Reinstate PUSHS clearing the SECTION scope (#870)

* Reinstate PUSHS clearing the SECTION scope

Otherwise you can use `PUSHS` to simulate the old `ds -21`, and possibly cause bugs

* Have PUSHS push LOAD block state as well

It does not make sense not to, and coud cause bugs.

include/asm/output.h

@@ -17,7 +17,7 @@ struct Expression;
 struct FileStackNode;
 
 extern char *objectName;
-extern struct Section *sectionList, *currentSection;
+extern struct Section *sectionList;
 
 void out_RegisterNode(struct FileStackNode *node);
 void out_ReplaceNode(struct FileStackNode *node);

include/asm/section.h

@@ -40,6 +40,8 @@ struct SectionSpec {
 	uint16_t alignOfs;
 };
 
+extern struct Section *currentSection;
+
 struct Section *out_FindSectionByName(const char *name);
 void out_NewSection(char const *name, uint32_t secttype, uint32_t org,
 		    struct SectionSpec const *attributes,

src/asm/output.c

@@ -53,8 +53,7 @@ struct Assertion {
 
 char *objectName;
 
-/* TODO: shouldn't `currentSection` be somewhere else? */
-struct Section *sectionList, *currentSection;
+struct Section *sectionList;
 
 /* Linked list of symbols to put in the object file */
 static struct Symbol *objectSymbols = NULL;

src/asm/section.c

@@ -22,13 +22,16 @@ uint8_t fillByte;
 
 struct SectionStackEntry {
 	struct Section *section;
+	struct Section *loadSection;
 	char const *scope; /* Section's symbol scope */
 	uint32_t offset;
+	int32_t loadOffset;
 	struct SectionStackEntry *next;
 };
 
 struct SectionStackEntry *sectionStack;
 uint32_t curOffset; /* Offset into the current section (see sect_GetSymbolOffset) */
+struct Section *currentSection = NULL;
 static struct Section *currentLoadSection = NULL;
 int32_t loadOffset; /* Offset into the LOAD section's parent (see sect_GetOutputOffset) */
 
@@ -44,7 +47,7 @@ struct UnionStackEntry {
 static void checksection(void)
 {
 	if (currentSection == NULL)
-		fatalerror("Code generation before SECTION directive\n");
+		fatalerror("Cannot output data outside of a SECTION\n");
 }
 
 /*
@@ -898,10 +901,17 @@ void out_PushSection(void)
 	if (sect == NULL)
 		fatalerror("No memory for section stack: %s\n",  strerror(errno));
 	sect->section = currentSection;
+	sect->loadSection = currentLoadSection;
 	sect->scope = sym_GetCurrentSymbolScope();
 	sect->offset = curOffset;
+	sect->loadOffset = loadOffset;
 	sect->next = sectionStack;
 	sectionStack = sect;
+
+	// Reset the section scope
+	currentSection = NULL;
+	currentLoadSection = NULL;
+	sym_SetCurrentSymbolScope(NULL);
 }
 
 void out_PopSection(void)
@@ -917,8 +927,10 @@ void out_PopSection(void)
 	sect = sectionStack;
 	changeSection();
 	currentSection = sect->section;
+	currentLoadSection = sect->loadSection;
 	sym_SetCurrentSymbolScope(sect->scope);
 	curOffset = sect->offset;
+	loadOffset = sect->loadOffset;
 
 	sectionStack = sect->next;
 	free(sect);

test/asm/align-pc-outside-section.err

@@ -1,2 +1,2 @@
 FATAL: align-pc-outside-section.asm(1):
-    Code generation before SECTION directive
+    Cannot output data outside of a SECTION

test/asm/pops-restore-no-section.err

@@ -1,4 +1,4 @@
 ERROR: pops-restore-no-section.asm(9):
     Label "DisallowedContent" created outside of a SECTION
 FATAL: pops-restore-no-section.asm(10):
-    Code generation before SECTION directive
+    Cannot output data outside of a SECTION

test/asm/pushs.asm

@@ -0,0 +1,5 @@
+SECTION "This is invalid", ROM0
+	ds 10, 42
+	PUSHS
+	; We should be outside of section scope now
+	db 69

test/asm/pushs.err

@@ -0,0 +1,2 @@
+FATAL: pushs.asm(5):
+    Cannot output data outside of a SECTION