vsk created this revision.
vsk added reviewers: jasonmolenda, ab.
DisassemblerLLVMC exposes a few MCInst predicates (e.g. `HasDelaySlot`).
Group the logic for evaluating the existing predicates together, to prep
for adding new ones.
This is NFC-ish: with this change, the existing predicates will return
the conservative defaults when the disassembler is unavailable instead
of false, but I'm not sure that really matters.
https://reviews.llvm.org/D69210
Files:
lldb/source/Plugins/Disassembler/llvm/DisassemblerLLVMC.cpp
Index: lldb/source/Plugins/Disassembler/llvm/DisassemblerLLVMC.cpp
===================================================================
--- lldb/source/Plugins/Disassembler/llvm/DisassemblerLLVMC.cpp
+++ lldb/source/Plugins/Disassembler/llvm/DisassemblerLLVMC.cpp
@@ -78,6 +78,42 @@
};
class InstructionLLVMC : public lldb_private::Instruction {
+private:
+ void VisitInstruction() {
+ // Be conservative. If we didn't understand the instruction, say it:
+ // - Might branch
+ // - Does not have a delay slot
+ // - Is not a call
+ m_does_branch = eLazyBoolYes;
+ m_has_delay_slot = eLazyBoolNo;
+ m_is_call = eLazyBoolNo;
+
+ DisassemblerScope disasm(*this);
+ if (!disasm)
+ return;
+
+ DataExtractor data;
+ if (!m_opcode.GetData(data))
+ return;
+
+ bool is_alternate_isa;
+ lldb::addr_t pc = m_address.GetFileAddress();
+ DisassemblerLLVMC::MCDisasmInstance *mc_disasm_ptr =
+ GetDisasmToUse(is_alternate_isa, disasm);
+ const uint8_t *opcode_data = data.GetDataStart();
+ const size_t opcode_data_len = data.GetByteSize();
+ llvm::MCInst inst;
+ const size_t inst_size =
+ mc_disasm_ptr->GetMCInst(opcode_data, opcode_data_len, pc, inst);
+ if (inst_size == 0)
+ return;
+
+ m_does_branch = mc_disasm_ptr->CanBranch(inst) ? eLazyBoolYes : eLazyBoolNo;
+ m_has_delay_slot =
+ mc_disasm_ptr->HasDelaySlot(inst) ? eLazyBoolYes : eLazyBoolNo;
+ m_is_call = mc_disasm_ptr->IsCall(inst) ? eLazyBoolYes : eLazyBoolNo;
+ }
+
public:
InstructionLLVMC(DisassemblerLLVMC &disasm,
const lldb_private::Address &address,
@@ -92,68 +128,14 @@
~InstructionLLVMC() override = default;
bool DoesBranch() override {
- if (m_does_branch == eLazyBoolCalculate) {
- DisassemblerScope disasm(*this);
- if (disasm) {
- DataExtractor data;
- if (m_opcode.GetData(data)) {
- bool is_alternate_isa;
- lldb::addr_t pc = m_address.GetFileAddress();
-
- DisassemblerLLVMC::MCDisasmInstance *mc_disasm_ptr =
- GetDisasmToUse(is_alternate_isa, disasm);
- const uint8_t *opcode_data = data.GetDataStart();
- const size_t opcode_data_len = data.GetByteSize();
- llvm::MCInst inst;
- const size_t inst_size =
- mc_disasm_ptr->GetMCInst(opcode_data, opcode_data_len, pc, inst);
- // Be conservative, if we didn't understand the instruction, say it
- // might branch...
- if (inst_size == 0)
- m_does_branch = eLazyBoolYes;
- else {
- const bool can_branch = mc_disasm_ptr->CanBranch(inst);
- if (can_branch)
- m_does_branch = eLazyBoolYes;
- else
- m_does_branch = eLazyBoolNo;
- }
- }
- }
- }
+ if (m_does_branch == eLazyBoolCalculate)
+ VisitInstruction();
return m_does_branch == eLazyBoolYes;
}
bool HasDelaySlot() override {
- if (m_has_delay_slot == eLazyBoolCalculate) {
- DisassemblerScope disasm(*this);
- if (disasm) {
- DataExtractor data;
- if (m_opcode.GetData(data)) {
- bool is_alternate_isa;
- lldb::addr_t pc = m_address.GetFileAddress();
-
- DisassemblerLLVMC::MCDisasmInstance *mc_disasm_ptr =
- GetDisasmToUse(is_alternate_isa, disasm);
- const uint8_t *opcode_data = data.GetDataStart();
- const size_t opcode_data_len = data.GetByteSize();
- llvm::MCInst inst;
- const size_t inst_size =
- mc_disasm_ptr->GetMCInst(opcode_data, opcode_data_len, pc, inst);
- // if we didn't understand the instruction, say it doesn't have a
- // delay slot...
- if (inst_size == 0)
- m_has_delay_slot = eLazyBoolNo;
- else {
- const bool has_delay_slot = mc_disasm_ptr->HasDelaySlot(inst);
- if (has_delay_slot)
- m_has_delay_slot = eLazyBoolYes;
- else
- m_has_delay_slot = eLazyBoolNo;
- }
- }
- }
- }
+ if (m_has_delay_slot == eLazyBoolCalculate)
+ VisitInstruction();
return m_has_delay_slot == eLazyBoolYes;
}
@@ -865,32 +847,8 @@
}
bool IsCall() override {
- if (m_is_call == eLazyBoolCalculate) {
- DisassemblerScope disasm(*this);
- if (disasm) {
- DataExtractor data;
- if (m_opcode.GetData(data)) {
- bool is_alternate_isa;
- lldb::addr_t pc = m_address.GetFileAddress();
-
- DisassemblerLLVMC::MCDisasmInstance *mc_disasm_ptr =
- GetDisasmToUse(is_alternate_isa, disasm);
- const uint8_t *opcode_data = data.GetDataStart();
- const size_t opcode_data_len = data.GetByteSize();
- llvm::MCInst inst;
- const size_t inst_size =
- mc_disasm_ptr->GetMCInst(opcode_data, opcode_data_len, pc, inst);
- if (inst_size == 0) {
- m_is_call = eLazyBoolNo;
- } else {
- if (mc_disasm_ptr->IsCall(inst))
- m_is_call = eLazyBoolYes;
- else
- m_is_call = eLazyBoolNo;
- }
- }
- }
- }
+ if (m_is_call == eLazyBoolCalculate)
+ VisitInstruction();
return m_is_call == eLazyBoolYes;
}
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