[FuncUnwinders] Use "symbol file" unwind plans for unwinding

Summary:
Previous patch (r360409) introduced the "symbol file unwind plan"
concept, but that plan wasn't used for unwinding yet. With this patch,
we start to consider the new plan as a possible strategy for both
synchronous and asynchronous unwinding. I also add a test that asserts
that unwinding via breakpad STACK CFI info works end-to-end.

Reviewers: jasonmolenda, clayborg

Subscribers: lldb-commits, amccarth, markmentovai

Differential Revision: https://reviews.llvm.org/D61853

llvm-svn: 361618

lldb/include/lldb/Symbol/FuncUnwinders.h

@@ -35,7 +35,7 @@ class FuncUnwinders {
 
   ~FuncUnwinders();
 
-  lldb::UnwindPlanSP GetUnwindPlanAtCallSite(Target &target);
+  lldb::UnwindPlanSP GetUnwindPlanAtCallSite(Target &target, Thread &thread);
 
   lldb::UnwindPlanSP GetUnwindPlanAtNonCallSite(Target &target,
                                                 lldb_private::Thread &thread);

lldb/lit/SymbolFile/Breakpad/Inputs/unwind-via-stack-cfi.syms

@@ -0,0 +1,6 @@
+MODULE Linux x86_64 603FCF6CA7FF4BCC86AE8FF44DB2576A0 linux-x86_64_not_crashed
+INFO CODE_ID 6CCF3F60FFA7CC4B86AE8FF44DB2576A68983611
+PUBLIC 420 0 bar
+PUBLIC 450 0 foo
+PUBLIC 480 0 _start
+STACK CFI INIT 420 29 .cfa: $rbp ^ .ra: .cfa 8 + ^ $rsp: .cfa 16 + $rbp: .cfa ^

lldb/lit/SymbolFile/Breakpad/Inputs/unwind-via-stack-cfi.yaml

@@ -0,0 +1,43 @@
+--- !minidump
+Streams:         
+  - Type:            ThreadList
+    Threads:         
+      - Thread Id:       0x000074F3
+        Context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
+        Stack:           
+          Start of Memory Range: 0x00007FFD4BC15080
+          Content:         30044000000000000000000000000000FFFFFFFF03000000B850C14BFD7F0000670440000000000000000000000000000000000001000000D850C14BFD7F0000970440000000000000000000000000000000000000000000000000000000000001000000000000009F67C14BFD7F00000000000000000000BA67C14BFD7F0000
+  - Type:            ModuleList
+    Modules:         
+      - Base of Image:   0x0000000000400000
+        Size of Image:   0x00001000
+        Module Name:     '/tmp/unwind-via-stack-cfi'
+        CodeView Record: 4C4570426CCF3F60FFA7CC4B86AE8FF44DB2576A68983611
+  - Type:            MemoryList
+    Memory Ranges:   
+      - Start of Memory Range: 0x00007FFD4BC15080
+        Content:         30044000000000000000000000000000FFFFFFFF03000000B850C14BFD7F0000670440000000000000000000000000000000000001000000D850C14BFD7F0000970440000000000000000000000000000000000000000000000000000000000001000000000000009F67C14BFD7F00000000000000000000BA67C14BFD7F0000
+  - Type:            SystemInfo
+    Processor Arch:  AMD64
+    Processor Level: 6
+    Processor Revision: 15876
+    Number of Processors: 40
+    Platform ID:     Linux
+    CSD Version:     'Linux 3.13.0-91-generic'
+    CPU:             
+      Vendor ID:       GenuineIntel
+      Version Info:    0x00000000
+      Feature Info:    0x00000000
+  - Type:            LinuxProcStatus
+    Text:             |
+      Name:	unwind-via-stack-cfi
+      State:	t (tracing stop)
+      Tgid:	29939
+      Ngid:	0
+      Pid:	29939
+      PPid:	29370
+      TracerPid:	29940
+      Uid:	1001	1001	1001	1001
+      Gid:	1001	1001	1001	1001
+
+...

lldb/lit/SymbolFile/Breakpad/stack-cfi-parsing.test

@@ -4,6 +4,8 @@
 
 image show-unwind -n func0
 # CHECK-LABEL: image show-unwind -n func0
+# CHECK: Asynchronous (not restricted to call-sites) UnwindPlan is 'breakpad STACK CFI'
+# CHECK: Synchronous (restricted to call-sites) UnwindPlan is 'breakpad STACK CFI'
 # CHECK:      Symbol file UnwindPlan:
 # CHECK-NEXT: This UnwindPlan originally sourced from breakpad STACK CFI
 # CHECK-NEXT: This UnwindPlan is sourced from the compiler: yes.
@@ -42,6 +44,8 @@ image show-unwind -n func7
 # Finally, try an unwind plan with just a single row
 image show-unwind -n func9
 # CHECK-LABEL: image show-unwind -n func9
+# CHECK: Asynchronous (not restricted to call-sites) UnwindPlan is 'breakpad STACK CFI'
+# CHECK: Synchronous (restricted to call-sites) UnwindPlan is 'breakpad STACK CFI'
 # CHECK: Symbol file UnwindPlan:
 # CHECK: Address range of this UnwindPlan: [stack-cfi-parsing.out..module_image + 9-0x000000000000000a)
 # CHECK: row[0]:    0: CFA=DW_OP_breg6 +0 => rip=DW_OP_breg0 +0

lldb/lit/SymbolFile/Breakpad/unwind-via-stack-cfi.test

@@ -0,0 +1,20 @@
+# RUN: yaml2obj %S/Inputs/unwind-via-stack-cfi.yaml > %t
+# RUN: %lldb -c %t -o "target symbols add %S/Inputs/unwind-via-stack-cfi.syms" \
+# RUN:   -s %s -b | FileCheck %s
+
+image show-unwind -n bar
+# CHECK-LABEL: image show-unwind -n bar
+# CHECK: Asynchronous (not restricted to call-sites) UnwindPlan is 'breakpad STACK CFI'
+# CHECK: Synchronous (restricted to call-sites) UnwindPlan is 'breakpad STACK CFI'
+# CHECK:      Symbol file UnwindPlan:
+# CHECK-NEXT: This UnwindPlan originally sourced from breakpad STACK CFI
+# CHECK-NEXT: This UnwindPlan is sourced from the compiler: yes.
+# CHECK-NEXT: This UnwindPlan is valid at all instruction locations: no.
+# CHECK-NEXT: Address range of this UnwindPlan: [unwind-via-stack-cfi..module_image + 1056-0x0000000000000449)
+# CHECK-NEXT: row[0]: 0: CFA=DW_OP_breg6 +0, DW_OP_deref => rbp=DW_OP_pick 0x00, DW_OP_deref rsp=DW_OP_pick 0x00, DW_OP_consts +16, DW_OP_plus rip=DW_OP_pick 0x00, DW_OP_consts +8, DW_OP_plus , DW_OP_deref
+
+thread backtrace
+# CHECK-LABEL: thread backtrace
+# CHECK: frame #0: 0x0000000000400430 unwind-via-stack-cfi`bar + 16
+# CHECK: frame #1: 0x0000000000400497 unwind-via-stack-cfi`_start + 23
+# CHECK-NOT: frame

lldb/source/Commands/CommandObjectTarget.cpp

@@ -3521,7 +3521,7 @@ class CommandObjectTargetModulesShowUnwind : public CommandObjectParsed {
             non_callsite_unwind_plan->GetSourceName().AsCString());
       }
       UnwindPlanSP callsite_unwind_plan =
-          func_unwinders_sp->GetUnwindPlanAtCallSite(*target);
+          func_unwinders_sp->GetUnwindPlanAtCallSite(*target, *thread);
       if (callsite_unwind_plan) {
         result.GetOutputStream().Printf(
             "Synchronous (restricted to call-sites) UnwindPlan is '%s'\n",

lldb/source/Plugins/Process/Utility/RegisterContextLLDB.cpp

@@ -244,8 +244,8 @@ void RegisterContextLLDB::InitializeZerothFrame() {
     }
 
     if (func_unwinders_sp.get() != nullptr)
-      call_site_unwind_plan =
-          func_unwinders_sp->GetUnwindPlanAtCallSite(process->GetTarget());
+      call_site_unwind_plan = func_unwinders_sp->GetUnwindPlanAtCallSite(
+          process->GetTarget(), m_thread);
 
     if (call_site_unwind_plan.get() != nullptr) {
       m_fallback_unwind_plan_sp = call_site_unwind_plan;
@@ -873,7 +873,8 @@ UnwindPlanSP RegisterContextLLDB::GetFullUnwindPlanForFrame() {
         // location what helps in the most common cases when the instruction
         // emulation fails.
         UnwindPlanSP call_site_unwind_plan =
-            func_unwinders_sp->GetUnwindPlanAtCallSite(process->GetTarget());
+            func_unwinders_sp->GetUnwindPlanAtCallSite(process->GetTarget(),
+                                                       m_thread);
         if (call_site_unwind_plan &&
             call_site_unwind_plan.get() != unwind_plan_sp.get() &&
             call_site_unwind_plan->GetSourceName() !=
@@ -909,8 +910,8 @@ UnwindPlanSP RegisterContextLLDB::GetFullUnwindPlanForFrame() {
   // Typically this is unwind info from an eh_frame section intended for
   // exception handling; only valid at call sites
   if (process) {
-    unwind_plan_sp =
-        func_unwinders_sp->GetUnwindPlanAtCallSite(process->GetTarget());
+    unwind_plan_sp = func_unwinders_sp->GetUnwindPlanAtCallSite(
+        process->GetTarget(), m_thread);
   }
   int valid_offset = -1;
   if (IsUnwindPlanValidForCurrentPC(unwind_plan_sp, valid_offset)) {
@@ -940,7 +941,8 @@ UnwindPlanSP RegisterContextLLDB::GetFullUnwindPlanForFrame() {
     // code it is often written in a way that it valid at all location what
     // helps in the most common cases when the instruction emulation fails.
     UnwindPlanSP call_site_unwind_plan =
-        func_unwinders_sp->GetUnwindPlanAtCallSite(process->GetTarget());
+        func_unwinders_sp->GetUnwindPlanAtCallSite(process->GetTarget(),
+                                                   m_thread);
     if (call_site_unwind_plan &&
         call_site_unwind_plan.get() != unwind_plan_sp.get() &&
         call_site_unwind_plan->GetSourceName() !=

lldb/source/Symbol/FuncUnwinders.cpp

@@ -54,9 +54,12 @@ FuncUnwinders::FuncUnwinders(UnwindTable &unwind_table, AddressRange range)
 
 FuncUnwinders::~FuncUnwinders() {}
 
-UnwindPlanSP FuncUnwinders::GetUnwindPlanAtCallSite(Target &target) {
+UnwindPlanSP FuncUnwinders::GetUnwindPlanAtCallSite(Target &target,
+                                                    Thread &thread) {
   std::lock_guard<std::recursive_mutex> guard(m_mutex);
 
+  if (UnwindPlanSP plan_sp = GetSymbolFileUnwindPlan(thread))
+    return plan_sp;
   if (UnwindPlanSP plan_sp = GetEHFrameUnwindPlan(target))
     return plan_sp;
   if (UnwindPlanSP plan_sp = GetDebugFrameUnwindPlan(target))
@@ -357,6 +360,8 @@ UnwindPlanSP FuncUnwinders::GetUnwindPlanAtNonCallSite(Target &target,
     return eh_frame_sp;
   }
 
+  if (UnwindPlanSP plan_sp = GetSymbolFileUnwindPlan(thread))
+    return plan_sp;
   if (UnwindPlanSP plan_sp = GetEHFrameAugmentedUnwindPlan(target, thread))
     return plan_sp;
   if (UnwindPlanSP plan_sp = GetDebugFrameAugmentedUnwindPlan(target, thread))