[toolchains]Tests for compilers path from conf in build context

conans/test/functional/toolchains/cmake/test_cmake_toolchain.py

@@ -7,8 +7,8 @@
 import pytest
 
 from conan.tools.cmake.presets import load_cmake_presets
-from conans.model.recipe_ref import RecipeReference
 from conan.tools.microsoft.visual import vcvars_command
+from conans.model.recipe_ref import RecipeReference
 from conans.test.assets.cmake import gen_cmakelists
 from conans.test.assets.genconanfile import GenConanfile
 from conans.test.utils.test_files import temp_folder

conans/test/integration/toolchains/cmake/test_cmaketoolchain.py

@@ -1334,3 +1334,83 @@ def test_toolchain_ends_newline():
     client.run("install . -g CMakeToolchain")
     toolchain = client.load("conan_toolchain.cmake")
     assert toolchain[-1] == "\n"
+
+
+def test_toolchain_and_compilers_build_context():
+    """
+    Tests how CMakeToolchain manages the build context profile if the build profile is
+    specifying another compiler path (using conf)
+
+    Issue related: https://github.com/conan-io/conan/issues/15878
+    """
+    host = textwrap.dedent("""
+    [settings]
+    arch=armv8
+    build_type=Release
+    compiler=gcc
+    compiler.cppstd=gnu17
+    compiler.libcxx=libstdc++11
+    compiler.version=11
+    os=Linux
+
+    [conf]
+    tools.build:compiler_executables={"c": "gcc", "cpp": "g++"}
+    """)
+    build = textwrap.dedent("""
+    [settings]
+    os=Linux
+    arch=x86_64
+    compiler=clang
+    compiler.version=12
+    compiler.libcxx=libc++
+    compiler.cppstd=11
+
+    [conf]
+    tools.build:compiler_executables={"c": "clang", "cpp": "clang++"}
+    """)
+    tool = textwrap.dedent("""
+    import os
+    from conan import ConanFile
+    from conan.tools.files import load
+
+    class toolRecipe(ConanFile):
+        name = "tool"
+        version = "1.0"
+        # Binary configuration
+        settings = "os", "compiler", "build_type", "arch"
+        generators = "CMakeToolchain"
+
+        def build(self):
+            toolchain = os.path.join(self.generators_folder, "conan_toolchain.cmake")
+            content = load(self, toolchain)
+            assert 'set(CMAKE_C_COMPILER "clang")' in content
+            assert 'set(CMAKE_CXX_COMPILER "clang++")' in content
+    """)
+    consumer = textwrap.dedent("""
+    import os
+    from conan import ConanFile
+    from conan.tools.files import load
+
+    class consumerRecipe(ConanFile):
+        name = "consumer"
+        version = "1.0"
+        # Binary configuration
+        settings = "os", "compiler", "build_type", "arch"
+        generators = "CMakeToolchain"
+        tool_requires = "tool/1.0"
+
+        def build(self):
+            toolchain = os.path.join(self.generators_folder, "conan_toolchain.cmake")
+            content = load(self, toolchain)
+            assert 'set(CMAKE_C_COMPILER "gcc")' in content
+            assert 'set(CMAKE_CXX_COMPILER "g++")' in content
+    """)
+    client = TestClient()
+    client.save({
+        "host": host,
+        "build": build,
+        "tool/conanfile.py": tool,
+        "consumer/conanfile.py": consumer
+    })
+    client.run("export tool")
+    client.run("create consumer -pr:h host -pr:b build --build=missing")

conans/test/integration/toolchains/gnu/test_autotoolstoolchain.py

@@ -195,3 +195,83 @@ def test_unknown_compiler():
     # this used to crash, because of build_type_flags in AutotoolsToolchain returning empty string
     client.run("install . -s compiler=xlc")
     assert "conanfile.py: Generator 'AutotoolsToolchain' calling 'generate()'" in client.out
+
+
+def test_toolchain_and_compilers_build_context():
+    """
+    Tests how AutotoolsToolchain manages the build context profile if the build profile is
+    specifying another compiler path (using conf)
+
+    Issue related: https://github.com/conan-io/conan/issues/15878
+    """
+    host = textwrap.dedent("""
+    [settings]
+    arch=armv8
+    build_type=Release
+    compiler=gcc
+    compiler.cppstd=gnu17
+    compiler.libcxx=libstdc++11
+    compiler.version=11
+    os=Linux
+
+    [conf]
+    tools.build:compiler_executables={"c": "gcc", "cpp": "g++"}
+    """)
+    build = textwrap.dedent("""
+    [settings]
+    os=Linux
+    arch=x86_64
+    compiler=clang
+    compiler.version=12
+    compiler.libcxx=libc++
+    compiler.cppstd=11
+
+    [conf]
+    tools.build:compiler_executables={"c": "clang", "cpp": "clang++"}
+    """)
+    tool = textwrap.dedent("""
+    import os
+    from conan import ConanFile
+    from conan.tools.files import load
+
+    class toolRecipe(ConanFile):
+        name = "tool"
+        version = "1.0"
+        # Binary configuration
+        settings = "os", "compiler", "build_type", "arch"
+        generators = "AutotoolsToolchain"
+
+        def build(self):
+            toolchain = os.path.join(self.generators_folder, "conanautotoolstoolchain.sh")
+            content = load(self, toolchain)
+            assert 'export CC="clang"' in content
+            assert 'export CXX="clang++"' in content
+    """)
+    consumer = textwrap.dedent("""
+    import os
+    from conan import ConanFile
+    from conan.tools.files import load
+
+    class consumerRecipe(ConanFile):
+        name = "consumer"
+        version = "1.0"
+        # Binary configuration
+        settings = "os", "compiler", "build_type", "arch"
+        generators = "AutotoolsToolchain"
+        tool_requires = "tool/1.0"
+
+        def build(self):
+            toolchain = os.path.join(self.generators_folder, "conanautotoolstoolchain.sh")
+            content = load(self, toolchain)
+            assert 'export CC="gcc"' in content
+            assert 'export CXX="g++"' in content
+    """)
+    client = TestClient()
+    client.save({
+        "host": host,
+        "build": build,
+        "tool/conanfile.py": tool,
+        "consumer/conanfile.py": consumer
+    })
+    client.run("export tool")
+    client.run("create consumer -pr:h host -pr:b build --build=missing")

conans/test/integration/toolchains/meson/test_mesontoolchain.py

@@ -309,3 +309,149 @@ def generate(self):
     base_folder = t.current_folder
     assert f"pkg_config_path = '{base_folder}'" in content
     assert f"build.pkg_config_path = '{os.path.join(base_folder, 'build')}'" in content
+
+
+
+def test_toolchain_and_compilers_build_context():
+    """
+    Tests how MesonToolchain manages the build context profile if the build profile is
+    specifying another compiler path (using conf).
+
+    It should create both native and cross files.
+
+    Issue related: https://github.com/conan-io/conan/issues/15878
+    """
+    host = textwrap.dedent("""
+    [settings]
+    arch=armv8
+    build_type=Release
+    compiler=gcc
+    compiler.cppstd=gnu17
+    compiler.libcxx=libstdc++11
+    compiler.version=11
+    os=Linux
+    """)
+    build = textwrap.dedent("""
+    [settings]
+    os=Linux
+    arch=x86_64
+    compiler=clang
+    compiler.version=12
+    compiler.libcxx=libc++
+    compiler.cppstd=11
+
+    [conf]
+    tools.build:compiler_executables={"asm": "clang", "c": "clang", "cpp": "clang++"}
+    """)
+    conanfile = textwrap.dedent("""
+    import os
+    from conan import ConanFile
+    from conan.tools.files import replace_in_file
+    class helloRecipe(ConanFile):
+        name = "hello"
+        version = "1.0.0"
+        package_type = "application"
+        # Binary configuration
+        settings = "os", "compiler", "build_type", "arch"
+        generators = "MesonToolchain"
+
+        def build(self):
+            native_path = os.path.join(self.generators_folder, "conan_meson_native.ini")
+            cross_path = os.path.join(self.generators_folder, "conan_meson_cross.ini")
+            assert os.path.exists(cross_path)  # sanity check
+            assert os.path.exists(native_path)  # sanity check
+            # This should not raise anything!! Notice the strict=True
+            replace_in_file(self, cross_path, 'c = gcc', "#Hey", strict=True)
+            replace_in_file(self, cross_path, 'cpp = g++', "#Hey", strict=True)
+            replace_in_file(self, native_path, 'c = clang', "#Hey", strict=True)
+            replace_in_file(self, native_path, 'cpp = clang++', "#Hey", strict=True)
+    """)
+    client = TestClient()
+    client.save({
+        "host": host,
+        "build": build,
+        "conanfile.py": conanfile
+    })
+    client.run("build . -pr:h host -pr:b build")
+
+
+def test_toolchain_and_compilers_build_context():
+    """
+    Tests how MesonToolchain manages the build context profile if the build profile is
+    specifying another compiler path (using conf).
+
+    It should create both native and cross files.
+
+    Issue related: https://github.com/conan-io/conan/issues/15878
+    """
+    host = textwrap.dedent("""
+    [settings]
+    arch=armv8
+    build_type=Release
+    compiler=gcc
+    compiler.cppstd=gnu17
+    compiler.libcxx=libstdc++11
+    compiler.version=11
+    os=Linux
+
+    [conf]
+    tools.build:compiler_executables={"c": "gcc", "cpp": "g++"}
+    """)
+    build = textwrap.dedent("""
+    [settings]
+    os=Linux
+    arch=x86_64
+    compiler=clang
+    compiler.version=12
+    compiler.libcxx=libc++
+    compiler.cppstd=11
+
+    [conf]
+    tools.build:compiler_executables={"c": "clang", "cpp": "clang++"}
+    """)
+    tool = textwrap.dedent("""
+    import os
+    from conan import ConanFile
+    from conan.tools.files import load
+
+    class toolRecipe(ConanFile):
+        name = "tool"
+        version = "1.0"
+        # Binary configuration
+        settings = "os", "compiler", "build_type", "arch"
+        generators = "MesonToolchain"
+
+        def build(self):
+            toolchain = os.path.join(self.generators_folder, "conan_meson_native.ini")
+            content = load(self, toolchain)
+            assert "c = 'clang'" in content
+            assert "cpp = 'clang++'" in content
+    """)
+    consumer = textwrap.dedent("""
+    import os
+    from conan import ConanFile
+    from conan.tools.files import load
+
+    class consumerRecipe(ConanFile):
+        name = "consumer"
+        version = "1.0"
+        # Binary configuration
+        settings = "os", "compiler", "build_type", "arch"
+        generators = "MesonToolchain"
+        tool_requires = "tool/1.0"
+
+        def build(self):
+            toolchain = os.path.join(self.generators_folder, "conan_meson_cross.ini")
+            content = load(self, toolchain)
+            assert "c = 'gcc'" in content
+            assert "cpp = 'g++'" in content
+    """)
+    client = TestClient()
+    client.save({
+        "host": host,
+        "build": build,
+        "tool/conanfile.py": tool,
+        "consumer/conanfile.py": consumer
+    })
+    client.run("export tool")
+    client.run("create consumer -pr:h host -pr:b build --build=missing")