Add section with (incomplete) checking for mach-o

src/compiler/llvm_codegen.c

@@ -362,6 +362,10 @@ void llvm_emit_global_variable_init(GenContext *c, Decl *decl)
 	// TODO fix name
 	LLVMValueRef old = decl->backend_ref;
 	decl->backend_ref = LLVMAddGlobal(c->module, LLVMTypeOf(init_value), decl->extname ?: decl->external_name);
+	if (decl->section)
+	{
+		LLVMSetSection(decl->backend_ref, decl->section);
+	}
 	llvm_set_alignment(decl->backend_ref, alignment);
 
 	LLVMValueRef failable_ref = decl->var.failable_ref;

src/compiler/sema_decls.c

@@ -9,6 +9,46 @@
 
 static bool sema_analyse_struct_union(Context *context, Decl *decl);
 
+static bool sema_check_section(Context *context, Decl *decl, Attr *attr)
+{
+	const char *section_string = attr->expr->const_expr.string.chars;
+	decl->section = section_string;
+	// No restrictions except for MACH-O
+	if (platform_target.object_format != OBJ_FORMAT_MACHO)
+	{
+		return true;
+	}
+	scratch_buffer_clear();
+	StringSlice slice = strtoslice(section_string);
+	StringSlice segment = strnexttok(&slice, ',');
+	StringSlice section = strnexttok(&slice, ',');
+	StringSlice attrs = strnexttok(&slice, ',');
+	StringSlice stub_size_str = strnexttok(&slice, ',');
+
+	if (slice.len)
+	{
+		SEMA_ERROR(attr->expr, "Too many parts to the Mach-o section description.");
+	}
+	slicetrim(&segment);
+	if (segment.len == 0)
+	{
+		SEMA_ERROR(attr->expr, "The segment is missing, did you type it correctly?");
+		return false;
+	}
+	slicetrim(&section);
+	if (section.len == 0)
+	{
+		SEMA_ERROR(attr->expr, "Mach-o requires 'segment,section' as the format, did you type it correctly?");
+		return false;
+	}
+	if (section.len > 16)
+	{
+		SEMA_ERROR(attr->expr, "Mach-o requires the section to be at the most 16 characters, can you shorten it?");
+		return false;
+	}
+	// TODO improve checking
+	return true;
+}
 static bool sema_check_unique_parameters(Decl **decls)
 {
 	STable *table = &global_context.scratch_table;
@@ -300,10 +340,6 @@ static bool sema_analyse_struct_union(Context *context, Decl *decl)
 				had = decl->extname != NULL;
 				decl->extname = attr->expr->const_expr.string.chars;
 				break;
-			case ATTRIBUTE_SECTION:
-				had = decl->section != NULL;
-				decl->section = attr->expr->const_expr.string.chars;
-				break;
 			case ATTRIBUTE_ALIGN:
 				had = decl->alignment != 0;
 				decl->alignment = attr->alignment;
@@ -994,7 +1030,7 @@ static inline bool sema_analyse_func(Context *context, Decl *decl)
 				break;
 			case ATTRIBUTE_SECTION:
 				had = decl->section != NULL;
-				decl->section = attr->expr->const_expr.string.chars;
+				if (!sema_check_section(context, decl, attr)) return decl_poison(decl);
 				break;
 			case ATTRIBUTE_ALIGN:
 				had = decl->alignment != 0;
@@ -1228,7 +1264,7 @@ static inline bool sema_analyse_global(Context *context, Decl *decl)
 				break;
 			case ATTRIBUTE_SECTION:
 				had = decl->section != NULL;
-				decl->section = attr->expr->const_expr.string.chars;
+				if (!sema_check_section(context, decl, attr)) return decl_poison(decl);
 				break;
 			case ATTRIBUTE_ALIGN:
 				had = decl->alignment != 0;

src/utils/lib.h

@@ -430,6 +430,7 @@ static inline StringSlice strtoslice(const char *data)
 {
 	return (StringSlice) { data, strlen(data) };
 }
+void slicetrim(StringSlice *slice);
 
 #define MAX(_a, _b) ({ \
   typeof(_a) __a__ = (_a); \

src/utils/stringutils.c

@@ -42,6 +42,23 @@ StringSlice strnexttok(StringSlice *slice, char separator)
 	return result;
 }
 
+void slicetrim(StringSlice *slice)
+{
+	size_t i;
+	for (i = 0; i < slice->len; i++)
+	{
+		if (slice->ptr[i] != ' ') break;
+	}
+	slice->ptr += i;
+	slice->len -= i;
+	for (i = slice->len; i > 0; i--)
+	{
+		if (slice->ptr[i - 1] != ' ') break;
+	}
+	slice->len = i;
+}
+
+
 char *strcopy(const char *start, size_t len)
 {
 	char *buffer = malloc_arena(len + 1);

test/src/tester.py

@@ -158,6 +158,8 @@ class Issues:
         if (line.startswith("warning:")):
             print("TODO" + line)
             exit(-1)
+        elif (line.startswith("target:")):
+            self.arch = line[7:].strip()
         elif (line.startswith("error:")):
             line = line[6:].strip()
             self.errors[self.current_file.filename + ":%d" % (self.line + self.current_file.line_offset)] = line

test/test_suite/abi/macho_section_attributes.c3

@@ -0,0 +1,8 @@
+// #target: x64-darwin
+
+int foo @section("foo,   12345678901234567      "); // #error: Mach-o requires the section to be at the most 16 characters
+int bar @section("foo,         "); // #error: Mach-o requires 'segment,section' as the format, did you type it correctly?
+int baz @section("foo"); // #error: Mach-o requires 'segment,section' as the format, did you type it correctly?
+int abc @section("foo,b,c,d,e,f"); // #error: Too many parts to the Mach-o section description.
+int def @section("foo,b,c,d");
+