Use C++ iterator for fragment/union "pieces" of RGBLINK sections

include/link/section.hpp

@@ -49,6 +49,39 @@ struct Section {
 	std::vector<Symbol> *fileSymbols;
 	std::vector<Symbol *> symbols;
 	std::unique_ptr<Section> nextPiece; // The next fragment or union "piece" of this section
+
+private:
+	// Template class for both const and non-const iterators over the "pieces" of this section
+	template<typename T>
+	class PiecesIterable {
+		T *_firstPiece;
+
+		class Iterator {
+			T *_piece;
+
+		public:
+			explicit Iterator(T *piece) : _piece(piece) {}
+
+			Iterator &operator++() {
+				_piece = _piece->nextPiece.get();
+				return *this;
+			}
+
+			T &operator*() const { return *_piece; }
+
+			bool operator==(Iterator const &rhs) const { return _piece == rhs._piece; }
+		};
+
+	public:
+		explicit PiecesIterable(T *firstPiece) : _firstPiece(firstPiece) {}
+
+		Iterator begin() { return Iterator(_firstPiece); }
+		Iterator end() { return Iterator(nullptr); }
+	};
+
+public:
+	PiecesIterable<Section> pieces() { return PiecesIterable(this); }
+	PiecesIterable<Section const> pieces() const { return PiecesIterable(this); }
 };
 
 // Execute a callback for each section currently registered.

src/asm/output.cpp

@@ -223,12 +223,10 @@ void out_WriteObject() {
 
 	putLong(fileStackNodes.size(), file);
 	for (auto it = fileStackNodes.begin(); it != fileStackNodes.end(); ++it) {
-		FileStackNode const &node = **it;
-
-		writeFileStackNode(node, file);
+		writeFileStackNode(**it, file);
 
 		// The list is supposed to have decrementing IDs
-		assume(it + 1 == fileStackNodes.end() || it[1]->ID == node.ID - 1);
+		assume(it + 1 == fileStackNodes.end() || it[1]->ID == it[0]->ID - 1);
 	}
 
 	for (Symbol const *sym : objectSymbols) {

src/link/assign.cpp

@@ -53,9 +53,9 @@ static void initFreeSpace() {
 static void assignSection(Section &section, MemoryLocation const &location) {
 	// Propagate the assigned location to all UNIONs/FRAGMENTs
 	// so `jr` patches in them will have the correct offset
-	for (Section *piece = &section; piece != nullptr; piece = piece->nextPiece.get()) {
-		piece->org = location.address;
-		piece->bank = location.bank;
+	for (Section &piece : section.pieces()) {
+		piece.org = location.address;
+		piece.bank = location.bank;
 	}
 	out_AddSection(section);
 }

src/link/layout.cpp

@@ -251,8 +251,8 @@ void layout_PlaceSection(std::string const &name, bool isOptional) {
 			);
 		} else {
 			// SDCC areas don't have a type assigned yet, so the linker script gives them one.
-			for (Section *piece = section; piece != nullptr; piece = piece->nextPiece.get()) {
-				piece->type = activeType;
+			for (Section &piece : section->pieces()) {
+				piece.type = activeType;
 			}
 		}
 	} else if (section->type != activeType) {

src/link/output.cpp

@@ -317,13 +317,13 @@ static bool compareSymbols(SortedSymbol const &sym1, SortedSymbol const &sym2) {
 template<typename F>
 static void forEachSortedSection(SortedSections const &bankSections, F callback) {
 	for (Section const *sect : bankSections.zeroLenSections) {
-		for (; sect != nullptr; sect = sect->nextPiece.get()) {
-			callback(*sect);
+		for (Section const &piece : sect->pieces()) {
+			callback(piece);
 		}
 	}
 	for (Section const *sect : bankSections.sections) {
-		for (; sect != nullptr; sect = sect->nextPiece.get()) {
-			callback(*sect);
+		for (Section const &piece : sect->pieces()) {
+			callback(piece);
 		}
 	}
 }
@@ -433,31 +433,32 @@ uint16_t forEachSection(SortedSections const &sectList, F callback) {
 	return used;
 }
 
-static void writeMapSymbols(Section const *sect) {
-	uint16_t org = sect->org;
-
-	for (bool announced = true; sect != nullptr; sect = sect->nextPiece.get(), announced = false) {
-		for (Symbol *sym : sect->symbols) {
+static void writeMapSymbols(Section const &sect) {
+	bool announced = true;
+	for (Section const &piece : sect.pieces()) {
+		for (Symbol *sym : piece.symbols) {
 			// Don't output symbols that begin with an illegal character
 			if (sym->name.empty() || !startsIdentifier(sym->name[0])) {
 				continue;
 			}
 			// Announce this "piece" before its contents
 			if (!announced) {
-				if (sect->modifier == SECTION_UNION) {
+				assume(sect.modifier == piece.modifier);
+				if (sect.modifier == SECTION_UNION) {
 					fputs("\t         ; Next union\n", mapFile);
-				} else if (sect->modifier == SECTION_FRAGMENT) {
+				} else if (sect.modifier == SECTION_FRAGMENT) {
 					fputs("\t         ; Next fragment\n", mapFile);
 				}
 				announced = true;
 			}
 			assume(std::holds_alternative<Label>(sym->data));
-			uint32_t address = std::get<Label>(sym->data).offset + org;
+			uint32_t address = std::get<Label>(sym->data).offset + sect.org;
 			// Space matches "\tSECTION: $xxxx ..."
 			fprintf(mapFile, "\t         $%04" PRIx32 " = ", address);
 			writeSymName(sym->name, mapFile);
 			putc('\n', mapFile);
 		}
+		announced = false;
 	}
 }
 
@@ -487,7 +488,7 @@ static void writeMapBank(SortedSections const &sectList, SectionType type, uint3
 
 		if (!options.noSymInMap) {
 			// Also print symbols in the following "pieces"
-			writeMapSymbols(&sect);
+			writeMapSymbols(sect);
 		}
 	});
 

src/link/patch.cpp

@@ -586,8 +586,8 @@ static void applyPatches(Section &section) {
 		return;
 	}
 
-	for (Section *piece = &section; piece != nullptr; piece = piece->nextPiece.get()) {
-		applyFilePatches(*piece, section);
+	for (Section &piece : section.pieces()) {
+		applyFilePatches(piece, section);
 	}
 }