X-Git-Url: http://plrg.eecs.uci.edu/git/?p=folly.git;a=blobdiff_plain;f=folly%2FDemangle.cpp;h=d1f53cfc89c33e6bf565f0b3f0b0c2c16bdf4aab;hp=765db5ac03fc52aa693e31469e1dfa067b0c018b;hb=bda67fde120837b77ddab74f23abcb22ae5b3029;hpb=ce64f0f685111ac24c7a321ea56d0c3524621df1

diff --git a/folly/Demangle.cpp b/folly/Demangle.cpp
index 765db5ac..d1f53cfc 100644
--- a/folly/Demangle.cpp
+++ b/folly/Demangle.cpp
@@ -1,5 +1,5 @@
 /*
- * Copyright 2014 Facebook, Inc.
+ * Copyright 2017 Facebook, Inc.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -17,18 +17,19 @@
 #include <folly/Demangle.h>
 
 #include <algorithm>
-#include <string.h>
+#include <cstring>
 
-#include <folly/Malloc.h>
+#include <folly/memory/Malloc.h>
+#include <folly/portability/Config.h>
 
 #if FOLLY_HAVE_CPLUS_DEMANGLE_V3_CALLBACK
-# include <cxxabi.h>
+#include <cxxabi.h>
 
 // From libiberty
 //
 // TODO(tudorb): Detect this with autoconf for the open-source version.
 //
-// __attribute__((weak)) doesn't work, because cplus_demangle_v3_callback
+// __attribute__((__weak__)) doesn't work, because cplus_demangle_v3_callback
 // is exported by an object file in libiberty.a, and the ELF spec says
 // "The link editor does not extract archive members to resolve undefined weak
 // symbols" (but, interestingly enough, will resolve undefined weak symbols
@@ -55,26 +56,23 @@ extern "C" int cplus_demangle_v3_callback(
 
 #endif
 
-namespace {
-
-// glibc doesn't have strlcpy
-size_t my_strlcpy(char* dest, const char* src, size_t size) {
-  size_t len = strlen(src);
-  if (size != 0) {
-    size_t n = std::min(len, size - 1);  // always null terminate!
-    memcpy(dest, src, n);
-    dest[n] = '\0';
-  }
-  return len;
-}
-
-}  // namespace
-
 namespace folly {
 
 #if FOLLY_HAVE_CPLUS_DEMANGLE_V3_CALLBACK
 
 fbstring demangle(const char* name) {
+#ifdef FOLLY_DEMANGLE_MAX_SYMBOL_SIZE
+  // GCC's __cxa_demangle() uses on-stack data structures for the
+  // parser state which are linear in the number of components of the
+  // symbol. For extremely long symbols, this can cause a stack
+  // overflow. We set an arbitrary symbol length limit above which we
+  // just return the mangled name.
+  size_t mangledLen = strlen(name);
+  if (mangledLen > FOLLY_DEMANGLE_MAX_SYMBOL_SIZE) {
+    return fbstring(name, mangledLen);
+  }
+#endif
+
   int status;
   size_t len = 0;
   // malloc() memory for the demangled type name
@@ -104,9 +102,21 @@ void demangleCallback(const char* str, size_t size, void* p) {
   buf->total += size;
 }
 
-}  // namespace
+} // namespace
 
 size_t demangle(const char* name, char* out, size_t outSize) {
+#ifdef FOLLY_DEMANGLE_MAX_SYMBOL_SIZE
+  size_t mangledLen = strlen(name);
+  if (mangledLen > FOLLY_DEMANGLE_MAX_SYMBOL_SIZE) {
+    if (outSize) {
+      size_t n = std::min(mangledLen, outSize - 1);
+      memcpy(out, name, n);
+      out[n] = '\0';
+    }
+    return mangledLen;
+  }
+#endif
+
   DemangleBuf dbuf;
   dbuf.dest = out;
   dbuf.remaining = outSize ? outSize - 1 : 0;   // leave room for null term
@@ -119,7 +129,7 @@ size_t demangle(const char* name, char* out, size_t outSize) {
       demangleCallback,
       &dbuf);
   if (status == 0) {  // failed, return original
-    return my_strlcpy(out, name, outSize);
+    return folly::strlcpy(out, name, outSize);
   }
   if (outSize != 0) {
     *dbuf.dest = '\0';
@@ -134,9 +144,19 @@ fbstring demangle(const char* name) {
 }
 
 size_t demangle(const char* name, char* out, size_t outSize) {
-  return my_strlcpy(out, name, outSize);
+  return folly::strlcpy(out, name, outSize);
 }
 
 #endif
 
-} // folly
+size_t strlcpy(char* dest, const char* const src, size_t size) {
+  size_t len = strlen(src);
+  if (size != 0) {
+    size_t n = std::min(len, size - 1);  // always null terminate!
+    memcpy(dest, src, n);
+    dest[n] = '\0';
+  }
+  return len;
+}
+
+} // namespace folly