[LLDB][MIPS] Fix TestStepOverBreakpoint.py failure.

Reviewers: jingham, labath

Subscribers: jaydeep, bhushan, lldb-commits, slthakur

Differential Revision: https://reviews.llvm.org/D32168

llvm-svn: 302139

lldb/include/lldb/API/SBAddress.h

@@ -103,6 +103,8 @@ protected:
 
   const lldb_private::Address *operator->() const;
 
+  friend bool operator==(const SBAddress &lhs, const SBAddress &rhs);
+
   lldb_private::Address *get();
 
   lldb_private::Address &ref();
@@ -117,6 +119,8 @@ private:
   std::unique_ptr<lldb_private::Address> m_opaque_ap;
 };
 
+bool operator==(const SBAddress &lhs, const SBAddress &rhs);
+
 } // namespace lldb
 
 #endif // LLDB_SBAddress_h_

lldb/include/lldb/API/SBInstruction.h

@@ -53,6 +53,8 @@ public:
 
   bool HasDelaySlot();
 
+  bool CanSetBreakpoint();
+
   void Print(FILE *out);
 
   bool GetDescription(lldb::SBStream &description);

lldb/include/lldb/API/SBInstructionList.h

@@ -32,6 +32,15 @@ public:
 
   lldb::SBInstruction GetInstructionAtIndex(uint32_t idx);
 
+  // ----------------------------------------------------------------------
+  // Returns the number of instructions between the start and end address.
+  // If canSetBreakpoint is true then the count will be the number of 
+  // instructions on which a breakpoint can be set.
+  // ----------------------------------------------------------------------
+  size_t GetInstructionsCount(const SBAddress &start,
+                              const SBAddress &end,
+                              bool canSetBreakpoint = false);                                   
+
   void Clear();
 
   void AppendInstruction(lldb::SBInstruction inst);

lldb/include/lldb/Core/Disassembler.h

@@ -173,6 +173,8 @@ public:
 
   virtual bool HasDelaySlot();
 
+  bool CanSetBreakpoint ();
+
   virtual size_t Decode(const Disassembler &disassembler,
                         const DataExtractor &data,
                         lldb::offset_t data_offset) = 0;

lldb/packages/Python/lldbsuite/test/functionalities/breakpoint/step_over_breakpoint/TestStepOverBreakpoint.py

@@ -62,12 +62,11 @@ class StepOverBreakpointsTestCase(TestBase):
         instructions = function.GetInstructions(self.target)
         addr_1 = self.breakpoint1.GetLocationAtIndex(0).GetAddress()
         addr_4 = self.breakpoint4.GetLocationAtIndex(0).GetAddress()
-        for i in range(instructions.GetSize()) :
-            addr = instructions.GetInstructionAtIndex(i).GetAddress()
-            if (addr == addr_1) : index_1 = i
-            if (addr == addr_4) : index_4 = i 
 
-        steps_expected = index_4 - index_1
+        # if third argument is true then the count will be the number of
+        # instructions on which a breakpoint can be set.
+        # start = addr_1, end = addr_4, canSetBreakpoint = True
+        steps_expected = instructions.GetInstructionsCount(addr_1, addr_4, True)
         step_count = 0
         # Step from breakpoint_1 to breakpoint_4
         while True:

lldb/scripts/interface/SBInstruction.i

@@ -54,6 +54,9 @@ public:
     bool
     HasDelaySlot ();
 
+    bool
+    CanSetBreakpoint ();
+
     void
     Print (FILE *out);
 

lldb/scripts/interface/SBInstructionList.i

@@ -44,6 +44,9 @@ public:
     lldb::SBInstruction
     GetInstructionAtIndex (uint32_t idx);
 
+    size_t GetInstructionsCount(const SBAddress &start, const SBAddress &end,
+                                bool canSetBreakpoint);
+
     void
     Clear ();
 

lldb/source/API/SBAddress.cpp

@@ -55,6 +55,12 @@ const SBAddress &SBAddress::operator=(const SBAddress &rhs) {
   return *this;
 }
 
+bool lldb::operator==(const SBAddress &lhs, const SBAddress &rhs) {
+  if (lhs.IsValid() && rhs.IsValid())
+    return lhs.ref() == rhs.ref();
+  return false;
+}
+
 bool SBAddress::IsValid() const {
   return m_opaque_ap.get() != NULL && m_opaque_ap->IsValid();
 }

lldb/source/API/SBInstruction.cpp

@@ -176,6 +176,13 @@ bool SBInstruction::HasDelaySlot() {
   return false;
 }
 
+bool SBInstruction::CanSetBreakpoint () {
+  lldb::InstructionSP inst_sp(GetOpaque());
+  if (inst_sp)
+    return inst_sp->CanSetBreakpoint();
+  return false;
+}
+
 lldb::InstructionSP SBInstruction::GetOpaque() {
   if (m_opaque_sp)
     return m_opaque_sp->GetSP();

lldb/source/API/SBInstructionList.cpp

@@ -9,6 +9,7 @@
 
 #include "lldb/API/SBInstructionList.h"
 #include "lldb/API/SBInstruction.h"
+#include "lldb/API/SBAddress.h"
 #include "lldb/API/SBStream.h"
 #include "lldb/Core/Disassembler.h"
 #include "lldb/Core/Module.h"
@@ -49,6 +50,31 @@ SBInstruction SBInstructionList::GetInstructionAtIndex(uint32_t idx) {
   return inst;
 }
 
+size_t SBInstructionList::GetInstructionsCount(const SBAddress &start,
+                                              const SBAddress &end, 
+                                              bool canSetBreakpoint) {
+  size_t num_instructions = GetSize();
+  size_t i = 0;
+  SBAddress addr;
+  size_t lower_index = 0;
+  size_t upper_index = 0;
+  size_t instructions_to_skip = 0;
+  for (i = 0; i < num_instructions; ++i) {
+    addr = GetInstructionAtIndex(i).GetAddress();
+    if (start == addr)
+      lower_index = i;
+    if (end == addr)
+      upper_index = i;
+  }
+  if (canSetBreakpoint)
+    for (i = lower_index; i <= upper_index; ++i) {
+      SBInstruction insn = GetInstructionAtIndex(i);
+      if (!insn.CanSetBreakpoint())
+        ++instructions_to_skip;
+    }
+  return upper_index - lower_index - instructions_to_skip;
+}
+
 void SBInstructionList::Clear() { m_opaque_sp.reset(); }
 
 void SBInstructionList::AppendInstruction(SBInstruction insn) {}

lldb/source/Core/Disassembler.cpp

@@ -759,6 +759,10 @@ bool Instruction::DumpEmulation(const ArchSpec &arch) {
   return false;
 }
 
+bool Instruction::CanSetBreakpoint () {
+  return !HasDelaySlot();
+}
+
 bool Instruction::HasDelaySlot() {
   // Default is false.
   return false;