PDB support of function-level linking and splitted functions

Summary:
The patch adds support of splitted functions (when MSVC is used with PGO) and function-level linking feature.

SymbolFilePDB::ParseCompileUnitLineTable function relies on fact that ranges of compiled source files in the binary are continuous and don't intersect each other. The function creates LineSequence for each file and inserts it into LineTable, and implementation of last one relies on continuity of the sequence. But it's not always true when function-level linking enabled, e.g. in added input test file test-pdb-function-level-linking.exe there is xstring's std__basic_string_char_std__char_traits_char__std__allocator_char_____max_size (.00454820) between test-pdb-function-level-linking.cpp's foo (.00454770) and main (.004548F0).

To fix the problem this patch renews the sequence on each address gap.

Reviewers: asmith, zturner

Reviewed By: asmith

Subscribers: mgorny, lldb-commits

Differential Revision: https://reviews.llvm.org/D47708

llvm-svn: 334030

9 files changed, 107 insertions, 0 deletions

diff --git a/lldb/source/Plugins/SymbolFile/PDB/SymbolFilePDB.cpp b/lldb/source/Plugins/SymbolFile/PDB/SymbolFilePDB.cpp
index f298749f10d..19a0e95d206 100644
--- a/lldb/source/Plugins/SymbolFile/PDB/SymbolFilePDB.cpp
+++ b/lldb/source/Plugins/SymbolFile/PDB/SymbolFilePDB.cpp
@@ -1571,6 +1571,9 @@ bool SymbolFilePDB::ParseCompileUnitLineTable(
         line_table->AppendLineEntryToSequence(
             sequence.get(), prev_addr + prev_length, prev_line, 0,
             prev_source_idx, false, false, false, false, true);
+
+        line_table->InsertSequence(sequence.release());
+        sequence.reset(line_table->CreateLineSequenceContainer());
       }
 
       if (ShouldAddLine(match_line, lno, length)) {
diff --git a/lldb/unittests/SymbolFile/PDB/CMakeLists.txt b/lldb/unittests/SymbolFile/PDB/CMakeLists.txt
index dd7e2248aed..b9dada09b91 100644
--- a/lldb/unittests/SymbolFile/PDB/CMakeLists.txt
+++ b/lldb/unittests/SymbolFile/PDB/CMakeLists.txt
@@ -17,6 +17,10 @@ add_lldb_unittest(SymbolFilePDBTests
 set(test_inputs
    test-pdb.exe
    test-pdb.pdb
+   test-pdb-function-level-linking.exe
+   test-pdb-function-level-linking.pdb
+   test-pdb-splitted-function.exe
+   test-pdb-splitted-function.pdb
    test-pdb-types.exe
    test-pdb-types.pdb)
 
diff --git a/lldb/unittests/SymbolFile/PDB/Inputs/test-pdb-function-level-linking.cpp b/lldb/unittests/SymbolFile/PDB/Inputs/test-pdb-function-level-linking.cpp
new file mode 100644
index 00000000000..e1d5aabb357
--- /dev/null
+++ b/lldb/unittests/SymbolFile/PDB/Inputs/test-pdb-function-level-linking.cpp
@@ -0,0 +1,17 @@
+// Compile with "cl /c /ZI /sdl /EHsc /MTd /permissive-
+// test-pdb-function-level-linking.cpp"
+// Link with "link /debug:full test-pdb-function-level-linking.obj"
+
+#include <memory>
+#include <string>
+
+std::string foo()
+{
+    return "Hello!";
+}
+
+int main()
+{
+    auto x = foo();
+    return 0;
+}
diff --git a/lldb/unittests/SymbolFile/PDB/Inputs/test-pdb-function-level-linking.exe b/lldb/unittests/SymbolFile/PDB/Inputs/test-pdb-function-level-linking.exe
new file mode 100644
index 00000000000..e69de29bb2d
--- /dev/null
+++ b/lldb/unittests/SymbolFile/PDB/Inputs/test-pdb-function-level-linking.exe
diff --git a/lldb/unittests/SymbolFile/PDB/Inputs/test-pdb-function-level-linking.pdb b/lldb/unittests/SymbolFile/PDB/Inputs/test-pdb-function-level-linking.pdb
new file mode 100644
index 00000000000..e69de29bb2d
--- /dev/null
+++ b/lldb/unittests/SymbolFile/PDB/Inputs/test-pdb-function-level-linking.pdb
diff --git a/lldb/unittests/SymbolFile/PDB/Inputs/test-pdb-splitted-function.cpp b/lldb/unittests/SymbolFile/PDB/Inputs/test-pdb-splitted-function.cpp
new file mode 100644
index 00000000000..5155b8cdb6c
--- /dev/null
+++ b/lldb/unittests/SymbolFile/PDB/Inputs/test-pdb-splitted-function.cpp
@@ -0,0 +1,27 @@
+// Compile with "cl /c /Zi /GL /O2 /EHsc /MTd test-pdb-splitted-function.cpp"
+// Link with "link /debug:full /LTCG /GENPROFILE
+//   test-pdb-splitted-function.obj"
+// Run several times
+// Link with "link /debug:full /LTCG /USEPROFILE
+//   test-pdb-splitted-function.obj"
+
+#include <cmath>
+#include <iostream>
+
+int main()
+{
+    auto b = false;
+    for (auto i = 1; i <= 1024; i++)
+    {
+        if (b)
+        {
+            std::cout << "Unreachable code" << std::endl;
+            auto x = std::sin(i);
+            return x;
+        }
+
+        b = (i % 2 + (i - 1) % 2) != 1;
+    }
+
+    return 0;
+}
diff --git a/lldb/unittests/SymbolFile/PDB/Inputs/test-pdb-splitted-function.exe b/lldb/unittests/SymbolFile/PDB/Inputs/test-pdb-splitted-function.exe
new file mode 100644
index 00000000000..e69de29bb2d
--- /dev/null
+++ b/lldb/unittests/SymbolFile/PDB/Inputs/test-pdb-splitted-function.exe
diff --git a/lldb/unittests/SymbolFile/PDB/Inputs/test-pdb-splitted-function.pdb b/lldb/unittests/SymbolFile/PDB/Inputs/test-pdb-splitted-function.pdb
new file mode 100644
index 00000000000..e69de29bb2d
--- /dev/null
+++ b/lldb/unittests/SymbolFile/PDB/Inputs/test-pdb-splitted-function.pdb
diff --git a/lldb/unittests/SymbolFile/PDB/SymbolFilePDBTests.cpp b/lldb/unittests/SymbolFile/PDB/SymbolFilePDBTests.cpp
index 1e867b172ee..9b93ab0f0c7 100644
--- a/lldb/unittests/SymbolFile/PDB/SymbolFilePDBTests.cpp
+++ b/lldb/unittests/SymbolFile/PDB/SymbolFilePDBTests.cpp
@@ -56,6 +56,10 @@ public:
     SymbolFilePDB::Initialize();
 
     m_pdb_test_exe = GetInputFilePath("test-pdb.exe");
+    m_function_level_linking_test_exe =
+        GetInputFilePath("test-pdb-function-level-linking.exe");
+    m_splitted_function_test_exe =
+        GetInputFilePath("test-pdb-splitted-function.exe");
     m_types_test_exe = GetInputFilePath("test-pdb-types.exe");
   }
 
@@ -73,6 +77,8 @@ public:
 
 protected:
   std::string m_pdb_test_exe;
+  std::string m_function_level_linking_test_exe;
+  std::string m_splitted_function_test_exe;
   std::string m_types_test_exe;
 
   bool FileSpecMatchesAsBaseOrFull(const FileSpec &left,
@@ -354,6 +360,56 @@ TEST_F(SymbolFilePDBTests, TestLineTablesMatchSpecific) {
   VerifyLineEntry(module, sc, header1, *lt, 9, 0x401090);
 }
 
+void TestLineTableConsistency(llvm::StringRef exe_path, llvm::StringRef source_name)
+{
+  // All line entries of compile unit's line table must be consistent
+  // even if compiled sources are not continuous in the binary file.
+  FileSpec fspec(exe_path, false);
+  ArchSpec aspec("i686-pc-windows");
+  lldb::ModuleSP module = std::make_shared<Module>(fspec, aspec);
+  SymbolVendor *plugin = module->GetSymbolVendor();
+  SymbolFile *symfile = plugin->GetSymbolFile();
+  FileSpec source_file(source_name, false);
+  uint32_t scope = lldb::eSymbolContextCompUnit | lldb::eSymbolContextLineEntry;
+  SymbolContextList sc_list;
+  uint32_t count =
+      symfile->ResolveSymbolContext(source_file, 0, true, scope, sc_list);
+  EXPECT_EQ(1u, count);
+
+  SymbolContext sc;
+  EXPECT_TRUE(sc_list.GetContextAtIndex(0, sc));
+
+  LineTable *lt = sc.comp_unit->GetLineTable();
+  EXPECT_NE(nullptr, lt);
+
+  count = lt->GetSize();
+  EXPECT_LT(0u, count);
+
+  LineEntry le;
+  EXPECT_TRUE(lt->GetLineEntryAtIndex(0, le));
+  for (int i = 1; i < count; i++)
+  {
+    lldb::addr_t curr_end =
+        le.range.GetBaseAddress().GetFileAddress() + le.range.GetByteSize();
+
+    EXPECT_TRUE(lt->GetLineEntryAtIndex(i, le));
+
+    EXPECT_LE(curr_end, le.range.GetBaseAddress().GetFileAddress());
+  }
+}
+
+TEST_F(SymbolFilePDBTests, TestFunctionLevelLinking) {
+  TestLineTableConsistency(
+      m_function_level_linking_test_exe,
+      "test-pdb-function-level-linking.cpp");
+}
+
+TEST_F(SymbolFilePDBTests, TestSplittedFunction) {
+  TestLineTableConsistency(
+      m_splitted_function_test_exe,
+      "test-pdb-splitted-function.cpp");
+}
+
 TEST_F(SymbolFilePDBTests, TestSimpleClassTypes) {
   FileSpec fspec(m_types_test_exe.c_str(), false);
   ArchSpec aspec("i686-pc-windows");