Merge pull request #42 from AetiasHax/fix-build

Update compiler flags and decompiling docs

5 files changed, 57 insertions, 71 deletions

diff --git a/.gitignore b/.gitignore
index b63315e9..a0a106e8 100644
--- a/.gitignore
+++ b/.gitignore
@@ -5,3 +5,4 @@ ph_*/
 *bios.bin
 /m2ctx
 *.sav
+*.xMAP
diff --git a/Makefile b/Makefile
index 004e8b16..0dc3c52a 100644
--- a/Makefile
+++ b/Makefile
@@ -49,8 +49,8 @@ LCF_FILE   := $(ROOT)/$(BUILD_DIR)/arm9_linker_script.lcf
 OBJS_FILE  := $(ROOT)/$(BUILD_DIR)/arm9_objects.txt
 
 ASM_FLAGS := -proc arm5te -d $(REGION) -i asm -msgstyle gcc
-CC_FLAGS  := -proc arm946e -interworking -O4,p -enum int -i include -i- -i libs/c/include -i libs/cpp/include -nolink -d $(REGION) -char signed -sym on -msgstyle gcc
-C_FLAGS := -lang=c
+CC_FLAGS  := -O4,p -enum int -char signed -str noreuse -proc arm946e -gccext,on -fp soft -inline on,noauto -Cpp_exceptions off -RTTI off -interworking -sym on -gccinc -i include -i libs/c/include -i libs/cpp/include -nolink -d $(REGION) -msgstyle gcc
+C_FLAGS   := -lang=c
 CXX_FLAGS := -lang=c++
 LD_FLAGS  := -proc arm946e -nostdlib -interworking -nodead -m Entry -map closure,unused -o main.bin -msgstyle gcc
 
diff --git a/docs/decompiling.md b/docs/decompiling.md
index bedb1cbb..3ff23f2b 100644
--- a/docs/decompiling.md
+++ b/docs/decompiling.md
@@ -2,6 +2,7 @@
 This document describes how you can start decompiling code and contribute to the project. Feel free to ask for help if you get
 stuck or need assistance.
 - [Pick a source file](#pick-a-source-file)
+- [Decompiling a source file](#decompiling-a-source-file)
 - [Decompiling a function](#decompiling-a-function)
 - [Decompiling `.init` functions](#decompiling-init-functions)
 - [The Ghidra project](#the-ghidra-project)
@@ -18,13 +19,24 @@ If you want to unclaim the file, leave another comment so we can be certain that
 again. Remember to make a pull request of any notable progress you made on the source file, which can include
 [non-matching functions](/CONTRIBUTING.md#non-matching-functions).
 
+## Decompiling a source file
+It can be tricky to fully decompile an assembly file into a C/C++ source file, so here's some advice to make it easier:
+- C/C++ code is built before assembly code
+    - This means you can take one function from the top of your assembly file, decompile it, and append it to the bottom of
+    your C/C++ file.
+- Build the ROM often
+    - We recommend building every time you decompile a function.
+    - This is because functions can sometimes match in decomp.me, but not when building.
+    - If your ROM doesn't match, it's easier to know which function is wrong if it's the only function added since the last
+    successful build.
+
 ## Decompiling a function
 Say you've found a function you want to decompile. Here are the steps we recommend for decompiling it:
 1. Visit [decomp.me](https://decomp.me/) and start decomping.
 1. Under the platforms, select "Nintendo DS".
-1. Select compiler version `2.0sp1p5`.
-1. Copy and paste the target assembly for your function, including the `func_start` and `func_end` macros, and the pool constants.
-For example:
+1. Select compiler preset "Phantom Hourglass".
+1. Copy and paste the target assembly for your function, including the `func_start` and `func_end` macros, and the pool
+constants. For example:
 ```arm
 	.global func_ov09_0211bf48
 	thumb_func_start func_ov09_0211bf48
@@ -36,13 +48,9 @@ func_ov09_0211bf48: ; 0x0211bf48
 	thumb_func_end func_ov09_0211bf48
 _0211bf50: .word data_ov09_0211f59c
 ```
-6. Run `m2ctx.py include/MyHeader.hpp -c` to generate a context and put it in your clipboard.
+5. Run `m2ctx.py include/MyHeader.hpp -c` to generate a context and put it in your clipboard.
     - If no suitable header file exists, make a new one and put any structs and types you need in there.
 1. Paste the context into decomp.me, and create the scratch.
-1. Copy the `CC_FLAGS` from `Makefile` into the arguments field in decomp.me.
-    - Also copy `CXX_FLAGS` if your function comes from a `.cpp` file. Otherwise, copy `C_FLAGS` if it's a `.c` file.
-    - Replace the `-d $(REGION)` flag with whichever region you intend to decompile for. You can also delete the flag entirely
-    if the function contains no region differences.
 1. Decompile the function and try to get a 100% match.
     - There's no ARM decompiler in decomp.me yet, but Ghidra does the job quite well. See [the Ghidra section](#the-ghidra-project)
     for more info.
@@ -70,6 +78,18 @@ is 12 (`0xc`) bytes long and is also implicit, so we don't need to define it our
 > [!IMPORTANT]
 > An important thing to keep in mind is that a static initializer can construct multiple global objects.
 
+## Decompiling data
+> [!NOTE]
+> Under construction! It's not fully clear how data is decompiled, as the compiler is strict on how it orders global variables.
+> Feel free to contribute to this section or provide us with more information!
+
+Other than `.text` and `.init` which contain code, there are the following sections for data:
+- `.rodata`: Global or static constants
+- `.data`: Global or static variables
+- `.bss`/`.sbss`: Global or static uninitialized variables
+
+You can see examples of these data sections in the [compilation section in `build_system.md`](/docs/build_system.md#compiling-code).
+
 ## The Ghidra project
 We use a shared Ghidra project to analyze the game and decompile functions. To gain access to the project, install
 [Ghidra version 10.2.3](https://github.com/NationalSecurityAgency/ghidra/releases/tag/Ghidra_10.2.3_build) and request access
diff --git a/tools/lcf.py b/tools/lcf.py
index 7122d656..f0fc74d8 100644
--- a/tools/lcf.py
+++ b/tools/lcf.py
@@ -13,8 +13,8 @@ def name(path: str): return path.split("/")[-1]
 ARM9_OBJECTS = [
     'asm/main/main_02000000.s',
 
-    'asm/main/Actor/ActorType.s',
     'src/Main/Actor/ActorType.cpp',
+    'asm/main/Actor/ActorType.s',
 
     'asm/main/main_0203e8a0.s',
 
@@ -86,13 +86,13 @@ ov00 = Overlay(name='ov00', after='ARM9', objects=[
 
     'asm/ov00/ov00_020b1498.s',
 
-    'asm/ov00/Actor/Actor.s',
     'src/00_Core/Actor/Actor.cpp',
+    'asm/ov00/Actor/Actor.s',
 
     'asm/ov00/ov00_020c3348.s',
 
-    'asm/ov00/Actor/ActorManager.s',
     'src/00_Core/Actor/ActorManager.cpp',
+    'asm/ov00/Actor/ActorManager.s',
 
     'asm/ov00/ov00_020c3e54.s',
 ])
diff --git a/tools/m2ctx.py b/tools/m2ctx.py
index 71562c0a..7bb5885a 100755
--- a/tools/m2ctx.py
+++ b/tools/m2ctx.py
@@ -5,6 +5,15 @@ import pyperclip
 import subprocess
 import os
 from pathlib import Path
+import argparse
+
+parser = argparse.ArgumentParser(description="Generates a context for decomp.me")
+parser.add_argument('file', help="Input file to preprocess")
+parser.add_argument('-f', type=str, dest='out_file', required=False, help='Output context file')
+parser.add_argument('-c', action=argparse.BooleanOptionalAction, dest='clipboard', required=False, help='Copy output to clipboard')
+parser.add_argument('-e', type=str, dest='encoding', required=False, default="Shift-JIS", help='Input file encoding')
+parser.add_argument('-v', action=argparse.BooleanOptionalAction, dest='verbose', required=False, help='Verbose error output')
+args = parser.parse_args()
 
 CXX_FLAGS = [
     '-nostdinc',
@@ -15,63 +24,19 @@ CXX_FLAGS = [
 script_dir = Path(os.path.dirname(os.path.realpath(__file__)))
 root_dir = script_dir / ".."
 
-program = os.path.basename(sys.argv[0])
-
 def eprint(*args, **kwargs):
     print(*args, file=sys.stderr, **kwargs)
 
-def print_usage():
-    eprint(f"Usage: {program} INFILE [-f OUTFILE] [-c] [-e ENCODING] [-v]")
-    eprint("    INFILE     \tInput file to preprocess")
-    eprint("    -f OUTFILE \tOutput context file")
-    eprint("    -c         \tCopy output to clipboard")
-    eprint("    -e ENCODING\tInput file encoding (Default: Shift-JIS)")
-    eprint("    -v         \tVerbose error output")
-
-if len(sys.argv) == 1:
-    print_usage()
-    exit(1)
-
-
-in_file = None
-out_file = None
-clipboard = False
-encoding = "Shift-JIS"
-verbose = False
-i = 1
-while i < len(sys.argv):
-    arg = sys.argv[i]
-    if arg == "-f":
-        i += 1
-        if i >= len(sys.argv):
-            eprint("Expected output file after -f")
-            exit(1)
-        out_file = sys.argv[i]
-    elif arg == "-c":
-        clipboard = True
-    elif arg == "-e":
-        i += 1
-        if i >= len(sys.argv):
-            eprint("Expected input file encoding after -e")
-            exit(1)
-        encoding = sys.argv[i]
-    elif arg == "-v":
-        verbose = True
-    elif arg.startswith("-"):
-        eprint(f"Unknown option '{arg}'")
-    elif in_file is None:
-        in_file = arg
-    else:
-        eprint(f"Duplicate input file '{arg}'")
-        exit(1)
-    i += 1
-
-
 try:
-    ctx: str = subprocess.check_output(['gcc', '-E', '-P', '-undef', '-dD', *CXX_FLAGS, in_file], cwd=root_dir, encoding=encoding)
+    ctx: str = subprocess.check_output([
+        'gcc',
+        '-E', '-P', '-fworking-directory', '-undef', '-dD',
+        *CXX_FLAGS,
+        args.file
+    ], cwd=root_dir, encoding=args.encoding)
 except subprocess.CalledProcessError as e:
-    eprint(f"Failed to preprocess '{in_file}'")
-    if verbose: eprint(e)
+    eprint(f"Failed to preprocess '{args.file}'")
+    if args.verbose: eprint(e)
     else: eprint("Use -v for more verbose error output")
     exit(1)
 
@@ -85,17 +50,17 @@ for i in reversed(range(len(lines))):
 
 ctx = ''.join(lines)
 
-if out_file:
+if args.out_file:
     try:
-        with open(out_file, "w") as file:
+        with open(args.out_file, "w") as file:
             file.write(ctx)
     except OSError as e:
-        eprint(f"Failed to write file '{out_file}'")
-        if verbose: eprint(e)
+        eprint(f"Failed to write file '{args.out_file}'")
+        if args.verbose: eprint(e)
         else: eprint("Use -v for more verbose error output")
         exit(1)
-if clipboard:
+if args.clipboard:
     pyperclip.copy(ctx)
     eprint("Copied context to clipboard")
-if out_file is None and not clipboard:
+if args.out_file is None and not args.clipboard:
     print(ctx)