[PATCH] D36556: [IR] AutoUpgrade ModuleFlagBehavior for PIC and PIE level

[Steven Wu via Phabricator via llvm-commits]

steven_wu updated this revision to Diff 111754.
steven_wu added a comment.

Here is a version that rebuilds the module flags to avoid replaceOperandsWith.


https://reviews.llvm.org/D36556

Files:
  lib/IR/AutoUpgrade.cpp
  test/Bitcode/upgrade-module-flag.ll
  test/Linker/module-flags-pic-1-a.ll


Index: test/Linker/module-flags-pic-1-a.ll
===================================================================
--- test/Linker/module-flags-pic-1-a.ll
+++ test/Linker/module-flags-pic-1-a.ll
@@ -2,8 +2,8 @@
 
 ; test linking modules with specified and default PIC levels
 
-!0 = !{ i32 1, !"PIC Level", i32 1 }
+!0 = !{ i32 7, !"PIC Level", i32 1 }
 
 !llvm.module.flags = !{!0}
 ; CHECK: !llvm.module.flags = !{!0}
-; CHECK: !0 = !{i32 1, !"PIC Level", i32 1}
+; CHECK: !0 = !{i32 7, !"PIC Level", i32 1}
Index: test/Bitcode/upgrade-module-flag.ll
===================================================================
--- test/Bitcode/upgrade-module-flag.ll
+++ test/Bitcode/upgrade-module-flag.ll
@@ -1,9 +1,13 @@
 ; RUN: llvm-as < %s | llvm-dis | FileCheck %s
 ; RUN: verify-uselistorder < %s
 
-!llvm.module.flags = !{!0}
+!llvm.module.flags = !{!0, !1, !2}
 
-!0 = !{i32 1, !"Objective-C Image Info Version", i32 0}
+!0 = !{i32 1, !"PIC Level", i32 1}
+!1 = !{i32 1, !"PIE Level", i32 1}
+!2 = !{i32 1, !"Objective-C Image Info Version", i32 0}
 
-; CHECK: !0 = !{i32 1, !"Objective-C Image Info Version", i32 0}
-; CHECK: !1 = !{i32 4, !"Objective-C Class Properties", i32 0}
+; CHECK: !0 = !{i32 7, !"PIC Level", i32 1}
+; CHECK: !1 = !{i32 7, !"PIE Level", i32 1}
+; CHECK: !2 = !{i32 1, !"Objective-C Image Info Version", i32 0}
+; CHECK: !3 = !{i32 4, !"Objective-C Class Properties", i32 0}
Index: lib/IR/AutoUpgrade.cpp
===================================================================
--- lib/IR/AutoUpgrade.cpp
+++ lib/IR/AutoUpgrade.cpp
@@ -2284,11 +2284,11 @@
 }
 
 bool llvm::UpgradeModuleFlags(Module &M) {
-  const NamedMDNode *ModFlags = M.getModuleFlagsMetadata();
+  NamedMDNode *ModFlags = M.getModuleFlagsMetadata();
   if (!ModFlags)
     return false;
 
-  bool HasObjCFlag = false, HasClassProperties = false;
+  bool HasObjCFlag = false, HasClassProperties = false, MFBUpdate = false;
   for (unsigned I = 0, E = ModFlags->getNumOperands(); I != E; ++I) {
     MDNode *Op = ModFlags->getOperand(I);
     if (Op->getNumOperands() < 2)
@@ -2300,6 +2300,32 @@
       HasObjCFlag = true;
     if (ID->getString() == "Objective-C Class Properties")
       HasClassProperties = true;
+    // Upgrade PIC/PIE Module Flags. The module flag behavior for these two
+    // field was Error and now they are Max.
+    if (ID->getString() == "PIC Level" || ID->getString() == "PIE Level") {
+      if (auto *Behavior =
+              mdconst::dyn_extract_or_null<ConstantInt>(Op->getOperand(0))) {
+        if (Behavior->getLimitedValue() == Module::Error)
+          MFBUpdate = true;
+      }
+    }
+  }
+  if (MFBUpdate) {
+    SmallVector<MDNode *, 4> Flags(ModFlags->op_begin(), ModFlags->op_end());
+    M.eraseNamedMetadata(ModFlags);
+    ModFlags = M.getOrInsertModuleFlagsMetadata();
+    for (auto *Op : Flags) {
+      if (Op->getNumOperands() == 3) {
+        if (MDString *ID = dyn_cast_or_null<MDString>(Op->getOperand(1))) {
+          if (ID->getString() == "PIC Level" ||
+              ID->getString() == "PIE Level") {
+            M.addModuleFlag(Module::Max, ID->getString(), Op->getOperand(2));
+            continue;
+          }
+        }
+      }
+      ModFlags->addOperand(Op);
+    }
   }
   // "Objective-C Class Properties" is recently added for Objective-C. We
   // upgrade ObjC bitcodes to contain a "Objective-C Class Properties" module
@@ -2311,7 +2337,8 @@
                     (uint32_t)0);
     return true;
   }
-  return false;
+
+  return MFBUpdate;
 }
 
 static bool isOldLoopArgument(Metadata *MD) {


-------------- next part --------------
A non-text attachment was scrubbed...
Name: D36556.111754.patch
Type: text/x-patch
Size: 3561 bytes
Desc: not available
URL: <http://lists.llvm.org/pipermail/llvm-commits/attachments/20170818/713d5b05/attachment.bin>