From 3a37b4503d23b624a3fd700de331609e13c7eb5a Mon Sep 17 00:00:00 2001
From: Mr-Wiseguy <mrwiseguyromhacking@gmail.com>
Date: Thu, 23 Jan 2025 02:48:48 -0500
Subject: [PATCH] Add manual patch symbols (syms.ld) to the output overlay file
 and relocs

---
 include/recompiler/context.h |  6 +++++
 src/main.cpp                 | 45 +++++++++++++++++++++++++++++-------
 src/recompilation.cpp        |  4 +---
 3 files changed, 44 insertions(+), 11 deletions(-)

diff --git a/include/recompiler/context.h b/include/recompiler/context.h
index 1d3f2e4..0d0009b 100644
--- a/include/recompiler/context.h
+++ b/include/recompiler/context.h
@@ -565,6 +565,12 @@ namespace N64Recomp {
         void set_all_reference_sections_relocatable() {
             all_reference_sections_relocatable = true;
         }
+
+        bool is_manual_patch_symbol(uint32_t vram) const {
+            // Zero-sized symbols between 0x8F000000 and 0x90000000 are manually specified symbols for use with patches.
+            // TODO make this configurable or come up with a more sensible solution for dealing with manual symbols for patches.
+            return vram >= 0x8F000000 && vram < 0x90000000;
+        }
     };
 
     class Generator;
diff --git a/src/main.cpp b/src/main.cpp
index 6c56954..aa28864 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -866,13 +866,6 @@ int main(int argc, char** argv) {
         );
     }
 
-    fmt::print(func_header_file,
-        "\n"
-        "#ifdef __cplusplus\n"
-        "}}\n"
-        "#endif\n"
-    );
-
     {
         std::ofstream overlay_file(config.output_func_path / "recomp_overlays.inl");
         std::string section_load_table = "static SectionTableEntry section_table[] = {\n";
@@ -933,7 +926,7 @@ int main(int argc, char** argv) {
                     fmt::print(overlay_file, "static RelocEntry {}[] = {{\n", section_relocs_array_name);
 
                     for (const N64Recomp::Reloc& reloc : section_relocs) {
-                        if (reloc.target_section != N64Recomp::SectionAbsolute) {
+                        if (reloc.target_section != N64Recomp::SectionAbsolute || context.is_manual_patch_symbol(reloc.target_section_offset)) {
                             uint32_t target_section_offset;
                             if (reloc.target_section == N64Recomp::SectionEvent) {
                                 target_section_offset = reloc.symbol_index;
@@ -1012,9 +1005,45 @@ int main(int argc, char** argv) {
             // Add a dummy element at the end to ensure the array has a valid length because C doesn't allow zero-size arrays.
             fmt::print(overlay_file, "    NULL\n");
             fmt::print(overlay_file, "}};\n");
+
+            // Collect manual patch symbols.
+            std::vector<std::pair<uint32_t, std::string>> manual_patch_syms{};
+
+            for (const auto& func : context.functions) {
+                if (func.words.empty() && context.is_manual_patch_symbol(func.vram)) {
+                    manual_patch_syms.emplace_back(func.vram, func.name);
+                }
+            }            
+
+            // Sort the manual patch symbols by vram.
+            std::sort(manual_patch_syms.begin(), manual_patch_syms.end(), [](const auto& lhs, const auto& rhs) {
+                return lhs.first < rhs.first;
+            });
+
+            // Emit the manual patch symbols.
+            fmt::print(overlay_file,
+                "\n"
+                "static const ManualPatchSymbol manual_patch_symbols[] = {{\n"
+            );
+            for (const auto& manual_patch_sym_entry : manual_patch_syms) {
+                fmt::print(overlay_file, "    {{ 0x{:08X}, {} }},\n", manual_patch_sym_entry.first, manual_patch_sym_entry.second);
+
+                fmt::print(func_header_file,
+                    "void {}(uint8_t* rdram, recomp_context* ctx);\n", manual_patch_sym_entry.second);
+            }
+            // Add a dummy element at the end to ensure the array has a valid length because C doesn't allow zero-size arrays.
+            fmt::print(overlay_file, "    {{ 0, NULL }}\n");
+            fmt::print(overlay_file, "}};\n");
         }
     }
 
+    fmt::print(func_header_file,
+        "\n"
+        "#ifdef __cplusplus\n"
+        "}}\n"
+        "#endif\n"
+    );
+
     if (!config.output_binary_path.empty()) {
         std::ofstream output_binary{config.output_binary_path, std::ios::binary};
         output_binary.write(reinterpret_cast<const char*>(context.rom.data()), context.rom.size());
diff --git a/src/recompilation.cpp b/src/recompilation.cpp
index 5403ff1..ceb8496 100644
--- a/src/recompilation.cpp
+++ b/src/recompilation.cpp
@@ -46,9 +46,7 @@ JalResolutionResult resolve_jal(const N64Recomp::Context& context, size_t cur_se
 
             // Zero-sized symbol handling. unless there's only one matching target.
             if (target_func.words.empty()) {
-                // Allow zero-sized symbols between 0x8F000000 and 0x90000000 for use with patches.
-                // TODO make this configurable or come up with a more sensible solution for dealing with manual symbols for patches.
-                if (target_func.vram < 0x8F000000 || target_func.vram > 0x90000000) {
+                if (!context.is_manual_patch_symbol(target_func.vram)) {
                     continue;
                 }
             }