`@(linkage=<string>)` for procedures and variables; `@(require)` for procedures; `package runtime` linkage improvements; Subsequence improvements to `lb_run_remove_unused_function_pass`

9 files changed, 109 insertions, 26 deletions

diff --git a/src/check_decl.cpp b/src/check_decl.cpp
index 33e85edf7..134dbb35b 100644
--- a/src/check_decl.cpp
+++ b/src/check_decl.cpp
@@ -730,7 +730,6 @@ void check_proc_decl(CheckerContext *ctx, Entity *e, DeclInfo *d) {
 	if (ac.set_cold) {
 		e->flags |= EntityFlag_Cold;
 	}
-
 	e->Procedure.optimization_mode = cast(ProcedureOptimizationMode)ac.optimization_mode;
 
 
@@ -760,6 +759,22 @@ void check_proc_decl(CheckerContext *ctx, Entity *e, DeclInfo *d) {
 
 	bool is_foreign = e->Procedure.is_foreign;
 	bool is_export  = e->Procedure.is_export;
+	
+	if (ac.linkage.len != 0) {
+		     if (ac.linkage == "internal")  { e->flags |= EntityFlag_CustomLinkage_Internal; }
+		else if (ac.linkage == "strong")    { e->flags |= EntityFlag_CustomLinkage_Strong;   }
+		else if (ac.linkage == "weak")      { e->flags |= EntityFlag_CustomLinkage_Weak;     }
+		else if (ac.linkage == "link_once") { e->flags |= EntityFlag_CustomLinkage_LinkOnce; }
+		
+		if (is_foreign && (e->flags & EntityFlag_CustomLinkage_Internal)) {
+			error(e->token, "A foreign procedure may not have an \"internal\" linkage");
+		}
+	}
+
+	if (ac.require_declaration) {
+		e->flags |= EntityFlag_Require;
+	}
+
 
 	if (e->pkg != nullptr && e->token.string == "main") {
 		if (pt->param_count != 0 ||
@@ -943,6 +958,7 @@ void check_global_variable_decl(CheckerContext *ctx, Entity *&e, Ast *type_expr,
 	}
 
 	if (ac.require_declaration) {
+		e->flags |= EntityFlag_Require;
 		mpmc_enqueue(&ctx->info->required_global_variable_queue, e);
 	}
 
diff --git a/src/checker.cpp b/src/checker.cpp
index 92e38a643..591377726 100644
--- a/src/checker.cpp
+++ b/src/checker.cpp
@@ -783,6 +783,7 @@ void init_universal(void) {
 	add_global_bool_constant("ODIN_DEFAULT_TO_NIL_ALLOCATOR", bc->ODIN_DEFAULT_TO_NIL_ALLOCATOR);
 	add_global_bool_constant("ODIN_NO_DYNAMIC_LITERALS",      bc->no_dynamic_literals);
 	add_global_bool_constant("ODIN_NO_CRT",                   bc->no_crt);
+	add_global_bool_constant("ODIN_USE_SEPARATE_MODULES",     bc->use_separate_modules);
 	add_global_bool_constant("ODIN_TEST",                     bc->command_kind == Command_test);
 
 
@@ -1388,7 +1389,9 @@ bool could_entity_be_lazy(Entity *e, DeclInfo *d) {
 					return false;
 				} else if (name == "init") {
 					return false;
-				}
+				} else if (name == "linkage") {
+					return false;
+				} 
 			}
 		}
 	}
@@ -2658,6 +2661,32 @@ DECL_ATTRIBUTE_PROC(proc_decl_attribute) {
 			return false;
 		}
 		return true;
+	} else if (name == "linkage") {
+		ExactValue ev = check_decl_attribute_value(c, value);
+		if (ev.kind != ExactValue_String) {
+			error(value, "Expected either a string 'linkage'");
+			return false;
+		}
+		String linkage = ev.value_string;
+		if (linkage == "internal" ||
+		    linkage == "strong" ||
+		    linkage == "weak" ||
+		    linkage == "link_once") {
+			ac->linkage = linkage;
+		} else {
+			error(elem, "Invalid linkage '%.*s'. Valid kinds:", LIT(linkage));
+			error_line("\tinternal\n");
+			error_line("\tstrong\n");
+			error_line("\tweak\n");
+			error_line("\tlink_once\n");
+		}
+		return true;
+	} else if (name == "require") {
+		if (value != nullptr) {
+			error(elem, "'require' does not have any parameters");
+		}
+		ac->require_declaration = true;
+		return true;
 	} else if (name == "init") {
 		if (value != nullptr) {
 			error(value, "'%.*s' expects no parameter, or a string literal containing \"file\" or \"package\"", LIT(name));
@@ -2894,7 +2923,7 @@ DECL_ATTRIBUTE_PROC(var_decl_attribute) {
 
 	if (name == "require") {
 		if (value != nullptr) {
-			error(elem, "'static' does not have any parameters");
+			error(elem, "'require' does not have any parameters");
 		}
 		ac->require_declaration = true;
 		return true;
@@ -2912,6 +2941,26 @@ DECL_ATTRIBUTE_PROC(var_decl_attribute) {
 			error(elem, "An exported variable cannot be thread local");
 		}
 		return true;
+	} else if (name == "linkage") {
+		ExactValue ev = check_decl_attribute_value(c, value);
+		if (ev.kind != ExactValue_String) {
+			error(value, "Expected either a string 'linkage'");
+			return false;
+		}
+		String linkage = ev.value_string;
+		if (linkage == "internal" ||
+		    linkage == "strong" ||
+		    linkage == "weak" ||
+		    linkage == "link_once") {
+			ac->linkage = linkage;
+		} else {
+			error(elem, "Invalid linkage '%.*s'. Valid kinds:", LIT(linkage));
+			error_line("\tinternal\n");
+			error_line("\tstrong\n");
+			error_line("\tweak\n");
+			error_line("\tlink_once\n");
+		}
+		return true;
 	} else if (name == "link_name") {
 		if (ev.kind == ExactValue_String) {
 			ac->link_name = ev.value_string;
@@ -3959,6 +4008,8 @@ DECL_ATTRIBUTE_PROC(foreign_import_decl_attribute) {
 	if (name == "force" || name == "require") {
 		if (value != nullptr) {
 			error(elem, "Expected no parameter for '%.*s'", LIT(name));
+		} else if (name == "force") {
+			warning(elem, "'force' is deprecated and is identical to 'require'");
 		}
 		ac->require_declaration = true;
 		return true;
diff --git a/src/checker.hpp b/src/checker.hpp
index 97631c547..c65d766ba 100644
--- a/src/checker.hpp
+++ b/src/checker.hpp
@@ -102,6 +102,7 @@ struct AttributeContext {
 	String  link_name;
 	String  link_prefix;
 	String  link_section;
+	String  linkage;
 	isize   init_expr_list_count;
 	String  thread_local_model;
 	String  deprecated_message;
diff --git a/src/entity.cpp b/src/entity.cpp
index d95c74f22..ef4f7e0fa 100644
--- a/src/entity.cpp
+++ b/src/entity.cpp
@@ -76,6 +76,12 @@ enum EntityFlag : u64 {
 	EntityFlag_Init          = 1ull<<31,
 	
 	EntityFlag_CustomLinkName = 1ull<<40,
+	EntityFlag_CustomLinkage_Internal = 1ull<<41,
+	EntityFlag_CustomLinkage_Strong   = 1ull<<42,
+	EntityFlag_CustomLinkage_Weak     = 1ull<<43,
+	EntityFlag_CustomLinkage_LinkOnce = 1ull<<44,
+	
+	EntityFlag_Require = 1ull<<50,
 
 	EntityFlag_Overridden    = 1ull<<63,
 };
diff --git a/src/llvm_backend.cpp b/src/llvm_backend.cpp
index c0a7b60df..928efbb54 100644
--- a/src/llvm_backend.cpp
+++ b/src/llvm_backend.cpp
@@ -1498,6 +1498,8 @@ void lb_generate_code(lbGenerator *gen) {
 				LLVMSetLinkage(g.value, LLVMInternalLinkage);
 			}
 		}
+		lb_set_linkage_from_entity_flags(m, g.value, e->flags);
+		
 		if (e->Variable.link_section.len > 0) {
 			LLVMSetSection(g.value, alloc_cstring(permanent_allocator(), e->Variable.link_section));
 		}
@@ -1675,7 +1677,7 @@ void lb_generate_code(lbGenerator *gen) {
 	for_array(i, gen->modules.entries) {
 		lbModule *m = gen->modules.entries[i].value;
 		
-		lb_run_remove_unused_function_pass(m->mod);
+		lb_run_remove_unused_function_pass(m);
 
 		auto wd = gb_alloc_item(permanent_allocator(), lbLLVMModulePassWorkerData);
 		wd->m = m;
diff --git a/src/llvm_backend.hpp b/src/llvm_backend.hpp
index 5fc5dfebf..16c9f752e 100644
--- a/src/llvm_backend.hpp
+++ b/src/llvm_backend.hpp
@@ -605,4 +605,6 @@ char const *llvm_linkage_strings[] = {
 	"common linkage",
 	"linker private linkage",
 	"linker private weak linkage"
-};
\ No newline at end of file
+};
+
+#define ODIN_METADATA_REQUIRE "odin-metadata-require", 21
diff --git a/src/llvm_backend_general.cpp b/src/llvm_backend_general.cpp
index b1c1f924b..5c664f0e0 100644
--- a/src/llvm_backend_general.cpp
+++ b/src/llvm_backend_general.cpp
@@ -2692,3 +2692,16 @@ lbAddr lb_add_local_generated_temp(lbProcedure *p, Type *type, i64 min_alignment
 	lb_try_update_alignment(res.addr, cast(unsigned)min_alignment);
 	return res;
 }
+
+
+void lb_set_linkage_from_entity_flags(lbModule *m, LLVMValueRef value, u64 flags) {
+	if (flags & EntityFlag_CustomLinkage_Internal) {
+		LLVMSetLinkage(value, LLVMInternalLinkage);
+	} else if (flags & EntityFlag_CustomLinkage_Strong) {
+		LLVMSetLinkage(value, LLVMExternalLinkage);
+	} else if (flags & EntityFlag_CustomLinkage_Weak) {
+		LLVMSetLinkage(value, LLVMExternalWeakLinkage);
+	} else if (flags & EntityFlag_CustomLinkage_LinkOnce) {
+		LLVMSetLinkage(value, LLVMLinkOnceAnyLinkage);
+	}
+}
diff --git a/src/llvm_backend_opt.cpp b/src/llvm_backend_opt.cpp
index 75a377e5b..2648863e2 100644
--- a/src/llvm_backend_opt.cpp
+++ b/src/llvm_backend_opt.cpp
@@ -357,14 +357,14 @@ void lb_run_function_pass_manager(LLVMPassManagerRef fpm, lbProcedure *p) {
 }
 
 
-void lb_run_remove_unused_function_pass(LLVMModuleRef mod) {
+void lb_run_remove_unused_function_pass(lbModule *m) {
 	isize removal_count = 0;
 	isize pass_count = 0;
 	isize const max_pass_count = 10;
 	// Custom remove dead function pass
 	for (; pass_count < max_pass_count; pass_count++) {
 		bool was_dead_function = false;	
-		for (LLVMValueRef func = LLVMGetFirstFunction(mod);
+		for (LLVMValueRef func = LLVMGetFirstFunction(m->mod);
 		     func != nullptr;
 		     /**/
 		     ) {
@@ -382,30 +382,20 @@ void lb_run_remove_unused_function_pass(LLVMModuleRef mod) {
 				// Ignore for the time being
 				continue;
 			}
-			
-			if (name == "memset" ||
-			    name == "memmove" ||
-			    name == "memcpy") {
+			LLVMLinkage linkage = LLVMGetLinkage(curr_func);
+			if (linkage != LLVMInternalLinkage) {
 				continue;
 			}
-			if (is_arch_wasm()) {
-				if (name == "__ashlti3") {
-					LLVMSetLinkage(curr_func, LLVMExternalLinkage);
+			
+			Entity **found = map_get(&m->procedure_values, hash_pointer(curr_func));
+			if (found && *found) {
+				Entity *e = *found;
+				bool is_required = (e->flags & EntityFlag_Require) == EntityFlag_Require;
+				if (is_required) {
 					continue;
 				}
 			}
-			
-			LLVMLinkage linkage = LLVMGetLinkage(curr_func);
-						
-			switch (linkage) {
-			case LLVMExternalLinkage:
-			case LLVMDLLImportLinkage:
-			case LLVMDLLExportLinkage:
-			default:
-				continue;
-			case LLVMInternalLinkage:
-				break;
-			}
+
 			LLVMDeleteFunction(curr_func);
 			was_dead_function = true;
 			removal_count += 1;
diff --git a/src/llvm_backend_proc.cpp b/src/llvm_backend_proc.cpp
index ed9aa4b8b..ee5b94cec 100644
--- a/src/llvm_backend_proc.cpp
+++ b/src/llvm_backend_proc.cpp
@@ -203,6 +203,8 @@ lbProcedure *lb_create_procedure(lbModule *m, Entity *entity, bool ignore_body)
 			}
 		}
 	}
+	lb_set_linkage_from_entity_flags(p->module, p->value, entity->flags);
+	
 	
 	if (p->is_foreign) {
 		lb_set_wasm_import_attributes(p->value, entity, p->name);