GH-3234 Add support for custom meta URLs at build time

This is not particularly interesting for non-developers.
Also includes some internal restructuring of URL constants in general.

buildconfig/BuildConfig.cpp.in

@@ -0,0 +1,55 @@
+#include "BuildConfig.h"
+#include <QObject>
+
+const Config BuildConfig;
+
+Config::Config()
+{
+    // Version information
+    VERSION_MAJOR = @MultiMC_VERSION_MAJOR@;
+    VERSION_MINOR = @MultiMC_VERSION_MINOR@;
+    VERSION_HOTFIX = @MultiMC_VERSION_HOTFIX@;
+    VERSION_BUILD = @MultiMC_VERSION_BUILD@;
+
+    BUILD_PLATFORM = "@MultiMC_BUILD_PLATFORM@";
+    CHANLIST_URL = "@MultiMC_CHANLIST_URL@";
+    ANALYTICS_ID = "@MultiMC_ANALYTICS_ID@";
+    NOTIFICATION_URL = "@MultiMC_NOTIFICATION_URL@";
+    FULL_VERSION_STR = "@MultiMC_VERSION_MAJOR@.@MultiMC_VERSION_MINOR@.@MultiMC_VERSION_BUILD@";
+
+    GIT_COMMIT = "@MultiMC_GIT_COMMIT@";
+    GIT_REFSPEC = "@MultiMC_GIT_REFSPEC@";
+    if(GIT_REFSPEC.startsWith("refs/heads/") && !CHANLIST_URL.isEmpty() && VERSION_BUILD >= 0)
+    {
+        VERSION_CHANNEL = GIT_REFSPEC;
+        VERSION_CHANNEL.remove("refs/heads/");
+        UPDATER_ENABLED = true;
+    }
+    else
+    {
+        VERSION_CHANNEL = QObject::tr("custom");
+    }
+
+    VERSION_STR = "@MultiMC_VERSION_STRING@";
+    NEWS_RSS_URL = "@MultiMC_NEWS_RSS_URL@";
+    PASTE_EE_KEY = "@MultiMC_PASTE_EE_API_KEY@";
+    META_URL = "@MultiMC_META_URL@";
+}
+
+QString Config::printableVersionString() const
+{
+    QString vstr = QString("%1.%2.%3").arg(QString::number(VERSION_MAJOR), QString::number(VERSION_MINOR), QString::number(VERSION_HOTFIX));
+
+    // If the build is not a main release, append the channel
+    if(VERSION_CHANNEL != "stable")
+    {
+        vstr += "-" + VERSION_CHANNEL;
+    }
+
+    // if a build number is set, also add it to the end
+    if(VERSION_BUILD >= 0)
+    {
+        vstr += "-" + QString::number(VERSION_BUILD);
+    }
+    return vstr;
+}

buildconfig/BuildConfig.h

@@ -0,0 +1,87 @@
+#pragma once
+#include <QString>
+
+/**
+ * \brief The Config class holds all the build-time information passed from the build system.
+ */
+class Config
+{
+public:
+    Config();
+    /// The major version number.
+    int VERSION_MAJOR;
+    /// The minor version number.
+    int VERSION_MINOR;
+    /// The hotfix number.
+    int VERSION_HOTFIX;
+    /// The build number.
+    int VERSION_BUILD;
+
+    /**
+     * The version channel
+     * This is used by the updater to determine what channel the current version came from.
+     */
+    QString VERSION_CHANNEL;
+
+    bool UPDATER_ENABLED = false;
+
+    /// A short string identifying this build's platform. For example, "lin64" or "win32".
+    QString BUILD_PLATFORM;
+
+    /// URL for the updater's channel
+    QString CHANLIST_URL;
+
+    /// Google analytics ID
+    QString ANALYTICS_ID;
+
+    /// URL for notifications
+    QString NOTIFICATION_URL;
+
+    /// Used for matching notifications
+    QString FULL_VERSION_STR;
+
+    /// The git commit hash of this build
+    QString GIT_COMMIT;
+
+    /// The git refspec of this build
+    QString GIT_REFSPEC;
+
+    /// This is printed on start to standard output
+    QString VERSION_STR;
+
+    /**
+     * This is used to fetch the news RSS feed.
+     * It defaults in CMakeLists.txt to "https://multimc.org/rss.xml"
+     */
+    QString NEWS_RSS_URL;
+
+    /**
+     * API key you can get from paste.ee when you register an account
+     */
+    QString PASTE_EE_KEY;
+
+    /**
+     * MultiMC Metadata repository URL prefix
+     */
+    QString META_URL;
+
+    QString RESOURCE_BASE = "https://resources.download.minecraft.net/";
+    QString LIBRARY_BASE = "https://libraries.minecraft.net/";
+    QString SKINS_BASE = "https://crafatar.com/skins/";
+    QString AUTH_BASE = "https://authserver.mojang.com/";
+    QString MOJANG_STATUS_URL = "https://status.mojang.com/check";
+    QString IMGUR_BASE_URL = "https://api.imgur.com/3/";
+    QString FMLLIBS_OUR_BASE_URL = "https://files.multimc.org/fmllibs/";
+    QString FMLLIBS_FORGE_BASE_URL = "https://files.minecraftforge.net/fmllibs/";
+    QString TRANSLATIONS_BASE_URL = "https://files.multimc.org/translations/";
+
+    QString LEGACY_FTB_CDN_BASE_URL = "https://dist.creeper.host/FTB2/";
+
+    /**
+     * \brief Converts the Version to a string.
+     * \return The version number in string format (major.minor.revision.build).
+     */
+    QString printableVersionString() const;
+};
+
+extern const Config BuildConfig;

buildconfig/CMakeLists.txt

@@ -0,0 +1,11 @@
+######## Configure the file with build properties ########
+
+configure_file("${CMAKE_CURRENT_SOURCE_DIR}/BuildConfig.cpp.in" "${CMAKE_CURRENT_BINARY_DIR}/BuildConfig.cpp")
+
+add_library(BuildConfig STATIC
+    BuildConfig.h
+    ${CMAKE_CURRENT_BINARY_DIR}/BuildConfig.cpp
+)
+
+target_link_libraries(BuildConfig Qt5::Core)
+target_include_directories(BuildConfig PUBLIC "${CMAKE_CURRENT_SOURCE_DIR}")