Add a depreciation message for '-rules' only shown in TTYs

Do this to avoid corruption of report analysis when capturing the GNATcheck output.

Author: HugoGGuerrier

lkql_checker/src/gnatcheck-options.ads

@@ -193,9 +193,9 @@ package Gnatcheck.Options is
    --  Whether the help message about the new instance system has already been
    --  emitted. This message should be removed in 26.0.
 
-   Mixed_Style_Warning_Emitted : Boolean := False;
-   --  Whether the message about usage of and new and legacy rule options for
-   --  the same GNATcheck run.
+   Rules_Depreciation_Emitted : Boolean := False;
+   --  Whether the message about the ``-rules`` section depreciation has been
+   --  emitted in the TTY.
 
    --------------------------------------
    -- Controlling the gnatcheck report --

lkql_checker/src/gnatcheck-output.adb

@@ -16,6 +16,8 @@ with GNAT.Traceback.Symbolic;
 with Gnatcheck.Options;          use Gnatcheck.Options;
 with Gnatcheck.String_Utilities; use Gnatcheck.String_Utilities;
 
+with Interfaces.C_Streams; use Interfaces.C_Streams;
+
 package body Gnatcheck.Output is
 
    Report_File_Name     : String_Access;
@@ -121,6 +123,17 @@ package body Gnatcheck.Output is
       end if;
    end Error_No_Tool_Name;
 
+   ------------------
+   -- Error_In_Tty --
+   ------------------
+
+   procedure Error_In_Tty (Message : String) is
+   begin
+      if isatty (fileno (stderr)) /= 0 then
+         Put_Line (Standard_Error, Executable & ": " & Message);
+      end if;
+   end Error_In_Tty;
+
    -----------------------
    -- Get_Indent_String --
    -----------------------

lkql_checker/src/gnatcheck-output.ads

@@ -43,6 +43,10 @@ package Gnatcheck.Output is
    procedure Error_No_Tool_Name (Message : String);
    --  Sends into Stderr the error message with no tool name prefix
 
+   procedure Error_In_Tty (Message : String);
+   --  Same as ``Error`` but send the message only if Stderr is a TTY. Also,
+   --  ``Message`` is not added to the stderr log file.
+
    procedure SLOC_Error
      (Message : String;
       SLOC    : String);

lkql_checker/src/gnatcheck-projects.adb

@@ -1109,16 +1109,14 @@ package body Gnatcheck.Projects is
                   Add_Rule_Option (Full_Switch (Parser => Parser));
                   Individual_Rules_Set := True;
             end case;
-            if not Mixed_Style_Warning_Emitted then
-               if Arg.Rules.Get'Length > 0
-                 or else Arg.Rule_File.Get /= Null_Unbounded_String
-               then
-                  Warning
-                    ("The '-rules' section usage is discouraged from now, " &
-                     "you should only use the '--rules' and '--rule-file' " &
-                     "command-line options");
-               end if;
-               Mixed_Style_Warning_Emitted := True;
+            if not Rules_Depreciation_Emitted then
+               Error_In_Tty
+                 ("The '-rules' section is now deprecated. You should only " &
+                  "use the '--rules' and '--rule-file' command-line options.");
+               Error_In_Tty
+                 ("You can use the '--emit-lkql-rule-file' flag to " &
+                  "automatically translate your rule configuration to the " &
+                  "new LKQL format.");
             end if;
          end loop;
       end Process_Sections;

testsuite/drivers/base_driver.py

@@ -1,7 +1,11 @@
+import errno
 import glob
 import os
 import os.path as P
+import pty
 import re
+import select
+import subprocess
 import sys
 from typing import TextIO
 
@@ -271,6 +275,60 @@ def run(*prefix):
             else:
                 raise TestAbortWithError(f"invalid perf mode: {mode}")
 
+    def run_in_tty(self, args: list[str], **kwargs) -> tuple[str, int]:
+        """
+        Run a process in a pseudo-TTY using the ``pty`` module. Returns a
+        tuple containing the process output and its status code.
+        """
+        # Ensure the current system is not windows, according to the
+        # documentation, the ``pty`` module is not working fine on it (see
+        # https://docs.python.org/fr/3/library/pty.html).
+        if self.env.build.os.name == "windows":
+            raise TestAbortWithError(
+                "Cannot run a pseudo-TTY on Windows systems"
+            )
+
+        # Ensure the process is run in the testsuite working dir
+        if not kwargs.get("cwd"):
+            kwargs["cwd"] = self.working_dir()
+
+        # Open a subprocess with using a pseudo TTY as output
+        m, s = pty.openpty()
+        p = subprocess.Popen(
+            args=args,
+            stdout=s,
+            stderr=s,
+            close_fds=True,
+            **kwargs
+        )
+        os.close(s)
+
+        # Read result of the process execution and get its return code
+        fully_read = False
+        output = b""
+        status_code = 0
+        try:
+            while not fully_read:
+                ready, _, _ = select.select([m], [], [], 0.05)
+                for fd in ready:
+                    try:
+                        data = os.read(fd, 512)
+                    except OSError as e:
+                        if e.errno != errno.EIO:
+                            raise e
+                        fully_read = True
+                    else:
+                        if not data:
+                            fully_read = True
+                        output += data
+        finally:
+            os.close(m)
+            if p.poll() is None:
+                p.kill()
+            status_code = p.wait()
+
+        return (output.decode(), status_code)
+
     def parse_flagged_lines(self, output: str) -> Flags:
         """
         Parse the output of a call and return an object containing files

testsuite/drivers/gnatcheck_driver.py

@@ -1,7 +1,6 @@
 import os
 import os.path as P
 import re
-import sys
 import xml.etree.ElementTree as ET
 
 from e3.testsuite.driver.diff import (
@@ -130,6 +129,8 @@ class GnatcheckDriver(BaseDriver):
         - ``worker``: Provide a custom worker for the GNATcheck run.
         - ``gnatkp_autoconfig`` (bool): Whether to automatically configure the
           target and runtime when running in "gnatkp" mode. Default is True.
+        - ``in_tty`` (bool): Whether to run GNATcheck in a pseudo TTY using the
+          ``pty`` Python module.
 
         - ``jobs`` (int): The number of jobs to forward to the GNATcheck command.
         - ``project`` (str): GPR build file to use (if any).
@@ -404,10 +405,17 @@ def run_one_test(test_data: dict[str, any]) -> None:
                 if label:
                     self.output += label + "\n" + ("=" * len(label)) + "\n\n"
 
-                p = self.shell(args, env=gnatcheck_env, catch_error=False, analyze_output=False)
-
-                # Get the GNATcheck execution output
-                exec_output = p.out
+                # Execute GNATcheck and get its output
+                exec_output = ""
+                status_code = 0
+                if test_data.get("in_tty"):
+                    exec_output, status_code = self.run_in_tty(args, env=gnatcheck_env)
+                else:
+                    p = self.shell(args, env=gnatcheck_env, catch_error=False, analyze_output=False)
+                    exec_output = p.out
+                    status_code = p.status
+
+                # Then read GNATcheck report file if there is one
                 report_file_content = ""
                 parse_output_for_flags = True
                 if output_format in ['full', 'short', 'xml']:
@@ -451,8 +459,8 @@ def run_one_test(test_data: dict[str, any]) -> None:
                         self.output += ("testsuite_driver: Cannot found the rule "
                                         f"list file '{test_data['rule_list_file']}'")
 
-                if (not brief and p.status not in [0, 1]) or (brief and p.status != 0):
-                    self.output += ">>>program returned status code {}\n".format(p.status)
+                if (not brief and status_code not in [0, 1]) or (brief and status_code != 0):
+                    self.output += ">>>program returned status code {}\n".format(status_code)
 
                 # List the content of directories if needed
                 if test_data.get('list_dirs'):

testsuite/tests/gnatcheck/lkql_rules_config/valid_rule_config/test.out

@@ -1,4 +1,3 @@
-gnatcheck: The '-rules' section usage is discouraged from now, you should only use the '--rules' and '--rule-file' command-line options
 ada_code.adb:2:09: Int does not end with type suffix _T [first_convention|identifier_suffixes]
 ada_code.adb:5:09: Int_A does not end with access suffix _PTR [first_convention|identifier_suffixes]
 ada_code.adb:6:09: Int_PTR does not end with access suffix _A [other_convention|identifier_suffixes]

testsuite/tests/gnatcheck/rules_depreciation_message/main.adb

@@ -0,0 +1,5 @@
+procedure Main is
+begin
+   goto lbl;   --  FLAG
+   <<lbl>>
+end Main;

testsuite/tests/gnatcheck/rules_depreciation_message/test.out

@@ -0,0 +1,3 @@
+gnatcheck: The '-rules' section is now deprecated. You should only use the '--rules' and '--rule-file' command-line options.
+gnatcheck: You can use the '--emit-lkql-rule-file' flag to automatically translate your rule configuration to the new LKQL format.
+main.adb:3:04: goto statement

testsuite/tests/gnatcheck/rules_depreciation_message/test.yaml

@@ -0,0 +1,11 @@
+driver: gnatcheck
+format: brief
+in_tty: True
+rules:
+  - +RGoto_Statements
+input_sources:
+  - main.adb
+control:
+  - [SKIP,
+     "os == 'windows'",
+     "Disable this test because 'pty' is not supported on Windows"]