Make ENDL optional like ENDSECTION (#1538)

Add warning for `LOAD` without `ENDL`

src/asm/main.cpp

@@ -381,6 +381,7 @@ int main(int argc, char *argv[]) {
 		nbErrors = 1;
 
 	sect_CheckUnionClosed();
+	sect_CheckLoadClosed();
 	sect_CheckSizes();
 
 	if (nbErrors != 0)

src/asm/parser.y

@@ -849,7 +849,7 @@ load:
 		sect_SetLoadSection($3, $5, $6, $7, $2);
 	}
 	| POP_ENDL {
-		sect_EndLoadSection();
+		sect_EndLoadSection(nullptr);
 	}
 ;
 

src/asm/section.cpp

@@ -425,14 +425,14 @@ void sect_NewSection(
     SectionSpec const &attrs,
     SectionModifier mod
 ) {
-	if (currentLoadSection)
-		fatalerror("Cannot change the section within a `LOAD` block\n");
-
 	for (SectionStackEntry &entry : sectionStack) {
 		if (entry.section && entry.section->name == name)
 			fatalerror("Section '%s' is already on the stack\n", name.c_str());
 	}
 
+	if (currentLoadSection)
+		sect_EndLoadSection("SECTION");
+
 	Section *sect = getSection(name, type, org, attrs, mod);
 
 	changeSection();
@@ -457,11 +457,6 @@ void sect_SetLoadSection(
 	if (!requireCodeSection())
 		return;
 
-	if (currentLoadSection) {
-		error("`LOAD` blocks cannot be nested\n");
-		return;
-	}
-
 	if (sect_HasData(type)) {
 		error("`LOAD` blocks cannot create a ROM section\n");
 		return;
@@ -472,6 +467,9 @@ void sect_SetLoadSection(
 		return;
 	}
 
+	if (currentLoadSection)
+		sect_EndLoadSection("LOAD");
+
 	Section *sect = getSection(name, type, org, attrs, mod);
 
 	currentLoadLabelScopes = sym_GetCurrentLabelScopes();
@@ -481,7 +479,14 @@ void sect_SetLoadSection(
 	currentLoadSection = sect;
 }
 
-void sect_EndLoadSection() {
+void sect_EndLoadSection(char const *cause) {
+	if (cause)
+		warning(
+		    WARNING_UNTERMINATED_LOAD,
+		    "`LOAD` block without `ENDL` terminated by `%s`\n",
+		    cause
+		);
+
 	if (!currentLoadSection) {
 		error("Found `ENDL` outside of a `LOAD` block\n");
 		return;
@@ -494,6 +499,11 @@ void sect_EndLoadSection() {
 	sym_SetCurrentLabelScopes(currentLoadLabelScopes);
 }
 
+void sect_CheckLoadClosed() {
+	if (currentLoadSection)
+		warning(WARNING_UNTERMINATED_LOAD, "`LOAD` block without `ENDL` terminated by EOF\n");
+}
+
 Section *sect_GetSymbolSection() {
 	return currentLoadSection ? currentLoadSection : currentSection;
 }
@@ -954,7 +964,7 @@ void sect_PopSection() {
 		fatalerror("No entries in the section stack\n");
 
 	if (currentLoadSection)
-		fatalerror("Cannot change the section within a `LOAD` block\n");
+		sect_EndLoadSection("POPS");
 
 	SectionStackEntry entry = sectionStack.front();
 	sectionStack.pop_front();
@@ -972,12 +982,12 @@ void sect_EndSection() {
 	if (!currentSection)
 		fatalerror("Cannot end the section outside of a SECTION\n");
 
-	if (currentLoadSection)
-		fatalerror("Cannot end the section within a `LOAD` block\n");
-
 	if (!currentUnionStack.empty())
 		fatalerror("Cannot end the section within a UNION\n");
 
+	if (currentLoadSection)
+		sect_EndLoadSection("ENDSECTION");
+
 	// Reset the section scope
 	currentSection = nullptr;
 	sym_ResetCurrentLabelScopes();

src/asm/warning.cpp

@@ -56,6 +56,7 @@ static const WarningFlag warningFlags[NB_WARNINGS] = {
     {"obsolete",             LEVEL_DEFAULT   },
     {"shift",                LEVEL_EVERYTHING},
     {"shift-amount",         LEVEL_EVERYTHING},
+    {"unterminated-load",    LEVEL_EXTRA     },
     {"user",                 LEVEL_DEFAULT   },
     // Parametric warnings
     {"numeric-string",       LEVEL_EVERYTHING},