From 52e75e6a2f5ff13a4df822ea8de8aa68137b020e Mon Sep 17 00:00:00 2001
From: Luciano Ciccariello <xeeynamo@hotmail.com>
Date: Sat, 15 Oct 2022 11:18:32 +0100
Subject: [PATCH] Create context with Makefile

---
 .gitignore     |  1 +
 Makefile       | 11 ++++++--
 README.md      |  4 ++-
 tools/m2ctx.py | 73 ++++++++++++++++++++++++++++++++++++++++++++++++++
 4 files changed, 86 insertions(+), 3 deletions(-)
 create mode 100644 tools/m2ctx.py

diff --git a/.gitignore b/.gitignore
index d9ab40665..f8e375740 100644
--- a/.gitignore
+++ b/.gitignore
@@ -6,6 +6,7 @@ ST/
 
 iso/
 
+ctx.c
 *.ld
 *auto.*.txt
 generated.symbols.*.txt
diff --git a/Makefile b/Makefile
index 4cc9f00a4..ac40000a7 100644
--- a/Makefile
+++ b/Makefile
@@ -40,9 +40,11 @@ MAIN_TARGET     := $(BUILD_DIR)/$(MAIN)
 PYTHON          := python3
 SPLAT_DIR       := $(TOOLS_DIR)/n64splat
 SPLAT_APP       := $(SPLAT_DIR)/split.py
-SPLAT           := $(PYTHON) $(SPLAT_DIR)/split.py
+SPLAT           := $(PYTHON) $(SPLAT_APP)
 ASMDIFFER_DIR   := $(TOOLS_DIR)/asm-differ
 ASMDIFFER_APP   := $(ASMDIFFER_DIR)/diff.py
+M2CTX_APP       := $(TOOLS_DIR)/m2ctx.py
+M2CTX           := $(PYTHON) $(M2CTX_APP)
 
 define list_src_files
 	$(foreach dir,$(ASM_DIR)/$(1),$(wildcard $(dir)/**.s))
@@ -194,7 +196,10 @@ extract_ric: require-tools
 extract_st%: require-tools
 	cat $(CONFIG_DIR)/symbols.txt $(CONFIG_DIR)/symbols.st$*.txt > $(CONFIG_DIR)/generated.symbols.st$*.txt
 	$(SPLAT) --basedir . $(CONFIG_DIR)/splat.st$*.yaml
-$(CONFIG_DIR)/generated.symbols.%.txt: 
+$(CONFIG_DIR)/generated.symbols.%.txt:
+
+ctx.c: $(M2CTX_APP)
+	$(M2CTX) $(SOURCE)
 
 require-tools: $(SPLAT_APP) $(ASMDIFFER_APP)
 update-tools: require-tools
@@ -206,6 +211,8 @@ $(SPLAT_APP):
 $(ASMDIFFER_APP):
 	git submodule init $(ASMDIFFER_DIR)
 	git submodule update $(ASMDIFFER_DIR)
+$(M2CTX_APP):
+	curl -o $@ https://raw.githubusercontent.com/ethteck/m2ctx/main/m2ctx.py
 
 $(BUILD_DIR)/%.s.o: %.s
 	$(AS) $(AS_FLAGS) -o $@ $<
diff --git a/README.md b/README.md
index 95b296275..e99914e52 100644
--- a/README.md
+++ b/README.md
@@ -60,7 +60,9 @@ This guides you step-by-step to contribute to the decompilation project.
 1. Look for one of those function which hasn't successfully decompiled yet (eg. `INCLUDE_ASM("asm/st/wrp/nonmatchings/6FD0", func_801873A0);`)
 1. Follow [the guide to check the function matching](#check-function-matching)
 1. Look for its assembly file (eg. `asm/st/wrp/nonmatchings/6FD0/func_801873A0.s`)
-1. Copy&paste the entire file content into [mips_to_c](https://simonsoftware.se/other/mips_to_c.py) and decompile it
+1. Copy&paste the entire assembly file content into [mips_to_c](https://simonsoftware.se/other/mips_to_c.py)
+1. Generate a `ctx.c` context with `SOURCE=src/st/wrp/6FD0.c make ctx.c` and copy&paste it to the bottom part of the page
+1. Click the decompile button!
 1. The code from `mips_to_c` might not be compilable, so keep following `asm-differ` output until you get some assembly code on the console
 1. You will probably have some differences from your compiled code to the original; keep refactoring the code and move variables around until you have a 100% match.
 
diff --git a/tools/m2ctx.py b/tools/m2ctx.py
new file mode 100644
index 000000000..fd89af32a
--- /dev/null
+++ b/tools/m2ctx.py
@@ -0,0 +1,73 @@
+#!/usr/bin/env python3
+
+import argparse
+import os
+import sys
+import subprocess
+import tempfile
+
+script_dir = os.path.dirname(os.path.realpath(__file__))
+root_dir = os.path.abspath(os.path.join(script_dir, ".."))
+src_dir = root_dir + "src/"
+
+# Project-specific
+CPP_FLAGS = [
+    "-Iinclude",
+    "-Isrc",
+    "-Iver/current/build/include",
+    "-D_LANGUAGE_C",
+    "-DF3DEX_GBI_2",
+    "-D_MIPS_SZLONG=32",
+    "-DSCRIPT(...)={}",
+    "-D__attribute__(...)=",
+    "-D__asm__(...)=",
+    "-ffreestanding",
+    "-DM2CTX",
+]
+
+def import_c_file(in_file) -> str:
+    in_file = os.path.relpath(in_file, root_dir)
+    cpp_command = ["gcc", "-E", "-P", "-dM", *CPP_FLAGS, in_file]
+    cpp_command2 = ["gcc", "-E", "-P", *CPP_FLAGS, in_file]
+
+    with tempfile.NamedTemporaryFile(suffix=".c") as tmp:
+        stock_macros = subprocess.check_output(["gcc", "-E", "-P", "-dM", tmp.name], cwd=root_dir, encoding="utf-8")
+
+    out_text = ""
+    try:
+        out_text += subprocess.check_output(cpp_command, cwd=root_dir, encoding="utf-8")
+        out_text += subprocess.check_output(cpp_command2, cwd=root_dir, encoding="utf-8")
+    except subprocess.CalledProcessError:
+        print(
+            "Failed to preprocess input file, when running command:\n"
+            + ' '.join(cpp_command),
+            file=sys.stderr,
+            )
+        sys.exit(1)
+
+    if not out_text:
+        print("Output is empty - aborting")
+        sys.exit(1)
+
+    for line in stock_macros.strip().splitlines():
+        out_text = out_text.replace(line + "\n", "")
+    return out_text
+
+def main():
+    parser = argparse.ArgumentParser(
+        description="""Create a context file which can be used for mips_to_c"""
+    )
+    parser.add_argument(
+        "c_file",
+        help="""File from which to create context""",
+    )
+    args = parser.parse_args()
+
+    output = import_c_file(args.c_file)
+
+    with open(os.path.join(root_dir, "ctx.c"), "w", encoding="UTF-8") as f:
+        f.write(output)
+
+
+if __name__ == "__main__":
+    main()