[feature][PkgConfigDeps] Warn about duplicated *.pc names

conan/tools/gnu/pkgconfigdeps/pc_files_creator.py

@@ -4,21 +4,32 @@
     get_single_package_info, get_aliases_info
 
 
-def _get_aliases_pc_files_and_content(dep, aliases_info):
+def _get_aliases_pc_files_and_content(conanfile, dep, aliases_info, root_pc_files):
     """
     Get all the PC files and content for the aliases defined previously
     for package and components names
     """
     pc_files = {}
     for name, aliases in aliases_info.items():
         for alias in aliases:
-            pc_alias_file = get_alias_pc_filename_and_content(
+            pc_name, pc_content = get_alias_pc_filename_and_content(
                 dep,
                 alias,
                 [name],  # require is the own name which is being used the aliases for.
                 description="Alias %s for %s" % (alias, name),
             )
-            pc_files.update(pc_alias_file)
+            if pc_name in pc_files:
+                conanfile.output.warn("[%s] The PC alias name %s already exists and it matches with "
+                                      "another alias one. Please, review all the "
+                                      "pkg_config_aliases defined. Skipping it!"
+                                      % (dep, pc_name))
+            elif pc_name in root_pc_files:
+                conanfile.output.warn("[%s] The PC alias name %s already exists and it matches with "
+                                      "another package/component one. Please, review all the "
+                                      "pkg_config_aliases defined. Skipping it!"
+                                      % (dep, pc_name))
+            else:
+                pc_files[pc_name] = pc_content
     return pc_files
 
 
@@ -31,14 +42,20 @@ def _get_components_pc_files_and_content(conanfile, dep, components_info):
     for pc_info_component in components_info:
         # Get the *.pc file content for each component
         description = "Conan component: %s" % pc_info_component.name
-        pc_file = get_pc_filename_and_content(
+        pc_name, pc_content = get_pc_filename_and_content(
             conanfile,
             dep,
             pc_info_component.name,
             pc_info_component.requires,
             description,
             cpp_info=pc_info_component.cpp_info)
-        pc_files.update(pc_file)
+        if pc_name in pc_files:
+            conanfile.output.warn("[%s] The PC component name %s already exists and it matches with "
+                                  "another component one. Please, review all the "
+                                  "component's pkg_config_name defined. Skipping it!"
+                                  % (dep, pc_name))
+        else:
+            pc_files[pc_name] = pc_content
     return pc_files
 
 
@@ -49,13 +66,18 @@ def _get_package_with_components_pc_files_and_content(conanfile, dep, package_in
     pc_files = {}
     pc_files.update(_get_components_pc_files_and_content(conanfile, dep, components_info))
     description = "Conan package: %s" % package_info.name
-    pc_alias_file_pkg = get_alias_pc_filename_and_content(
+    pc_name, pc_content = get_alias_pc_filename_and_content(
         dep,
         package_info.name,
         package_info.requires,
         description
     )
-    pc_files.update(pc_alias_file_pkg)
+    if pc_name in pc_files:
+        conanfile.output.warn("[%s] The PC package name %s already exists and it matches with "
+                              "another component one. Please, review all the "
+                              "component's pkg_config_name defined. Skipping it!" % (dep, pc_name))
+    else:
+        pc_files[pc_name] = pc_content
     return pc_files
 
 
@@ -64,9 +86,9 @@ def _get_single_package_pc_file_and_content(conanfile, dep, package_info):
     Get the PC files for dependencies without components
     """
     description = "Conan package: %s" % package_info.name
-    pc_file = get_pc_filename_and_content(conanfile, dep, package_info.name,
-                                          package_info.requires, description)
-    return pc_file
+    pc_name, pc_content = get_pc_filename_and_content(conanfile, dep, package_info.name,
+                                                      package_info.requires, description)
+    return {pc_name: pc_content}
 
 
 def get_pc_files_and_content(conanfile, dep):
@@ -85,5 +107,5 @@ def get_pc_files_and_content(conanfile, dep):
         pc_files.update(_get_single_package_pc_file_and_content(conanfile, dep, pkg_info))
     # Package and components names aliases
     aliases_info = get_aliases_info(dep, pkg_info, components_info)
-    pc_files.update(_get_aliases_pc_files_and_content(dep, aliases_info))
+    pc_files.update(_get_aliases_pc_files_and_content(conanfile, dep, aliases_info, pc_files))
     return pc_files

conan/tools/gnu/pkgconfigdeps/pc_files_templates.py

@@ -110,7 +110,7 @@ def get_pc_filename_and_content(conanfile, dep, name, requires, description, cpp
     }
     template = Template(_get_pc_file_template(), trim_blocks=True, lstrip_blocks=True,
                         undefined=StrictUndefined)
-    return {name + ".pc": template.render(context)}
+    return name + ".pc", template.render(context)
 
 
 def get_alias_pc_filename_and_content(dep, name, requires, description):
@@ -122,4 +122,4 @@ def get_alias_pc_filename_and_content(dep, name, requires, description):
     }
     template = Template(_get_alias_pc_file_template(), trim_blocks=True,
                         lstrip_blocks=True, undefined=StrictUndefined)
-    return {name + ".pc": template.render(context)}
+    return name + ".pc", template.render(context)

conan/tools/gnu/pkgconfigdeps/pkgconfigdeps.py

@@ -13,12 +13,22 @@ def content(self):
         pc_files = {}
         host_req = self._conanfile.dependencies.host
         for _, dep in host_req.items():
-            pc_files.update(get_pc_files_and_content(self._conanfile, dep))
+            dep_name = str(dep)
+            for pc_name, pc_content in get_pc_files_and_content(self._conanfile, dep).items():
+                if pc_name in pc_files:
+                    _, analyzed_dep_name = pc_files[pc_name]
+                    self._conanfile.output.warn(
+                        "[%s] The PC file name %s already exists and it matches with another "
+                        "name/alias declared in %s package. Please, review all the "
+                        "pkg_config_name/pkg_config_aliases defined. Skipping it!"
+                        % (dep_name, pc_name, analyzed_dep_name))
+                else:
+                    pc_files[pc_name] = (pc_content, dep_name)
         return pc_files
 
     def generate(self):
         """Save all the *.pc files"""
         # Current directory is the generators_folder
         generator_files = self.content
-        for generator_file, content in generator_files.items():
+        for generator_file, (content, _) in generator_files.items():
             save(generator_file, content)

conans/test/functional/toolchains/gnu/test_pkgconfigdeps.py

@@ -1,3 +1,4 @@
+import glob
 import os
 import textwrap
 
@@ -462,3 +463,87 @@ def package_info(self):
 
     pc_content = client.load("second-mycomponent.pc")
     assert "Requires: compo1" == get_requires_from_content(pc_content)
+
+
+def test_duplicated_names_warnings():
+    """
+    Testing some WARN messages if there are duplicated pkg_config_name/pkg_config_aliases defined
+
+    Scenario: consumer -> pkgA/1.0 -> pkgB/1.0
+    Expected WARN cases:
+        - Duplicated aliases.
+        - Duplicated names, alias and component name
+        - Duplicated components names.
+        - Duplicated package and component name.
+        - Duplicated names between different dependencies.
+    """
+    client = TestClient()
+    conanfile = textwrap.dedent("""
+        from conans import ConanFile
+
+        class Recipe(ConanFile):
+
+            def package_info(self):
+                self.cpp_info.set_property("pkg_config_name", "libpkg")
+                # Duplicated components
+                self.cpp_info.components["cmp1"].set_property("pkg_config_name", "component1")
+                self.cpp_info.components["cmp2"].set_property("pkg_config_name", "component1")
+                # Duplicated package and component name
+                self.cpp_info.components["cmp3"].set_property("pkg_config_name", "libpkg")
+    """)
+    client.save({"conanfile.py": conanfile})
+    client.run("create . pkgB/1.0@")
+
+    conanfile = textwrap.dedent("""
+        from conans import ConanFile
+
+        class PkgConfigConan(ConanFile):
+            requires = "pkgB/1.0"
+
+            def package_info(self):
+                # Duplicated name as pkgB
+                self.cpp_info.set_property("pkg_config_name", "libpkg")
+                self.cpp_info.components["cmp1"].requires.append("pkgB::cmp1")
+                self.cpp_info.components["cmp1"].set_property("pkg_config_name", "component1")
+                # Duplicated aliases
+                self.cpp_info.components["cmp2"].set_property("pkg_config_aliases", ["alias1"])
+                self.cpp_info.components["cmp3"].set_property("pkg_config_aliases", ["alias1"])
+                # Duplicated names, alias and component name
+                self.cpp_info.components["cmp2"].set_property("pkg_config_name", "libcmp")
+                self.cpp_info.components["cmp4"].set_property("pkg_config_aliases", ["libcmp"])
+        """)
+    client.save({"conanfile.py": conanfile}, clean_first=True)
+    client.run("create . pkgA/1.0@")
+
+    conanfile = textwrap.dedent("""
+        [requires]
+        pkgA/1.0
+
+        [generators]
+        PkgConfigDeps
+        """)
+    client.save({"conanfile.txt": conanfile}, clean_first=True)
+    client.run("install .")
+    output = client.out
+    # Duplicated aliases from pkgA
+    assert "WARN: [pkgA/1.0] The PC alias name alias1.pc already exists and it matches with " \
+           "another alias one" in output
+    # Duplicated names, alias and component name from pkgA
+    assert "WARN: [pkgA/1.0] The PC alias name libcmp.pc already exists and it matches with " \
+           "another package/component one" in output
+    # Duplicated components from pkgB
+    assert "WARN: [pkgB/1.0] The PC component name component1.pc already exists and it matches " \
+           "with another component one" in output
+    # Duplicated package and component name from pkgB
+    assert "WARN: [pkgB/1.0] The PC package name libpkg.pc already exists and it matches with " \
+           "another component one" in output
+    # Duplicated names between pkgB and pkgA
+    assert "WARN: [pkgB/1.0] The PC file name component1.pc already exists and it matches with " \
+           "another name/alias declared in pkgA/1.0 package" in output
+    assert "WARN: [pkgB/1.0] The PC file name libpkg.pc already exists and it matches with " \
+           "another name/alias declared in pkgA/1.0 package" in output
+    pc_files = [os.path.basename(i) for i in glob.glob(os.path.join(client.current_folder, '*.pc'))]
+    pc_files.sort()
+    # Let's check all the PC file names created just in case
+    assert pc_files == ['alias1.pc', 'component1.pc', 'libcmp.pc', 'libpkg-cmp3.pc',
+                        'libpkg-cmp4.pc', 'libpkg.pc']