[GR-40811] Ignore @llvm.used and @llvm.compiler.used globals during module init

PullRequest: graal/12630

Author: lewurm

sulong/projects/com.oracle.truffle.llvm.parser/src/com/oracle/truffle/llvm/parser/LLVMParser.java

@@ -85,11 +85,24 @@ public LLVMParserResult parse(ModelModule module, DataLayout targetDataLayout) {
         defineAliases(module.getAliases(), targetDataLayout);
 
         return new LLVMParserResult(runtime, definedFunctions, externalFunctions, definedGlobals, externalGlobals, threadLocalGlobals, threadLocalGlobalObjectCounter, targetDataLayout,
-                        module.getTargetInformation(TargetTriple.class));
+                        module.getTargetInformation(TargetTriple.class), module.getTotalSize());
+    }
+
+    private static boolean ignoreGlobal(GlobalVariable g) {
+        String name = g.getName();
+        /*
+         * Dummy array to keep other globals alive during compilation and linking. We do not
+         * initialize it as it's not relevant for execution, and it can cause problems during module
+         * initialization (e.g. if a TLS variable is referenced).
+         */
+        return name.equals("llvm.used") || name.equals("llvm.compiler.used");
     }
 
     private void defineGlobals(List<GlobalVariable> globals, List<GlobalVariable> definedGlobals, List<GlobalVariable> externalGlobals, List<GlobalVariable> threadLocalGlobals) {
         for (GlobalVariable global : globals) {
+            if (ignoreGlobal(global)) {
+                continue;
+            }
             if (global.isExternal()) {
                 externalGlobals.add(global);
             } else {

sulong/projects/com.oracle.truffle.llvm.parser/src/com/oracle/truffle/llvm/parser/LLVMParserResult.java

@@ -57,7 +57,8 @@ public final class LLVMParserResult {
                     List<GlobalVariable> threadLocalGlobals,
                     int threadLocalGlobalObjectCounter,
                     DataLayout dataLayout,
-                    TargetTriple targetTriple) {
+                    TargetTriple targetTriple,
+                    int totalSize) {
         this.runtime = runtime;
         this.definedFunctions = definedFunctions;
         this.externalFunctions = externalFunctions;
@@ -67,7 +68,8 @@ public final class LLVMParserResult {
         this.externalGlobals = externalGlobals;
         this.dataLayout = dataLayout;
         this.targetTriple = targetTriple;
-        this.symbolTableSize = definedFunctions.size() + externalFunctions.size() + definedGlobals.size() + externalGlobals.size() + threadLocalGlobals.size();
+        assert totalSize >= definedFunctions.size() + externalFunctions.size() + definedGlobals.size() + externalGlobals.size() + threadLocalGlobals.size();
+        this.symbolTableSize = totalSize;
     }
 
     public LLVMParserRuntime getRuntime() {

sulong/projects/com.oracle.truffle.llvm.parser/src/com/oracle/truffle/llvm/parser/listeners/Module.java

@@ -86,6 +86,11 @@ public final class Module implements ParserListener {
         index = new AtomicInteger(0);
     }
 
+    @Override
+    public void exit() {
+        module.setTotalSize(index.get());
+    }
+
     // private static final int STRTAB_RECORD_OFFSET = 2;
     // private static final int STRTAB_RECORD_OFFSET_INDEX = 0;
     // private static final int STRTAB_RECORD_LENGTH_INDEX = 1;

sulong/projects/com.oracle.truffle.llvm.parser/src/com/oracle/truffle/llvm/parser/model/ModelModule.java

@@ -65,6 +65,7 @@ public final class ModelModule {
     private String targetDataLayout = defaultLayout;
     private DebugInfoFunctionProcessor functionProcessor = null;
     private final ArrayList<LLVMSourceFileReference> sourceFiles = new ArrayList<>();
+    private int totalSize;
 
     public ModelModule() {
     }
@@ -170,4 +171,12 @@ public <TI extends TargetInformation> TI getTargetInformation(Class<TI> targetIn
         }
         return null;
     }
+
+    public void setTotalSize(int index) {
+        totalSize = index;
+    }
+
+    public int getTotalSize() {
+        return totalSize;
+    }
 }

sulong/tests/com.oracle.truffle.llvm.tests.sulong.native/c/attributes/used/used-tls-var.c

@@ -0,0 +1,43 @@
+/*
+ * Copyright (c) 2022, Oracle and/or its affiliates.
+ *
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without modification, are
+ * permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice, this list of
+ * conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice, this list of
+ * conditions and the following disclaimer in the documentation and/or other materials provided
+ * with the distribution.
+ *
+ * 3. Neither the name of the copyright holder nor the names of its contributors may be used to
+ * endorse or promote products derived from this software without specific prior written
+ * permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS
+ * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
+ * GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+ * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
+ * OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+#include <stdlib.h>
+
+/* On some platforms this TLS variable will end up being referenced by the
+ * global @llvm.used or @llvm.compiler.used array in the final bitcode. This
+ * can cause problems during global variable initialization. */
+
+__attribute__((used)) __thread int tls_val = 4;
+
+int main(void) {
+    if (tls_val != 4) {
+        abort();
+    }
+    return 0;
+}