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 // Copyright (c) 2010, Google Inc.

 // All rights reserved.

 //

 // Redistribution and use in source and binary forms, with or without

 // modification, are permitted provided that the following conditions are

 // met:

 //

 //     * Redistributions of source code must retain the above copyright

 // notice, this list of conditions and the following disclaimer.

 //     * Redistributions in binary form must reproduce the above

 // copyright notice, this list of conditions and the following disclaimer

 // in the documentation and/or other materials provided with the

 // distribution.

 //     * Neither the name of Google Inc. nor the names of its

 // contributors may be used to endorse or promote products derived from

 // this software without specific prior written permission.

 //

 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS

 // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT

 // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR

 // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT

 // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,

 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT

 // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,

 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY

 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT

 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE

 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

 // Original author: Jim Blandy <jimb@mozilla.com> <jimb@red-bean.com>

 // stackwalker_arm_unittest.cc: Unit tests for StackwalkerARM class.

 #include <string.h>

 #include <string>

 #include <vector>

 #include "breakpad_googletest_includes.h"

 #include "common/test_assembler.h"

 #include "common/using_std_string.h"

 #include "google_breakpad/common/minidump_format.h"

 #include "google_breakpad/processor/basic_source_line_resolver.h"

 #include "google_breakpad/processor/call_stack.h"

 #include "google_breakpad/processor/code_module.h"

 #include "google_breakpad/processor/source_line_resolver_interface.h"

 #include "google_breakpad/processor/stack_frame_cpu.h"

 #include "processor/stackwalker_unittest_utils.h"

 #include "processor/stackwalker_arm.h"

 #include "processor/windows_frame_info.h"

 using google_breakpad::BasicSourceLineResolver;

 using google_breakpad::CallStack;

 using google_breakpad::CodeModule;

 using google_breakpad::StackFrameSymbolizer;

 using google_breakpad::StackFrame;

 using google_breakpad::StackFrameARM;

 using google_breakpad::StackwalkerARM;

 using google_breakpad::SystemInfo;

 using google_breakpad::WindowsFrameInfo;

 using google_breakpad::test_assembler::kLittleEndian;

 using google_breakpad::test_assembler::Label;

 using google_breakpad::test_assembler::Section;

 using std::vector;

 using testing::_;

 using testing::Return;

 using testing::SetArgumentPointee;

 using testing::Test;

 class StackwalkerARMFixture {

  public:

   StackwalkerARMFixture()

     : stack_section(kLittleEndian),

       // Give the two modules reasonable standard locations and names

       // for tests to play with.

       module1(0x40000000, 0x10000, "module1", "version1"),

       module2(0x50000000, 0x10000, "module2", "version2") {

     // Identify the system as a Linux system.

     system_info.os = "Linux";

     system_info.os_short = "linux";

     system_info.os_version = "Lugubrious Labrador";

     system_info.cpu = "arm";

     system_info.cpu_info = "";

     // Put distinctive values in the raw CPU context.

     BrandContext(&raw_context);

     // Create some modules with some stock debugging information.

     modules.Add(&module1);

     modules.Add(&module2);

     // By default, none of the modules have symbol info; call

     // SetModuleSymbols to override this.

     EXPECT_CALL(supplier, GetCStringSymbolData(_, _, _, _))

       .WillRepeatedly(Return(MockSymbolSupplier::NOT_FOUND));

   }

   // Set the Breakpad symbol information that supplier should return for

   // MODULE to INFO.

   void SetModuleSymbols(MockCodeModule *module, const string &info) {

     char *buffer = supplier.CopySymbolDataAndOwnTheCopy(info);

     EXPECT_CALL(supplier, GetCStringSymbolData(module, &system_info, _, _))

       .WillRepeatedly(DoAll(SetArgumentPointee<3>(buffer),

                             Return(MockSymbolSupplier::FOUND)));

   }

   // Populate stack_region with the contents of stack_section. Use

   // stack_section.start() as the region's starting address.

   void RegionFromSection() {

     string contents;

     ASSERT_TRUE(stack_section.GetContents(&contents));

     stack_region.Init(stack_section.start().Value(), contents);

   }

   // Fill RAW_CONTEXT with pseudo-random data, for round-trip checking.

   void BrandContext(MDRawContextARM *raw_context) {

     uint8_t x = 173;

     for (size_t i = 0; i < sizeof(*raw_context); i++)

       reinterpret_cast<uint8_t *>(raw_context)[i] = (x += 17);

   }

   SystemInfo system_info;

   MDRawContextARM raw_context;

   Section stack_section;

   MockMemoryRegion stack_region;

   MockCodeModule module1;

   MockCodeModule module2;

   MockCodeModules modules;

   MockSymbolSupplier supplier;

   BasicSourceLineResolver resolver;

   CallStack call_stack;

   const vector<StackFrame *> *frames;

 };

 class SanityCheck: public StackwalkerARMFixture, public Test { };

 TEST_F(SanityCheck, NoResolver) {

   // Since we have no call frame information, and all unwinding

   // requires call frame information, the stack walk will end after

   // the first frame.

   StackFrameSymbolizer frame_symbolizer(NULL, NULL);

   StackwalkerARM walker(&system_info, &raw_context, -1, &stack_region, &modules,

                         &frame_symbolizer);

   // This should succeed even without a resolver or supplier.

   vector<const CodeModule*> modules_without_symbols;

   ASSERT_TRUE(walker.Walk(&call_stack, &modules_without_symbols));

   ASSERT_EQ(0U, modules_without_symbols.size());

   frames = call_stack.frames();

   ASSERT_EQ(1U, frames->size());

   StackFrameARM *frame = static_cast<StackFrameARM *>(frames->at(0));

   // Check that the values from the original raw context made it

   // through to the context in the stack frame.

   EXPECT_EQ(0, memcmp(&raw_context, &frame->context, sizeof(raw_context)));

 }

 class GetContextFrame: public StackwalkerARMFixture, public Test { };

 TEST_F(GetContextFrame, Simple) {

   // Since we have no call frame information, and all unwinding

   // requires call frame information, the stack walk will end after

   // the first frame.

   StackFrameSymbolizer frame_symbolizer(&supplier, &resolver);

   StackwalkerARM walker(&system_info, &raw_context, -1, &stack_region, &modules,

                         &frame_symbolizer);

   vector<const CodeModule*> modules_without_symbols;

   ASSERT_TRUE(walker.Walk(&call_stack, &modules_without_symbols));

   ASSERT_EQ(0U, modules_without_symbols.size());

   frames = call_stack.frames();

   ASSERT_EQ(1U, frames->size());

   StackFrameARM *frame = static_cast<StackFrameARM *>(frames->at(0));

   // Check that the values from the original raw context made it

   // through to the context in the stack frame.

   EXPECT_EQ(0, memcmp(&raw_context, &frame->context, sizeof(raw_context)));

 }

 // The stackwalker should be able to produce the context frame even

 // without stack memory present.

 TEST_F(GetContextFrame, NoStackMemory) {

   StackFrameSymbolizer frame_symbolizer(&supplier, &resolver);

   StackwalkerARM walker(&system_info, &raw_context, -1, NULL, &modules,

                         &frame_symbolizer);

   vector<const CodeModule*> modules_without_symbols;

   ASSERT_TRUE(walker.Walk(&call_stack, &modules_without_symbols));

   ASSERT_EQ(0U, modules_without_symbols.size());

   frames = call_stack.frames();

   ASSERT_EQ(1U, frames->size());

   StackFrameARM *frame = static_cast<StackFrameARM *>(frames->at(0));

   // Check that the values from the original raw context made it

   // through to the context in the stack frame.

   EXPECT_EQ(0, memcmp(&raw_context, &frame->context, sizeof(raw_context)));

 }

 class GetCallerFrame: public StackwalkerARMFixture, public Test { };

 TEST_F(GetCallerFrame, ScanWithoutSymbols) {

   // When the stack walker resorts to scanning the stack,

   // only addresses located within loaded modules are

   // considered valid return addresses.

   // Force scanning through three frames to ensure that the

   // stack pointer is set properly in scan-recovered frames.

   stack_section.start() = 0x80000000;

   uint32_t return_address1 = 0x50000100;

   uint32_t return_address2 = 0x50000900;

   Label frame1_sp, frame2_sp;

   stack_section

     // frame 0

     .Append(16, 0)                      // space

     .D32(0x40090000)                    // junk that's not

     .D32(0x60000000)                    // a return address

     .D32(return_address1)               // actual return address

     // frame 1

     .Mark(&frame1_sp)

     .Append(16, 0)                      // space

     .D32(0xF0000000)                    // more junk

     .D32(0x0000000D)

     .D32(return_address2)               // actual return address

     // frame 2

     .Mark(&frame2_sp)

     .Append(32, 0);                     // end of stack

   RegionFromSection();

   raw_context.iregs[MD_CONTEXT_ARM_REG_PC] = 0x40005510;

   raw_context.iregs[MD_CONTEXT_ARM_REG_SP] = stack_section.start().Value();

   StackFrameSymbolizer frame_symbolizer(&supplier, &resolver);

   StackwalkerARM walker(&system_info, &raw_context, -1, &stack_region, &modules,

                         &frame_symbolizer);

   vector<const CodeModule*> modules_without_symbols;

   ASSERT_TRUE(walker.Walk(&call_stack, &modules_without_symbols));

   ASSERT_EQ(2U, modules_without_symbols.size());

   ASSERT_EQ("module1", modules_without_symbols[0]->debug_file());

   ASSERT_EQ("module2", modules_without_symbols[1]->debug_file());

   frames = call_stack.frames();

   ASSERT_EQ(3U, frames->size());

   StackFrameARM *frame0 = static_cast<StackFrameARM *>(frames->at(0));

   EXPECT_EQ(StackFrame::FRAME_TRUST_CONTEXT, frame0->trust);

   ASSERT_EQ(StackFrameARM::CONTEXT_VALID_ALL, frame0->context_validity);

   EXPECT_EQ(0, memcmp(&raw_context, &frame0->context, sizeof(raw_context)));

   StackFrameARM *frame1 = static_cast<StackFrameARM *>(frames->at(1));

   EXPECT_EQ(StackFrame::FRAME_TRUST_SCAN, frame1->trust);

   ASSERT_EQ((StackFrameARM::CONTEXT_VALID_PC |

              StackFrameARM::CONTEXT_VALID_SP),

             frame1->context_validity);

   EXPECT_EQ(return_address1, frame1->context.iregs[MD_CONTEXT_ARM_REG_PC]);

   EXPECT_EQ(frame1_sp.Value(), frame1->context.iregs[MD_CONTEXT_ARM_REG_SP]);

   StackFrameARM *frame2 = static_cast<StackFrameARM *>(frames->at(2));

   EXPECT_EQ(StackFrame::FRAME_TRUST_SCAN, frame2->trust);

   ASSERT_EQ((StackFrameARM::CONTEXT_VALID_PC |

              StackFrameARM::CONTEXT_VALID_SP),

             frame2->context_validity);

   EXPECT_EQ(return_address2, frame2->context.iregs[MD_CONTEXT_ARM_REG_PC]);

   EXPECT_EQ(frame2_sp.Value(), frame2->context.iregs[MD_CONTEXT_ARM_REG_SP]);

 }

 TEST_F(GetCallerFrame, ScanWithFunctionSymbols) {

   // During stack scanning, if a potential return address

   // is located within a loaded module that has symbols,

   // it is only considered a valid return address if it

   // lies within a function's bounds.

   stack_section.start() = 0x80000000;

   uint32_t return_address = 0x50000200;

   Label frame1_sp;

   stack_section

     // frame 0

     .Append(16, 0)                      // space

     .D32(0x40090000)                    // junk that's not

     .D32(0x60000000)                    // a return address

     .D32(0x40001000)                    // a couple of plausible addresses

     .D32(0x5000F000)                    // that are not within functions

     .D32(return_address)                // actual return address

     // frame 1

     .Mark(&frame1_sp)

     .Append(32, 0);                     // end of stack

   RegionFromSection();

   raw_context.iregs[MD_CONTEXT_ARM_REG_PC] = 0x40000200;

   raw_context.iregs[MD_CONTEXT_ARM_REG_SP] = stack_section.start().Value();

   SetModuleSymbols(&module1,

                    // The youngest frame's function.

                    "FUNC 100 400 10 monotreme\n");

   SetModuleSymbols(&module2,

                    // The calling frame's function.

                    "FUNC 100 400 10 marsupial\n");

   StackFrameSymbolizer frame_symbolizer(&supplier, &resolver);

   StackwalkerARM walker(&system_info, &raw_context, -1, &stack_region, &modules,

                         &frame_symbolizer);

   vector<const CodeModule*> modules_without_symbols;

   ASSERT_TRUE(walker.Walk(&call_stack, &modules_without_symbols));

   ASSERT_EQ(0U, modules_without_symbols.size());

   frames = call_stack.frames();

   ASSERT_EQ(2U, frames->size());

   StackFrameARM *frame0 = static_cast<StackFrameARM *>(frames->at(0));

   EXPECT_EQ(StackFrame::FRAME_TRUST_CONTEXT, frame0->trust);

   ASSERT_EQ(StackFrameARM::CONTEXT_VALID_ALL, frame0->context_validity);

   EXPECT_EQ(0, memcmp(&raw_context, &frame0->context, sizeof(raw_context)));

   EXPECT_EQ("monotreme", frame0->function_name);

   EXPECT_EQ(0x40000100U, frame0->function_base);

   StackFrameARM *frame1 = static_cast<StackFrameARM *>(frames->at(1));

   EXPECT_EQ(StackFrame::FRAME_TRUST_SCAN, frame1->trust);

   ASSERT_EQ((StackFrameARM::CONTEXT_VALID_PC |

              StackFrameARM::CONTEXT_VALID_SP),

             frame1->context_validity);

   EXPECT_EQ(return_address, frame1->context.iregs[MD_CONTEXT_ARM_REG_PC]);

   EXPECT_EQ(frame1_sp.Value(), frame1->context.iregs[MD_CONTEXT_ARM_REG_SP]);

   EXPECT_EQ("marsupial", frame1->function_name);

   EXPECT_EQ(0x50000100U, frame1->function_base);

 }

 TEST_F(GetCallerFrame, ScanFirstFrame) {

   // If the stackwalker resorts to stack scanning, it will scan much

   // farther to find the caller of the context frame.

   stack_section.start() = 0x80000000;

   uint32_t return_address1 = 0x50000100;

   uint32_t return_address2 = 0x50000900;

   Label frame1_sp, frame2_sp;

   stack_section

     // frame 0

     .Append(32, 0)                      // space

     .D32(0x40090000)                    // junk that's not

     .D32(0x60000000)                    // a return address

     .Append(96, 0)                      // more space

     .D32(return_address1)               // actual return address

     // frame 1

     .Mark(&frame1_sp)

     .Append(32, 0)                      // space

     .D32(0xF0000000)                    // more junk

     .D32(0x0000000D)

     .Append(96, 0)                      // more space

     .D32(return_address2)               // actual return address

                                         // (won't be found)

     // frame 2

     .Mark(&frame2_sp)

     .Append(32, 0);                     // end of stack

   RegionFromSection();

   raw_context.iregs[MD_CONTEXT_ARM_REG_PC] = 0x40005510;

   raw_context.iregs[MD_CONTEXT_ARM_REG_SP] = stack_section.start().Value();

   StackFrameSymbolizer frame_symbolizer(&supplier, &resolver);

   StackwalkerARM walker(&system_info, &raw_context, -1, &stack_region, &modules,

                         &frame_symbolizer);

   vector<const CodeModule*> modules_without_symbols;

   ASSERT_TRUE(walker.Walk(&call_stack, &modules_without_symbols));

   ASSERT_EQ(2U, modules_without_symbols.size());

   ASSERT_EQ("module1", modules_without_symbols[0]->debug_file());

   ASSERT_EQ("module2", modules_without_symbols[1]->debug_file());

   frames = call_stack.frames();

   ASSERT_EQ(2U, frames->size());

   StackFrameARM *frame0 = static_cast<StackFrameARM *>(frames->at(0));

   EXPECT_EQ(StackFrame::FRAME_TRUST_CONTEXT, frame0->trust);

   ASSERT_EQ(StackFrameARM::CONTEXT_VALID_ALL, frame0->context_validity);

   EXPECT_EQ(0, memcmp(&raw_context, &frame0->context, sizeof(raw_context)));

   StackFrameARM *frame1 = static_cast<StackFrameARM *>(frames->at(1));

   EXPECT_EQ(StackFrame::FRAME_TRUST_SCAN, frame1->trust);

   ASSERT_EQ((StackFrameARM::CONTEXT_VALID_PC |

              StackFrameARM::CONTEXT_VALID_SP),

             frame1->context_validity);

   EXPECT_EQ(return_address1, frame1->context.iregs[MD_CONTEXT_ARM_REG_PC]);

   EXPECT_EQ(frame1_sp.Value(), frame1->context.iregs[MD_CONTEXT_ARM_REG_SP]);

 }

 struct CFIFixture: public StackwalkerARMFixture {

   CFIFixture() {

     // Provide a bunch of STACK CFI records; we'll walk to the caller

     // from every point in this series, expecting to find the same set

     // of register values.

     SetModuleSymbols(&module1,

                      // The youngest frame's function.

                      "FUNC 4000 1000 10 enchiridion\n"

                      // Initially, nothing has been pushed on the stack,

                      // and the return address is still in the link register.

                      "STACK CFI INIT 4000 100 .cfa: sp .ra: lr\n"

                      // Push r4, the frame pointer, and the link register.

                      "STACK CFI 4001 .cfa: sp 12 + r4: .cfa 12 - ^"

                      " r11: .cfa 8 - ^ .ra: .cfa 4 - ^\n"

                      // Save r4..r7 in r0..r3: verify that we populate

                      // the youngest frame with all the values we have.

                      "STACK CFI 4002 r4: r0 r5: r1 r6: r2 r7: r3\n"

                      // Restore r4..r7. Save the non-callee-saves register r1.

                      "STACK CFI 4003 .cfa: sp 16 + r1: .cfa 16 - ^"

                      " r4: r4 r5: r5 r6: r6 r7: r7\n"

                      // Move the .cfa back four bytes, to point at the return

                      // address, and restore the sp explicitly.

                      "STACK CFI 4005 .cfa: sp 12 + r1: .cfa 12 - ^"

                      " r11: .cfa 4 - ^ .ra: .cfa ^ sp: .cfa 4 +\n"

                      // Recover the PC explicitly from a new stack slot;

                      // provide garbage for the .ra.

                      "STACK CFI 4006 .cfa: sp 16 + pc: .cfa 16 - ^\n"

                      // The calling function.

                      "FUNC 5000 1000 10 epictetus\n"

                      // Mark it as end of stack.

                      "STACK CFI INIT 5000 1000 .cfa: 0 .ra: 0\n"

                      // A function whose CFI makes the stack pointer

                      // go backwards.

                      "FUNC 6000 1000 20 palinal\n"

                      "STACK CFI INIT 6000 1000 .cfa: sp 4 - .ra: lr\n"

                      // A function with CFI expressions that can't be

                      // evaluated.

                      "FUNC 7000 1000 20 rhetorical\n"

                      "STACK CFI INIT 7000 1000 .cfa: moot .ra: ambiguous\n");

     // Provide some distinctive values for the caller's registers.

     expected.iregs[MD_CONTEXT_ARM_REG_PC] = 0x40005510;

     expected.iregs[MD_CONTEXT_ARM_REG_SP] = 0x80000000;

     expected.iregs[4] = 0xb5d55e68;

     expected.iregs[5] = 0xebd134f3;

     expected.iregs[6] = 0xa31e74bc;

     expected.iregs[7] = 0x2dcb16b3;

     expected.iregs[8] = 0x2ada2137;

     expected.iregs[9] = 0xbbbb557d;

     expected.iregs[10] = 0x48bf8ca7;

     expected.iregs[MD_CONTEXT_ARM_REG_FP] = 0x8112e110;

     // Expect CFI to recover all callee-saves registers. Since CFI is the

     // only stack frame construction technique we have, aside from the

     // context frame itself, there's no way for us to have a set of valid

     // registers smaller than this.

     expected_validity = (StackFrameARM::CONTEXT_VALID_PC |

                          StackFrameARM::CONTEXT_VALID_SP |

                          StackFrameARM::CONTEXT_VALID_R4 |

                          StackFrameARM::CONTEXT_VALID_R5 |

                          StackFrameARM::CONTEXT_VALID_R6 |

                          StackFrameARM::CONTEXT_VALID_R7 |

                          StackFrameARM::CONTEXT_VALID_R8 |

                          StackFrameARM::CONTEXT_VALID_R9 |

                          StackFrameARM::CONTEXT_VALID_R10 |

                          StackFrameARM::CONTEXT_VALID_FP);

     // By default, context frames provide all registers, as normal.

     context_frame_validity = StackFrameARM::CONTEXT_VALID_ALL;

     // By default, registers are unchanged.

     raw_context = expected;

   }

   // Walk the stack, using stack_section as the contents of the stack

   // and raw_context as the current register values. (Set the stack

   // pointer to the stack's starting address.) Expect two stack

   // frames; in the older frame, expect the callee-saves registers to

   // have values matching those in 'expected'.

   void CheckWalk() {

     RegionFromSection();

     raw_context.iregs[MD_CONTEXT_ARM_REG_SP] = stack_section.start().Value();

     StackFrameSymbolizer frame_symbolizer(&supplier, &resolver);

     StackwalkerARM walker(&system_info, &raw_context, -1, &stack_region,

                           &modules, &frame_symbolizer);

     walker.SetContextFrameValidity(context_frame_validity);

     vector<const CodeModule*> modules_without_symbols;

     ASSERT_TRUE(walker.Walk(&call_stack, &modules_without_symbols));

     ASSERT_EQ(0U, modules_without_symbols.size());

     frames = call_stack.frames();

     ASSERT_EQ(2U, frames->size());

     StackFrameARM *frame0 = static_cast<StackFrameARM *>(frames->at(0));

     EXPECT_EQ(StackFrame::FRAME_TRUST_CONTEXT, frame0->trust);

     ASSERT_EQ(context_frame_validity, frame0->context_validity);

     EXPECT_EQ("enchiridion", frame0->function_name);

     EXPECT_EQ(0x40004000U, frame0->function_base);

     StackFrameARM *frame1 = static_cast<StackFrameARM *>(frames->at(1));

     EXPECT_EQ(StackFrame::FRAME_TRUST_CFI, frame1->trust);

     ASSERT_EQ(expected_validity, frame1->context_validity);

     if (expected_validity & StackFrameARM::CONTEXT_VALID_R1)

       EXPECT_EQ(expected.iregs[1], frame1->context.iregs[1]);

     if (expected_validity & StackFrameARM::CONTEXT_VALID_R4)

       EXPECT_EQ(expected.iregs[4], frame1->context.iregs[4]);

     if (expected_validity & StackFrameARM::CONTEXT_VALID_R5)

       EXPECT_EQ(expected.iregs[5], frame1->context.iregs[5]);

     if (expected_validity & StackFrameARM::CONTEXT_VALID_R6)

       EXPECT_EQ(expected.iregs[6], frame1->context.iregs[6]);

     if (expected_validity & StackFrameARM::CONTEXT_VALID_R7)

       EXPECT_EQ(expected.iregs[7], frame1->context.iregs[7]);

     if (expected_validity & StackFrameARM::CONTEXT_VALID_R8)

       EXPECT_EQ(expected.iregs[8], frame1->context.iregs[8]);

     if (expected_validity & StackFrameARM::CONTEXT_VALID_R9)

       EXPECT_EQ(expected.iregs[9], frame1->context.iregs[9]);

     if (expected_validity & StackFrameARM::CONTEXT_VALID_R10)

       EXPECT_EQ(expected.iregs[10], frame1->context.iregs[10]);

     if (expected_validity & StackFrameARM::CONTEXT_VALID_FP)

       EXPECT_EQ(expected.iregs[MD_CONTEXT_ARM_REG_FP],

                 frame1->context.iregs[MD_CONTEXT_ARM_REG_FP]);

     // We would never have gotten a frame in the first place if the SP

     // and PC weren't valid or ->instruction weren't set.

     EXPECT_EQ(expected.iregs[MD_CONTEXT_ARM_REG_SP],

               frame1->context.iregs[MD_CONTEXT_ARM_REG_SP]);

     EXPECT_EQ(expected.iregs[MD_CONTEXT_ARM_REG_PC],

               frame1->context.iregs[MD_CONTEXT_ARM_REG_PC]);

     EXPECT_EQ(expected.iregs[MD_CONTEXT_ARM_REG_PC],

               frame1->instruction + 2);

     EXPECT_EQ("epictetus", frame1->function_name);

   }

   // The values we expect to find for the caller's registers.

   MDRawContextARM expected;

   // The validity mask for expected.

   int expected_validity;

   // The validity mask to impose on the context frame.

   int context_frame_validity;

 };

 class CFI: public CFIFixture, public Test { };

 TEST_F(CFI, At4000) {

   stack_section.start() = expected.iregs[MD_CONTEXT_ARM_REG_SP];

   raw_context.iregs[MD_CONTEXT_ARM_REG_PC] = 0x40004000;

   raw_context.iregs[MD_CONTEXT_ARM_REG_LR] = 0x40005510;

   CheckWalk();

 }

 TEST_F(CFI, At4001) {

   Label frame1_sp = expected.iregs[MD_CONTEXT_ARM_REG_SP];

   stack_section

     .D32(0xb5d55e68)            // saved r4

     .D32(0x8112e110)            // saved fp

     .D32(0x40005510)            // return address

     .Mark(&frame1_sp);          // This effectively sets stack_section.start().

   raw_context.iregs[MD_CONTEXT_ARM_REG_PC] = 0x40004001;

   raw_context.iregs[4] = 0x635adc9f;                     // distinct callee r4

   raw_context.iregs[MD_CONTEXT_ARM_REG_FP] = 0xbe145fc4; // distinct callee fp

   CheckWalk();

 }

 // As above, but unwind from a context that has only the PC and SP.

 TEST_F(CFI, At4001LimitedValidity) {

   context_frame_validity =

     StackFrameARM::CONTEXT_VALID_PC | StackFrameARM::CONTEXT_VALID_SP;

   raw_context.iregs[MD_CONTEXT_ARM_REG_PC] = 0x40004001;

   raw_context.iregs[MD_CONTEXT_ARM_REG_FP] = 0xbe145fc4; // distinct callee fp

   Label frame1_sp = expected.iregs[MD_CONTEXT_ARM_REG_SP];

   stack_section

     .D32(0xb5d55e68)            // saved r4

     .D32(0x8112e110)            // saved fp

     .D32(0x40005510)            // return address

     .Mark(&frame1_sp);          // This effectively sets stack_section.start().

   expected_validity = (StackFrameARM::CONTEXT_VALID_PC

                        | StackFrameARM::CONTEXT_VALID_SP

                        | StackFrameARM::CONTEXT_VALID_FP

                        | StackFrameARM::CONTEXT_VALID_R4);

   CheckWalk();

 }

 TEST_F(CFI, At4002) {

   Label frame1_sp = expected.iregs[MD_CONTEXT_ARM_REG_SP];

   stack_section

     .D32(0xfb81ff3d)            // no longer saved r4

     .D32(0x8112e110)            // saved fp

     .D32(0x40005510)            // return address

     .Mark(&frame1_sp);          // This effectively sets stack_section.start().

   raw_context.iregs[MD_CONTEXT_ARM_REG_PC] = 0x40004002;

   raw_context.iregs[0] = 0xb5d55e68;  // saved r4

   raw_context.iregs[1] = 0xebd134f3;  // saved r5

   raw_context.iregs[2] = 0xa31e74bc;  // saved r6

   raw_context.iregs[3] = 0x2dcb16b3;  // saved r7

   raw_context.iregs[4] = 0xfdd35466;  // distinct callee r4

   raw_context.iregs[5] = 0xf18c946c;  // distinct callee r5

   raw_context.iregs[6] = 0xac2079e8;  // distinct callee r6

   raw_context.iregs[7] = 0xa449829f;  // distinct callee r7

   raw_context.iregs[MD_CONTEXT_ARM_REG_FP] = 0xbe145fc4; // distinct callee fp

   CheckWalk();

 }

 TEST_F(CFI, At4003) {

   Label frame1_sp = expected.iregs[MD_CONTEXT_ARM_REG_SP];

   stack_section

     .D32(0x48c8dd5a)            // saved r1 (even though it's not callee-saves)

     .D32(0xcb78040e)            // no longer saved r4

     .D32(0x8112e110)            // saved fp

     .D32(0x40005510)            // return address

     .Mark(&frame1_sp);          // This effectively sets stack_section.start().

   raw_context.iregs[MD_CONTEXT_ARM_REG_PC] = 0x40004003;

   raw_context.iregs[1] = 0xfb756319;                     // distinct callee r1

   raw_context.iregs[MD_CONTEXT_ARM_REG_FP] = 0x0a2857ea; // distinct callee fp

   expected.iregs[1] = 0x48c8dd5a;    // caller's r1

   expected_validity |= StackFrameARM::CONTEXT_VALID_R1;

   CheckWalk();

 }

 // We have no new rule at module offset 0x4004, so the results here should

 // be the same as those at module offset 0x4003.

 TEST_F(CFI, At4004) {

   Label frame1_sp = expected.iregs[MD_CONTEXT_ARM_REG_SP];

   stack_section

     .D32(0x48c8dd5a)            // saved r1 (even though it's not callee-saves)

     .D32(0xcb78040e)            // no longer saved r4

     .D32(0x8112e110)            // saved fp

     .D32(0x40005510)            // return address

     .Mark(&frame1_sp);          // This effectively sets stack_section.start().

   raw_context.iregs[MD_CONTEXT_ARM_REG_PC] = 0x40004004;

   raw_context.iregs[1] = 0xfb756319; // distinct callee r1

   expected.iregs[1] = 0x48c8dd5a; // caller's r1

   expected_validity |= StackFrameARM::CONTEXT_VALID_R1;

   CheckWalk();

 }

 // Here we move the .cfa, but provide an explicit rule to recover the SP,

 // so again there should be no change in the registers recovered.

 TEST_F(CFI, At4005) {

   Label frame1_sp = expected.iregs[MD_CONTEXT_ARM_REG_SP];

   stack_section

     .D32(0x48c8dd5a)            // saved r1 (even though it's not callee-saves)

     .D32(0xf013f841)            // no longer saved r4

     .D32(0x8112e110)            // saved fp

     .D32(0x40005510)            // return address

     .Mark(&frame1_sp);          // This effectively sets stack_section.start().

   raw_context.iregs[MD_CONTEXT_ARM_REG_PC] = 0x40004005;

   raw_context.iregs[1] = 0xfb756319; // distinct callee r1

   expected.iregs[1] = 0x48c8dd5a; // caller's r1

   expected_validity |= StackFrameARM::CONTEXT_VALID_R1;

   CheckWalk();

 }

 // Here we provide an explicit rule for the PC, and have the saved .ra be

 // bogus.

 TEST_F(CFI, At4006) {

   Label frame1_sp = expected.iregs[MD_CONTEXT_ARM_REG_SP];

   stack_section

     .D32(0x40005510)            // saved pc

     .D32(0x48c8dd5a)            // saved r1 (even though it's not callee-saves)

     .D32(0xf013f841)            // no longer saved r4

     .D32(0x8112e110)            // saved fp

     .D32(0xf8d15783)            // .ra rule recovers this, which is garbage

     .Mark(&frame1_sp);          // This effectively sets stack_section.start().

   raw_context.iregs[MD_CONTEXT_ARM_REG_PC] = 0x40004006;

   raw_context.iregs[1] = 0xfb756319; // callee's r1, different from caller's

   expected.iregs[1] = 0x48c8dd5a; // caller's r1

   expected_validity |= StackFrameARM::CONTEXT_VALID_R1;

   CheckWalk();

 }

 // Check that we reject rules that would cause the stack pointer to

 // move in the wrong direction.

 TEST_F(CFI, RejectBackwards) {

   raw_context.iregs[MD_CONTEXT_ARM_REG_PC] = 0x40006000;

   raw_context.iregs[MD_CONTEXT_ARM_REG_SP] = 0x80000000;

   raw_context.iregs[MD_CONTEXT_ARM_REG_LR] = 0x40005510;

   StackFrameSymbolizer frame_symbolizer(&supplier, &resolver);

   StackwalkerARM walker(&system_info, &raw_context, -1, &stack_region, &modules,

                         &frame_symbolizer);

   vector<const CodeModule*> modules_without_symbols;

   ASSERT_TRUE(walker.Walk(&call_stack, &modules_without_symbols));

   ASSERT_EQ(0U, modules_without_symbols.size());

   frames = call_stack.frames();

   ASSERT_EQ(1U, frames->size());

 }

 // Check that we reject rules whose expressions' evaluation fails.

 TEST_F(CFI, RejectBadExpressions) {

   raw_context.iregs[MD_CONTEXT_ARM_REG_PC] = 0x40007000;

   raw_context.iregs[MD_CONTEXT_ARM_REG_SP] = 0x80000000;

   StackFrameSymbolizer frame_symbolizer(&supplier, &resolver);

   StackwalkerARM walker(&system_info, &raw_context, -1, &stack_region, &modules,

                         &frame_symbolizer);

   vector<const CodeModule*> modules_without_symbols;

   ASSERT_TRUE(walker.Walk(&call_stack, &modules_without_symbols));

   ASSERT_EQ(0U, modules_without_symbols.size());

   frames = call_stack.frames();

   ASSERT_EQ(1U, frames->size());

 }

 class StackwalkerARMFixtureIOS : public StackwalkerARMFixture {

  public:

   StackwalkerARMFixtureIOS() {

     system_info.os = "iOS";

     system_info.os_short = "ios";

   }

 };

 class GetFramesByFramePointer: public StackwalkerARMFixtureIOS, public Test { };

 TEST_F(GetFramesByFramePointer, OnlyFramePointer) {

   stack_section.start() = 0x80000000;

   uint32_t return_address1 = 0x50000100;

   uint32_t return_address2 = 0x50000900;

   Label frame1_sp, frame2_sp;

   Label frame1_fp, frame2_fp;

   stack_section

     // frame 0

     .Append(32, 0)           // Whatever values on the stack.

     .D32(0x0000000D)         // junk that's not

     .D32(0xF0000000)         // a return address.

     .Mark(&frame1_fp)        // Next fp will point to the next value.

     .D32(frame2_fp)          // Save current frame pointer.

     .D32(return_address2)    // Save current link register.

     .Mark(&frame1_sp)

     // frame 1

     .Append(32, 0)           // Whatever values on the stack.

     .D32(0x0000000D)         // junk that's not

     .D32(0xF0000000)         // a return address.

     .Mark(&frame2_fp)

     .D32(0)

     .D32(0)

     .Mark(&frame2_sp)

     // frame 2

     .Append(32, 0)           // Whatever values on the stack.

     .D32(0x0000000D)         // junk that's not

     .D32(0xF0000000);        // a return address.

   RegionFromSection();

   raw_context.iregs[MD_CONTEXT_ARM_REG_PC] = 0x40005510;

   raw_context.iregs[MD_CONTEXT_ARM_REG_LR] = return_address1;

   raw_context.iregs[MD_CONTEXT_ARM_REG_IOS_FP] = frame1_fp.Value();

   raw_context.iregs[MD_CONTEXT_ARM_REG_SP] = stack_section.start().Value();

   StackFrameSymbolizer frame_symbolizer(&supplier, &resolver);

   StackwalkerARM walker(&system_info, &raw_context, MD_CONTEXT_ARM_REG_IOS_FP,

                         &stack_region, &modules, &frame_symbolizer);

   vector<const CodeModule*> modules_without_symbols;

   ASSERT_TRUE(walker.Walk(&call_stack, &modules_without_symbols));

   ASSERT_EQ(2U, modules_without_symbols.size());

   ASSERT_EQ("module1", modules_without_symbols[0]->debug_file());

   ASSERT_EQ("module2", modules_without_symbols[1]->debug_file());

   frames = call_stack.frames();

   ASSERT_EQ(3U, frames->size());

   StackFrameARM *frame0 = static_cast<StackFrameARM *>(frames->at(0));

   EXPECT_EQ(StackFrame::FRAME_TRUST_CONTEXT, frame0->trust);

   ASSERT_EQ(StackFrameARM::CONTEXT_VALID_ALL, frame0->context_validity);

   EXPECT_EQ(0, memcmp(&raw_context, &frame0->context, sizeof(raw_context)));

   StackFrameARM *frame1 = static_cast<StackFrameARM *>(frames->at(1));

   EXPECT_EQ(StackFrame::FRAME_TRUST_FP, frame1->trust);

   ASSERT_EQ((StackFrameARM::CONTEXT_VALID_PC |

              StackFrameARM::CONTEXT_VALID_LR |

              StackFrameARM::RegisterValidFlag(MD_CONTEXT_ARM_REG_IOS_FP) |

              StackFrameARM::CONTEXT_VALID_SP),

             frame1->context_validity);

   EXPECT_EQ(return_address1, frame1->context.iregs[MD_CONTEXT_ARM_REG_PC]);

   EXPECT_EQ(return_address2, frame1->context.iregs[MD_CONTEXT_ARM_REG_LR]);

   EXPECT_EQ(frame1_sp.Value(), frame1->context.iregs[MD_CONTEXT_ARM_REG_SP]);

   EXPECT_EQ(frame2_fp.Value(),

             frame1->context.iregs[MD_CONTEXT_ARM_REG_IOS_FP]);

   StackFrameARM *frame2 = static_cast<StackFrameARM *>(frames->at(2));

   EXPECT_EQ(StackFrame::FRAME_TRUST_FP, frame2->trust);

   ASSERT_EQ((StackFrameARM::CONTEXT_VALID_PC |

              StackFrameARM::CONTEXT_VALID_LR |

              StackFrameARM::RegisterValidFlag(MD_CONTEXT_ARM_REG_IOS_FP) |

              StackFrameARM::CONTEXT_VALID_SP),

             frame2->context_validity);

   EXPECT_EQ(return_address2, frame2->context.iregs[MD_CONTEXT_ARM_REG_PC]);

   EXPECT_EQ(0U, frame2->context.iregs[MD_CONTEXT_ARM_REG_LR]);

   EXPECT_EQ(frame2_sp.Value(), frame2->context.iregs[MD_CONTEXT_ARM_REG_SP]);

   EXPECT_EQ(0U, frame2->context.iregs[MD_CONTEXT_ARM_REG_IOS_FP]);

 }

 TEST_F(GetFramesByFramePointer, FramePointerAndCFI) {

   // Provide the standatd STACK CFI records that is obtained when exmining an

   // executable produced by XCode.

   SetModuleSymbols(&module1,

                      // Adding a function in CFI.

                      "FUNC 4000 1000 10 enchiridion\n"

                      "STACK CFI INIT 4000 100 .cfa: sp 0 + .ra: lr\n"

                      "STACK CFI 4001 .cfa: sp 8 + .ra: .cfa -4 + ^"

                      " r7: .cfa -8 + ^\n"

                      "STACK CFI 4002 .cfa: r7 8 +\n"

                   );

   stack_section.start() = 0x80000000;

   uint32_t return_address1 = 0x40004010;

   uint32_t return_address2 = 0x50000900;

   Label frame1_sp, frame2_sp;

   Label frame1_fp, frame2_fp;

   stack_section

     // frame 0

     .Append(32, 0)           // Whatever values on the stack.

     .D32(0x0000000D)         // junk that's not

     .D32(0xF0000000)         // a return address.

     .Mark(&frame1_fp)        // Next fp will point to the next value.

     .D32(frame2_fp)          // Save current frame pointer.

     .D32(return_address2)    // Save current link register.

     .Mark(&frame1_sp)

     // frame 1

     .Append(32, 0)           // Whatever values on the stack.

     .D32(0x0000000D)         // junk that's not

     .D32(0xF0000000)         // a return address.

     .Mark(&frame2_fp)

     .D32(0)

     .D32(0)

     .Mark(&frame2_sp)

     // frame 2

     .Append(32, 0)           // Whatever values on the stack.

     .D32(0x0000000D)         // junk that's not

     .D32(0xF0000000);        // a return address.

   RegionFromSection();

   raw_context.iregs[MD_CONTEXT_ARM_REG_PC] = 0x50000400;

   raw_context.iregs[MD_CONTEXT_ARM_REG_LR] = return_address1;

   raw_context.iregs[MD_CONTEXT_ARM_REG_IOS_FP] = frame1_fp.Value();

   raw_context.iregs[MD_CONTEXT_ARM_REG_SP] = stack_section.start().Value();

   StackFrameSymbolizer frame_symbolizer(&supplier, &resolver);

   StackwalkerARM walker(&system_info, &raw_context, MD_CONTEXT_ARM_REG_IOS_FP,

                         &stack_region, &modules, &frame_symbolizer);

   vector<const CodeModule*> modules_without_symbols;

   ASSERT_TRUE(walker.Walk(&call_stack, &modules_without_symbols));

   ASSERT_EQ(1U, modules_without_symbols.size());

   ASSERT_EQ("module2", modules_without_symbols[0]->debug_file());

   frames = call_stack.frames();

   ASSERT_EQ(3U, frames->size());

   StackFrameARM *frame0 = static_cast<StackFrameARM *>(frames->at(0));

   EXPECT_EQ(StackFrame::FRAME_TRUST_CONTEXT, frame0->trust);

   ASSERT_EQ(StackFrameARM::CONTEXT_VALID_ALL, frame0->context_validity);

   EXPECT_EQ(0, memcmp(&raw_context, &frame0->context, sizeof(raw_context)));

   StackFrameARM *frame1 = static_cast<StackFrameARM *>(frames->at(1));

   EXPECT_EQ(StackFrame::FRAME_TRUST_FP, frame1->trust);

   ASSERT_EQ((StackFrameARM::CONTEXT_VALID_PC |

              StackFrameARM::CONTEXT_VALID_LR |

              StackFrameARM::RegisterValidFlag(MD_CONTEXT_ARM_REG_IOS_FP) |

              StackFrameARM::CONTEXT_VALID_SP),

             frame1->context_validity);

   EXPECT_EQ(return_address1, frame1->context.iregs[MD_CONTEXT_ARM_REG_PC]);

   EXPECT_EQ(return_address2, frame1->context.iregs[MD_CONTEXT_ARM_REG_LR]);

   EXPECT_EQ(frame1_sp.Value(), frame1->context.iregs[MD_CONTEXT_ARM_REG_SP]);

   EXPECT_EQ(frame2_fp.Value(),

             frame1->context.iregs[MD_CONTEXT_ARM_REG_IOS_FP]);

   EXPECT_EQ("enchiridion", frame1->function_name);

   EXPECT_EQ(0x40004000U, frame1->function_base);

   StackFrameARM *frame2 = static_cast<StackFrameARM *>(frames->at(2));

   EXPECT_EQ(StackFrame::FRAME_TRUST_CFI, frame2->trust);

   ASSERT_EQ((StackFrameARM::CONTEXT_VALID_PC |

              StackFrameARM::CONTEXT_VALID_LR |

              StackFrameARM::RegisterValidFlag(MD_CONTEXT_ARM_REG_IOS_FP) |

              StackFrameARM::CONTEXT_VALID_SP),

             frame2->context_validity);

   EXPECT_EQ(return_address2, frame2->context.iregs[MD_CONTEXT_ARM_REG_PC]);

   EXPECT_EQ(0U, frame2->context.iregs[MD_CONTEXT_ARM_REG_LR]);

   EXPECT_EQ(frame2_sp.Value(), frame2->context.iregs[MD_CONTEXT_ARM_REG_SP]);

   EXPECT_EQ(0U, frame2->context.iregs[MD_CONTEXT_ARM_REG_IOS_FP]);

 }