gnatcheck: log debug information in a file

The gnatcheck worker now saves some debug information in a log file.
At this point those information are limited to the Ada stack traces
generated by Libadaland during failures occuring while traversing
generic instantiations.

Author: thvnx

lkql_checker/src/gnatcheck-compiler.adb

@@ -1581,7 +1581,8 @@ package body Gnatcheck.Compiler is
    function Spawn_Gnatcheck_Worker
      (Rule_File   : String;
       Msg_File    : String;
-      Source_File : String) return Process_Id
+      Source_File : String;
+      Log_File    : String) return Process_Id
    is
       use GNAT.String_Split;
 
@@ -1662,6 +1663,10 @@ package body Gnatcheck.Compiler is
          Args (Num_Args) := new String'("-d");
       end if;
 
+      Num_Args := @ + 1;
+      Args (Num_Args) :=
+         new String'("--log-file=" & Log_File);
+
       if Arg.Follow_Symbolic_Links.Get then
          Num_Args := @ + 1;
          Args (Num_Args) := new String'("-eL");

lkql_checker/src/gnatcheck-compiler.ads

@@ -162,11 +162,13 @@ package Gnatcheck.Compiler is
    function Spawn_Gnatcheck_Worker
      (Rule_File   : String;
       Msg_File    : String;
-      Source_File : String) return Process_Id;
+      Source_File : String;
+      Log_File    : String) return Process_Id;
    --  Spawn a gnatcheck worker (LKQL) on the main project file with the
    --  relevant options on the rules given by Rule_File, redirecting the
    --  output to Msg_File. Source_File is the name of a file listing all the
-   --  source files to analyze.
+   --  source files to analyze. Log_File is the name of a file used to store
+   --  worker's logs.
 
    function Spawn_LKQL_Rule_File_Parser
      (LKQL_RF_Name : String;

lkql_checker/src/gnatcheck_main.adb

@@ -352,7 +352,8 @@ procedure Gnatcheck_Main is
               Spawn_Gnatcheck_Worker
                 (File_Name ("rules", 0),
                  File_Name ("out", Job),
-                 File_Name ("files", Job));
+                 File_Name ("files", Job),
+                 File_Name ("log", Job));
 
             if Next_SF > Last_Argument_Source then
                Total_Jobs := @ - Num_Jobs + Job;

lkql_jit/cli/src/main/java/com/adacore/lkql_jit/cli/GNATCheckWorker.java

@@ -8,7 +8,11 @@
 import com.adacore.lkql_jit.options.LKQLOptions;
 import com.adacore.lkql_jit.options.RuleInstance;
 import java.io.File;
+import java.io.FileNotFoundException;
+import java.io.FileOutputStream;
 import java.io.IOException;
+import java.io.OutputStream;
+import java.nio.file.FileSystems;
 import java.nio.file.Files;
 import java.nio.file.Paths;
 import java.util.*;
@@ -94,6 +98,11 @@ public static class Args implements Callable<Integer> {
         @CommandLine.Option(names = "--files-from", description = "The file containing the files")
         public String filesFrom = null;
 
+        @CommandLine.Option(
+                names = "--log-file",
+                description = "The file used by the worker to output logs")
+        public String gnatcheckLogFile = null;
+
         @CommandLine.Option(
                 names = "--ignore-project-switches",
                 description =
@@ -244,6 +253,18 @@ protected int executeScript(Context.Builder contextBuilder) {
         // Finally, pass the options to the LKQL engine
         contextBuilder.option("lkql.options", optionsBuilder.build().toJson().toString());
 
+        try {
+            // Install a log handler only if gnatcheckLogFile is set
+            if (this.args.gnatcheckLogFile != null) {
+                var logFile = FileSystems.getDefault().getPath(this.args.gnatcheckLogFile);
+                OutputStream outputStream = new FileOutputStream(logFile.toFile());
+                contextBuilder.logHandler(outputStream);
+            }
+        } catch (FileNotFoundException e) {
+            System.err.println(
+                    "WORKER_ERROR: Could not create log file: " + this.args.gnatcheckLogFile);
+        }
+
         // Create the context and run the script in it
         try (Context context = contextBuilder.build()) {
             final Source source = Source.newBuilder("lkql", checkerSource, "checker.lkql").build();

lkql_jit/language/src/main/java/com/adacore/lkql_jit/LKQLContext.java

@@ -21,6 +21,7 @@
 import com.adacore.lkql_jit.utils.source_location.LalLocationWrapper;
 import com.oracle.truffle.api.CompilerDirectives;
 import com.oracle.truffle.api.TruffleLanguage;
+import com.oracle.truffle.api.TruffleLogger;
 import com.oracle.truffle.api.source.Source;
 import java.io.File;
 import java.util.*;
@@ -301,6 +302,11 @@ public String getConfigFile() {
         return this.getOptions().configFile().orElse("");
     }
 
+    @CompilerDirectives.TruffleBoundary
+    public TruffleLogger getLogger() {
+        return TruffleLogger.getLogger(Constants.LKQL_ID);
+    }
+
     /** Return the list of scenario variables to specify when loading the GPR project file. */
     public Libadalang.ScenarioVariable[] getScenarioVars() {
         if (this.scenarioVars == null) {

lkql_jit/language/src/main/java/com/adacore/lkql_jit/checker/built_ins/NodeCheckerFunction.java

@@ -111,6 +111,11 @@ public Object alwaysTrue(VirtualFrame frame, Libadalang.AdaNode root) {
                                     e.getMessage(),
                                     new LalLocationWrapper(currentNode, context.linesCache),
                                     new SourceSectionWrapper(this.callNode.getSourceSection()));
+                    if (context.isCheckerDebug()) {
+                        context.getLogger().severe(e.getMessage());
+                        context.getLogger()
+                                .severe(e.adaStackTrace.orElse("ERROR: can't get Ada stack trace"));
+                    }
                     continue;
                 }
 

testsuite/tests/gnatcheck/subdirs/test.out

@@ -9,4 +9,4 @@ main.adb:3:05: goto statement
 main.adb:6:05: error: "Put_Line" is undefined
 main.adb:6:05: error: possible missing "with Ada.Text_IO; use Ada.Text_IO"
    no internal error detected
-Content of custom_subdirs/gnatcheck : ['main.adb.stderr', 'main.adb.stdout', 'restriction_pragmas.adc']
+Content of custom_subdirs/gnatcheck : ['gnatcheck-log1.TMP', 'main.adb.stderr', 'main.adb.stdout', 'restriction_pragmas.adc']

testsuite/tests/gnatcheck/target/linux/test.out

@@ -1,23 +1,23 @@
 With target in project file
 ===========================
 
-<gnatcheck_worker_exe> -Pwith_target.gpr --target=x86_64-linux -d --files-from=<working-dir>/gnatcheck/gnatcheck-files1.TMP --rules-from=<working-dir>/gnatcheck/gnatcheck-rules0.TMP
+<gnatcheck_worker_exe> -Pwith_target.gpr --target=x86_64-linux -d --log-file=<working-dir>/gnatcheck/gnatcheck-log1.TMP --files-from=<working-dir>/gnatcheck/gnatcheck-files1.TMP --rules-from=<working-dir>/gnatcheck/gnatcheck-rules0.TMP
 main.adb:3:04: goto statement
 
 With target in config file
 ==========================
 
-<gnatcheck_worker_exe> -Pwithout_target.gpr --target=x86_64-linux -d --files-from=<working-dir>/gnatcheck/gnatcheck-files1.TMP --rules-from=<working-dir>/gnatcheck/gnatcheck-rules0.TMP
+<gnatcheck_worker_exe> -Pwithout_target.gpr --target=x86_64-linux -d --log-file=<working-dir>/gnatcheck/gnatcheck-log1.TMP --files-from=<working-dir>/gnatcheck/gnatcheck-files1.TMP --rules-from=<working-dir>/gnatcheck/gnatcheck-rules0.TMP
 main.adb:3:04: goto statement
 
 With target through command-line
 ================================
 
-<gnatcheck_worker_exe> -Pwithout_target.gpr --target=x86_64-linux -d --files-from=<working-dir>/gnatcheck/gnatcheck-files1.TMP --rules-from=<working-dir>/gnatcheck/gnatcheck-rules0.TMP
+<gnatcheck_worker_exe> -Pwithout_target.gpr --target=x86_64-linux -d --log-file=<working-dir>/gnatcheck/gnatcheck-log1.TMP --files-from=<working-dir>/gnatcheck/gnatcheck-files1.TMP --rules-from=<working-dir>/gnatcheck/gnatcheck-rules0.TMP
 main.adb:3:04: goto statement
 
 Without any target specified
 ============================
 
-<gnatcheck_worker_exe> -Pwithout_target.gpr --target=x86_64-linux -d --files-from=<working-dir>/gnatcheck/gnatcheck-files1.TMP --rules-from=<working-dir>/gnatcheck/gnatcheck-rules0.TMP
+<gnatcheck_worker_exe> -Pwithout_target.gpr --target=x86_64-linux -d --log-file=<working-dir>/gnatcheck/gnatcheck-log1.TMP --files-from=<working-dir>/gnatcheck/gnatcheck-files1.TMP --rules-from=<working-dir>/gnatcheck/gnatcheck-rules0.TMP
 main.adb:3:04: goto statement