Raise error when a generator is defined in generators and generate()

conan/internal/__init__.py

@@ -0,0 +1,8 @@
+from conan.errors import ConanException
+
+
+def check_duplicated_generator(generator, conanfile):
+    if generator.__class__.__name__ in conanfile.generators:
+        raise ConanException(f"{generator.__class__.__name__} is declared in the generators "
+                             "attribute, but was instantiated in the generate() method too. "
+                             "It should only be present in one of them.")

conan/tools/__init__.py

@@ -1,2 +1,4 @@
 CONAN_TOOLCHAIN_ARGS_FILE = "conanbuild.conf"
 CONAN_TOOLCHAIN_ARGS_SECTION = "toolchain"
+
+

conan/tools/apple/apple.py

@@ -1,6 +1,5 @@
 import os
 
-from conans.errors import ConanException
 from conans.util.runners import check_output_runner
 from conan.tools.build import cmd_args_to_string
 from conans.errors import ConanException

conan/tools/apple/xcodebuild.py

@@ -1,5 +1,3 @@
-import os
-
 from conan.tools.apple import to_apple_arch
 from conans.errors import ConanException
 

conan/tools/apple/xcodedeps.py

@@ -4,6 +4,7 @@
 
 from jinja2 import Template
 
+from conan.internal import check_duplicated_generator
 from conans.errors import ConanException
 from conans.model.dependencies import get_transitive_requires
 from conans.util.files import load, save
@@ -115,6 +116,7 @@ def __init__(self, conanfile):
         self.sdk_version = conanfile.settings.get_safe("os.sdk_version")
 
     def generate(self):
+        check_duplicated_generator(self, self._conanfile)
         if self.configuration is None:
             raise ConanException("XcodeDeps.configuration is None, it should have a value")
         if self.architecture is None:

conan/tools/apple/xcodetoolchain.py

@@ -1,5 +1,6 @@
 import textwrap
 
+from conan.internal import check_duplicated_generator
 from conan.tools.apple.apple import to_apple_arch
 from conan.tools.apple.xcodedeps import GLOBAL_XCCONFIG_FILENAME, GLOBAL_XCCONFIG_TEMPLATE, \
     _add_includes_to_file_or_create, _xcconfig_settings_filename, _xcconfig_conditional
@@ -46,6 +47,7 @@ def __init__(self, conanfile):
         self._global_ldflags = sharedlinkflags + exelinkflags
 
     def generate(self):
+        check_duplicated_generator(self, self._conanfile)
         save(self._agreggated_xconfig_filename, self._agreggated_xconfig_content)
         save(self._vars_xconfig_filename, self._vars_xconfig_content)
         if self._check_if_extra_flags:

conan/tools/cmake/cmakedeps/cmakedeps.py

@@ -1,5 +1,6 @@
 import os
 
+from conan.internal import check_duplicated_generator
 from conan.tools.cmake.cmakedeps import FIND_MODE_CONFIG, FIND_MODE_NONE, FIND_MODE_BOTH, \
     FIND_MODE_MODULE
 from conan.tools.cmake.cmakedeps.templates.config import ConfigTemplate
@@ -35,6 +36,7 @@ def generate(self):
         """
         This method will save the generated files to the conanfile.generators_folder
         """
+        check_duplicated_generator(self, self._conanfile)
         # FIXME: Remove this in 2.0
         if not hasattr(self._conanfile, "settings_build") and \
                       (self.build_context_activated or self.build_context_build_modules or

conan/tools/cmake/toolchain/toolchain.py

@@ -4,6 +4,7 @@
 
 from jinja2 import Template
 
+from conan.internal import check_duplicated_generator
 from conan.tools.build import use_win_mingw
 from conan.tools.cmake.presets import write_cmake_presets
 from conan.tools.cmake.toolchain import CONAN_TOOLCHAIN_FILENAME
@@ -173,6 +174,7 @@ def generate(self):
         """
           This method will save the generated files to the conanfile.generators_folder
         """
+        check_duplicated_generator(self, self._conanfile)
         toolchain_file = self._conanfile.conf.get("tools.cmake.cmaketoolchain:toolchain_file")
         if toolchain_file is None:  # The main toolchain file generated only if user dont define
             save(os.path.join(self._conanfile.generators_folder, self.filename), self.content)

conan/tools/env/virtualbuildenv.py

@@ -1,3 +1,4 @@
+from conan.internal import check_duplicated_generator
 from conan.tools.env import Environment
 from conan.tools.env.virtualrunenv import runenv_from_cpp_info
 
@@ -78,6 +79,6 @@ def generate(self, scope="build"):
 
         :param scope: Scope to be used.
         """
-
+        check_duplicated_generator(self, self._conanfile)
         build_env = self.environment()
         build_env.vars(self._conanfile, scope=scope).save_script(self._filename)

conan/tools/env/virtualrunenv.py

@@ -1,5 +1,6 @@
 import os
 
+from conan.internal import check_duplicated_generator
 from conan.tools.env import Environment
 
 
@@ -89,5 +90,6 @@ def generate(self, scope="run"):
 
         :param scope: Scope to be used.
         """
+        check_duplicated_generator(self, self._conanfile)
         run_env = self.environment()
         run_env.vars(self._conanfile, scope=scope).save_script(self._filename)

conan/tools/files/files.py

@@ -1,7 +1,6 @@
 import configparser
 import errno
 import gzip
-import hashlib
 import os
 import platform
 import shutil

conan/tools/gnu/autotoolsdeps.py

@@ -1,3 +1,4 @@
+from conan.internal import check_duplicated_generator
 from conan.tools.env import Environment
 from conan.tools.gnu.gnudeps_flags import GnuDepsFlags
 from conans.model.build_info import CppInfo
@@ -79,4 +80,5 @@ def vars(self, scope="build"):
         return self.environment.vars(self._conanfile, scope=scope)
 
     def generate(self,  scope="build"):
+        check_duplicated_generator(self, self._conanfile)
         self.vars(scope).save_script("conanautotoolsdeps")

conan/tools/gnu/autotoolstoolchain.py

@@ -1,3 +1,4 @@
+from conan.internal import check_duplicated_generator
 from conan.tools.apple.apple import apple_min_version_flag, to_apple_arch
 from conan.tools.apple.apple import get_apple_sdk_fullname
 from conan.tools.build import cmd_args_to_string
@@ -6,7 +7,7 @@
 from conan.tools.env import Environment
 from conan.tools.files.files import save_toolchain_args
 from conan.tools.gnu.get_gnu_triplet import _get_gnu_triplet
-from conan.tools.microsoft import VCVars, is_msvc, msvc_runtime_flag
+from conan.tools.microsoft import VCVars, msvc_runtime_flag
 from conans.errors import ConanException
 
 
@@ -158,6 +159,7 @@ def vars(self):
         return self.environment().vars(self._conanfile, scope="build")
 
     def generate(self, env=None, scope="build"):
+        check_duplicated_generator(self, self._conanfile)
         env = env or self.environment()
         env = env.vars(self._conanfile, scope=scope)
         env.save_script("conanautotoolstoolchain")

conan/tools/gnu/pkgconfigdeps.py

@@ -4,6 +4,7 @@
 
 from jinja2 import Template, StrictUndefined
 
+from conan.internal import check_duplicated_generator
 from conan.tools.gnu.gnudeps_flags import GnuDepsFlags
 from conans.errors import ConanException
 from conans.util.files import save
@@ -414,6 +415,7 @@ def generate(self):
         """
         Save all the `*.pc` files
         """
+        check_duplicated_generator(self, self._conanfile)
         # Current directory is the generators_folder
         generator_files = self.content
         for generator_file, content in generator_files.items():

conan/tools/google/bazeldeps.py

@@ -4,6 +4,7 @@
 
 from jinja2 import Template
 
+from conan.internal import check_duplicated_generator
 from conans.errors import ConanException
 from conans.util.files import save
 
@@ -13,6 +14,7 @@ def __init__(self, conanfile):
         self._conanfile = conanfile
 
     def generate(self):
+        check_duplicated_generator(self, self._conanfile)
         local_repositories = []
         generators_folder = self._conanfile.generators_folder
 

conan/tools/google/toolchain.py

@@ -1,3 +1,4 @@
+from conan.internal import check_duplicated_generator
 from conan.tools.files.files import save_toolchain_args
 
 
@@ -8,6 +9,7 @@ def __init__(self, conanfile, namespace=None):
         self._namespace = namespace
 
     def generate(self):
+        check_duplicated_generator(self, self._conanfile)
         content = {}
         configs = ",".join(self._conanfile.conf.get("tools.google.bazel:configs",
                                                     default=[],

conan/tools/intel/intel_cc.py

@@ -21,6 +21,7 @@
 import platform
 import textwrap
 
+from conan.internal import check_duplicated_generator
 from conans.errors import ConanException
 
 
@@ -72,6 +73,7 @@ def ms_toolset(self):
 
     def generate(self, scope="build"):
         """Generate the Conan Intel file to be loaded in build environment by default"""
+        check_duplicated_generator(self, self._conanfile)
         if platform.system() == "Windows" and not self._conanfile.win_bash:
             content = textwrap.dedent("""\
                 @echo off

conan/tools/meson/mesondeps.py

@@ -2,6 +2,7 @@
 
 from jinja2 import Template
 
+from conan.internal import check_duplicated_generator
 from conan.tools.gnu.gnudeps_flags import GnuDepsFlags
 from conan.tools.meson.helpers import to_meson_value
 from conans.model.build_info import CppInfo
@@ -102,4 +103,5 @@ def _content(self):
         return content
 
     def generate(self):
+        check_duplicated_generator(self, self._conanfile)
         save(self.filename, self._content())

conan/tools/meson/toolchain.py

@@ -3,6 +3,7 @@
 
 from jinja2 import Template
 
+from conan.internal import check_duplicated_generator
 from conan.tools.apple.apple import to_apple_arch, is_apple_os, apple_min_version_flag
 from conan.tools.build.cross_building import cross_building
 from conan.tools.build.flags import libcxx_flags
@@ -427,6 +428,7 @@ def generate(self):
         ``conan_meson_cross.ini`` (if cross builds) with the proper content.
         If Windows OS, it will be created a ``conanvcvars.bat`` as well.
         """
+        check_duplicated_generator(self, self._conanfile)
         filename = self.native_filename if not self.cross_build else self.cross_filename
         save(filename, self._content)
         # FIXME: Should we check the OS and compiler to call VCVars?

conan/tools/microsoft/msbuilddeps.py

@@ -6,6 +6,7 @@
 
 from jinja2 import Template
 
+from conan.internal import check_duplicated_generator
 from conans.errors import ConanException
 from conans.model.dependencies import get_transitive_requires
 from conans.util.files import load, save
@@ -113,6 +114,7 @@ def generate(self):
         Generates ``conan_<pkg>_<config>_vars.props``, ``conan_<pkg>_<config>.props``,
         and ``conan_<pkg>.props`` files into the ``conanfile.generators_folder``.
         """
+        check_duplicated_generator(self, self._conanfile)
         if self.configuration is None:
             raise ConanException("MSBuildDeps.configuration is None, it should have a value")
         if self.platform is None:

conan/tools/microsoft/nmakedeps.py

@@ -1,5 +1,6 @@
 import os
 
+from conan.internal import check_duplicated_generator
 from conan.tools.env import Environment
 from conans.model.build_info import CppInfo
 
@@ -58,4 +59,5 @@ def vars(self, scope="build"):
         return self.environment.vars(self._conanfile, scope=scope)
 
     def generate(self, scope="build"):
+        check_duplicated_generator(self, self._conanfile)
         self.vars(scope).save_script("conannmakedeps")

conan/tools/microsoft/nmaketoolchain.py

@@ -1,3 +1,4 @@
+from conan.internal import check_duplicated_generator
 from conan.tools.build.flags import build_type_flags, cppstd_flag
 from conan.tools.env import Environment
 
@@ -51,6 +52,7 @@ def vars(self, scope="build"):
         return self.environment.vars(self._conanfile, scope=scope)
 
     def generate(self, scope="build"):
+        check_duplicated_generator(self, self._conanfile)
         self.vars(scope).save_script("conannmaketoolchain")
         from conan.tools.microsoft import VCVars
         VCVars(self._conanfile).generate()

conan/tools/microsoft/toolchain.py

@@ -4,6 +4,7 @@
 
 from jinja2 import Template
 
+from conan.internal import check_duplicated_generator
 from conan.tools.build import build_jobs
 from conan.tools.intel.intel_cc import IntelCC
 from conan.tools.microsoft.visual import VCVars, msvc_version_to_toolset_version
@@ -91,6 +92,7 @@ def generate(self):
         valid XML format with all the good settings like any other VS project ``*.props`` file. The
         last one emulates the ``vcvarsall.bat`` env script. See also :class:`VCVars`.
         """
+        check_duplicated_generator(self, self._conanfile)
         name, condition = self._name_condition(self._conanfile.settings)
         config_filename = "conantoolchain{}.props".format(name)
         # Writing the props files

conan/tools/microsoft/visual.py

@@ -1,6 +1,7 @@
 import os
 import textwrap
 
+from conan.internal import check_duplicated_generator
 from conans.client.conf.detect_vs import vs_installation_path
 from conans.errors import ConanException, ConanInvalidConfiguration
 from conan.tools.scm import Version
@@ -90,6 +91,7 @@ def generate(self, scope="build"):
         :param scope: ``str`` Launcher to be used to run all the variables. For instance,
                       if ``build``, then it'll be used the ``conanbuild`` launcher.
         """
+        check_duplicated_generator(self, self._conanfile)
         conanfile = self._conanfile
         os_ = conanfile.settings.get_safe("os")
         if os_ != "Windows":

conan/tools/premake/premakedeps.py

@@ -1,3 +1,4 @@
+from conan.internal import check_duplicated_generator
 from conans.model.build_info import CppInfo
 from conans.util.files import save
 
@@ -41,6 +42,7 @@ def __init__(self, conanfile):
         self._conanfile = conanfile
 
     def generate(self):
+        check_duplicated_generator(self, self._conanfile)
         # Current directory is the generators_folder
         generator_files = self.content
         for generator_file, content in generator_files.items():

conan/tools/qbs/qbsprofile.py

@@ -4,6 +4,8 @@
 
 from io import StringIO
 from jinja2 import Template
+
+from conan.internal import check_duplicated_generator
 from conans.errors import ConanException
 from conans.util.files import save
 
@@ -284,6 +286,7 @@ def __init__(self, conanfile):
             conanfile.options.get_safe('fPIC'))
 
     def generate(self):
+        check_duplicated_generator(self, self._conanfile)
         save(self.old_filename, self.content)
         save(self.filename, self.content)
 

conans/client/generators/__init__.py

@@ -93,21 +93,30 @@ def write_generators(conanfile, hook_manager):
 
     if conanfile.generators:
         conanfile.output.info(f"Writing generators to {new_gen_folder}")
-    for generator_name in set(conanfile.generators):
-        generator_class = _get_generator_class(generator_name)
-        if generator_class:
-            try:
-                generator = generator_class(conanfile)
-                conanfile.output.highlight(f"Generator '{generator_name}' calling 'generate()'")
-                mkdir(new_gen_folder)
-                with chdir(new_gen_folder):
-                    generator.generate()
-                continue
-            except Exception as e:
-                # When a generator fails, it is very useful to have the whole stacktrace
-                conanfile.output.error(traceback.format_exc())
-                raise ConanException("Error in generator '{}': {}".format(generator_name, str(e)))
-
+    # generators check that they are not present in the generators field,
+    # to avoid duplicates between the generators attribute and the generate() method
+    # They would raise an exception here if we don't invalidate the field while we call them
+    old_generators = set(conanfile.generators)
+    conanfile.generators = []
+    try:
+        for generator_name in old_generators:
+            generator_class = _get_generator_class(generator_name)
+            if generator_class:
+                try:
+                    generator = generator_class(conanfile)
+                    conanfile.output.highlight(f"Generator '{generator_name}' calling 'generate()'")
+                    mkdir(new_gen_folder)
+                    with chdir(new_gen_folder):
+                        generator.generate()
+                    continue
+                except Exception as e:
+                    # When a generator fails, it is very useful to have the whole stacktrace
+                    conanfile.output.error(traceback.format_exc())
+                    raise ConanException(f"Error in generator '{generator_name}': {str(e)}") from e
+    finally:
+        # restore the generators attribute, so it can raise
+        # if the user tries to instantiate a generator already present in generators
+        conanfile.generators = old_generators
     if hasattr(conanfile, "generate"):
         conanfile.output.highlight("Calling generate()")
         mkdir(new_gen_folder)