+}
+
+// Always claim we succeeded, so that RenderDataInfo will be called.
+bool Symbolizer::SymbolizeData(uptr addr, DataInfo *info) {
+  info->Clear();
+  info->start = addr;
+  return true;
+}
+
+void RenderDataInfo(InternalScopedString *buffer, const DataInfo *DI) {
+  buffer->append(kFormatData, DI->start);
+}
+
+void RenderStackFrame(InternalScopedString *buffer,
+                      unsigned int frame_no, uptr pc) {
+  buffer->append(kFormatFrame, frame_no, pc);
+}
+
+}  // namespace __sanitizer
+
+#endif  // SANITIZER_FUCHSIA
Index: lib/sanitizer_common/sanitizer_symbolizer_libcdep.cc
===================================================================
--- lib/sanitizer_common/sanitizer_symbolizer_libcdep.cc
+++ lib/sanitizer_common/sanitizer_symbolizer_libcdep.cc
@@ -11,6 +11,9 @@
 // run-time libraries.
 //===----------------------------------------------------------------------===//
 
+#include "sanitizer_platform.h"
+#if !SANITIZER_FUCHSIA
+
 #include "sanitizer_allocator_internal.h"
 #include "sanitizer_internal_defs.h"
 #include "sanitizer_symbolizer_internal.h"
@@ -473,3 +476,5 @@
 }
 
 }  // namespace __sanitizer
+
+#endif // !SANITIZER_FUCHSIA