Merge branch 'topic/lkql_jit/preload_libjsig' into 'master'

Use LD_PRELOAD to load libjsig.so when running LKQL JIT in JVM mode

Closes #577

See merge request eng/libadalang/langkit-query-language!577

Author: HugoGGuerrier

lkql_jit/cli/pom.xml

@@ -67,7 +67,13 @@
         <dependency>
             <groupId>com.adacore</groupId>
             <artifactId>liblkqllang</artifactId>
-            <version>0.1</version>
+            <version>${config.liblkqllangVersion}</version>
+        </dependency>
+
+        <dependency>
+            <groupId>com.adacore</groupId>
+            <artifactId>langkit_support</artifactId>
+            <version>${config.langkit_supportVersion}</version>
         </dependency>
 
         <dependency>

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

@@ -5,6 +5,7 @@
 
 package com.adacore.lkql_jit.cli;
 
+import com.adacore.langkit_support.NativeTools;
 import java.util.concurrent.Callable;
 import picocli.CommandLine;
 import picocli.CommandLine.Command;
@@ -39,6 +40,17 @@ public Integer call() throws Exception {
     }
 
     public static void main(String[] args) {
+        // Start by unsetting the "LD_PRELOAD" environment variable to make
+        // sure child processes aren't impacted by it.
+        try {
+            NativeTools.setenv("LD_PRELOAD", "");
+        } catch (Throwable t) {
+            System.err.println("Error while calling the 'setenv' function");
+            t.printStackTrace();
+            System.exit(1);
+        }
+
+        // Then call the main processing function
         int rc = new CommandLine(new LKQLMain()).execute(args);
         System.exit(rc);
     }

lkql_jit/standalone/lkql.py

@@ -58,6 +58,11 @@
         "PATH" if os.name == "nt" else "LD_LIBRARY_PATH", ""
     )
 
+    # Add "libjsig.so" to the LD_PRELOAD on Linux to avoid SIGILL errors
+    env = dict(os.environ)
+    if os.name != "nt":
+        env |= {"LD_PRELOAD": P.join(graal_home, "lib", "libjsig.so")}
+
     # Run the full Java command
     subprocess.run(
         [
@@ -102,5 +107,6 @@
             ['--engine.CompileImmediately=true']
             if args.compile_immediately
             else []
-        )
+        ),
+        env=env
     )