Add an option to show / hide filtered frames vs printing a placeholder

include/cpptrace/formatting.hpp

@@ -37,6 +37,7 @@ namespace cpptrace {
         formatter& set_snippets(bool);
         formatter& set_snippet_context(int);
         formatter& include_column(bool);
+        formatter& show_filtered_frames(bool);
         formatter& set_filter(std::function<bool(const stacktrace_frame&)>);
 
         std::string format(const stacktrace_frame&) const;

src/formatting.cpp

@@ -21,6 +21,7 @@ namespace cpptrace {
             bool snippets = false;
             int context_lines = 2;
             bool columns = true;
+            bool show_filtered_frames = true;
             std::function<bool(const stacktrace_frame&)> filter;
         } options;
 
@@ -43,6 +44,9 @@ namespace cpptrace {
         void include_column(bool columns) {
             options.columns = columns;
         }
+        void show_filtered_frames(bool show) {
+            options.show_filtered_frames = show;
+        }
         void set_filter(std::function<bool(const stacktrace_frame&)> filter) {
             options.filter = filter;
         }
@@ -140,9 +144,12 @@ namespace cpptrace {
             const auto frame_number_width = detail::n_digits(static_cast<int>(frames.size()) - 1);
             for(const auto& frame : frames) {
                 if(options.filter && !options.filter(frame)) {
+                    if(!options.show_filtered_frames) {
                         counter++;
                         continue;
                     }
+                    print_placeholder_frame(stream, frame_number_width, counter);
+                } else {
                     print_frame_internal(stream, frame, color, frame_number_width, counter);
                     if(frame.line.has_value() && !frame.filename.empty() && options.snippets) {
                         auto snippet = detail::get_snippet(
@@ -156,6 +163,7 @@ namespace cpptrace {
                             stream << snippet;
                         }
                     }
+                }
                 if(newline_at_end || &frame != &frames.back()) {
                     stream << '\n';
                 }
@@ -174,6 +182,11 @@ namespace cpptrace {
             stream << line;
         }
 
+        void print_placeholder_frame(std::ostream& stream, unsigned frame_number_width, std::size_t counter) const {
+            std::string line = microfmt::format("#{<{}} (filtered)", frame_number_width, counter);
+            stream << line;
+        }
+
         void print_frame_internal(
             std::ostream& stream,
             const stacktrace_frame& frame,
@@ -258,6 +271,10 @@ namespace cpptrace {
         pimpl->include_column(columns);
         return *this;
     }
+    formatter& formatter::show_filtered_frames(bool show) {
+        pimpl->show_filtered_frames(show);
+        return *this;
+    }
     formatter& formatter::set_filter(std::function<bool(const stacktrace_frame&)> filter) {
         pimpl->set_filter(std::move(filter));
         return *this;

test/unit/lib/formatting.cpp

@@ -191,6 +191,24 @@ TEST(FormatterTest, Filtering) {
             return frame.filename.find("foo.cpp") != std::string::npos;
         });
     auto res = split(formatter.format(make_test_stacktrace()), "\n");
+    EXPECT_THAT(
+        res,
+        ElementsAre(
+            "Stack trace (most recent call first):",
+            "#0 0x0000000000000001 in foo() at foo.cpp:20:30",
+            "#1 (filtered)",
+            "#2 0x0000000000000003 in main at foo.cpp:40:25"
+        )
+    );
+}
+
+TEST(FormatterTest, DontShowFilteredFrames) {
+    auto formatter = cpptrace::formatter{}
+        .set_filter([] (const cpptrace::stacktrace_frame& frame) -> bool {
+            return frame.filename.find("foo.cpp") != std::string::npos;
+        })
+        .show_filtered_frames(false);
+    auto res = split(formatter.format(make_test_stacktrace()), "\n");
     EXPECT_THAT(
         res,
         ElementsAre(
@@ -213,6 +231,7 @@ TEST(FormatterTest, MoveSemantics) {
         ElementsAre(
             "Stack trace (most recent call first):",
             "#0 0x0000000000000001 in foo() at foo.cpp:20:30",
+            "#1 (filtered)",
             "#2 0x0000000000000003 in main at foo.cpp:40:25"
         )
     );
@@ -224,6 +243,7 @@ TEST(FormatterTest, MoveSemantics) {
         ElementsAre(
             "Stack trace (most recent call first):",
             "#0 0x0000000000000001 in foo() at foo.cpp:20:30",
+            "#1 (filtered)",
             "#2 0x0000000000000003 in main at foo.cpp:40:25"
         )
     );
@@ -241,6 +261,7 @@ TEST(FormatterTest, CopySemantics) {
         ElementsAre(
             "Stack trace (most recent call first):",
             "#0 0x0000000000000001 in foo() at foo.cpp:20:30",
+            "#1 (filtered)",
             "#2 0x0000000000000003 in main at foo.cpp:40:25"
         )
     );
@@ -252,6 +273,7 @@ TEST(FormatterTest, CopySemantics) {
         ElementsAre(
             "Stack trace (most recent call first):",
             "#0 0x0000000000000001 in foo() at foo.cpp:20:30",
+            "#1 (filtered)",
             "#2 0x0000000000000003 in main at foo.cpp:40:25"
         )
     );