feat: improve formatting of error messages from C

.gitignore

@@ -27,3 +27,4 @@ cran
 /.vscode/launch.json
 /Rplots.pdf
 /_codeql_detected_source_root
+tests/testthat/_problems/

R/utils.R

@@ -94,3 +94,23 @@ modify_list <- function(x, y) {
 
   utils::modifyList(x, y)
 }
+
+#' Test function to verify error formatting with file and line information
+#'
+#' @description
+#' This is a test function that throws an error from C code with file and line
+#' information.
+#' The error message should include the source file and line number where the
+#' error occurred.
+#'
+#' @return This function never returns; it always throws an error.
+#' @keywords internal
+#' @noRd
+#' @examples
+#' \dontrun{
+#' # This will throw an error with source location information
+#' test_error_with_source()
+#' }
+test_error_with_source <- function() {
+  .Call(Rx_igraph_test_error_with_source)
+}

src/cpp11.cpp

@@ -598,6 +598,7 @@ extern SEXP Rx_igraph_st_vertex_connectivity(SEXP, SEXP, SEXP);
 extern SEXP Rx_igraph_star(SEXP, SEXP, SEXP);
 extern SEXP Rx_igraph_subcomponent(SEXP, SEXP, SEXP);
 extern SEXP Rx_igraph_subisomorphic_lad(SEXP, SEXP, SEXP, SEXP, SEXP, SEXP, SEXP);
+extern SEXP Rx_igraph_test_error_with_source(void);
 extern SEXP Rx_igraph_transitivity_local_undirected_all(SEXP, SEXP);
 extern SEXP Rx_igraph_union(SEXP, SEXP);
 extern SEXP Rx_igraph_vcount(SEXP);
@@ -1192,6 +1193,7 @@ static const R_CallMethodDef CallEntries[] = {
     {"Rx_igraph_star",                                      (DL_FUNC) &Rx_igraph_star,                                       3},
     {"Rx_igraph_subcomponent",                              (DL_FUNC) &Rx_igraph_subcomponent,                               3},
     {"Rx_igraph_subisomorphic_lad",                         (DL_FUNC) &Rx_igraph_subisomorphic_lad,                          7},
+    {"Rx_igraph_test_error_with_source",                    (DL_FUNC) &Rx_igraph_test_error_with_source,                     0},
     {"Rx_igraph_transitivity_local_undirected_all",         (DL_FUNC) &Rx_igraph_transitivity_local_undirected_all,          2},
     {"Rx_igraph_union",                                     (DL_FUNC) &Rx_igraph_union,                                      2},
     {"Rx_igraph_vcount",                                    (DL_FUNC) &Rx_igraph_vcount,                                     1},

src/rinterface_extra.c

@@ -2315,6 +2315,18 @@ static inline const char* maybe_add_punctuation(const char* msg, const char* pun
   return is_punctuated(msg) ? "" : punctuation;
 }
 
+/* Strip vendor/cigraph/src/ prefix from file path. This prefix depends on the
+ * build procedure, namely on the directory that the compiler is invoked from. */
+static inline const char* simplify_file_path(const char *file) {
+  const char prefix[] = "vendor/cigraph/src/";
+  const size_t prefix_len = sizeof(prefix) - 1;
+
+  if (strncmp(file, prefix, prefix_len) == 0) {
+    return file + prefix_len;
+  }
+  return file;
+}
+
 void Rx_igraph_fatal_handler(const char *reason, const char *file, int line) {
 #ifdef IGRAPH_SANITIZER_AVAILABLE
     __sanitizer_print_stack_trace();
@@ -2336,10 +2348,12 @@ void Rx_igraph_error_handler(const char *reason, const char *file,
    * IGRAPH_FINALLY_FREE() can then clean it up. */
 
   if (Rx_igraph_errors_count == 0 || !Rx_igraph_in_r_check) {
+    const char* simplified_path = simplify_file_path(file);
     snprintf(Rx_igraph_error_reason, sizeof(Rx_igraph_error_reason),
-      "At %s:%i : %s%s %s", file, line, reason,
-      maybe_add_punctuation(reason, ","),
-      igraph_strerror(igraph_errno));
+      "%s%s %s\nSource: %s:%i", reason,
+      maybe_add_punctuation(reason, "."),
+      igraph_strerror(igraph_errno),
+      simplified_path, line);
     Rx_igraph_error_reason[sizeof(Rx_igraph_error_reason) - 1] = 0;
 
     // FIXME: This is a hack, we should replace all memory allocations in the
@@ -2356,8 +2370,10 @@ void Rx_igraph_error_handler(const char *reason, const char *file,
 
 void Rx_igraph_warning_handler(const char *reason, const char *file, int line) {
   if (Rx_igraph_warnings_count == 0) {
+    const char* simplified_path = simplify_file_path(file);
     snprintf(Rx_igraph_warning_reason, sizeof(Rx_igraph_warning_reason),
-      "At %s:%i : %s%s", file, line, reason, maybe_add_punctuation(reason, "."));
+      "%s%s\nSource: %s:%i", reason, maybe_add_punctuation(reason, "."),
+      simplified_path, line);
     Rx_igraph_warning_reason[sizeof(Rx_igraph_warning_reason) - 1] = 0;
   }
   Rx_igraph_warnings_count++;

src/sources-glue-c.mk

@@ -1 +1 @@
-GLUE_C_SOURCES=rcallback.o rinterface.o rinterface_extra.o rrandom.o uuid.o
+GLUE_C_SOURCES=rcallback.o rinterface.o rinterface_extra.o rrandom.o test_error_with_source.o uuid.o

src/test_error_with_source.c

@@ -0,0 +1,33 @@
+/* -*- mode: C -*-  */
+/*
+   IGraph library R interface.
+   Copyright (C) 2013  Gabor Csardi <csardi.gabor@gmail.com>
+   334 Harvard street, Cambridge, MA 02139 USA
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software
+   Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+   02110-1301 USA
+
+*/
+
+#include "rinterface.h"
+
+#include <R_ext/Visibility.h>
+
+/* Test function to verify error formatting with file and line information */
+attribute_visible SEXP Rx_igraph_test_error_with_source(void) {
+  igraph_errorf("Test error message for verifying source location formatting",
+                __FILE__, __LINE__, IGRAPH_EINVAL);
+  return R_NilValue;
+}

src/test_error_with_source.dd

@@ -0,0 +1,4 @@
+# Generated by deps.mk, do not edit by hand and do not add dependencies to system headers
+test_error_with_source.o: \
+  rinterface.h \
+  test_error_with_source.c \