pysymfix.cpp

#include "extension.h"

#include <engextcpp.hpp>

#include <filesystem>
#include <string>
#include <stdexcept>
#include <cassert>
using namespace std;


namespace {

	auto getSymbolPath(IDebugSymbols* pSymbols) -> string
	{
		// Get the size we'll need first.
		ULONG pathSize = 0;
		HRESULT hr = pSymbols->GetSymbolPath(nullptr, 0, &pathSize);
		if (FAILED(hr))
			throw runtime_error("GetSymbolPath failed to get path size with hr=" + hr);

		// Now get the buffer.
		string buff(pathSize, '\0');
		hr = pSymbols->GetSymbolPath(buff.data(), pathSize, &pathSize);
		if (FAILED(hr))
			throw runtime_error("GetSymbolPath failed to get path size with hr=" + hr);

		assert(pathSize == buff.size() && "Unexpected symbol path size after second call to GetSymbolPath.");
		buff.erase(buff.find('\0')); //< Trim off any extra from our string.

		return buff;
	}


	auto setSymbolPath(IDebugSymbols* pSymbols, const string& path) -> void
	{
		HRESULT hr = pSymbols->SetSymbolPath(path.c_str());
		if (FAILED(hr))
			throw runtime_error("SetSymbolPath failed with hr=" + hr);
	}

	string concatenatePaths(const string& path1, const string& path2, char delim = ';')
	{
		auto cattedPath = path1;
		if (!cattedPath.empty() && cattedPath.back() != delim) {
			cattedPath += delim;
		}
		cattedPath += path2;
		return cattedPath;
	}

}


namespace PyExt {

	EXT_COMMAND(pysymfix, "Adds python symbols to the symbol path.", "")
	{
		auto sympath = getSymbolPath(m_Symbols);
		Out("Current symbol path: %s\n", sympath.c_str());

		// Check for local PDBs next to each python*.dll and append their directories.
		ULONG moduleCount = 0, unloadedCount = 0;
		if (SUCCEEDED(m_Symbols->GetNumberModules(&moduleCount, &unloadedCount))) {
			for (ULONG i = 0; i < moduleCount; i++) {
				char modName[MAX_PATH] = {};
				char imagePath[MAX_PATH] = {};
				if (FAILED(m_Symbols->GetModuleNames(i, 0,
				                                     imagePath, sizeof(imagePath), nullptr,
				                                     modName, sizeof(modName), nullptr,
				                                     nullptr, 0, nullptr)))
					continue;
				if (_strnicmp(modName, "python", 6) != 0)
					continue;

				auto dir = filesystem::path(imagePath).parent_path();
				if (!filesystem::exists(dir / (string(modName) + ".pdb")))
					continue;

				string dirStr = dir.string();
				if (sympath.find(dirStr) != string::npos)
					continue;

				Out("Found local PDB in %s, adding to symbol path.\n", dirStr.c_str());
				sympath = concatenatePaths(sympath, dirStr);
			}
		}

		if (sympath.find("pythonsymbols.sdcline.com/symbols") == string::npos) {
			Out("Adding symbol server to path...\n");
			sympath = concatenatePaths(sympath, "srv*http://pythonsymbols.sdcline.com/symbols");
		} else {
			Out("Python symbol server already in path.\n");
		}

		setSymbolPath(m_Symbols, sympath);
		Out("New symbol path: %s\n", getSymbolPath(m_Symbols).c_str());

		Out("Loading symbols...\n");
		ensureSymbolsLoaded();
	}

}