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techy4shri edited this page Nov 25, 2025 · 1 revision

Compiler & Toolchain Configuration

This document explains how CppLab IDE manages MinGW toolchains and compiler configuration.

Overview

CppLab IDE bundles two complete MinGW toolchains:

Toolchain Bits Purpose Compiler Libraries
mingw32 32-bit Graphics (graphics.h) GCC 8.1.0+ WinBGIm, GDI32
mingw64 64-bit OpenMP, Modern C++ GCC 8.1.0+ libgomp, pthread

Directory Structure

compilers/
├── mingw32/                    # 32-bit toolchain
│   ├── bin/
│   │   ├── gcc.exe            # C compiler
│   │   ├── g++.exe            # C++ compiler
│   │   ├── gdb.exe            # Debugger (future)
│   │   └── *.dll              # Runtime libraries
│   ├── include/
│   │   ├── graphics.h         # WinBGIm header
│   │   ├── winbgim.h
│   │   └── ...                # Standard headers
│   ├── lib/
│   │   ├── libbgi.a           # WinBGIm library
│   │   ├── libgdi32.a         # Windows GDI
│   │   └── ...
│   └── libexec/
│       └── gcc/
│           └── ...            # GCC internals
│
└── mingw64/                    # 64-bit toolchain
    ├── bin/
    │   ├── gcc.exe
    │   ├── g++.exe
    │   └── ...
    ├── include/
    │   ├── omp.h              # OpenMP header
    │   └── ...
    ├── lib/
    │   ├── libgomp.a          # OpenMP library
    │   ├── libpthread.a
    │   └── ...
    └── libexec/
        └── ...

Toolchain Discovery

Initialization

File: src/cpplab/core/toolchains.py

def get_toolchains() -> dict:
    """Discover and return available MinGW toolchains."""
    app_root = get_app_root()
    compilers_dir = app_root / "compilers"
    
    toolchains = {}
    
    # Check mingw32
    mingw32_path = compilers_dir / "mingw32"
    if mingw32_path.exists():
        gcc_path = mingw32_path / "bin" / "gcc.exe"
        gpp_path = mingw32_path / "bin" / "g++.exe"
        if gcc_path.exists() and gpp_path.exists():
            toolchains["mingw32"] = Toolchain(
                name="mingw32",
                root=mingw32_path,
                gcc=gcc_path,
                gpp=gpp_path,
                bits=32
            )
    
    # Check mingw64
    mingw64_path = compilers_dir / "mingw64"
    if mingw64_path.exists():
        gcc_path = mingw64_path / "bin" / "gcc.exe"
        gpp_path = mingw64_path / "bin" / "g++.exe"
        if gcc_path.exists() and gpp_path.exists():
            toolchains["mingw64"] = Toolchain(
                name="mingw64",
                root=mingw64_path,
                gcc=gcc_path,
                gpp=gpp_path,
                bits=64
            )
    
    return toolchains

Toolchain Data Structure

@dataclass
class Toolchain:
    name: str           # "mingw32" or "mingw64"
    root: Path          # C:/path/to/CppLabIDE/compilers/mingw32
    gcc: Path           # Path to gcc.exe
    gpp: Path           # Path to g++.exe
    bits: int           # 32 or 64
    
    def is_available(self) -> bool:
        return self.gcc.exists() and self.gpp.exists()

Toolchain Selection Logic

Decision Tree

┌─────────────────────────────────────┐
│  Project/File Configuration         │
└─────────────┬───────────────────────┘
              │
              ↓
    ┌─────────────────┐
    │ graphics=true?  │
    └────┬────────────┘
         │
    YES  │  NO
         │
    ┌────↓────┐       ┌──────────────┐
    │ mingw32 │       │ openmp=true? │
    └─────────┘       └──────┬───────┘
                             │
                        YES  │  NO
                             │
                        ┌────↓────┐  ┌──────────┐
                        │ mingw64 │  │ mingw64  │
                        └─────────┘  └──────────┘
                                     (default)

Implementation

File: src/cpplab/core/toolchains.py

def select_toolchain(config: ProjectConfig, toolchains: dict) -> Toolchain:
    """Select appropriate toolchain based on project features."""
    
    # User override takes precedence
    if config.toolchain_preference != "auto":
        return toolchains.get(config.toolchain_preference)
    
    # Graphics requires 32-bit
    if config.features.get("graphics", False):
        return toolchains["mingw32"]
    
    # OpenMP prefers 64-bit
    if config.features.get("openmp", False):
        return toolchains["mingw64"]
    
    # Default to 64-bit
    return toolchains["mingw64"]

Why This Logic?

  1. Graphics → 32-bit: WinBGIm library is 32-bit only
  2. OpenMP → 64-bit: Better performance, more memory
  3. Default → 64-bit: Modern systems, better performance

Compiler Configuration

Language Standards

C Standards

C_STANDARDS = {
    "c99": "-std=c99",
    "c11": "-std=c11",
    "c17": "-std=c17",
    "c18": "-std=c18",   # Alias for c17
    "c23": "-std=c23",   # Experimental
}

C++ Standards

CPP_STANDARDS = {
    "c++11": "-std=c++11",
    "c++14": "-std=c++14",
    "c++17": "-std=c++17",
    "c++20": "-std=c++20",
    "c++23": "-std=c++23",  # Experimental
}

Compiler Flags

Base Flags (Always Included)

-Wall              # Enable all warnings
-Wextra            # Extra warnings
-o <output_file>   # Output file

Optional Flags

Graphics.h Projects (32-bit):

-lbgi              # WinBGIm library
-lgdi32            # Windows GDI
-lcomdlg32         # Windows dialogs
-luuid             # Windows UUID
-lole32            # Windows OLE
-loleaut32         # Windows OLE Automation

OpenMP Projects (64-bit):

-fopenmp           # Enable OpenMP

Debug Mode (future):

-g                 # Include debug symbols
-O0                # No optimization

Release Mode (future):

-O2                # Optimize for speed
-DNDEBUG           # Disable assertions

Build Command Construction

Example: Graphics Project

Input:

ProjectConfig(
    name="CircleDemo",
    language="cpp",
    standard="c++17",
    features={"graphics": True, "openmp": False},
    files=["src/main.cpp"],
    main_file="src/main.cpp"
)

Output Command:

C:/CppLabIDE/compilers/mingw32/bin/g++.exe \
    src/main.cpp \
    -std=c++17 \
    -Wall \
    -Wextra \
    -o build/CircleDemo.exe \
    -lbgi \
    -lgdi32 \
    -lcomdlg32 \
    -luuid \
    -lole32 \
    -loleaut32

Example: OpenMP Project

Input:

ProjectConfig(
    name="ParallelSum",
    language="cpp",
    standard="c++20",
    features={"graphics": False, "openmp": True},
    files=["src/main.cpp"],
    main_file="src/main.cpp"
)

Output Command:

C:/CppLabIDE/compilers/mingw64/bin/g++.exe \
    src/main.cpp \
    -std=c++20 \
    -Wall \
    -Wextra \
    -fopenmp \
    -o build/ParallelSum.exe

Example: Plain Console Project

Input:

ProjectConfig(
    name="HelloWorld",
    language="c",
    standard="c17",
    features={"graphics": False, "openmp": False},
    files=["src/main.c"],
    main_file="src/main.c"
)

Output Command:

C:/CppLabIDE/compilers/mingw64/bin/gcc.exe \
    src/main.c \
    -std=c17 \
    -Wall \
    -Wextra \
    -o build/HelloWorld.exe

Auto-Detection

Feature Detection from Source Code

File: src/cpplab/core/builder.py

def detect_features_from_source(source_path: Path) -> dict:
    """Detect graphics.h and OpenMP usage by scanning source code."""
    features = {"graphics": False, "openmp": False}
    
    try:
        with open(source_path, 'r', encoding='utf-8', errors='ignore') as f:
            content = f.read()
        
        # Check for graphics.h
        if '#include' in content and 'graphics.h' in content:
            features["graphics"] = True
        
        # Check for OpenMP
        if '#pragma' in content and 'omp' in content:
            features["openmp"] = True
    
    except Exception:
        pass
    
    return features

Standalone File Workflow

1. User opens: test.cpp
2. User presses F7 (Build)
3. detect_features_from_source(test.cpp)
   → Scans for #include <graphics.h>
   → Scans for #pragma omp
4. Select toolchain based on features
5. Build with appropriate flags

Toolchain Verification

Startup Check

Location: src/cpplab/app.py → _check_toolchains()

def _check_toolchains(self):
    """Check if toolchains are available and show warning if not."""
    self.toolchains = get_toolchains()
    
    mingw32 = self.toolchains.get("mingw32")
    mingw64 = self.toolchains.get("mingw64")
    
    missing = []
    if not mingw32 or not mingw32.is_available():
        missing.append("mingw32 (32-bit, required for graphics.h)")
    if not mingw64 or not mingw64.is_available():
        missing.append("mingw64 (64-bit, required for OpenMP)")
    
    if missing:
        msg = (
            "<h3>Toolchains Not Found</h3>"
            "<p>The following MinGW toolchains are missing:</p>"
            "<ul>"
        )
        for item in missing:
            msg += f"<li>{item}</li>"
        msg += (
            "</ul>"
            "<p>Expected location: <code>compilers/</code> directory</p>"
            "<p>Building will not work until toolchains are installed.</p>"
        )
        QMessageBox.warning(self, "Toolchains Missing", msg)

User Feedback

If toolchains are missing:

┌─────────────────────────────────────────┐
│ ⚠ Toolchains Not Found                 │
├─────────────────────────────────────────┤
│ The following MinGW toolchains are      │
│ missing:                                │
│                                         │
│ • mingw32 (32-bit, required for        │
│   graphics.h)                          │
│ • mingw64 (64-bit, required for        │
│   OpenMP)                              │
│                                         │
│ Expected location: compilers/ directory │
│                                         │
│ Building will not work until toolchains │
│ are installed.                          │
└─────────────────────────────────────────┘

Frozen Mode Support

Challenge

  • Development: compilers/ relative to source code
  • Frozen: compilers/ relative to .exe

Solution

def get_app_root() -> Path:
    """Get application root directory (works in dev and frozen modes)."""
    if getattr(sys, 'frozen', False):
        # Running as PyInstaller bundle
        return Path(sys._MEIPASS).parent
    else:
        # Running from source
        return Path(__file__).parent.parent.parent

Usage:

app_root = get_app_root()
# Dev:    C:/Users/Dev/CppLabEngine
# Frozen: C:/Program Files/CppLabIDE

compilers_dir = app_root / "compilers"
# Dev:    C:/Users/Dev/CppLabEngine/compilers
# Frozen: C:/Program Files/CppLabIDE/compilers

Toolchain UI

Toolbar Combo Box

Location: src/cpplab/app.py → _setup_combo_boxes()

self.toolchainComboBox = QComboBox()
self.toolchainComboBox.addItem("Auto", "auto")
self.toolchainComboBox.addItem("64-bit (mingw64)", "mingw64")
self.toolchainComboBox.addItem("32-bit (mingw32)", "mingw32")

Behavior:

  • Auto: Selects based on project features (default)
  • 64-bit: Forces mingw64 (even for graphics - may fail)
  • 32-bit: Forces mingw32 (even for OpenMP - slower)

User Override

Users can override toolchain selection:

def on_toolchain_changed(self, index: int):
    """Handle toolchain combo box selection change."""
    toolchain_map = {0: "auto", 1: "mingw64", 2: "mingw32"}
    value = toolchain_map.get(index, "auto")
    
    if self.current_project:
        self.current_project.toolchain_preference = value
        self.current_project.save()  # Persist to JSON
    else:
        self.standalone_toolchain_preference = value

Troubleshooting

Toolchains Not Detected

Symptom: Warning on startup "Toolchains Not Found"

Causes:

  1. Missing compilers/ directory
  2. Missing mingw32/ or mingw64/ subdirectories
  3. Missing bin/gcc.exe or bin/g++.exe

Solution:

  1. Check directory structure matches expected layout
  2. Verify compiler executables exist and are not corrupted
  3. Re-extract toolchains from release package

Build Fails with "No such file or directory"

Symptom: Build error: gcc.exe: error: CreateProcess: No such file or directory

Cause: Toolchain path contains spaces or special characters

Solution: Install CppLabIDE to path without spaces (e.g., C:\CppLabIDE)

Graphics Build Fails on 64-bit

Symptom: Linker error: cannot find -lbgi

Cause: Graphics project trying to use mingw64 (64-bit)

Solution:

  1. Check project configuration: "features": {"graphics": true}
  2. Set toolchain to "Auto" or "32-bit" explicitly
  3. Rebuild project

Performance Considerations

Toolchain Caching

Toolchains discovered once at startup:

# MainWindow.__init__
self.toolchains = get_toolchains()  # Cached for session

Benefit: No repeated filesystem checks during builds

Path Resolution

Absolute paths used throughout:

# Bad: Relative path (requires working directory)
cmd = ["gcc", "main.c"]

# Good: Absolute path (works from any directory)
cmd = [str(toolchain.gcc), "main.c"]

Benefit: Builds work regardless of current directory

Next: Language Standards Support
Previous: Asynchronous Build System

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