Postfix: move more code out of the PDB plugin

Summary:
Previously we moved the code which parses a single expression out of the PDB
plugin, because that was useful for DWARF expressions in breakpad. However, FPO
programs are used in breakpad files too (when unwinding on windows), so this
completes the job, and moves the rest of the FPO parser too.

Reviewers: amccarth, aleksandr.urakov

Subscribers: aprantl, markmentovai, rnk, lldb-commits

Differential Revision: https://reviews.llvm.org/D66634

llvm-svn: 369894

1 files changed, 13 insertions, 47 deletions

diff --git a/lldb/source/Plugins/SymbolFile/NativePDB/PdbFPOProgramToDWARFExpression.cpp b/lldb/source/Plugins/SymbolFile/NativePDB/PdbFPOProgramToDWARFExpression.cpp
index 79dd010ff31..a7bc2351971 100644
--- a/lldb/source/Plugins/SymbolFile/NativePDB/PdbFPOProgramToDWARFExpression.cpp
+++ b/lldb/source/Plugins/SymbolFile/NativePDB/PdbFPOProgramToDWARFExpression.cpp
@@ -51,54 +51,23 @@ static uint32_t ResolveLLDBRegisterNum(llvm::StringRef reg_name, llvm::Triple::A
   return npdb::GetLLDBRegisterNumber(arch_type, reg_id);
 }
 
-static bool ParseFPOSingleAssignmentProgram(llvm::StringRef program,
-                                            llvm::BumpPtrAllocator &alloc,
-                                            llvm::StringRef &register_name,
-                                            Node *&ast) {
-  // lvalue of assignment is always first token
-  // rvalue program goes next
-  std::tie(register_name, program) = getToken(program);
-  if (register_name.empty())
-    return false;
-
-  ast = Parse(program, alloc);
-  return ast != nullptr;
-}
-
-static Node *ParseFPOProgram(llvm::StringRef program,
+static Node *ResolveFPOProgram(llvm::StringRef program,
                              llvm::StringRef register_name,
                              llvm::Triple::ArchType arch_type,
                              llvm::BumpPtrAllocator &alloc) {
-  llvm::DenseMap<llvm::StringRef, Node *> dependent_programs;
-
-  size_t cur = 0;
-  while (true) {
-    size_t assign_index = program.find('=', cur);
-    if (assign_index == llvm::StringRef::npos) {
-      llvm::StringRef tail = program.slice(cur, llvm::StringRef::npos);
-      if (!tail.trim().empty()) {
-        // missing assign operator
-        return nullptr;
-      }
-      break;
-    }
-    llvm::StringRef assignment_program = program.slice(cur, assign_index);
-
-    llvm::StringRef lvalue_name;
-    Node *rvalue_ast = nullptr;
-    if (!ParseFPOSingleAssignmentProgram(assignment_program, alloc, lvalue_name,
-                                         rvalue_ast)) {
-      return nullptr;
-    }
-
-    lldbassert(rvalue_ast);
+  std::vector<std::pair<llvm::StringRef, Node *>> parsed =
+      postfix::ParseFPOProgram(program, alloc);
 
+  for (auto it = parsed.begin(), end = parsed.end(); it != end; ++it) {
     // Emplace valid dependent subtrees to make target assignment independent
     // from predecessors. Resolve all other SymbolNodes as registers.
     bool success =
-        ResolveSymbols(rvalue_ast, [&](SymbolNode &symbol) -> Node * {
-          if (Node *node = dependent_programs.lookup(symbol.GetName()))
-            return node;
+        ResolveSymbols(it->second, [&](SymbolNode &symbol) -> Node * {
+          for (const auto &pair : llvm::make_range(parsed.begin(), it)) {
+            if (pair.first == symbol.GetName())
+              return pair.second;
+          }
+
           uint32_t reg_num =
               ResolveLLDBRegisterNum(symbol.GetName().drop_front(1), arch_type);
 
@@ -110,13 +79,10 @@ static Node *ParseFPOProgram(llvm::StringRef program,
     if (!success)
       return nullptr;
 
-    if (lvalue_name == register_name) {
+    if (it->first == register_name) {
       // found target assignment program - no need to parse further
-      return rvalue_ast;
+      return it->second;
     }
-
-    dependent_programs[lvalue_name] = rvalue_ast;
-    cur = assign_index + 1;
   }
 
   return nullptr;
@@ -127,7 +93,7 @@ bool lldb_private::npdb::TranslateFPOProgramToDWARFExpression(
     llvm::Triple::ArchType arch_type, Stream &stream) {
   llvm::BumpPtrAllocator node_alloc;
   Node *target_program =
-      ParseFPOProgram(program, register_name, arch_type, node_alloc);
+      ResolveFPOProgram(program, register_name, arch_type, node_alloc);
   if (target_program == nullptr) {
     return false;
   }