PostfixExpression: Use signed integers in IntegerNode

Summary:
This is necessary to support parsing expressions like ".cfa -16 + ^", as
that format is used in breakpad STACK CFI expressions.

Since the PDB expressions use the same parser, this change will affect
them too, but I don't believe that should be a problem in practice. If
PDBs do contain the negative values, it's very likely that they are
intended to be parsed the same way, and if they don't, then it doesn't
matter.

In case that we do ever need to handle this differently, we can always
make the parser behavior customizable, or just use a different parser.

To make sure that the integer size is big enough for everyone, I switch
from using a (unsigned) 32-bit integer to a 64-bit (signed) one.

Reviewers: amccarth, clayborg, aleksandr.urakov

Subscribers: markmentovai, lldb-commits

Differential Revision: https://reviews.llvm.org/D61311

llvm-svn: 360166

lldb/include/lldb/Symbol/PostfixExpression.h

@@ -87,14 +87,14 @@ class InitialValueNode: public Node {
 /// A node representing an integer literal.
 class IntegerNode : public Node {
 public:
-  IntegerNode(uint32_t value) : Node(Integer), m_value(value) {}
+  IntegerNode(int64_t value) : Node(Integer), m_value(value) {}
 
-  uint32_t GetValue() const { return m_value; }
+  int64_t GetValue() const { return m_value; }
 
   static bool classof(const Node *node) { return node->GetKind() == Integer; }
 
 private:
-  uint32_t m_value;
+  int64_t m_value;
 };
 
 /// A node representing the value of a register with the given register number.

lldb/source/Symbol/PostfixExpression.cpp

@@ -67,7 +67,7 @@ Node *postfix::Parse(llvm::StringRef expr, llvm::BumpPtrAllocator &alloc) {
       continue;
     }
 
-    uint32_t value;
+    int64_t value;
     if (to_integer(token, value, 10)) {
       // token is integer literal
       stack.push_back(MakeNode<IntegerNode>(alloc, value));
@@ -129,8 +129,8 @@ class DWARFCodegen : public Visitor<> {
   void Visit(InitialValueNode &val, Node *&) override;
 
   void Visit(IntegerNode &integer, Node *&) override {
-    m_out_stream.PutHex8(DW_OP_constu);
-    m_out_stream.PutULEB128(integer.GetValue());
+    m_out_stream.PutHex8(DW_OP_consts);
+    m_out_stream.PutSLEB128(integer.GetValue());
     ++m_stack_depth;
   }
 

lldb/unittests/Symbol/PostfixExpressionTest.cpp

@@ -88,6 +88,7 @@ TEST(PostfixExpression, Parse) {
   EXPECT_EQ("^(^(int(1)))", ParseAndStringify("1 ^ ^"));
   EXPECT_EQ("^(+(int(1), ^(int(2))))", ParseAndStringify("1 2 ^ + ^"));
   EXPECT_EQ("-($foo, int(47))", ParseAndStringify("$foo 47 -"));
+  EXPECT_EQ("+(int(47), int(-42))", ParseAndStringify("47 -42 +"));
 
   EXPECT_EQ("nullptr", ParseAndStringify("+"));
   EXPECT_EQ("nullptr", ParseAndStringify("^"));
@@ -137,7 +138,7 @@ static std::string ParseAndGenerateDWARF(llvm::StringRef expr) {
 }
 
 TEST(PostfixExpression, ToDWARF) {
-  EXPECT_EQ("DW_OP_constu 0x0", ParseAndGenerateDWARF("0"));
+  EXPECT_EQ("DW_OP_consts +0", ParseAndGenerateDWARF("0"));
 
   EXPECT_EQ("DW_OP_breg1 +0", ParseAndGenerateDWARF("R1"));
 
@@ -151,18 +152,18 @@ TEST(PostfixExpression, ToDWARF) {
   EXPECT_EQ("DW_OP_breg1 +0, DW_OP_pick 0x01, DW_OP_plus ",
             ParseAndGenerateDWARF("R1 INIT +"));
 
-  EXPECT_EQ("DW_OP_constu 0x1, DW_OP_pick 0x01, DW_OP_deref , DW_OP_plus ",
+  EXPECT_EQ("DW_OP_consts +1, DW_OP_pick 0x01, DW_OP_deref , DW_OP_plus ",
             ParseAndGenerateDWARF("1 INIT ^ +"));
 
-  EXPECT_EQ("DW_OP_constu 0x4, DW_OP_constu 0x5, DW_OP_plus ",
+  EXPECT_EQ("DW_OP_consts +4, DW_OP_consts +5, DW_OP_plus ",
             ParseAndGenerateDWARF("4 5 +"));
 
-  EXPECT_EQ("DW_OP_constu 0x4, DW_OP_constu 0x5, DW_OP_minus ",
+  EXPECT_EQ("DW_OP_consts +4, DW_OP_consts +5, DW_OP_minus ",
             ParseAndGenerateDWARF("4 5 -"));
 
-  EXPECT_EQ("DW_OP_constu 0x4, DW_OP_deref ", ParseAndGenerateDWARF("4 ^"));
+  EXPECT_EQ("DW_OP_consts +4, DW_OP_deref ", ParseAndGenerateDWARF("4 ^"));
 
-  EXPECT_EQ("DW_OP_breg6 +0, DW_OP_constu 0x80, DW_OP_lit1 "
+  EXPECT_EQ("DW_OP_breg6 +0, DW_OP_consts +128, DW_OP_lit1 "
             ", DW_OP_minus , DW_OP_not , DW_OP_and ",
             ParseAndGenerateDWARF("R6 128 @"));
 }

lldb/unittests/SymbolFile/NativePDB/PdbFPOProgramToDWARFExpressionTests.cpp

@@ -58,20 +58,20 @@ TEST(PDBFPOProgramToDWARFExpressionTests, SingleAssignmentRegisterRef) {
 }
 
 TEST(PDBFPOProgramToDWARFExpressionTests, MultipleIndependentAssignments) {
-  CheckValidProgramTranslation("$T1 1 = $T0 0 =", "$T0", "DW_OP_constu 0x0");
+  CheckValidProgramTranslation("$T1 1 = $T0 0 =", "$T0", "DW_OP_consts +0");
 }
 
 TEST(PDBFPOProgramToDWARFExpressionTests, MultipleDependentAssignments) {
   CheckValidProgramTranslation(
       "$T1 $ebp 4 + = $T0 $T1 8 - 128 @ = ", "$T0",
-      "DW_OP_breg6 +0, DW_OP_constu 0x4, DW_OP_plus , DW_OP_constu 0x8, "
-      "DW_OP_minus , DW_OP_constu 0x80, DW_OP_lit1 , DW_OP_minus , DW_OP_not , "
+      "DW_OP_breg6 +0, DW_OP_consts +4, DW_OP_plus , DW_OP_consts +8, "
+      "DW_OP_minus , DW_OP_consts +128, DW_OP_lit1 , DW_OP_minus , DW_OP_not , "
       "DW_OP_and ");
 }
 
 TEST(PDBFPOProgramToDWARFExpressionTests, DependencyChain) {
   CheckValidProgramTranslation("$T1 0 = $T0 $T1 = $ebp $T0 =", "$ebp",
-                               "DW_OP_constu 0x0");
+                               "DW_OP_consts +0");
 }
 
 /// Invalid programs tests