From 84f2bcd885296433a4ccf2188639b377293306e4 Mon Sep 17 00:00:00 2001
From: gingerBill <bill+github@gingerbill.org>
Date: Thu, 11 Aug 2016 22:05:09 +0100
Subject: [PATCH] Nested Procedures

---
 examples/main.ll           |  6 +++---
 examples/main.odin         | 10 ++++++----
 src/codegen/print_llvm.cpp |  3 +++
 src/codegen/ssa.cpp        | 25 +++++++++++++++++++++++--
 4 files changed, 35 insertions(+), 9 deletions(-)

diff --git a/examples/main.ll b/examples/main.ll
index fce46ccd9..d513bdfa8 100644
--- a/examples/main.ll
+++ b/examples/main.ll
@@ -4,7 +4,7 @@
 
 declare void @llvm.memmove.p0i8.p0i8.i64(i8*, i8*, i64, i32, i1)
 
-define void @thing(i64 ()* %p) {
+define void @exec(i64 ()* %p) {
 "entry - 0":
 	%0 = alloca i64 ()*, align 8 ; p
 	store i64 ()* zeroinitializer, i64 ()** %0
@@ -26,11 +26,11 @@ define void @main() {
 	call void @print_int(i64 %2)
 	call void @print_rune(i32 128149)
 	call void @print_rune(i32 10)
-	call void @thing(i64 ()* @main$0)
+	call void @exec(i64 ()* @main$cool_beans)
 	ret void
 }
 
-define i64 @main$0() {
+define i64 @main$cool_beans() {
 "entry - 0":
 	%0 = alloca i64, align 8 ; a
 	store i64 zeroinitializer, i64* %0
diff --git a/examples/main.odin b/examples/main.odin
index 1263a77eb..686e2884b 100644
--- a/examples/main.odin
+++ b/examples/main.odin
@@ -2,7 +2,7 @@ import "basic"
 
 TWO_HEARTS :: '💕';
 
-thing :: proc(p : proc() -> int) {
+exec :: proc(p : proc() -> int) {
 	print_int(p());
 	print_rune('\n');
 }
@@ -12,12 +12,14 @@ main :: proc() {
 	print_int(cast(int)a);
 	print_rune(TWO_HEARTS);
 	print_rune('\n');
-	thing(proc() -> int {
+
+	cool_beans :: proc() -> int {
 		a : int = 1337;
-		print_rune(TWO_HEARTS);
+		print_rune('💕');
 		print_rune('\n');
 		return a;
-	});
+	}
+	exec(cool_beans);
 }
 
 /*
diff --git a/src/codegen/print_llvm.cpp b/src/codegen/print_llvm.cpp
index a9645cca1..71daf9851 100644
--- a/src/codegen/print_llvm.cpp
+++ b/src/codegen/print_llvm.cpp
@@ -595,6 +595,9 @@ void ssa_print_proc(gbFile *f, ssaModule *m, ssaProcedure *proc) {
 	gb_for_array(i, proc->anon_procs) {
 		ssa_print_proc(f, m, proc->anon_procs[i]);
 	}
+	gb_for_array(i, proc->nested_procs) {
+		ssa_print_proc(f, m, proc->nested_procs[i]);
+	}
 }
 
 void ssa_print_llvm_ir(gbFile *f, ssaModule *m) {
diff --git a/src/codegen/ssa.cpp b/src/codegen/ssa.cpp
index a126ae5f2..f07fed9dc 100644
--- a/src/codegen/ssa.cpp
+++ b/src/codegen/ssa.cpp
@@ -40,7 +40,6 @@ struct ssaProcedure {
 	ssaProcedure *parent;
 	ssaModule *   module;
 	String        name;
-	Entity *      entity;
 	Type *        type;
 	AstNode *     type_expr;
 	AstNode *     body;
@@ -50,6 +49,7 @@ struct ssaProcedure {
 	ssaTargetList *     target_list;
 
 	gbArray(ssaProcedure *) anon_procs;
+	gbArray(ssaProcedure *) nested_procs;
 };
 
 
@@ -1256,6 +1256,7 @@ ssaValue *ssa_build_single_expr(ssaProcedure *proc, AstNode *expr, TypeAndValue
 				return v;
 			return ssa_emit_load(proc, v);
 		}
+		return NULL;
 	case_end;
 
 	case_ast_node(pe, ParenExpr, expr);
@@ -1481,7 +1482,7 @@ ssaValue *ssa_build_single_expr(ssaProcedure *proc, AstNode *expr, TypeAndValue
 	case_end;
 	}
 
-	GB_PANIC("Unexpected expression");
+	GB_PANIC("Unexpected expression: %.*s", LIT(ast_node_strings[expr->kind]));
 	return NULL;
 }
 
@@ -1767,6 +1768,26 @@ void ssa_build_stmt(ssaProcedure *proc, AstNode *node) {
 	case_end;
 
 	case_ast_node(pd, ProcDecl, node);
+		if (proc->nested_procs == NULL) {
+			// TODO(bill): Cleanup
+			gb_array_init(proc->nested_procs, gb_heap_allocator());
+		}
+		// NOTE(bill): Generate a new name
+		// parent$name
+		String pd_name = pd->name->Ident.token.string;
+		isize name_len = proc->name.len + 1 + pd_name.len + 1;
+		u8 *name_text = gb_alloc_array(proc->module->allocator, u8, name_len);
+		name_len = gb_snprintf(cast(char *)name_text, name_len, "%.*s$%.*s", LIT(proc->name), LIT(pd_name));
+		String name = make_string(name_text, name_len-1);
+
+		Entity *e = *map_get(&proc->module->info->definitions, hash_pointer(pd->name));
+		ssaValue *value = ssa_make_value_procedure(proc->module->allocator,
+		                                           proc->module, e->type, pd->type, pd->body, name);
+		ssaProcedure *np = &value->proc;
+		gb_array_append(proc->nested_procs, np);
+		ssa_build_proc(value, proc);
+
+		map_set(&proc->module->values, hash_pointer(e), value);
 
 	case_end;