AutotoolsToolchain: curate paths coming from tools.build:compiler_executables on Windows before defining CC, CXX etc

conan/tools/gnu/autotoolstoolchain.py

@@ -4,18 +4,21 @@
 from conan.tools.apple.apple import apple_min_version_flag, to_apple_arch, \
     apple_sdk_path
 from conan.tools.build.cross_building import cross_building, get_cross_building_settings
-from conan.tools.env import Environment
+from conan.tools.env import Environment, VirtualBuildEnv
 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, is_msvc, msvc_runtime_flag, unix_path
 from conans.errors import ConanException
 from conans.tools import args_to_string
+import os
 
 
 class AutotoolsToolchain:
-    def __init__(self, conanfile, namespace=None):
+    def __init__(self, conanfile, namespace=None, compile_wrapper=None, ar_wrapper=None):
         self._conanfile = conanfile
         self._namespace = namespace
+        self._compile_wrapper = compile_wrapper
+        self._ar_wrapper = ar_wrapper
 
         self.configure_args = self._default_configure_shared_flags() + self._default_configure_install_flags()
         self.autoreconf_args = self._default_autoreconf_flags()
@@ -43,6 +46,16 @@ def __init__(self, conanfile, namespace=None):
         self.fpic = self._conanfile.options.get_safe("fPIC")
         self.msvc_runtime_flag = self._get_msvc_runtime_flag()
 
+        # standard build toolchains env vars
+        self.cc = self._get_cc()
+        self.cxx = self._get_cxx()
+        self.ld = self._get_ld()
+        self.ar = self._get_ar()
+        self.nm = self._get_nm()
+        self.objdump = self._get_objdump()
+        self.ranlib = self._get_ranlib()
+        self.strip = self._get_strip()
+
         # Cross build
         self._host = None
         self._build = None
@@ -120,11 +133,99 @@ def defines(self):
         ret = [self.ndebug, self.gcc_cxx11_abi] + conf_flags + self.extra_defines
         return self._filter_list_empty_fields(ret)
 
+    def _get_cc(self):
+        return self._exe_env_var_to_unix_path(
+            "CC",
+            "cl" if is_msvc(self._conanfile) else None,
+            ["-nologo"] if is_msvc(self._conanfile) else [],
+            self._compile_wrapper,
+        )
+
+    def _get_cxx(self):
+        return self._exe_env_var_to_unix_path(
+            "CXX",
+            "cl" if is_msvc(self._conanfile) else None,
+            ["-nologo"] if is_msvc(self._conanfile) else [],
+            self._compile_wrapper,
+        )
+
+    def _get_ld(self):
+        return self._exe_env_var_to_unix_path(
+            "LD",
+            "link" if is_msvc(self._conanfile) else None,
+            ["-nologo"] if is_msvc(self._conanfile) else [],
+        )
+
+    def _get_ar(self):
+        return self._exe_env_var_to_unix_path(
+            "AR",
+            "lib" if is_msvc(self._conanfile) else None,
+            None, # do not add any option, ar wrapper may not like this
+            self._ar_wrapper,
+        )
+
+    def _get_nm(self):
+        return self._exe_env_var_to_unix_path(
+            "NM",
+            "dumpbin" if is_msvc(self._conanfile) else None,
+            ["-nologo", "-symbols"] if is_msvc(self._conanfile) else [],
+        )
+
+    def _get_objdump(self):
+        return self._exe_env_var_to_unix_path(
+            "OBJDUMP",
+            ":" if is_msvc(self._conanfile) else None,
+        )
+
+    def _get_ranlib(self):
+        return self._exe_env_var_to_unix_path(
+            "RANLIB",
+            ":" if is_msvc(self._conanfile) else None,
+        )
+
+    def _get_strip(self):
+        return self._exe_env_var_to_unix_path(
+            "STRIP",
+            ":" if is_msvc(self._conanfile) else None,
+        )
+
+    def _exe_env_var_to_unix_path(self, env_var, default=None, extra_options=None, wrapper=None):
+        """
+            Convenient method to convert env vars like CC, CXX or LD to values compatible with autotools.
+            If env var doesn't exist, returns default.
+        """
+        exe = VirtualBuildEnv(self._conanfile).vars().get(env_var)
+        if exe:
+            if os.path.exists(exe):
+                exe = unix_path(self._conanfile, exe)
+        else:
+            exe = default
+        if exe:
+            if wrapper:
+                if os.path.exists(wrapper):
+                    wrapper = unix_path(self._conanfile, wrapper)
+                exe = f"{wrapper} {exe}"
+            if extra_options:
+                for option in extra_options:
+                    if option not in exe:
+                        exe += f" {option}"
+        return exe
+
     def environment(self):
         env = Environment()
-        if is_msvc(self._conanfile):
-            env.define("CXX", "cl")
-            env.define("CC", "cl")
+        build_env = VirtualBuildEnv(self._conanfile).vars()
+        for env_var, new_env_var_value in [
+            ("CC", self.cc),
+            ("CXX", self.cxx),
+            ("LD", self.ld),
+            ("AR", self.ar),
+            ("NM", self.nm),
+            ("OBJDUMP", self.objdump),
+            ("RANLIB", self.ranlib),
+            ("STRIP", self.strip),
+        ]:
+            if new_env_var_value and new_env_var_value != build_env.get(env_var):
+                env.define(env_var, new_env_var_value)
         env.append("CPPFLAGS", ["-D{}".format(d) for d in self.defines])
         env.append("CXXFLAGS", self.cxxflags)
         env.append("CFLAGS", self.cflags)