Add -B/--backtrace option to RGBASM and RGBLINK (#1787)

src/link/fstack.cpp

@@ -0,0 +1,80 @@
+#include "link/fstack.hpp"
+
+#include <inttypes.h>
+#include <utility>
+
+#include "style.hpp"
+
+#include "link/warning.hpp"
+
+std::vector<std::pair<std::string, uint32_t>> FileStackNode::backtrace(uint32_t curLineNo) const {
+	if (std::holds_alternative<std::vector<uint32_t>>(data)) {
+		assume(parent); // REPT nodes use their parent's name
+		std::vector<std::pair<std::string, uint32_t>> nodes = parent->backtrace(lineNo);
+		assume(!nodes.empty());
+		std::string reptChain = nodes.back().first;
+		for (uint32_t iter : iters()) {
+			reptChain.append("::REPT~");
+			reptChain.append(std::to_string(iter));
+		}
+		nodes.emplace_back(reptChain, curLineNo);
+		return nodes;
+	} else if (parent) {
+		std::vector<std::pair<std::string, uint32_t>> nodes = parent->backtrace(lineNo);
+		nodes.emplace_back(name(), curLineNo);
+		return nodes;
+	} else {
+		return {
+		    {name(), curLineNo}
+		};
+	}
+}
+
+static void printNode(std::pair<std::string, uint32_t> const &node) {
+	style_Set(stderr, STYLE_CYAN, true);
+	fputs(node.first.c_str(), stderr);
+	style_Set(stderr, STYLE_CYAN, false);
+	fprintf(stderr, "(%" PRIu32 ")", node.second);
+}
+
+void FileStackNode::printBacktrace(uint32_t curLineNo) const {
+	std::vector<std::pair<std::string, uint32_t>> nodes = backtrace(curLineNo);
+	size_t n = nodes.size();
+
+	if (warnings.traceDepth == TRACE_COLLAPSE) {
+		fputs("   ", stderr); // Just three spaces; the fourth will be handled by the loop
+		for (size_t i = 0; i < n; ++i) {
+			style_Reset(stderr);
+			fprintf(stderr, " %s ", i == 0 ? "at" : "<-");
+			printNode(nodes[n - i - 1]);
+		}
+		putc('\n', stderr);
+	} else if (warnings.traceDepth == 0 || static_cast<size_t>(warnings.traceDepth) >= n) {
+		for (size_t i = 0; i < n; ++i) {
+			style_Reset(stderr);
+			fprintf(stderr, "    %s ", i == 0 ? "at" : "<-");
+			printNode(nodes[n - i - 1]);
+			putc('\n', stderr);
+		}
+	} else {
+		size_t last = warnings.traceDepth / 2;
+		size_t first = warnings.traceDepth - last;
+		size_t skipped = n - warnings.traceDepth;
+		for (size_t i = 0; i < first; ++i) {
+			style_Reset(stderr);
+			fprintf(stderr, "    %s ", i == 0 ? "at" : "<-");
+			printNode(nodes[n - i - 1]);
+			putc('\n', stderr);
+		}
+		style_Reset(stderr);
+		fprintf(stderr, "    ...%zu more%s\n", skipped, last ? "..." : "");
+		for (size_t i = n - last; i < n; ++i) {
+			style_Reset(stderr);
+			fputs("    <- ", stderr);
+			printNode(nodes[n - i - 1]);
+			putc('\n', stderr);
+		}
+	}
+
+	style_Reset(stderr);
+}