PNaCl Dynamic Linking: Storing dependencies from command line in PLL.

lib/Transforms/NaCl/ConvertToPSO.cpp

Index: lib/Transforms/NaCl/ConvertToPSO.cpp
diff --git a/lib/Transforms/NaCl/ConvertToPSO.cpp b/lib/Transforms/NaCl/ConvertToPSO.cpp
index a9663087341d548e4f4e9c81e14a00b291d17d5a..1291a9988d7a45c4b21db51b3ed1008ce53aa91d 100644
--- a/lib/Transforms/NaCl/ConvertToPSO.cpp
+++ b/lib/Transforms/NaCl/ConvertToPSO.cpp
@@ -62,6 +62,13 @@ namespace {
   // increment TOOLCHAIN_FEATURE_VERSION instead.
   const int PSOFormatVersion = 2;
 
+  // Command line arguments consist of a list of PLL dependencies.
+  static cl::list<std::string>
+  LibraryDependencies("deps",

[Mark Seaborn, 2016/03/29 15:29:39]

Remember that this is an option for the 'opt' tool.  "-deps" is a bit too
generic.  How about "-convert-to-pso-deps"?

[Sean Klein, 2016/03/29 17:58:29]

Done.

+                      cl::CommaSeparated,
+                      cl::desc("The dependencies of the PLL being built"),
+                      cl::value_desc("PLL to list as dependency"));
+
   // This is a ModulePass because it inherently operates on a whole module.
   class ConvertToPSO : public ModulePass {
   public:
@@ -651,6 +658,18 @@ bool ConvertToPSO::runOnModule(Module &M) {
       M, StringTableArray->getType(), true, GlobalValue::InternalLinkage,
       StringTableArray, "string_table");
 
+  // Set up string of PLL dependencies.
+  SmallString<1024> DependenciesList;
+  for (unsigned i = 0; i != LibraryDependencies.size(); ++i) {

[Mark Seaborn, 2016/03/29 15:29:39]

You can use "for (... : LibrariesDependencies)"

[Sean Klein, 2016/03/29 17:58:29]

Done.

+    DependenciesList.append(LibraryDependencies[i]);
+    DependenciesList.push_back(0);
+  }
+  Constant *DependenciesListArray = ConstantDataArray::getString(
+      C, StringRef(DependenciesList.data(), DependenciesList.size()), false);
+  Constant *DependenciesListVar = new GlobalVariable(
+      M, DependenciesListArray->getType(), true, GlobalValue::InternalLinkage,
+      DependenciesListArray, "dependencies_list");
+
   SmallVector<Constant *, 32> PsoRoot = {
     ConstantInt::get(IntPtrType, PSOFormatVersion),
 
@@ -676,6 +695,10 @@ bool ConvertToPSO::runOnModule(Module &M) {
     ConstantInt::get(IntPtrType, MaskWords - 1),
     ConstantInt::get(IntPtrType, Shift2),
     createDataArray(M, "bloom_filter", &BloomFilter),
+
+    // Dependencies List

[Mark Seaborn, 2016/03/29 15:40:06]

When you rebase, this should go at the end, after the TLS template fields, so as
not to break when rolled in.

[Sean Klein, 2016/03/29 17:58:29]

Do you mean that I should place these fields after the
"PsoRoot.push_back(FieldVal)" below? This CL is up-to-date.

[Mark Seaborn, 2016/03/29 18:50:44]

Yes, that would be better in the sense that it avoids the need for a 2-sided
change -- i.e. it avoids the need to update pll_root.h at the same time.  That
also means you can run the trybots for this change.

(We can reorder these fields to have a more coherent order at some point in the
future.)
Ah yes, I forgot that the TLS fields are added via push_back() rather than in
this initialiser.

+    ConstantInt::get(IntPtrType, LibraryDependencies.size()),
+    DependenciesListVar,
   };
   for (auto FieldVal : PsoRootTlsFields)
     PsoRoot.push_back(FieldVal);