Implement compact file stacks in object files

Gets rid of `open_memstream`, enabling Windows compatibility again
Also fixes #491 as a nice bonus!

Makefile

@@ -186,7 +186,7 @@ checkpatch:
 # compilation and make the continous integration infrastructure return failure.
 
 develop:
-	$Qenv $(MAKE) -j WARNFLAGS="-Werror -Wall -Wextra -Wpedantic \
+	$Qenv $(MAKE) -j WARNFLAGS="-Werror -Wall -Wextra -Wpedantic -Wno-type-limits \
 		-Wno-sign-compare -Wformat -Wformat-security -Wformat-overflow=2 \
 		-Wformat-truncation=1 -Wformat-y2k -Wswitch-enum -Wunused \
 		-Wuninitialized -Wunknown-pragmas -Wstrict-overflow=5 \

include/asm/fstack.h

@@ -21,26 +21,44 @@
 
 #include "types.h"
 
-struct MacroArgs;
+struct FileStackNode {
+	struct FileStackNode *parent; /* Pointer to parent node, for error reporting */
+	/* Line at which the parent context was exited; meaningless for the root level */
+	uint32_t lineNo;
+
+	struct FileStackNode *next; /* Next node in the output linked list */
+	bool referenced; /* If referenced, don't free! */
+	uint32_t ID; /* Set only if referenced: ID within the object file, -1 if not output yet */
+
+	enum {
+		NODE_REPT,
+		NODE_FILE,
+		NODE_MACRO,
+	} type;
+};
+
+struct FileStackReptNode { /* NODE_REPT */
+	struct FileStackNode node;
+	uint32_t reptDepth;
+	/* WARNING: if changing this type, change overflow check in `fstk_Init` */
+	uint32_t iters[]; /* REPT iteration counts since last named node, in reverse depth order */
+};
 
-struct sContext {
-	struct LexerState *lexerState;
-	struct Symbol const *pMacro;
-	struct sContext *next;
-	char tzFileName[_MAX_PATH + 1];
-	struct MacroArgs *macroArgs;
-	uint32_t uniqueID;
-	int32_t nLine;
-	uint32_t nStatus;
-	char const *pREPTBlock;
-	uint32_t nREPTBlockCount;
-	uint32_t nREPTBlockSize;
-	int32_t nREPTBodyFirstLine;
-	int32_t nREPTBodyLastLine;
+struct FileStackNamedNode { /* NODE_FILE, NODE_MACRO */
+	struct FileStackNode node;
+	char name[]; /* File name for files, file::macro name for macros */
 };
 
 extern size_t nMaxRecursionDepth;
 
+struct MacroArgs;
+
+void fstk_Dump(struct FileStackNode const *node, uint32_t lineNo);
+void fstk_DumpCurrent(void);
+struct FileStackNode *fstk_GetFileStack(void);
+/* The lifetime of the returned chars is until reaching the end of that file */
+char const *fstk_GetFileName(void);
+
 void fstk_AddIncludePath(char const *s);
 /**
  * @param path The user-provided file name
@@ -53,14 +71,9 @@ bool fstk_FindFile(char const *path, char **fullPath, size_t *size);
 
 bool yywrap(void);
 void fstk_RunInclude(char const *path);
-void fstk_RunMacro(char *macroName, struct MacroArgs *args);
+void fstk_RunMacro(char const *macroName, struct MacroArgs *args);
 void fstk_RunRept(uint32_t count, int32_t nReptLineNo, char *body, size_t size);
 
-void fstk_Dump(void);
-char *fstk_DumpToStr(void);
-char const *fstk_GetFileName(void);
-uint32_t fstk_GetLine(void);
-
-void fstk_Init(char *mainPath, size_t maxRecursionDepth);
+void fstk_Init(char const *mainPath, size_t maxRecursionDepth);
 
 #endif /* RGBDS_ASM_FSTACK_H */

include/asm/lexer.h

@@ -43,6 +43,9 @@ static inline void lexer_SetGfxDigits(char const *digits)
 	gfxDigits = digits;
 }
 
+/*
+ * `path` is referenced, but not held onto..!
+ */
 struct LexerState *lexer_OpenFile(char const *path);
 struct LexerState *lexer_OpenFileView(char *buf, size_t size, uint32_t lineNo);
 void lexer_RestartRept(uint32_t lineNo);

include/asm/output.h

@@ -18,6 +18,8 @@ struct Expression;
 extern char *tzObjectname;
 extern struct Section *pSectionList, *pCurrentSection;
 
+void out_RegisterNode(struct FileStackNode *node);
+void out_ReplaceNode(struct FileStackNode *node);
 void out_SetFileName(char *s);
 void out_CreatePatch(uint32_t type, struct Expression const *expr,
 		     uint32_t ofs);

include/asm/symbol.h

@@ -36,8 +36,8 @@ struct Symbol {
 	bool isBuiltin;  /* Whether the symbol is a built-in */
 	struct Symbol const *scope;
 	struct Section *section;
-	char fileName[_MAX_PATH + 1]; /* File where the symbol was defined. */
-	uint32_t fileLine; /* Line where the symbol was defined. */
+	struct FileStackNode *src; /* Where the symbol was defined */
+	uint32_t fileLine; /* Line where the symbol was defined */
 
 	bool hasCallback;
 	union {

include/link/main.h

@@ -29,15 +29,45 @@ extern bool beVerbose;
 extern bool isWRA0Mode;
 extern bool disablePadding;
 
+struct FileStackNode {
+	struct FileStackNode *parent;
+	/* Line at which the parent context was exited; meaningless for the root level */
+	uint32_t lineNo;
+
+	enum {
+		NODE_REPT,
+		NODE_FILE,
+		NODE_MACRO,
+	} type;
+	union {
+		char *name; /* NODE_FILE, NODE_MACRO */
+		struct { /* NODE_REPT */
+			uint32_t reptDepth;
+			uint32_t *iters;
+		};
+	};
+};
+
 /* Helper macro for printing verbose-mode messages */
 #define verbosePrint(...)   do { \
 					if (beVerbose) \
 						fprintf(stderr, __VA_ARGS__); \
 				} while (0)
 
-void error(char const *fmt, ...);
+/**
+ * Dump a file stack to stderr
+ * @param node The leaf node to dump the context of
+ */
+char const *dumpFileStack(struct FileStackNode const *node);
+
+void warning(struct FileStackNode const *where, uint32_t lineNo,
+	     char const *fmt, ...) format_(printf, 3, 4);
+
+void error(struct FileStackNode const *where, uint32_t lineNo,
+	   char const *fmt, ...) format_(printf, 3, 4);
 
-noreturn_ void fatal(char const *fmt, ...);
+noreturn_ void fatal(struct FileStackNode const *where, uint32_t lineNo,
+		     char const *fmt, ...) format_(printf, 3, 4);
 
 /**
  * Opens a file if specified, and aborts on error.

include/link/object.h

@@ -14,8 +14,9 @@
 /**
  * Read an object (.o) file, and add its info to the data structures.
  * @param fileName A path to the object file to be read
+ * @param i The ID of the file
  */
-void obj_ReadFile(char const *fileName);
+void obj_ReadFile(char const *fileName, unsigned int i);
 
 /**
  * Perform validation on the object files' contents
@@ -27,6 +28,12 @@ void obj_DoSanityChecks(void);
  */
 void obj_CheckAssertions(void);
 
+/**
+ * Sets up object file reading
+ * @param nbFiles The number of object files that will be read
+ */
+void obj_Setup(unsigned int nbFiles);
+
 /**
  * `free`s all object memory that was allocated.
  */

include/link/section.h

@@ -19,6 +19,7 @@
 
 #include "linkdefs.h"
 
+struct FileStackNode;
 struct Section;
 
 struct AttachedSymbol {
@@ -27,7 +28,8 @@ struct AttachedSymbol {
 };
 
 struct Patch {
-	char *fileName;
+	struct FileStackNode const *src;
+	uint32_t lineNo;
 	int32_t offset;
 	uint32_t pcSectionID;
 	uint32_t pcOffset;

include/link/symbol.h

@@ -16,12 +16,14 @@
 
 #include "linkdefs.h"
 
+struct FileStackNode;
+
 struct Symbol {
 	/* Info contained in the object files */
 	char *name;
 	enum ExportLevel type;
 	char const *objFileName;
-	char *fileName;
+	struct FileStackNode const *src;
 	int32_t lineNo;
 	int32_t sectionID;
 	union {

include/linkdefs.h

@@ -14,7 +14,7 @@
 
 #define RGBDS_OBJECT_VERSION_STRING "RGB%1u"
 #define RGBDS_OBJECT_VERSION_NUMBER 9U
-#define RGBDS_OBJECT_REV 5U
+#define RGBDS_OBJECT_REV 6U
 
 enum AssertionType {
 	ASSERT_WARN,