Add in-memory function deactivation mode to Windows BAT scripts

conan/internal/api/install/generators.py

@@ -1,5 +1,7 @@
 import inspect
 import os
+import tempfile
+import textwrap
 import traceback
 import importlib
 
@@ -221,13 +223,27 @@ def sh_content(files):
                 save(os.path.join(conanfile.generators_folder, "deactivate_{}".format(filename)),
                      sh_content(deactivates(shs)))
         if bats:
-            def bat_content(files):
-                return "\r\n".join(["@echo off"] + ['call "{}"'.format(b) for b in files])
+            def bat_content(files, is_deactivate=False):
+                content = ""
+                if deactivation_mode == "function":
+                    deactivates_var = f"_CONAN_{group}_DEACTIVATES_DIR"
+                    if is_deactivate:
+                        call_prefix = f"%{deactivates_var}%\\"
+                        files = [f.replace("%~dp0\\", call_prefix) for f in files]
+                    else:
+                        content += "\r\n".join([f'set "{deactivates_var}=%TEMP%\\.conan_{group}_deactivate_envs_%RANDOM%"',
+                                                f'mkdir "%{deactivates_var}%"',
+                                                ''])
+                content += "\r\n".join(["@echo off"] + [f'call "{b}"' for b in files])
+
+                return content
+
             filename = "conan{}.bat".format(group)
             generated.append(filename)
             save(os.path.join(conanfile.generators_folder, filename), bat_content(bats))
+            # if not deactivation_mode:
             save(os.path.join(conanfile.generators_folder, "deactivate_{}".format(filename)),
-                 bat_content(deactivates(bats)))
+                 bat_content(deactivates(bats), True))
         if ps1s:
             def ps1_content(files):
                 content = "\r\n".join(['& "{}"'.format(b) for b in files])

conan/tools/env/environment.py

@@ -418,36 +418,19 @@ def save_dotenv(self, file_location):
 
     def save_bat(self, file_location, generate_deactivate=True):
         _, filename = os.path.split(file_location)
-        deactivate_file = "deactivate_{}".format(filename)
-        deactivate = textwrap.dedent("""\
-            setlocal
-            echo @echo off > "%~dp0/{deactivate_file}"
-            echo echo Restoring environment >> "%~dp0/{deactivate_file}"
-            for %%v in ({vars}) do (
-                set foundenvvar=
-                for /f "delims== tokens=1,2" %%a in ('set') do (
-                    if /I "%%a" == "%%v" (
-                        echo set "%%a=%%b">> "%~dp0/{deactivate_file}"
-                        set foundenvvar=1
-                    )
-                )
-                if not defined foundenvvar (
-                    echo set %%v=>> "%~dp0/{deactivate_file}"
-                )
-            )
-            endlocal
-            """).format(deactivate_file=deactivate_file, vars=" ".join(self._values.keys()))
-        capture = textwrap.dedent("""\
-            @echo off
-            chcp 65001 > nul
-            {deactivate}
-            """).format(deactivate=deactivate if generate_deactivate else "")
-        result = [capture]
+        result = []
         abs_base_path, new_path = relativize_paths(self._conanfile, "%~dp0")
         for varname, varvalues in self._values.items():
             value = varvalues.get_str("%{name}%", subsystem=self._subsystem, pathsep=self._pathsep,
                                       root_path=abs_base_path, script_path=new_path)
-            result.append('set "{}={}"'.format(varname, value))
+            if value:
+                result.append(f'set "{varname}={value}"')
+            else:
+                result.append(f'set "{varname}="')
+
+        if generate_deactivate:
+            deactivate_content = _bat_deactivate_contents(self._deactivation_mode, self._values, filename, self._scope)
+            result.insert(0, deactivate_content)
 
         content = "\n".join(result)
         # It is very important to save it correctly with utf-8, the Conan util save() is broken
@@ -576,6 +559,35 @@ def _old_env_prefix(filename):
     return f"_CONAN_OLD_{_deactivate_func_name(filename).upper()}"
 
 
+def _bat_deactivate_contents(use_deactivate_function, values, filename, scope):
+    deactivate_file = "deactivate_{}".format(filename)
+    dest_variable = f"%_CONAN_{scope}_DEACTIVATES_DIR%" if use_deactivate_function else "%~dp0"
+    return textwrap.dedent("""\
+        @echo off
+        chcp 65001 > nul
+
+        setlocal
+        echo @echo off > "{dest_variable}/{deactivate_file}"
+        echo echo Restoring environment for {filename} with {vars} >> "{dest_variable}/{deactivate_file}"
+        for %%v in ({vars}) do (
+            set foundenvvar=
+            for /f "delims== tokens=1,2" %%a in ('set') do (
+                if /I "%%a" == "%%v" (
+                    echo set "%%a=%%b">> "{dest_variable}/{deactivate_file}"
+                    set foundenvvar=1
+                )
+            )
+            if not defined foundenvvar (
+                echo set %%v=>> "{dest_variable}/{deactivate_file}"
+            )
+        )
+        endlocal
+        """).format(deactivate_file=deactivate_file,
+                    vars=" ".join(values.keys()),
+                    dest_variable=dest_variable,
+                    filename=filename,)
+
+
 def _ps1_deactivate_contents(deactivation_mode, values, filename):
     vars_list = ", ".join(f'"{v}"' for v in values.keys())
     if deactivation_mode == "function":

test/integration/environment/test_env.py

@@ -518,7 +518,7 @@ def generate(self):
 
     for _ in range(2):  # Just repeat it, so we can check things keep working
         if platform.system() == "Windows":
-            cmd = "conanbuild.bat && display.bat && deactivate_conanbuild.bat && display.bat"
+            cmd = f"conanbuild.bat && display.bat && deactivate_conanbuild.bat && display.bat"
         else:
             deactivate_cmd = "deactivate_conanbuild" if deactivation_mode else ". ./deactivate_conanbuild.sh"
             cmd = f'. ./conanbuild.sh && ./display.sh && {deactivate_cmd} && ./display.sh'