Qt toolchain

.bazelrc

@@ -0,0 +1,20 @@
+#############################
+## Terminal output options ##
+#############################
+
+# Print debug information while finding toolchains for a rule
+build --toolchain_resolution_debug
+
+# If a command fails, print out the full command line
+build --verbose_failures
+
+# Display the subcommands used to generate each target
+# Uncomment to see the effect, if you have it allways enabled it will increase quite a log the logs
+# build --subcommands=pretty_print
+
+#####################
+## Caching options ##
+#####################
+
+# Enable disk cache
+build --disk_cache=~/.bazel/disk_cache/

qt_configure.bzl

@@ -13,37 +13,70 @@ def qt_autoconf_impl(repository_ctx):
        repository_ctx: repository context
     """
     os_name = repository_ctx.os.name.lower()
-    is_linux_machine = False
-    if os_name.find("windows") != -1:
+    if os_name.find("windows") == -1 and os_name.find("linux") == -1:
+        fail("Unsupported OS: %s" % os_name)
+    is_linux_machine = os_name.find("windows") == -1
+
+    # Location of the different Qt artifacts on Linux system installed standalone as well as Windows
+    # Qt includes
+    # <location>/include
+    #
+    # Qt libraries
+    # <location>/lib
+    #
+    # uic, rcc, moc
+    # <location>/bin
+
+    # Location of the different Qt artifacts on Linux system installed with apt
+    # Qt includes
+    # /usr/include/x86_64-linux-gnu/qt5
+    #
+    # Qt libraries
+    # /lib/x86_64-linux-gnu/
+    # /usr/lib/x86_64-linux-gnu/
+    #
+    # uic, rcc, moc
+    # /usr/bin/
+
+    # If QT_DIR is defined and it exists, we consider that it is a standalone installation
+    # Only in the case that is linux and QT_DIR is not defined it is considerd a none standalone
+    # installation
+    qt_dir_path = _get_env_var(repository_ctx, "QT_DIR", None)
+    is_standalone = qt_dir_path != None and repository_ctx.path(qt_dir_path).exists
+    if not is_linux_machine:
         # Inside this folder, in Windows you can find include, lib and bin folder
         default_qt_path = "C:\\\\Qt\\\\5.9.9\\\\msvc2017_64\\\\"
-    elif os_name.find("linux") != -1:
-        is_linux_machine = True
-        # In Linux, this is the equivalent to the include folder, the binaries are located in
-        # /usr/bin/
-        # This would be the path if it has been installed using a package manager
-        default_qt_path = "/usr/include/x86_64-linux-gnu/qt5"
-        if not repository_ctx.path(default_qt_path).exists:
-            default_qt_path = "/usr/include/qt"
+        qt_prefix = default_qt_path
+        if is_standalone:
+            qt_prefix = qt_dir_path
+        qt_includes = qt_prefix + "\\\\include"
+        qt_libs = qt_prefix + "\\\\lib"
+        qt_bins = qt_prefix + "\\\\bin"
     else:
-        fail("Unsupported OS: %s" % os_name)
-
-    if repository_ctx.path(default_qt_path).exists:
-        print("Installation available on the default path: ", default_qt_path)
+        if is_standalone:
+            qt_prefix = qt_dir_path
+            qt_includes = qt_prefix + "/include"
+            qt_libs = qt_prefix + "/lib"
+            qt_bins = qt_prefix + "/bin"
+        else:
+            default_qt_include_path = "/usr/include/x86_64-linux-gnu/qt5"
+            if repository_ctx.path(default_qt_include_path).exists:
+                qt_includes = default_qt_include_path
+            else:
+                qt_includes = "/usr/include/qt"
+            qt_libs = "/lib/x86_64-linux-gnu/"
+            qt_bins = "/usr/bin/"
 
-    qt_path = _get_env_var(repository_ctx, "QT_DIR", default_qt_path)
-    if qt_path != default_qt_path:
-        print("However QT_DIR is defined and will be used: ", qt_path)
-        # In Linux in case that we have a standalone installation, we need to provide the path inside the include folder
-        qt_path_with_include = qt_path + "/include"
-        if is_linux_machine and repository_ctx.path(qt_path_with_include).exists:
-            qt_path = qt_path_with_include
+    print("Qt installation found in:")
+    print("Qt includes: ", qt_includes)
+    print("Qt libs: ", qt_libs)
+    print("Qt bins: ", qt_bins)
 
     repository_ctx.file("BUILD", "# empty BUILD file so that bazel sees this as a valid package directory")
     repository_ctx.template(
         "local_qt.bzl",
         repository_ctx.path(Label("//:BUILD.local_qt.tpl")),
-        {"%{path}": qt_path},
+        {"%{path}": qt_includes},
     )
 
 qt_autoconf = repository_rule(

qt_toolchain.bzl

@@ -0,0 +1,77 @@
+QtSDK = provider(
+    doc = "Contains information about the Qt SDK used in the toolchain",
+    fields = {
+        "qt_include_path": "Path where the Qt include files are located",
+        "qt_lib_path": "Path where the Qt libraries are located",
+        "rcc_path": "Path where the rcc binary is located",
+        "moc_path": "Path where the moc binary is located",
+        "uic_path": "Path where the uic binary is located",
+    },
+)
+
+def _qt_toolchain_impl(ctx):
+    toolchain_info = platform_common.ToolchainInfo(
+        qt_sdk = QtSDK(
+            qt_include_path = ctx.attr.qt_include_path,
+            qt_lib_path = ctx.attr.qt_lib_path,
+            rcc_path = ctx.attr.rcc_path,
+            moc_path = ctx.attr.moc_path,
+            uic_path = ctx.attr.uic_path,
+        ),
+    )
+    return [toolchain_info]
+
+qt_toolchain = repository_rule(
+    implementation = _qt_toolchain_impl,
+    attrs = {
+        "qt_include_path": attr.string(),
+        "qt_lib_path": attr.string(),
+        "rcc_path": attr.string(),
+        "moc_path": attr.string(),
+        "uic_path": attr.string(),
+    },
+)
+
+def declare_windows_toolchain():
+    toolchain_name = "qt_windows_amd64"
+    toolchain_impl_name = toolchain_name + "_impl"
+    qt_toolchain(
+        name = toolchain_impl_name,
+        tags = ["manual"],
+    )
+    native.toolchain(
+        name = toolchain_name,
+        exec_compatible_with = [
+            "@platforms//os:windows",
+            "@platforms//cpu:x86_64",
+        ],
+        target_compatible_with = [
+            "@platforms//os:windows",
+            "@platforms//cpu:x86_64",
+        ],
+        toolchain = ":" + toolchain_impl_name,
+    )
+
+def declare_linux_toolchain():
+    toolchain_name = "qt_linux_amd64"
+    toolchain_impl_name = toolchain_name + "_impl"
+    qt_toolchain(
+        name = toolchain_impl_name,
+    )
+    native.toolchain(
+        name = toolchain_name,
+        exec_compatible_with = [
+            "@platforms//os:linux",
+            "@platforms//cpu:x86_64",
+        ],
+        target_compatible_with = [
+            "@platforms//os:linux",
+            "@platforms//cpu:x86_64",
+        ],
+        toolchain = ":" + toolchain_impl_name,
+    )
+
+def declare_toolchains():
+    declare_linux_toolchain()
+    declare_windows_toolchain()
+    native.register_toolchains(":qt_linux_amd64", ":qt_windows_amd64")