Breakpad: Parse Stack CFI records

Summary:
This patch adds support for parsing STACK CFI records from breakpad
files. The expressions specifying the values of registers are not
parsed.The idea is that these will be handed off to the postfix
expression -> dwarf compiler, once it is extracted from the internals of
the NativePDB plugin.

Reviewers: clayborg, amccarth, markmentovai

Subscribers: aprantl, lldb-commits

Differential Revision: https://reviews.llvm.org/D60268

llvm-svn: 357975

diff --git a/lldb/lit/Modules/Breakpad/sections.test b/lldb/lit/Modules/Breakpad/sections.test
index cbb0330..90f3d92 100644 (file)
--- a/lldb/lit/Modules/Breakpad/sections.test
+++ b/lldb/lit/Modules/Breakpad/sections.test
@@ -73,7 +73,7 @@ CHECK-NEXT:   )
 
 CHECK:        Index: 5
 CHECK-NEXT:   ID: 0x6
-CHECK-NEXT:   Name: STACK CFI INIT
+CHECK-NEXT:   Name: STACK CFI
 CHECK-NEXT:   Type: regular
 CHECK-NEXT:   Permissions: ---
 CHECK-NEXT:   Thread specific: no

diff --git a/lldb/source/Plugins/ObjectFile/Breakpad/BreakpadRecords.cpp b/lldb/source/Plugins/ObjectFile/Breakpad/BreakpadRecords.cpp
index 6807563..d5b87e3 100644 (file)
--- a/lldb/source/Plugins/ObjectFile/Breakpad/BreakpadRecords.cpp
+++ b/lldb/source/Plugins/ObjectFile/Breakpad/BreakpadRecords.cpp
@@ -143,8 +143,7 @@ llvm::Optional<Record::Kind> Record::classify(llvm::StringRef Line) {
     Tok = consume<Token>(Line);
     switch (Tok) {
     case Token::CFI:
-      Tok = consume<Token>(Line);
-      return Tok == Token::Init ? Record::StackCFIInit : Record::StackCFI;
+      return Record::StackCFI;
     default:
       return llvm::None;
     }
@@ -359,6 +358,55 @@ llvm::raw_ostream &breakpad::operator<<(llvm::raw_ostream &OS,
                              R.Name);
 }
 
+llvm::Optional<StackCFIRecord> StackCFIRecord::parse(llvm::StringRef Line) {
+  // STACK CFI INIT address size reg1: expr1 reg2: expr2 ...
+  // or
+  // STACK CFI address reg1: expr1 reg2: expr2 ...
+  // No token in exprN ends with a colon.
+
+  if (consume<Token>(Line) != Token::Stack)
+    return llvm::None;
+  if (consume<Token>(Line) != Token::CFI)
+    return llvm::None;
+
+  llvm::StringRef Str;
+  std::tie(Str, Line) = getToken(Line);
+
+  bool IsInitRecord = stringTo<Token>(Str) == Token::Init;
+  if (IsInitRecord)
+    std::tie(Str, Line) = getToken(Line);
+
+  lldb::addr_t Address;
+  if (!to_integer(Str, Address, 16))
+    return llvm::None;
+
+  llvm::Optional<lldb::addr_t> Size;
+  if (IsInitRecord) {
+    Size.emplace();
+    std::tie(Str, Line) = getToken(Line);
+    if (!to_integer(Str, *Size, 16))
+      return llvm::None;
+  }
+
+  return StackCFIRecord(Address, Size, Line.trim());
+}
+
+bool breakpad::operator==(const StackCFIRecord &L, const StackCFIRecord &R) {
+  return L.Address == R.Address && L.Size == R.Size &&
+         L.UnwindRules == R.UnwindRules;
+}
+
+llvm::raw_ostream &breakpad::operator<<(llvm::raw_ostream &OS,
+                                        const StackCFIRecord &R) {
+  OS << "STACK CFI ";
+  if (R.Size)
+    OS << "INIT ";
+  OS << llvm::formatv("{0:x-} ", R.Address);
+  if (R.Size)
+    OS << llvm::formatv("{0:x-} ", *R.Size);
+  return OS << " " << R.UnwindRules;
+}
+
 llvm::StringRef breakpad::toString(Record::Kind K) {
   switch (K) {
   case Record::Module:
@@ -373,8 +421,6 @@ llvm::StringRef breakpad::toString(Record::Kind K) {
     return "LINE";
   case Record::Public:
     return "PUBLIC";
-  case Record::StackCFIInit:
-    return "STACK CFI INIT";
   case Record::StackCFI:
     return "STACK CFI";
   }

diff --git a/lldb/source/Plugins/ObjectFile/Breakpad/BreakpadRecords.h b/lldb/source/Plugins/ObjectFile/Breakpad/BreakpadRecords.h
index e80cc22..5d5cdb3 100644 (file)
--- a/lldb/source/Plugins/ObjectFile/Breakpad/BreakpadRecords.h
+++ b/lldb/source/Plugins/ObjectFile/Breakpad/BreakpadRecords.h
@@ -20,7 +20,7 @@ namespace breakpad {
 
 class Record {
 public:
-  enum Kind { Module, Info, File, Func, Line, Public, StackCFIInit, StackCFI };
+  enum Kind { Module, Info, File, Func, Line, Public, StackCFI };
 
   /// Attempt to guess the kind of the record present in the argument without
   /// doing a full parse. The returned kind will always be correct for valid
@@ -141,6 +141,22 @@ public:
 bool operator==(const PublicRecord &L, const PublicRecord &R);
 llvm::raw_ostream &operator<<(llvm::raw_ostream &OS, const PublicRecord &R);
 
+class StackCFIRecord : public Record {
+public:
+  static llvm::Optional<StackCFIRecord> parse(llvm::StringRef Line);
+  StackCFIRecord(lldb::addr_t Address, llvm::Optional<lldb::addr_t> Size,
+                 llvm::StringRef UnwindRules)
+      : Record(StackCFI), Address(Address), Size(Size),
+        UnwindRules(UnwindRules) {}
+
+  lldb::addr_t Address;
+  llvm::Optional<lldb::addr_t> Size;
+  llvm::StringRef UnwindRules;
+};
+
+bool operator==(const StackCFIRecord &L, const StackCFIRecord &R);
+llvm::raw_ostream &operator<<(llvm::raw_ostream &OS, const StackCFIRecord &R);
+
 } // namespace breakpad
 } // namespace lldb_private
 

diff --git a/lldb/source/Plugins/ObjectFile/Breakpad/ObjectFileBreakpad.cpp b/lldb/source/Plugins/ObjectFile/Breakpad/ObjectFileBreakpad.cpp
index e68d80c..60dd9f9 100644 (file)
--- a/lldb/source/Plugins/ObjectFile/Breakpad/ObjectFileBreakpad.cpp
+++ b/lldb/source/Plugins/ObjectFile/Breakpad/ObjectFileBreakpad.cpp
@@ -153,9 +153,6 @@ void ObjectFileBreakpad::CreateSections(SectionList &unified_section_list) {
       // Line records logically belong to the preceding Func record, so we put
       // them in the same section.
       next_section = Record::Func;
-    } else if (next_section == Record::StackCFI) {
-      // Same goes for StackCFI and StackCFIInit
-      next_section = Record::StackCFIInit;
     }
     if (next_section == current_section)
       continue;

diff --git a/lldb/unittests/ObjectFile/Breakpad/BreakpadRecordsTest.cpp b/lldb/unittests/ObjectFile/Breakpad/BreakpadRecordsTest.cpp
index ad0b7d3..a25a707 100644 (file)
--- a/lldb/unittests/ObjectFile/Breakpad/BreakpadRecordsTest.cpp
+++ b/lldb/unittests/ObjectFile/Breakpad/BreakpadRecordsTest.cpp
@@ -19,7 +19,6 @@ TEST(Record, classify) {
   EXPECT_EQ(Record::File, Record::classify("FILE"));
   EXPECT_EQ(Record::Func, Record::classify("FUNC"));
   EXPECT_EQ(Record::Public, Record::classify("PUBLIC"));
-  EXPECT_EQ(Record::StackCFIInit, Record::classify("STACK CFI INIT"));
   EXPECT_EQ(Record::StackCFI, Record::classify("STACK CFI"));
 
   // Any obviously incorrect lines will be classified as such.
@@ -97,3 +96,26 @@ TEST(PublicRecord, parse) {
   EXPECT_EQ(llvm::None, PublicRecord::parse("PUBLIC m"));
   EXPECT_EQ(llvm::None, PublicRecord::parse("PUBLIC"));
 }
+
+TEST(StackCFIRecord, parse) {
+  EXPECT_EQ(StackCFIRecord(0x47, 0x8, ".cfa: $esp 4 + $eip: .cfa 4 - ^"),
+            StackCFIRecord::parse(
+                "STACK CFI INIT 47 8 .cfa: $esp 4 + $eip: .cfa 4 - ^"));
+
+  EXPECT_EQ(StackCFIRecord(0x47, 0x8, ".cfa: $esp 4 +"),
+            StackCFIRecord::parse("STACK CFI INIT 47 8 .cfa: $esp 4 +  "));
+
+  EXPECT_EQ(StackCFIRecord(0x47, llvm::None, ".cfa: $esp 4 +"),
+            StackCFIRecord::parse("STACK CFI 47 .cfa: $esp 4 +"));
+
+  // The validity of the register value expressions is not checked
+  EXPECT_EQ(StackCFIRecord(0x47, 0x8, ".cfa: ^ ^ ^"),
+            StackCFIRecord::parse("STACK CFI INIT 47 8 .cfa: ^ ^ ^"));
+
+  EXPECT_EQ(llvm::None, StackCFIRecord::parse("STACK CFI INIT 47"));
+  EXPECT_EQ(llvm::None, StackCFIRecord::parse("STACK CFI INIT"));
+  EXPECT_EQ(llvm::None, StackCFIRecord::parse("STACK CFI"));
+  EXPECT_EQ(llvm::None, StackCFIRecord::parse("STACK"));
+  EXPECT_EQ(llvm::None, StackCFIRecord::parse("FILE 47 foo"));
+  EXPECT_EQ(llvm::None, StackCFIRecord::parse("42 47"));
+}