diff --git a/llvm/docs/CommandGuide/llvm-addr2line.rst b/llvm/docs/CommandGuide/llvm-addr2line.rst
--- a/llvm/docs/CommandGuide/llvm-addr2line.rst
+++ b/llvm/docs/CommandGuide/llvm-addr2line.rst
@@ -17,6 +17,9 @@
 
 Here are some of those differences:
 
+-  Requires addresses to be in hexadecimal (with an optional leading ``0x``)
+   instead of interpreting them as C literals.
+
 -  Defaults not to print function names. Use `-f`_ to enable that.
 
 -  Defaults not to demangle function names. Use `-C`_ to switch the
diff --git a/llvm/test/lit.cfg.py b/llvm/test/lit.cfg.py
--- a/llvm/test/lit.cfg.py
+++ b/llvm/test/lit.cfg.py
@@ -145,7 +145,7 @@
 
 # FIXME: Why do we have both `lli` and `%lli` that do slightly different things?
 tools.extend([
-    'dsymutil', 'lli', 'lli-child-target', 'llvm-ar', 'llvm-as',
+    'dsymutil', 'lli', 'lli-child-target', 'llvm-ar', 'llvm-as', 'llvm-addr2line',
     'llvm-bcanalyzer', 'llvm-config', 'llvm-cov', 'llvm-cxxdump', 'llvm-cvtres',
     'llvm-diff', 'llvm-dis', 'llvm-dwarfdump', 'llvm-exegesis', 'llvm-extract',
     'llvm-isel-fuzzer', 'llvm-ifs', 'llvm-install-name-tool',
diff --git a/llvm/test/tools/llvm-symbolizer/input-base.test b/llvm/test/tools/llvm-symbolizer/input-base.test
new file mode 100644
--- /dev/null
+++ b/llvm/test/tools/llvm-symbolizer/input-base.test
@@ -0,0 +1,17 @@
+llvm-symbolizer infers the number base from the form of the address.
+RUN: llvm-symbolizer -e /dev/null -a 0x1234 | FileCheck %s
+RUN: llvm-symbolizer -e /dev/null -a 4660 | FileCheck %s
+RUN: llvm-symbolizer -e /dev/null -a 011064 | FileCheck %s
+RUN: llvm-symbolizer -e /dev/null -a 0b1001000110100 | FileCheck %s
+RUN: llvm-symbolizer -e /dev/null -a 0o11064 | FileCheck %s
+
+llvm-addr2line always assumes hexadecimal, but accepts an optional 0x prefix.
+RUN: llvm-addr2line -e /dev/null -a 0x1234 | FileCheck %s
+RUN: llvm-addr2line -e /dev/null -a 1234 | FileCheck %s
+RUN: llvm-addr2line -e /dev/null -a 01234 | FileCheck %s
+RUN: llvm-addr2line -e /dev/null -a 0b1010 | FileCheck %s --check-prefix=HEXADECIMAL-NOT-BINARY
+RUN: llvm-addr2line -e /dev/null -a 0o1234 | FileCheck %s --check-prefix=INVALID-NOT-OCTAL
+
+CHECK: 0x1234
+HEXADECIMAL-NOT-BINARY: 0xb1010
+INVALID-NOT-OCTAL: 0o1234
diff --git a/llvm/tools/llvm-symbolizer/llvm-symbolizer.cpp b/llvm/tools/llvm-symbolizer/llvm-symbolizer.cpp
--- a/llvm/tools/llvm-symbolizer/llvm-symbolizer.cpp
+++ b/llvm/tools/llvm-symbolizer/llvm-symbolizer.cpp
@@ -183,7 +183,7 @@
   Frame,
 };
 
-static bool parseCommand(StringRef InputString, Command &Cmd,
+static bool parseCommand(bool IsAddr2Line, StringRef InputString, Command &Cmd,
                          std::string &ModuleName, uint64_t &ModuleOffset) {
   const char kDelimiters[] = " \n\r";
   ModuleName = "";
@@ -220,15 +220,21 @@
   // Skip delimiters and parse module offset.
   pos += strspn(pos, kDelimiters);
   int offset_length = strcspn(pos, kDelimiters);
-  return !StringRef(pos, offset_length).getAsInteger(0, ModuleOffset);
+  StringRef offset(pos, offset_length);
+  // GNU addr2line assumes the offset is hexadecimal and allows a redundant
+  // "0x" or "0X" prefix; do the same for compatibility.
+  if (IsAddr2Line)
+    offset.consume_front("0x") || offset.consume_front("0X");
+  return !offset.getAsInteger(IsAddr2Line ? 16 : 0, ModuleOffset);
 }
 
-static void symbolizeInput(StringRef InputString, LLVMSymbolizer &Symbolizer,
-                           DIPrinter &Printer) {
+static void symbolizeInput(bool IsAddr2Line, StringRef InputString,
+                           LLVMSymbolizer &Symbolizer, DIPrinter &Printer) {
   Command Cmd;
   std::string ModuleName;
   uint64_t Offset = 0;
-  if (!parseCommand(StringRef(InputString), Cmd, ModuleName, Offset)) {
+  if (!parseCommand(IsAddr2Line, StringRef(InputString), Cmd, ModuleName,
+                    Offset)) {
     outs() << InputString << "\n";
     return;
   }
@@ -335,12 +341,12 @@
           std::remove_if(StrippedInputString.begin(), StrippedInputString.end(),
                          [](char c) { return c == '\r' || c == '\n'; }),
           StrippedInputString.end());
-      symbolizeInput(StrippedInputString, Symbolizer, Printer);
+      symbolizeInput(IsAddr2Line, StrippedInputString, Symbolizer, Printer);
       outs().flush();
     }
   } else {
     for (StringRef Address : ClInputAddresses)
-      symbolizeInput(Address, Symbolizer, Printer);
+      symbolizeInput(IsAddr2Line, Address, Symbolizer, Printer);
   }
 
   return 0;