Implement a simple demangler.

The purpose of this demangler is to avoid crashes for any string.

- It does one pass and should avoid going past the end of the string.
- The code avoids recursion to minimize the amount of stack required.
- It cannot demangle all mangled names, but it should be able to work
  on nearly all names in normal stack traces.
- If the mangled name is too large, it will stop demangling and return
  as if the name is not a demangled name.

Test: Passes new unit tests.

Change-Id: I596f74a533c0e093d1517c6bd11cced07009d321

demangle/Android.bp

@@ -0,0 +1,65 @@
+//
+// Copyright (C) 2017 The Android Open Source Project
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+
+cc_defaults {
+    name: "libdemangle_defaults",
+
+    host_supported: true,
+
+    cflags: [
+        "-Wall",
+        "-Werror",
+        "-Wextra",
+    ],
+}
+
+cc_library {
+    name: "libdemangle",
+    defaults: ["libdemangle_defaults"],
+
+    srcs: [
+        "Demangler.cpp",
+    ],
+
+    local_include_dirs: [
+       "include",
+    ],
+
+    export_include_dirs: [
+       "include",
+    ],
+}
+
+//-------------------------------------------------------------------------
+// Unit Tests
+//-------------------------------------------------------------------------
+cc_test {
+    name: "libdemangle_test",
+    defaults: ["libdemangle_defaults"],
+
+    srcs: [
+        "DemangleTest.cpp",
+    ],
+
+    cflags: [
+        "-O0",
+        "-g",
+    ],
+
+    shared_libs: [
+        "libdemangle",
+    ],
+}

demangle/DemangleTest.cpp

@@ -0,0 +1,436 @@
+/*
+ * Copyright (C) 2017 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <stdlib.h>
+
+#include <gtest/gtest.h>
+
+#include <demangle.h>
+
+#include "Demangler.h"
+
+TEST(DemangleTest, VoidArgumentTest) {
+  Demangler demangler;
+
+  ASSERT_EQ("func()", demangler.Parse("_ZN4funcEv"));
+  ASSERT_EQ("func(void&)", demangler.Parse("_ZN4funcERv"));
+  ASSERT_EQ("func(void, void)", demangler.Parse("_ZN4funcEvv"));
+  ASSERT_EQ("func(void*)", demangler.Parse("_ZN4funcEPv"));
+  ASSERT_EQ("func(void const)", demangler.Parse("_ZN4funcEKv"));
+  ASSERT_EQ("func(void volatile)", demangler.Parse("_ZN4funcEVv"));
+}
+
+TEST(DemangleTest, ArgumentModifiers) {
+  Demangler demangler;
+
+  ASSERT_EQ("func(char)", demangler.Parse("_ZN4funcEc"));
+  ASSERT_EQ("func(char*)", demangler.Parse("_ZN4funcEPc"));
+  ASSERT_EQ("func(char**)", demangler.Parse("_ZN4funcEPPc"));
+  ASSERT_EQ("func(char***)", demangler.Parse("_ZN4funcEPPPc"));
+  ASSERT_EQ("func(char&)", demangler.Parse("_ZN4funcERc"));
+  ASSERT_EQ("func(char*&)", demangler.Parse("_ZN4funcERPc"));
+  ASSERT_EQ("func(char&)", demangler.Parse("_ZN4funcERRc"));
+  ASSERT_EQ("func(char*&*)", demangler.Parse("_ZN4funcEPRPc"));
+  ASSERT_EQ("func(char**&)", demangler.Parse("_ZN4funcERRPPc"));
+  ASSERT_EQ("func(char const)", demangler.Parse("_ZN4funcEKc"));
+  ASSERT_EQ("func(char volatile)", demangler.Parse("_ZN4funcEVc"));
+  ASSERT_EQ("func(char volatile const)", demangler.Parse("_ZN4funcEKVc"));
+  ASSERT_EQ("func(char const volatile)", demangler.Parse("_ZN4funcEVKc"));
+  ASSERT_EQ("func(char const* volatile&)", demangler.Parse("_ZN4funcERVPKc"));
+  ASSERT_EQ("func(void, char, short)", demangler.Parse("_ZN4funcEvcs"));
+  ASSERT_EQ("func(void*, char&, short&*)", demangler.Parse("_ZN4funcEPvRcPRs"));
+}
+
+TEST(DemangleTest, FunctionModifiers) {
+  Demangler demangler;
+
+  ASSERT_EQ("func() const", demangler.Parse("_ZNK4funcEv"));
+  ASSERT_EQ("func() volatile", demangler.Parse("_ZNV4funcEv"));
+  ASSERT_EQ("func() volatile const", demangler.Parse("_ZNKV4funcEv"));
+  ASSERT_EQ("func() const volatile", demangler.Parse("_ZNVK4funcEv"));
+}
+
+TEST(DemangleTest, MultiplePartsInName) {
+  Demangler demangler;
+
+  ASSERT_EQ("one::two()", demangler.Parse("_ZN3one3twoEv"));
+  ASSERT_EQ("one::two::three()", demangler.Parse("_ZN3one3two5threeEv"));
+  ASSERT_EQ("one::two::three::four()", demangler.Parse("_ZN3one3two5three4fourEv"));
+  ASSERT_EQ("one::two::three::four::five()", demangler.Parse("_ZN3one3two5three4four4fiveEv"));
+  ASSERT_EQ("one(two::three::four::five)", demangler.Parse("_ZN3oneEN3two5three4four4fiveE"));
+}
+
+TEST(DemangleTest, AnonymousNamespace) {
+  Demangler demangler;
+
+  ASSERT_EQ("(anonymous namespace)::two()", demangler.Parse("_ZN12_GLOBAL__N_13twoEv"));
+  ASSERT_EQ("one::two((anonymous namespace))", demangler.Parse("_ZN3one3twoE12_GLOBAL__N_1"));
+}
+
+TEST(DemangleTest, DestructorValues) {
+  Demangler demangler;
+
+  ASSERT_EQ("one::two::~two()", demangler.Parse("_ZN3one3twoD0Ev"));
+  ASSERT_EQ("one::two::~two()", demangler.Parse("_ZN3one3twoD1Ev"));
+  ASSERT_EQ("one::two::~two()", demangler.Parse("_ZN3one3twoD2Ev"));
+  ASSERT_EQ("one::two::~two()", demangler.Parse("_ZN3one3twoD5Ev"));
+  ASSERT_EQ("one::two::three::~three()", demangler.Parse("_ZN3one3two5threeD0Ev"));
+
+  ASSERT_EQ("_ZN3one3twoD3Ev", demangler.Parse("_ZN3one3twoD3Ev"));
+  ASSERT_EQ("_ZN3one3twoD4Ev", demangler.Parse("_ZN3one3twoD4Ev"));
+  ASSERT_EQ("_ZN3one3twoD6Ev", demangler.Parse("_ZN3one3twoD6Ev"));
+  ASSERT_EQ("_ZN3one3twoD7Ev", demangler.Parse("_ZN3one3twoD7Ev"));
+  ASSERT_EQ("_ZN3one3twoD8Ev", demangler.Parse("_ZN3one3twoD8Ev"));
+  ASSERT_EQ("_ZN3one3twoD9Ev", demangler.Parse("_ZN3one3twoD9Ev"));
+
+  ASSERT_EQ("one::two<three::four>::~two()", demangler.Parse("_ZN3one3twoIN5three4fourEED2Ev"));
+}
+
+TEST(DemangleTest, ConstructorValues) {
+  Demangler demangler;
+
+  ASSERT_EQ("one::two::two()", demangler.Parse("_ZN3one3twoC1Ev"));
+  ASSERT_EQ("one::two::two()", demangler.Parse("_ZN3one3twoC2Ev"));
+  ASSERT_EQ("one::two::two()", demangler.Parse("_ZN3one3twoC3Ev"));
+  ASSERT_EQ("one::two::two()", demangler.Parse("_ZN3one3twoC5Ev"));
+  ASSERT_EQ("one::two::three::three()", demangler.Parse("_ZN3one3two5threeC1Ev"));
+
+  ASSERT_EQ("_ZN3one3twoC0Ev", demangler.Parse("_ZN3one3twoC0Ev"));
+  ASSERT_EQ("_ZN3one3twoC4Ev", demangler.Parse("_ZN3one3twoC4Ev"));
+  ASSERT_EQ("_ZN3one3twoC6Ev", demangler.Parse("_ZN3one3twoC6Ev"));
+  ASSERT_EQ("_ZN3one3twoC7Ev", demangler.Parse("_ZN3one3twoC7Ev"));
+  ASSERT_EQ("_ZN3one3twoC8Ev", demangler.Parse("_ZN3one3twoC8Ev"));
+  ASSERT_EQ("_ZN3one3twoC9Ev", demangler.Parse("_ZN3one3twoC9Ev"));
+
+  ASSERT_EQ("one::two<three::four>::two()", demangler.Parse("_ZN3one3twoIN5three4fourEEC1Ev"));
+}
+
+TEST(DemangleTest, OperatorValues) {
+  Demangler demangler;
+
+  ASSERT_EQ("operator&&()", demangler.Parse("_Zaav"));
+  ASSERT_EQ("operator&()", demangler.Parse("_Zadv"));
+  ASSERT_EQ("operator&()", demangler.Parse("_Zanv"));
+  ASSERT_EQ("operator&=()", demangler.Parse("_ZaNv"));
+  ASSERT_EQ("operator=()", demangler.Parse("_ZaSv"));
+  ASSERT_EQ("operator()()", demangler.Parse("_Zclv"));
+  ASSERT_EQ("operator,()", demangler.Parse("_Zcmv"));
+  ASSERT_EQ("operator~()", demangler.Parse("_Zcov"));
+  ASSERT_EQ("operator delete[]()", demangler.Parse("_Zdav"));
+  ASSERT_EQ("operator*()", demangler.Parse("_Zdev"));
+  ASSERT_EQ("operator delete()", demangler.Parse("_Zdlv"));
+  ASSERT_EQ("operator/()", demangler.Parse("_Zdvv"));
+  ASSERT_EQ("operator/=()", demangler.Parse("_ZdVv"));
+  ASSERT_EQ("operator^()", demangler.Parse("_Zeov"));
+  ASSERT_EQ("operator^=()", demangler.Parse("_ZeOv"));
+  ASSERT_EQ("operator==()", demangler.Parse("_Zeqv"));
+  ASSERT_EQ("operator>=()", demangler.Parse("_Zgev"));
+  ASSERT_EQ("operator>()", demangler.Parse("_Zgtv"));
+  ASSERT_EQ("operator[]()", demangler.Parse("_Zixv"));
+  ASSERT_EQ("operator<=()", demangler.Parse("_Zlev"));
+  ASSERT_EQ("operator<<()", demangler.Parse("_Zlsv"));
+  ASSERT_EQ("operator<<=()", demangler.Parse("_ZlSv"));
+  ASSERT_EQ("operator<()", demangler.Parse("_Zltv"));
+  ASSERT_EQ("operator-()", demangler.Parse("_Zmiv"));
+  ASSERT_EQ("operator-=()", demangler.Parse("_ZmIv"));
+  ASSERT_EQ("operator*()", demangler.Parse("_Zmlv"));
+  ASSERT_EQ("operator*=()", demangler.Parse("_ZmLv"));
+  ASSERT_EQ("operator--()", demangler.Parse("_Zmmv"));
+  ASSERT_EQ("operator new[]()", demangler.Parse("_Znav"));
+  ASSERT_EQ("operator!=()", demangler.Parse("_Znev"));
+  ASSERT_EQ("operator-()", demangler.Parse("_Zngv"));
+  ASSERT_EQ("operator!()", demangler.Parse("_Zntv"));
+  ASSERT_EQ("operator new()", demangler.Parse("_Znwv"));
+  ASSERT_EQ("operator||()", demangler.Parse("_Zoov"));
+  ASSERT_EQ("operator|()", demangler.Parse("_Zorv"));
+  ASSERT_EQ("operator|=()", demangler.Parse("_ZoRv"));
+  ASSERT_EQ("operator->*()", demangler.Parse("_Zpmv"));
+  ASSERT_EQ("operator+()", demangler.Parse("_Zplv"));
+  ASSERT_EQ("operator+=()", demangler.Parse("_ZpLv"));
+  ASSERT_EQ("operator++()", demangler.Parse("_Zppv"));
+  ASSERT_EQ("operator+()", demangler.Parse("_Zpsv"));
+  ASSERT_EQ("operator->()", demangler.Parse("_Zptv"));
+  ASSERT_EQ("operator?()", demangler.Parse("_Zquv"));
+  ASSERT_EQ("operator%()", demangler.Parse("_Zrmv"));
+  ASSERT_EQ("operator%=()", demangler.Parse("_ZrMv"));
+  ASSERT_EQ("operator>>()", demangler.Parse("_Zrsv"));
+  ASSERT_EQ("operator>>=()", demangler.Parse("_ZrSv"));
+
+  // Spot check using an operator as part of function name.
+  ASSERT_EQ("operator&&()", demangler.Parse("_ZNaaEv"));
+  ASSERT_EQ("operator++()", demangler.Parse("_ZNppEv"));
+  ASSERT_EQ("one::operator++()", demangler.Parse("_ZN3oneppEv"));
+
+  // Spot check using an operator in an argument name.
+  ASSERT_EQ("operator+(operator|=)", demangler.Parse("_ZNpsENoRE"));
+  ASSERT_EQ("operator==()", demangler.Parse("_Zeqv"));
+  ASSERT_EQ("one(arg1::operator|=, arg2::operator==)",
+            demangler.Parse("_ZN3oneEN4arg1oREN4arg2eqE"));
+}
+
+TEST(DemangleTest, FunctionStartsWithNumber) {
+  Demangler demangler;
+
+  ASSERT_EQ("value(char, int)", demangler.Parse("_Z5valueci"));
+  ASSERT_EQ("abcdefjklmn(signed char)", demangler.Parse("_Z11abcdefjklmna"));
+  ASSERT_EQ("value(one, signed char)", demangler.Parse("_Z5value3onea"));
+}
+
+TEST(DemangleTest, StdTypes) {
+  Demangler demangler;
+
+  ASSERT_EQ("std::one", demangler.Parse("_ZNSt3oneE"));
+  ASSERT_EQ("std::one(std::two)", demangler.Parse("_ZNSt3oneESt3two"));
+  ASSERT_EQ("std::std::one(std::two)", demangler.Parse("_ZNStSt3oneESt3two"));
+  ASSERT_EQ("std()", demangler.Parse("_ZNStEv"));
+  ASSERT_EQ("one::std::std::two::~two(one::std::std::two)",
+            demangler.Parse("_ZN3oneStSt3twoD0ES0_"));
+
+  ASSERT_EQ("std::allocator", demangler.Parse("_ZNSaE"));
+  ASSERT_EQ("std::basic_string", demangler.Parse("_ZNSbE"));
+  ASSERT_EQ("_ZNScE", demangler.Parse("_ZNScE"));
+  ASSERT_EQ("std::iostream", demangler.Parse("_ZNSdE"));
+  ASSERT_EQ("_ZNSeE", demangler.Parse("_ZNSeE"));
+  ASSERT_EQ("_ZNSfE", demangler.Parse("_ZNSfE"));
+  ASSERT_EQ("_ZNSgE", demangler.Parse("_ZNSgE"));
+  ASSERT_EQ("_ZNShE", demangler.Parse("_ZNShE"));
+  ASSERT_EQ("std::istream", demangler.Parse("_ZNSiE"));
+  ASSERT_EQ("_ZNSjE", demangler.Parse("_ZNSjE"));
+  ASSERT_EQ("_ZNSkE", demangler.Parse("_ZNSkE"));
+  ASSERT_EQ("_ZNSlE", demangler.Parse("_ZNSlE"));
+  ASSERT_EQ("_ZNSmE", demangler.Parse("_ZNSmE"));
+  ASSERT_EQ("_ZNSnE", demangler.Parse("_ZNSnE"));
+  ASSERT_EQ("std::ostream", demangler.Parse("_ZNSoE"));
+  ASSERT_EQ("_ZNSpE", demangler.Parse("_ZNSpE"));
+  ASSERT_EQ("_ZNSqE", demangler.Parse("_ZNSqE"));
+  ASSERT_EQ("_ZNSrE", demangler.Parse("_ZNSrE"));
+  ASSERT_EQ("std::string", demangler.Parse("_ZNSsE"));
+  ASSERT_EQ("_ZNSuE", demangler.Parse("_ZNSuE"));
+  ASSERT_EQ("_ZNSvE", demangler.Parse("_ZNSvE"));
+  ASSERT_EQ("_ZNSwE", demangler.Parse("_ZNSwE"));
+  ASSERT_EQ("_ZNSxE", demangler.Parse("_ZNSxE"));
+  ASSERT_EQ("_ZNSyE", demangler.Parse("_ZNSyE"));
+  ASSERT_EQ("_ZNSzE", demangler.Parse("_ZNSzE"));
+}
+
+TEST(DemangleTest, SingleLetterArguments) {
+  Demangler demangler;
+
+  ASSERT_EQ("func(signed char)", demangler.Parse("_ZN4funcEa"));
+  ASSERT_EQ("func(bool)", demangler.Parse("_ZN4funcEb"));
+  ASSERT_EQ("func(char)", demangler.Parse("_ZN4funcEc"));
+  ASSERT_EQ("func(double)", demangler.Parse("_ZN4funcEd"));
+  ASSERT_EQ("func(long double)", demangler.Parse("_ZN4funcEe"));
+  ASSERT_EQ("func(float)", demangler.Parse("_ZN4funcEf"));
+  ASSERT_EQ("func(__float128)", demangler.Parse("_ZN4funcEg"));
+  ASSERT_EQ("func(unsigned char)", demangler.Parse("_ZN4funcEh"));
+  ASSERT_EQ("func(int)", demangler.Parse("_ZN4funcEi"));
+  ASSERT_EQ("func(unsigned int)", demangler.Parse("_ZN4funcEj"));
+  ASSERT_EQ("_ZN4funcEk", demangler.Parse("_ZN4funcEk"));
+  ASSERT_EQ("func(long)", demangler.Parse("_ZN4funcEl"));
+  ASSERT_EQ("func(unsigned long)", demangler.Parse("_ZN4funcEm"));
+  ASSERT_EQ("func(__int128)", demangler.Parse("_ZN4funcEn"));
+  ASSERT_EQ("func(unsigned __int128)", demangler.Parse("_ZN4funcEo"));
+  ASSERT_EQ("_ZN4funcEp", demangler.Parse("_ZN4funcEp"));
+  ASSERT_EQ("_ZN4funcEq", demangler.Parse("_ZN4funcEq"));
+  ASSERT_EQ("_ZN4funcEr", demangler.Parse("_ZN4funcEr"));
+  ASSERT_EQ("func(short)", demangler.Parse("_ZN4funcEs"));
+  ASSERT_EQ("func(unsigned short)", demangler.Parse("_ZN4funcEt"));
+  ASSERT_EQ("_ZN4funcEu", demangler.Parse("_ZN4funcEu"));
+  ASSERT_EQ("func()", demangler.Parse("_ZN4funcEv"));
+  ASSERT_EQ("func(wchar_t)", demangler.Parse("_ZN4funcEw"));
+  ASSERT_EQ("func(long long)", demangler.Parse("_ZN4funcEx"));
+  ASSERT_EQ("func(unsigned long long)", demangler.Parse("_ZN4funcEy"));
+  ASSERT_EQ("func(...)", demangler.Parse("_ZN4funcEz"));
+}
+
+TEST(DemangleTest, DArguments) {
+  Demangler demangler;
+
+  ASSERT_EQ("func(auto)", demangler.Parse("_ZN4funcEDa"));
+  ASSERT_EQ("_ZN4funcEDb", demangler.Parse("_ZN4funcEDb"));
+  ASSERT_EQ("_ZN4funcEDc", demangler.Parse("_ZN4funcEDc"));
+  ASSERT_EQ("func(decimal64)", demangler.Parse("_ZN4funcEDd"));
+  ASSERT_EQ("func(decimal128)", demangler.Parse("_ZN4funcEDe"));
+  ASSERT_EQ("func(decimal32)", demangler.Parse("_ZN4funcEDf"));
+  ASSERT_EQ("_ZN4funcEDg", demangler.Parse("_ZN4funcEDg"));
+  ASSERT_EQ("func(half)", demangler.Parse("_ZN4funcEDh"));
+  ASSERT_EQ("func(char32_t)", demangler.Parse("_ZN4funcEDi"));
+  ASSERT_EQ("_ZN4funcEDj", demangler.Parse("_ZN4funcEDj"));
+  ASSERT_EQ("_ZN4funcEDk", demangler.Parse("_ZN4funcEDk"));
+  ASSERT_EQ("_ZN4funcEDl", demangler.Parse("_ZN4funcEDl"));
+  ASSERT_EQ("_ZN4funcEDm", demangler.Parse("_ZN4funcEDm"));
+  ASSERT_EQ("func(decltype(nullptr))", demangler.Parse("_ZN4funcEDn"));
+  ASSERT_EQ("_ZN4funcEDo", demangler.Parse("_ZN4funcEDo"));
+  ASSERT_EQ("_ZN4funcEDp", demangler.Parse("_ZN4funcEDp"));
+  ASSERT_EQ("_ZN4funcEDq", demangler.Parse("_ZN4funcEDq"));
+  ASSERT_EQ("_ZN4funcEDr", demangler.Parse("_ZN4funcEDr"));
+  ASSERT_EQ("func(char16_t)", demangler.Parse("_ZN4funcEDs"));
+  ASSERT_EQ("_ZN4funcEDt", demangler.Parse("_ZN4funcEDt"));
+  ASSERT_EQ("_ZN4funcEDu", demangler.Parse("_ZN4funcEDu"));
+  ASSERT_EQ("_ZN4funcEDv", demangler.Parse("_ZN4funcEDv"));
+  ASSERT_EQ("_ZN4funcEDw", demangler.Parse("_ZN4funcEDw"));
+  ASSERT_EQ("_ZN4funcEDx", demangler.Parse("_ZN4funcEDx"));
+  ASSERT_EQ("_ZN4funcEDy", demangler.Parse("_ZN4funcEDy"));
+  ASSERT_EQ("_ZN4funcEDz", demangler.Parse("_ZN4funcEDz"));
+}
+
+TEST(DemangleTest, FunctionArguments) {
+  Demangler demangler;
+
+  ASSERT_EQ("func(char ())", demangler.Parse("_ZN4funcEFcvE"));
+  ASSERT_EQ("func(char (*)())", demangler.Parse("_ZN4funcEPFcvE"));
+  ASSERT_EQ("func(char (&)())", demangler.Parse("_ZN4funcERFcvE"));
+  ASSERT_EQ("func(char (&)())", demangler.Parse("_ZN4funcERFcvE"));
+  ASSERT_EQ("func(char (*&)())", demangler.Parse("_ZN4funcERPFcvE"));
+  ASSERT_EQ("func(char (*)(int) const)", demangler.Parse("_ZN4funcEPKFciE"));
+  ASSERT_EQ("func(char (&)() const)", demangler.Parse("_ZN4funcERKFcvE"));
+  ASSERT_EQ("func(char (&)() volatile)", demangler.Parse("_ZN4funcERVFcvE"));
+  ASSERT_EQ("func(char (&)() volatile const)", demangler.Parse("_ZN4funcERKVFcvE"));
+  ASSERT_EQ("func(char (&)() const volatile)", demangler.Parse("_ZN4funcERVKFcvE"));
+  ASSERT_EQ("func(char (&)(int, signed char) const)", demangler.Parse("_ZN4funcERKFciaE"));
+  ASSERT_EQ("fake(char (&* volatile const)(void, void, signed char), signed char)",
+            demangler.Parse("_ZN4fakeEKVPRFcvvaEa"));
+}
+
+TEST(DemangleTest, TemplateFunction) {
+  Demangler demangler;
+
+  ASSERT_EQ("one<char>", demangler.Parse("_ZN3oneIcEE"));
+  ASSERT_EQ("one<void>", demangler.Parse("_ZN3oneIvEE"));
+  ASSERT_EQ("one<void*>", demangler.Parse("_ZN3oneIPvEE"));
+  ASSERT_EQ("one<void const>", demangler.Parse("_ZN3oneIKvEE"));
+  ASSERT_EQ("one<char, int, bool>", demangler.Parse("_ZN3oneIcibEE"));
+  ASSERT_EQ("one::two<three>", demangler.Parse("_ZN3one3twoIN5threeEEE"));
+  ASSERT_EQ("one<char, int, two::three>", demangler.Parse("_ZN3oneIciN3two5threeEEE"));
+  // Template within templates.
+  ASSERT_EQ("one::two<three<char, int>>", demangler.Parse("_ZN3one3twoIN5threeIciEEEE"));
+  ASSERT_EQ("one::two<three<char, four<int>>>", demangler.Parse("_ZN3one3twoIN5threeIcN4fourIiEEEEEE"));
+}
+
+TEST(DemangleTest, TemplateArguments) {
+  Demangler demangler;
+
+  ASSERT_EQ("one(two<char>)", demangler.Parse("_ZN3oneE3twoIcE"));
+  ASSERT_EQ("one(two<char, void>)", demangler.Parse("_ZN3oneE3twoIcvE"));
+  ASSERT_EQ("one(two<char, void, three<four, int>>)",
+            demangler.Parse("_ZN3oneE3twoIcv5threeI4fouriEE"));
+}
+
+TEST(DemangleTest, SubstitutionUnderscore) {
+  Demangler demangler;
+
+  ASSERT_EQ("a::a", demangler.Parse("_ZN1aS_E"));
+  ASSERT_EQ("one::one", demangler.Parse("_ZN3oneS_E"));
+  ASSERT_EQ("one::two::one", demangler.Parse("_ZN3one3twoS_E"));
+  ASSERT_EQ("one::two::three::one", demangler.Parse("_ZN3one3two5threeS_E"));
+  ASSERT_EQ("one::two(one)", demangler.Parse("_ZN3one3twoES_"));
+  ASSERT_EQ("one::two(three::one)", demangler.Parse("_ZN3one3twoEN5threeS_E"));
+
+  // Special case that St is part of the saved value used in the substitution.
+  ASSERT_EQ("std::one::std::one", demangler.Parse("_ZNSt3oneS_E"));
+
+  // Multiple substitutions in the string.
+  ASSERT_EQ("one::one(one, one)", demangler.Parse("_ZN3oneS_ES_S_"));
+  ASSERT_EQ("std::one::two::std::one(std::one)", demangler.Parse("_ZNSt3one3twoS_ES_"));
+}
+
+TEST(DemangleTest, SubstitutionByNumber) {
+  Demangler demangler;
+
+  // Basic substitution.
+  ASSERT_EQ("a::b::c(a::b)", demangler.Parse("_ZN1a1b1cES0_"));
+  ASSERT_EQ("_ZN1a1b1cES1_", demangler.Parse("_ZN1a1b1cES1_"));
+  ASSERT_EQ("a::b::c::d(a::b::c)", demangler.Parse("_ZN1a1b1c1dES1_"));
+  ASSERT_EQ("a::b::c::d::e::f::g::h::i::j::k::l::m::n::o::p::q(a::b::c::d::e::f::g::h::i::j::k::l)",
+            demangler.Parse("_ZN1a1b1c1d1e1f1g1h1i1j1k1l1m1n1o1p1qESA_"));
+  ASSERT_EQ("a::b::c::d::e::f::g::h::i::j::k::l::m::n::o::p::q(a::b::c::d::e::f::g::h::i::j::k::l::m)",
+            demangler.Parse("_ZN1a1b1c1d1e1f1g1h1i1j1k1l1m1n1o1p1qESB_"));
+
+  // Verify argument modifiers are included in substitution list.
+  ASSERT_EQ("one::two(char&* volatile const, char&)", demangler.Parse("_ZN3one3twoEKVPRcS0_"));
+  ASSERT_EQ("one::two(char&* volatile const, char&*)", demangler.Parse("_ZN3one3twoEKVPRcS1_"));
+  ASSERT_EQ("one::two(char&* volatile const, char&* volatile const)",
+            demangler.Parse("_ZN3one3twoEKVPRcS2_"));
+  ASSERT_EQ("one::two(int&* volatile* const, int&)", demangler.Parse("_ZN3one3twoEKPVPRiS0_"));
+  ASSERT_EQ("one::two(int&* volatile const, int&*)", demangler.Parse("_ZN3one3twoEKVPRiS1_"));
+  ASSERT_EQ("one::two(int&* volatile const, int&* volatile const)",
+            demangler.Parse("_ZN3one3twoEKVPRiS2_"));
+
+  // Verify Constructor/Destructor does properly save from function name.
+  ASSERT_EQ("_ZN1a1bES0_", demangler.Parse("_ZN1a1bES0_"));
+  ASSERT_EQ("a::b::b(a::b)", demangler.Parse("_ZN1a1bC1ES0_"));
+  ASSERT_EQ("a::b::~b(a::b)", demangler.Parse("_ZN1a1bD0ES0_"));
+
+  // Make sure substitution values are not saved.
+  ASSERT_EQ("a::b::b(a::b, char*, char*)", demangler.Parse("_ZN1a1bC1ES0_PcS1_"));
+}
+
+TEST(DemangleTest, ComplexSubstitution) {
+  Demangler demangler;
+
+  ASSERT_EQ("one::two<one::three>::two()", demangler.Parse("_ZN3one3twoINS_5threeEEC1Ev"));
+  ASSERT_EQ("one::two::two(one::two const&, bool, one::three*)",
+            demangler.Parse("_ZN3one3twoC2ERKS0_bPNS_5threeE"));
+  ASSERT_EQ("one::two::three::four<one::five>::~four(one::two*)",
+            demangler.Parse("_ZN3one3two5three4fourINS_4fiveEED2EPS0_"));
+  ASSERT_EQ("one::two::three::four<one::five>::~four(one::two::three*)",
+            demangler.Parse("_ZN3one3two5three4fourINS_4fiveEED2EPS1_"));
+  ASSERT_EQ("one::two::three::four<one::five>::~four(one::two::three::four*)",
+            demangler.Parse("_ZN3one3two5three4fourINS_4fiveEED2EPS2_"));
+  ASSERT_EQ("one::two::three::four<one::five>::~four(one::five*)",
+            demangler.Parse("_ZN3one3two5three4fourINS_4fiveEED2EPS3_"));
+}
+
+TEST(DemangleTest, StringTooLong) {
+  Demangler demangler;
+
+  ASSERT_EQ("_ZN3one3twoC2ERKS0_bPNS_5threeE",
+            demangler.Parse("_ZN3one3twoC2ERKS0_bPNS_5threeE", 10));
+  ASSERT_EQ("_ZN3one3twoC2ERKS0_bPNS_5threeE",
+            demangler.Parse("_ZN3one3twoC2ERKS0_bPNS_5threeE", 30));
+  ASSERT_EQ("one::two::two(one::two const&, bool, one::three*)",
+            demangler.Parse("_ZN3one3twoC2ERKS0_bPNS_5threeE", 31));
+
+  // Check the length check only occurs after the two letter value
+  // has been processed.
+  ASSERT_EQ("one::two(auto)", demangler.Parse("_ZN3one3twoEDa", 15));
+  ASSERT_EQ("one::two(auto)", demangler.Parse("_ZN3one3twoEDa", 14));
+  ASSERT_EQ("one::two(auto)", demangler.Parse("_ZN3one3twoEDa", 13));
+  ASSERT_EQ("_ZN3one3twoEDa", demangler.Parse("_ZN3one3twoEDa", 12));
+}
+
+TEST(DemangleTest, demangle) {
+  std::string str;
+
+  str = demangle("_ZN1a1b1cES0_");
+  ASSERT_EQ("a::b::c(a::b)", str);
+
+  str = demangle("_");
+  ASSERT_EQ("_", str);
+
+  str = demangle("_Z");
+  ASSERT_EQ("_Z", str);
+
+  str = demangle("_Za");
+  ASSERT_EQ("_Za", str);
+
+  str = demangle("_Zaa");
+  ASSERT_EQ("operator&&", str);
+
+  str = demangle("Xa");
+  ASSERT_EQ("Xa", str);
+}

demangle/Demangler.cpp

@@ -0,0 +1,746 @@
+/*
+ * Copyright (C) 2017 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <assert.h>
+
+#include <cctype>
+#include <stack>
+#include <string>
+#include <vector>
+
+#include "Demangler.h"
+
+constexpr const char* Demangler::kTypes[];
+constexpr const char* Demangler::kDTypes[];
+constexpr const char* Demangler::kSTypes[];
+
+void Demangler::Save(const std::string& str, bool is_name) {
+  saves_.push_back(str);
+  last_save_name_ = is_name;
+}
+
+std::string Demangler::GetArgumentsString() {
+  size_t num_args = cur_state_.args.size();
+  std::string arg_str;
+  if (num_args > 0) {
+    arg_str = cur_state_.args[0];
+    for (size_t i = 1; i < num_args; i++) {
+      arg_str += ", " + cur_state_.args[i];
+    }
+  }
+  return arg_str;
+}
+
+const char* Demangler::AppendOperatorString(const char* name) {
+  const char* oper = nullptr;
+  switch (*name) {
+  case 'a':
+    name++;
+    switch (*name) {
+    case 'a':
+      oper = "operator&&";
+      break;
+    case 'd':
+    case 'n':
+      oper = "operator&";
+      break;
+    case 'N':
+      oper = "operator&=";
+      break;
+    case 'S':
+      oper = "operator=";
+      break;
+    }
+    break;
+  case 'c':
+    name++;
+    switch (*name) {
+    case 'l':
+      oper = "operator()";
+      break;
+    case 'm':
+      oper = "operator,";
+      break;
+    case 'o':
+      oper = "operator~";
+      break;
+    }
+    break;
+  case 'd':
+    name++;
+    switch (*name) {
+    case 'a':
+      oper = "operator delete[]";
+      break;
+    case 'e':
+      oper = "operator*";
+      break;
+    case 'l':
+      oper = "operator delete";
+      break;
+    case 'v':
+      oper = "operator/";
+      break;
+    case 'V':
+      oper = "operator/=";
+      break;
+    }
+    break;
+  case 'e':
+    name++;
+    switch (*name) {
+    case 'o':
+      oper = "operator^";
+      break;
+    case 'O':
+      oper = "operator^=";
+      break;
+    case 'q':
+      oper = "operator==";
+      break;
+    }
+    break;
+  case 'g':
+    name++;
+    switch (*name) {
+    case 'e':
+      oper = "operator>=";
+      break;
+    case 't':
+      oper = "operator>";
+      break;
+    }
+    break;
+  case 'i':
+    name++;
+    switch (*name) {
+    case 'x':
+      oper = "operator[]";
+      break;
+    }
+    break;
+  case 'l':
+    name++;
+    switch (*name) {
+    case 'e':
+      oper = "operator<=";
+      break;
+    case 's':
+      oper = "operator<<";
+      break;
+    case 'S':
+      oper = "operator<<=";
+      break;
+    case 't':
+      oper = "operator<";
+      break;
+    }
+    break;
+  case 'm':
+    name++;
+    switch (*name) {
+    case 'i':
+      oper = "operator-";
+      break;
+    case 'I':
+      oper = "operator-=";
+      break;
+    case 'l':
+      oper = "operator*";
+      break;
+    case 'L':
+      oper = "operator*=";
+      break;
+    case 'm':
+      oper = "operator--";
+      break;
+    }
+    break;
+  case 'n':
+    name++;
+    switch (*name) {
+    case 'a':
+      oper = "operator new[]";
+      break;
+    case 'e':
+      oper = "operator!=";
+      break;
+    case 'g':
+      oper = "operator-";
+      break;
+    case 't':
+      oper = "operator!";
+      break;
+    case 'w':
+      oper = "operator new";
+      break;
+    }
+    break;
+  case 'o':
+    name++;
+    switch (*name) {
+    case 'o':
+      oper = "operator||";
+      break;
+    case 'r':
+      oper = "operator|";
+      break;
+    case 'R':
+      oper = "operator|=";
+      break;
+    }
+    break;
+  case 'p':
+    name++;
+    switch (*name) {
+    case 'm':
+      oper = "operator->*";
+      break;
+    case 'l':
+      oper = "operator+";
+      break;
+    case 'L':
+      oper = "operator+=";
+      break;
+    case 'p':
+      oper = "operator++";
+      break;
+    case 's':
+      oper = "operator+";
+      break;
+    case 't':
+      oper = "operator->";
+      break;
+    }
+    break;
+  case 'q':
+    name++;
+    switch (*name) {
+    case 'u':
+      oper = "operator?";
+      break;
+    }
+    break;
+  case 'r':
+    name++;
+    switch (*name) {
+    case 'm':
+      oper = "operator%";
+      break;
+    case 'M':
+      oper = "operator%=";
+      break;
+    case 's':
+      oper = "operator>>";
+      break;
+    case 'S':
+      oper = "operator>>=";
+      break;
+    }
+    break;
+  }
+  if (oper == nullptr) {
+    return nullptr;
+  }
+  AppendCurrent(oper);
+  cur_state_.last_save = oper;
+  return name + 1;
+}
+
+const char* Demangler::GetStringFromLength(const char* name, std::string* str) {
+  assert(std::isdigit(*name));
+
+  size_t length = *name - '0';
+  name++;
+  while (*name != '\0' && std::isdigit(*name)) {
+    length = length * 10 + *name - '0';
+    name++;
+  }
+
+  std::string read_str;
+  while (*name != '\0' && length != 0) {
+    read_str += *name;
+    name++;
+    length--;
+  }
+  if (length != 0) {
+    return nullptr;
+  }
+  // Special replacement of _GLOBAL__N_1 to (anonymous namespace).
+  if (read_str == "_GLOBAL__N_1") {
+    *str += "(anonymous namespace)";
+  } else {
+    *str += read_str;
+  }
+  return name;
+}
+
+void Demangler::AppendCurrent(const std::string& str) {
+  if (!cur_state_.str.empty()) {
+    cur_state_.str += "::";
+  }
+  cur_state_.str += str;
+}
+
+void Demangler::AppendCurrent(const char* str) {
+  if (!cur_state_.str.empty()) {
+    cur_state_.str += "::";
+  }
+  cur_state_.str += str;
+}
+
+const char* Demangler::ParseS(const char* name) {
+  if (std::islower(*name)) {
+    const char* type = kSTypes[*name - 'a'];
+    if (type == nullptr) {
+      return nullptr;
+    }
+    AppendCurrent(type);
+    return name + 1;
+  }
+
+  if (saves_.empty()) {
+    return nullptr;
+  }
+
+  if (*name == '_') {
+    last_save_name_ = false;
+    AppendCurrent(saves_[0]);
+    return name + 1;
+  }
+
+  bool isdigit = std::isdigit(*name);
+  if (!isdigit && !std::isupper(*name)) {
+    return nullptr;
+  }
+
+  size_t index;
+  if (isdigit) {
+    index = *name - '0' + 1;
+  } else {
+    index = *name - 'A' + 11;
+  }
+  name++;
+  if (*name != '_') {
+    return nullptr;
+  }
+
+  if (index >= saves_.size()) {
+    return nullptr;
+  }
+
+  last_save_name_ = false;
+  AppendCurrent(saves_[index]);
+  return name + 1;
+}
+
+const char* Demangler::ParseFunctionName(const char* name) {
+  if (*name == 'E') {
+    if (parse_funcs_.empty()) {
+      return nullptr;
+    }
+    parse_func_ = parse_funcs_.back();
+    parse_funcs_.pop_back();
+
+    // Remove the last saved part so that the full function name is not saved.
+    // But only if the last save was not something like a substitution.
+    if (!saves_.empty() && last_save_name_) {
+      saves_.pop_back();
+    }
+
+    function_name_ = cur_state_.str;
+    while (!cur_state_.suffixes.empty()) {
+      function_suffix_ += cur_state_.suffixes.back();
+      cur_state_.suffixes.pop_back();
+    }
+    cur_state_.Clear();
+
+    return name + 1;
+  }
+
+  return ParseComplexString(name);
+}
+
+const char* Demangler::ParseComplexArgument(const char* name) {
+  if (*name == 'E') {
+    if (parse_funcs_.empty()) {
+      return nullptr;
+    }
+    parse_func_ = parse_funcs_.back();
+    parse_funcs_.pop_back();
+
+    AppendArgument(cur_state_.str);
+    cur_state_.str.clear();
+
+    return name + 1;
+  }
+
+  return ParseComplexString(name);
+}
+
+void Demangler::FinalizeTemplate() {
+  std::string arg_str(GetArgumentsString());
+  cur_state_ = state_stack_.top();
+  state_stack_.pop();
+  cur_state_.str += '<' + arg_str + '>';
+}
+
+const char* Demangler::ParseComplexString(const char* name) {
+  if (*name == 'S') {
+    name++;
+    if (*name == 't') {
+      AppendCurrent("std");
+      return name + 1;
+    }
+    return ParseS(name);
+  }
+  if (*name == 'L') {
+    name++;
+    if (!std::isdigit(*name)) {
+      return nullptr;
+    }
+  }
+  if (std::isdigit(*name)) {
+    std::string str;
+    name = GetStringFromLength(name, &str);
+    if (name == nullptr) {
+      return name;
+    }
+    AppendCurrent(str);
+    Save(cur_state_.str, true);
+    cur_state_.last_save = std::move(str);
+    return name;
+  }
+  if (*name == 'D') {
+    name++;
+    if (saves_.empty() || (*name != '0' && *name != '1' && *name != '2'
+        && *name != '5')) {
+      return nullptr;
+    }
+    last_save_name_ = false;
+    AppendCurrent("~" + cur_state_.last_save);
+    return name + 1;
+  }
+  if (*name == 'C') {
+    name++;
+    if (saves_.empty() || (*name != '1' && *name != '2' && *name != '3'
+        && *name != '5')) {
+      return nullptr;
+    }
+    last_save_name_ = false;
+    AppendCurrent(cur_state_.last_save);
+    return name + 1;
+  }
+  if (*name == 'K') {
+    cur_state_.suffixes.push_back(" const");
+    return name + 1;
+  }
+  if (*name == 'V') {
+    cur_state_.suffixes.push_back(" volatile");
+    return name + 1;
+  }
+  if (*name == 'I') {
+    // Save the current argument state.
+    state_stack_.push(cur_state_);
+    cur_state_.Clear();
+
+    parse_funcs_.push_back(parse_func_);
+    parse_func_ = &Demangler::ParseTemplateArgumentsComplex;
+    return name + 1;
+  }
+  name = AppendOperatorString(name);
+  if (name != nullptr) {
+    Save(cur_state_.str, true);
+  }
+  return name;
+}
+
+void Demangler::AppendArgument(const std::string& str) {
+  std::string arg(str);
+  while (!cur_state_.suffixes.empty()) {
+    arg += cur_state_.suffixes.back();
+    cur_state_.suffixes.pop_back();
+    Save(arg, false);
+  }
+  cur_state_.args.push_back(arg);
+}
+
+const char* Demangler::ParseFunctionArgument(const char* name) {
+  if (*name == 'E') {
+    // The first argument is the function modifier.
+    // The second argument is the function type.
+    // The third argument is the return type of the function.
+    // The rest of the arguments are the function arguments.
+    size_t num_args = cur_state_.args.size();
+    if (num_args < 4) {
+      return nullptr;
+    }
+    std::string function_modifier = cur_state_.args[0];
+    std::string function_type = cur_state_.args[1];
+
+    std::string str = cur_state_.args[2] + ' ';
+    if (!cur_state_.args[1].empty()) {
+      str += '(' + cur_state_.args[1] + ')';
+    }
+
+    if (num_args == 4 && cur_state_.args[3] == "void") {
+      str += "()";
+    } else {
+      str += '(' + cur_state_.args[3];
+      for (size_t i = 4; i < num_args; i++) {
+        str += ", " + cur_state_.args[i];
+      }
+      str += ')';
+    }
+    str += cur_state_.args[0];
+
+    cur_state_ = state_stack_.top();
+    state_stack_.pop();
+    cur_state_.args.emplace_back(std::move(str));
+
+    parse_func_ = parse_funcs_.back();
+    parse_funcs_.pop_back();
+    return name + 1;
+  }
+  return ParseArguments(name);
+}
+
+const char* Demangler::ParseArguments(const char* name) {
+  switch (*name) {
+  case 'P':
+    cur_state_.suffixes.push_back("*");
+    return name + 1;
+
+  case 'R':
+    // This should always be okay because the string is guaranteed to have
+    // at least two characters before this. A mangled string always starts
+    // with _Z.
+    if (name[-1] != 'R') {
+      // Multiple 'R's in a row only add a single &.
+      cur_state_.suffixes.push_back("&");
+    }
+    return name + 1;
+
+  case 'K':
+  case 'V': {
+    const char* suffix;
+    if (*name == 'K') {
+      suffix = " const";
+    } else {
+      suffix = " volatile";
+    }
+    if (name[-1] == 'K' || name[-1] == 'V') {
+      // Special case, const/volatile apply as a single entity.
+      assert(!cur_state_.suffixes.empty());
+      size_t index = cur_state_.suffixes.size();
+      cur_state_.suffixes[index-1].insert(0, suffix);
+    } else {
+      cur_state_.suffixes.push_back(suffix);
+    }
+    return name + 1;
+  }
+
+  case 'F': {
+    std::string function_modifier;
+    std::string function_type;
+    if (!cur_state_.suffixes.empty()) {
+      // If the first element starts with a ' ', then this modifies the
+      // function itself.
+      if (cur_state_.suffixes.back()[0] == ' ') {
+        function_modifier = cur_state_.suffixes.back();
+        cur_state_.suffixes.pop_back();
+      }
+      while (!cur_state_.suffixes.empty()) {
+        function_type += cur_state_.suffixes.back();
+        cur_state_.suffixes.pop_back();
+      }
+    }
+
+    state_stack_.push(cur_state_);
+
+    cur_state_.Clear();
+
+    // The function parameter has this format:
+    //   First argument is the function modifier.
+    //   Second argument is the function type.
+    //   Third argument will be the return function type but has not
+    //     been parsed yet.
+    //   Any other parameters are the arguments to the function. There
+    //     must be at least one or this isn't valid.
+    cur_state_.args.push_back(function_modifier);
+    cur_state_.args.push_back(function_type);
+
+    parse_funcs_.push_back(parse_func_);
+    parse_func_ = &Demangler::ParseFunctionArgument;
+    return name + 1;
+  }
+
+  case 'N':
+    parse_funcs_.push_back(parse_func_);
+    parse_func_ = &Demangler::ParseComplexArgument;
+    return name + 1;
+
+  case 'S':
+    name++;
+    if (*name == 't') {
+      cur_state_.str = "std::";
+      return name + 1;
+    }
+    name = ParseS(name);
+    if (name == nullptr) {
+      return nullptr;
+    }
+    AppendArgument(cur_state_.str);
+    cur_state_.str.clear();
+    return name;
+
+  case 'D':
+    name++;
+    if (*name >= 'a' && *name <= 'z') {
+      const char* arg = Demangler::kDTypes[*name - 'a'];
+      if (arg == nullptr) {
+        return nullptr;
+      }
+      AppendArgument(arg);
+      return name + 1;
+    }
+    return nullptr;
+
+  case 'I':
+    // Save the current argument state.
+    state_stack_.push(cur_state_);
+    cur_state_.Clear();
+
+    parse_funcs_.push_back(parse_func_);
+    parse_func_ = &Demangler::ParseTemplateArguments;
+    return name + 1;
+
+  case 'v':
+    AppendArgument("void");
+    return name + 1;
+
+  default:
+    if (*name >= 'a' && *name <= 'z') {
+      const char* arg = Demangler::kTypes[*name - 'a'];
+      if (arg == nullptr) {
+        return nullptr;
+      }
+      AppendArgument(arg);
+      return name + 1;
+    } else if (std::isdigit(*name)) {
+      std::string arg = cur_state_.str;
+      name = GetStringFromLength(name, &arg);
+      if (name == nullptr) {
+        return nullptr;
+      }
+      Save(arg, true);
+      if (*name == 'I') {
+        // There is one case where this argument is not complete, and that's
+        // where this is a template argument.
+        cur_state_.str = arg;
+      } else {
+        AppendArgument(arg);
+        cur_state_.str.clear();
+      }
+      return name;
+    }
+  }
+  return nullptr;
+}
+
+const char* Demangler::ParseTemplateArgumentsComplex(const char* name) {
+  if (*name == 'E') {
+    if (parse_funcs_.empty()) {
+      return nullptr;
+    }
+    parse_func_ = parse_funcs_.back();
+    parse_funcs_.pop_back();
+    FinalizeTemplate();
+    Save(cur_state_.str, false);
+    return name + 1;
+  }
+  return ParseArguments(name);
+}
+
+const char* Demangler::ParseTemplateArguments(const char* name) {
+  if (*name == 'E') {
+    if (parse_funcs_.empty()) {
+      return nullptr;
+    }
+    parse_func_ = parse_funcs_.back();
+    parse_funcs_.pop_back();
+    FinalizeTemplate();
+    AppendArgument(cur_state_.str);
+    cur_state_.str.clear();
+    return name + 1;
+  }
+  return ParseArguments(name);
+}
+
+const char* Demangler::FindFunctionName(const char* name) {
+  if (*name == 'N') {
+    parse_funcs_.push_back(&Demangler::ParseArguments);
+    parse_func_ = &Demangler::ParseFunctionName;
+    return name + 1;
+  }
+
+  if (std::isdigit(*name)) {
+    name = GetStringFromLength(name, &function_name_);
+  } else {
+    name = AppendOperatorString(name);
+    function_name_ = cur_state_.str;
+  }
+  parse_func_ = &Demangler::ParseArguments;
+  cur_state_.Clear();
+  return name;
+}
+
+std::string Demangler::Parse(const char* name, size_t max_length) {
+  if (name[0] == '\0' || name[0] != '_' || name[1] == '\0' || name[1] != 'Z') {
+    // Name is not mangled.
+    return name;
+  }
+
+  Clear();
+
+  parse_func_ = &Demangler::FindFunctionName;
+  parse_funcs_.push_back(&Demangler::Fail);
+  const char* cur_name = name + 2;
+  while (cur_name != nullptr && *cur_name != '\0'
+      && static_cast<size_t>(cur_name - name) < max_length) {
+    cur_name = (this->*parse_func_)(cur_name);
+  }
+  if (cur_name == nullptr || *cur_name != '\0' || function_name_.empty()) {
+    return name;
+  }
+
+  std::string arg_str;
+  if (cur_state_.args.size() == 1 && cur_state_.args[0] == "void") {
+    // If the only argument is void, then don't print any args.
+    arg_str = "()";
+  } else {
+    arg_str = GetArgumentsString();
+    if (!arg_str.empty()) {
+      arg_str = '(' + arg_str + ')';
+    }
+  }
+  return function_name_ + arg_str + function_suffix_;
+}
+
+std::string demangle(const char* name) {
+  Demangler demangler;
+  return demangler.Parse(name);
+}

demangle/Demangler.h

@@ -0,0 +1,191 @@
+/*
+ * Copyright (C) 2017 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef __LIB_DEMANGLE_DEMANGLER_H
+#define __LIB_DEMANGLE_DEMANGLER_H
+
+#include <assert.h>
+
+#include <stack>
+#include <string>
+#include <vector>
+
+class Demangler {
+ public:
+  Demangler() = default;
+
+  // NOTE: The max_length is not guaranteed to be the absolute max length
+  // of a string that will be rejected. Under certain circumstances the
+  // length check will not occur until after the second letter of a pair
+  // is checked.
+  std::string Parse(const char* name, size_t max_length = kMaxDefaultLength);
+
+  void AppendCurrent(const std::string& str);
+  void AppendCurrent(const char* str);
+  void AppendArgument(const std::string& str);
+  std::string GetArgumentsString();
+  void FinalizeTemplate();
+  const char* ParseS(const char* name);
+  const char* AppendOperatorString(const char* name);
+  void Save(const std::string& str, bool is_name);
+
+ private:
+  void Clear() {
+    parse_funcs_.clear();
+    function_name_.clear();
+    function_suffix_.clear();
+    first_save_.clear();
+    cur_state_.Clear();
+    saves_.clear();
+    while (!state_stack_.empty()) {
+      state_stack_.pop();
+    }
+    last_save_name_ = false;
+  }
+
+  using parse_func_type = const char* (Demangler::*)(const char*);
+  parse_func_type parse_func_;
+  std::vector<parse_func_type> parse_funcs_;
+  std::vector<std::string> saves_;
+  bool last_save_name_;
+
+  std::string function_name_;
+  std::string function_suffix_;
+
+  struct StateData {
+    void Clear() {
+      str.clear();
+      args.clear();
+      prefix.clear();
+      suffixes.clear();
+      last_save.clear();
+    }
+
+    std::string str;
+    std::vector<std::string> args;
+    std::string prefix;
+    std::vector<std::string> suffixes;
+    std::string last_save;
+  };
+  std::stack<StateData> state_stack_;
+  std::string first_save_;
+  StateData cur_state_;
+
+  static const char* GetStringFromLength(const char* name, std::string* str);
+
+  // Parsing functions.
+  const char* ParseComplexString(const char* name);
+  const char* ParseComplexArgument(const char* name);
+  const char* ParseArguments(const char* name);
+  const char* ParseTemplateArguments(const char* name);
+  const char* ParseTemplateArgumentsComplex(const char* name);
+  const char* ParseFunctionArgument(const char* name);
+  const char* ParseFunctionName(const char* name);
+  const char* FindFunctionName(const char* name);
+  const char* Fail(const char*) { return nullptr; }
+
+  // The default maximum string length string to process.
+  static constexpr size_t kMaxDefaultLength = 2048;
+
+  static constexpr const char* kTypes[] = {
+    "signed char",        // a
+    "bool",               // b
+    "char",               // c
+    "double",             // d
+    "long double",        // e
+    "float",              // f
+    "__float128",         // g
+    "unsigned char",      // h
+    "int",                // i
+    "unsigned int",       // j
+    nullptr,              // k
+    "long",               // l
+    "unsigned long",      // m
+    "__int128",           // n
+    "unsigned __int128",  // o
+    nullptr,              // p
+    nullptr,              // q
+    nullptr,              // r
+    "short",              // s
+    "unsigned short",     // t
+    nullptr,              // u
+    "void",               // v
+    "wchar_t",            // w
+    "long long",          // x
+    "unsigned long long", // y
+    "...",                // z
+  };
+
+  static constexpr const char* kDTypes[] = {
+    "auto",               // a
+    nullptr,              // b
+    nullptr,              // c
+    "decimal64",          // d
+    "decimal128",         // e
+    "decimal32",          // f
+    nullptr,              // g
+    "half",               // h
+    "char32_t",           // i
+    nullptr,              // j
+    nullptr,              // k
+    nullptr,              // l
+    nullptr,              // m
+    "decltype(nullptr)",  // n
+    nullptr,              // o
+    nullptr,              // p
+    nullptr,              // q
+    nullptr,              // r
+    "char16_t",           // s
+    nullptr,              // t
+    nullptr,              // u
+    nullptr,              // v
+    nullptr,              // w
+    nullptr,              // x
+    nullptr,              // y
+    nullptr,              // z
+  };
+
+  static constexpr const char* kSTypes[] = {
+    "std::allocator",     // a
+    "std::basic_string",  // b
+    nullptr,              // c
+    "std::iostream",      // d
+    nullptr,              // e
+    nullptr,              // f
+    nullptr,              // g
+    nullptr,              // h
+    "std::istream",       // i
+    nullptr,              // j
+    nullptr,              // k
+    nullptr,              // l
+    nullptr,              // m
+    nullptr,              // n
+    "std::ostream",       // o
+    nullptr,              // p
+    nullptr,              // q
+    nullptr,              // r
+    "std::string",        // s
+    nullptr,              // t
+    nullptr,              // u
+    nullptr,              // v
+    nullptr,              // w
+    nullptr,              // x
+    nullptr,              // y
+    nullptr,              // z
+  };
+};
+
+#endif  // __LIB_DEMANGLE_DEMANGLER_H

demangle/include/demangle.h

@@ -0,0 +1,27 @@
+/*
+ * Copyright (C) 2017 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef __LIB_DEMANGLE_H_
+#define __LIB_DEMANGLE_H_
+
+#include <string>
+
+// If the name cannot be demangled, the original name will be returned as
+// a std::string. If the name can be demangled, then the demangled name
+// will be returned as a std::string.
+std::string demangle(const char* name);
+
+#endif  // __LIB_DEMANGLE_H_