Cleanup stack parsing / demangling

Fixes #596

Author: jimhester

inst/unitTests/cpp/exceptions.cpp

@@ -38,6 +38,14 @@ double takeLogRcpp(double val) {
     return log(val);
 }
 
+// [[Rcpp::export]]
+double takeLogStop(double val) {
+    if (val <= 0.0) {
+        Rcpp::stop("Inadmissible value");
+    }
+    return log(val);
+}
+
 // [[Rcpp::export]]
 double takeLogRcppLocation(double val) {
     if (val <= 0.0) {

inst/unitTests/runit.exceptions.R

@@ -58,6 +58,24 @@ test.rcppException <- function() {
   checkEquals(condition$call, quote(takeLogRcpp(-1L)))
 }
 
+test.rcppStop <- function() {
+
+  # Code works normally without an exception
+  checkIdentical(takeLog(1L), log(1L))
+
+  # C++ exceptions are converted to R conditions
+  condition <- tryCatch(takeLogStop(-1L), error = identity)
+
+  checkIdentical(condition$message, "Inadmissible value")
+  checkIdentical(class(condition), c("Rcpp::exception", "C++Error", "error", "condition"))
+
+  checkTrue(!is.null(condition$cppstack))
+
+  checkIdentical(class(condition$cppstack), "Rcpp_stack_trace")
+
+  checkEquals(condition$call, quote(takeLogStop(-1L)))
+}
+
 test.rcppExceptionLocation <- function() {
 
   # Code works normally without an exception

src/api.cpp

@@ -38,15 +38,24 @@ using namespace Rcpp;
     #else
         #include <execinfo.h>
 
+        // Extract mangled name e.g. ./test(baz+0x14)[0x400962]
         static std::string demangler_one(const char* input) {
             static std::string buffer;
             buffer = input;
-            buffer.resize(buffer.find_last_of('+') - 1);
-            buffer.erase(
-                buffer.begin(),
-                buffer.begin() + buffer.find_last_of(' ') + 1
-            );
-            return demangle(buffer);
+            size_t last_open = buffer.find_last_of('(');
+            size_t last_close = buffer.find_last_of(')');
+            if (last_open == std::string::npos ||
+                last_close == std::string::npos) {
+              return input;
+            }
+            std::string function_name = buffer.substr(last_open + 1, last_close - last_open - 1);
+            // Strip the +0x14 (if it exists, which it does not in earlier versions of gcc)
+            size_t function_plus = function_name.find_last_of('+');
+            if (function_plus != std::string::npos) {
+              function_name.resize(function_plus);
+            }
+            buffer.replace(last_open + 1, function_name.size(), demangle(function_name));
+            return buffer;
         }
     #endif
 #endif