llvmbot wrote:
<!--LLVM PR SUMMARY COMMENT--> @llvm/pr-subscribers-lldb Author: None (jimingham) <details> <summary>Changes</summary> Reapply the support for stepping through branch islands, add support for a branch that takes multiple hops to get to the target. --- Full diff: https://github.com/llvm/llvm-project/pull/138781.diff 9 Files Affected: - (modified) lldb/source/Plugins/DynamicLoader/MacOSX-DYLD/DynamicLoaderDarwin.cpp (+25-7) - (added) lldb/test/API/macosx/branch-islands/Makefile (+16) - (added) lldb/test/API/macosx/branch-islands/TestBranchIslands.py (+35) - (added) lldb/test/API/macosx/branch-islands/foo.c (+6) - (added) lldb/test/API/macosx/branch-islands/main.c (+6) - (added) lldb/test/API/macosx/branch-islands/padding1.s (+3) - (added) lldb/test/API/macosx/branch-islands/padding2.s (+3) - (added) lldb/test/API/macosx/branch-islands/padding3.s (+3) - (added) lldb/test/API/macosx/branch-islands/padding4.s (+3) ``````````diff diff --git a/lldb/source/Plugins/DynamicLoader/MacOSX-DYLD/DynamicLoaderDarwin.cpp b/lldb/source/Plugins/DynamicLoader/MacOSX-DYLD/DynamicLoaderDarwin.cpp index e25c4ff55e408..ad3b63cf59135 100644 --- a/lldb/source/Plugins/DynamicLoader/MacOSX-DYLD/DynamicLoaderDarwin.cpp +++ b/lldb/source/Plugins/DynamicLoader/MacOSX-DYLD/DynamicLoaderDarwin.cpp @@ -26,6 +26,7 @@ #include "lldb/Target/Thread.h" #include "lldb/Target/ThreadPlanCallFunction.h" #include "lldb/Target/ThreadPlanRunToAddress.h" +#include "lldb/Target/ThreadPlanStepInstruction.h" #include "lldb/Utility/DataBuffer.h" #include "lldb/Utility/DataBufferHeap.h" #include "lldb/Utility/LLDBLog.h" @@ -923,15 +924,15 @@ DynamicLoaderDarwin::GetStepThroughTrampolinePlan(Thread &thread, if (current_symbol != nullptr) { std::vector<Address> addresses; + ConstString current_name = + current_symbol->GetMangled().GetName(Mangled::ePreferMangled); if (current_symbol->IsTrampoline()) { - ConstString trampoline_name = - current_symbol->GetMangled().GetName(Mangled::ePreferMangled); - if (trampoline_name) { + if (current_name) { const ModuleList &images = target_sp->GetImages(); SymbolContextList code_symbols; - images.FindSymbolsWithNameAndType(trampoline_name, eSymbolTypeCode, + images.FindSymbolsWithNameAndType(current_name, eSymbolTypeCode, code_symbols); for (const SymbolContext &context : code_symbols) { Address addr = context.GetFunctionOrSymbolAddress(); @@ -945,8 +946,8 @@ DynamicLoaderDarwin::GetStepThroughTrampolinePlan(Thread &thread, } SymbolContextList reexported_symbols; - images.FindSymbolsWithNameAndType( - trampoline_name, eSymbolTypeReExported, reexported_symbols); + images.FindSymbolsWithNameAndType(current_name, eSymbolTypeReExported, + reexported_symbols); for (const SymbolContext &context : reexported_symbols) { if (context.symbol) { Symbol *actual_symbol = @@ -968,7 +969,7 @@ DynamicLoaderDarwin::GetStepThroughTrampolinePlan(Thread &thread, } SymbolContextList indirect_symbols; - images.FindSymbolsWithNameAndType(trampoline_name, eSymbolTypeResolver, + images.FindSymbolsWithNameAndType(current_name, eSymbolTypeResolver, indirect_symbols); for (const SymbolContext &context : indirect_symbols) { @@ -1028,6 +1029,23 @@ DynamicLoaderDarwin::GetStepThroughTrampolinePlan(Thread &thread, thread_plan_sp = std::make_shared<ThreadPlanRunToAddress>( thread, load_addrs, stop_others); } + // One more case we have to consider is "branch islands". These are regular + // TEXT symbols but their names end in .island plus maybe a .digit suffix. + // They are to allow arm64 code to branch further than the size of the + // address slot allows. We just need to single-instruction step in that + // case. + static const char *g_branch_island_pattern = "\\.island\\.?[0-9]*$"; + static RegularExpression g_branch_island_regex(g_branch_island_pattern); + + bool is_branch_island = g_branch_island_regex.Execute(current_name); + if (!thread_plan_sp && is_branch_island) { + thread_plan_sp = std::make_shared<ThreadPlanStepInstruction>( + thread, + /* step_over= */ false, /* stop_others */ false, eVoteNoOpinion, + eVoteNoOpinion); + LLDB_LOG(log, "Stepping one instruction over branch island: '{0}'.", + current_name); + } } else { LLDB_LOGF(log, "Could not find symbol for step through."); } diff --git a/lldb/test/API/macosx/branch-islands/Makefile b/lldb/test/API/macosx/branch-islands/Makefile new file mode 100644 index 0000000000000..062e947f6d6ee --- /dev/null +++ b/lldb/test/API/macosx/branch-islands/Makefile @@ -0,0 +1,16 @@ +C_SOURCES := main.c foo.c +CFLAGS_EXTRAS := -std=c99 + +include Makefile.rules + +a.out: main.o padding1.o padding2.o padding3.o padding4.o foo.o + ${CC} ${LDFLAGS} foo.o padding1.o padding2.o padding3.o padding4.o main.o -o a.out + +%.o: $(SRCDIR)/%.s + ${CC} -c $< + +#padding1.o: padding1.s +# ${CC} -c $(SRCDIR)/padding1.s + +#padding2.o: padding2.s +# ${CC} -c $(SRCDIR)/padding2.s diff --git a/lldb/test/API/macosx/branch-islands/TestBranchIslands.py b/lldb/test/API/macosx/branch-islands/TestBranchIslands.py new file mode 100644 index 0000000000000..b397e0c229b08 --- /dev/null +++ b/lldb/test/API/macosx/branch-islands/TestBranchIslands.py @@ -0,0 +1,35 @@ +""" +Make sure that we can step in across an arm64 branch island +""" + + +import lldb +import lldbsuite.test.lldbutil as lldbutil +from lldbsuite.test.lldbtest import * +from lldbsuite.test.decorators import * + + +class TestBranchIslandStepping(TestBase): + NO_DEBUG_INFO_TESTCASE = True + + @skipUnlessDarwin + def test_step_in_branch_island(self): + """Make sure we can step in across a branch island""" + self.build() + self.main_source_file = lldb.SBFileSpec("main.c") + self.do_test() + + def do_test(self): + (target, process, thread, bkpt) = lldbutil.run_to_source_breakpoint( + self, "Set a breakpoint here", self.main_source_file + ) + + # Make sure that we did manage to generate a branch island for foo: + syms = target.FindSymbols("foo.island", lldb.eSymbolTypeCode) + self.assertEqual(len(syms), 1, "We did generate an island for foo") + + thread.StepInto() + stop_frame = thread.frames[0] + self.assertIn("foo", stop_frame.name, "Stepped into foo") + var = stop_frame.FindVariable("a_variable_in_foo") + self.assertTrue(var.IsValid(), "Found the variable in foo") diff --git a/lldb/test/API/macosx/branch-islands/foo.c b/lldb/test/API/macosx/branch-islands/foo.c new file mode 100644 index 0000000000000..a5dd2e59e1d82 --- /dev/null +++ b/lldb/test/API/macosx/branch-islands/foo.c @@ -0,0 +1,6 @@ +#include <stdio.h> + +void foo() { + int a_variable_in_foo = 10; + printf("I am foo: %d.\n", a_variable_in_foo); +} diff --git a/lldb/test/API/macosx/branch-islands/main.c b/lldb/test/API/macosx/branch-islands/main.c new file mode 100644 index 0000000000000..b5578bdd715df --- /dev/null +++ b/lldb/test/API/macosx/branch-islands/main.c @@ -0,0 +1,6 @@ +extern void foo(); + +int main() { + foo(); // Set a breakpoint here + return 0; +} diff --git a/lldb/test/API/macosx/branch-islands/padding1.s b/lldb/test/API/macosx/branch-islands/padding1.s new file mode 100644 index 0000000000000..4911e53b0240d --- /dev/null +++ b/lldb/test/API/macosx/branch-islands/padding1.s @@ -0,0 +1,3 @@ +.text +_padding1: +.space 120*1024*1024 diff --git a/lldb/test/API/macosx/branch-islands/padding2.s b/lldb/test/API/macosx/branch-islands/padding2.s new file mode 100644 index 0000000000000..5ad1bad11263b --- /dev/null +++ b/lldb/test/API/macosx/branch-islands/padding2.s @@ -0,0 +1,3 @@ +.text +_padding2: +.space 120*1024*1024 diff --git a/lldb/test/API/macosx/branch-islands/padding3.s b/lldb/test/API/macosx/branch-islands/padding3.s new file mode 100644 index 0000000000000..9f614eecf56d9 --- /dev/null +++ b/lldb/test/API/macosx/branch-islands/padding3.s @@ -0,0 +1,3 @@ +.text +_padding3: +.space 120*1024*1024 diff --git a/lldb/test/API/macosx/branch-islands/padding4.s b/lldb/test/API/macosx/branch-islands/padding4.s new file mode 100644 index 0000000000000..12896cf5e5b8e --- /dev/null +++ b/lldb/test/API/macosx/branch-islands/padding4.s @@ -0,0 +1,3 @@ +.text +_padding4: +.space 120*1024*1024 `````````` </details> https://github.com/llvm/llvm-project/pull/138781 _______________________________________________ lldb-commits mailing list lldb-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/lldb-commits
