Split RGBLINK linkerscript parser functions into their own file

include/link/layout.hpp

@@ -0,0 +1,39 @@
+// SPDX-License-Identifier: MIT
+
+#ifndef RGBDS_LINK_LAYOUT_HPP
+#define RGBDS_LINK_LAYOUT_HPP
+
+#include <fstream>
+#include <stdint.h>
+#include <string>
+
+#include "linkdefs.hpp"
+
+struct LexerStackEntry {
+	std::filebuf file;
+	std::string path;
+	uint32_t lineNo;
+
+	explicit LexerStackEntry(std::string &&path_) : file(), path(path_), lineNo(1) {}
+};
+
+#define scriptError(context, fmt, ...) \
+	::error( \
+	    "%s(%" PRIu32 "): " fmt, context.path.c_str(), context.lineNo __VA_OPT__(, ) __VA_ARGS__ \
+	)
+
+LexerStackEntry &lexer_Context();
+void lexer_IncludeFile(std::string &&path);
+void lexer_IncLineNo();
+bool lexer_Init(char const *linkerScriptName);
+
+void layout_SetFloatingSectionType(SectionType type);
+void layout_SetSectionType(SectionType type);
+void layout_SetSectionType(SectionType type, uint32_t bank);
+void layout_SetAddr(uint32_t addr);
+void layout_MakeAddrFloating();
+void layout_AlignTo(uint32_t alignment, uint32_t offset);
+void layout_Pad(uint32_t length);
+void layout_PlaceSection(std::string const &name, bool isOptional);
+
+#endif // RGBDS_LINK_LAYOUT_HPP