[Lldb-commits] [lldb] [llvm] [lldb] Encode operands and arity in Dwarf.def and use them in LLDB. (PR #94679)
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Thu Jun 6 13:40:05 PDT 2024
llvmbot wrote:
<!--LLVM PR SUMMARY COMMENT-->
@llvm/pr-subscribers-objectyaml
Author: Jonas Devlieghere (JDevlieghere)
<details>
<summary>Changes</summary>
This PR extends Dwarf.def to include the number of operands and the arity (the number of entries on the DWARF stack) and use it from the LLDB DWARF expression evaluator.
---
Patch is 42.88 KiB, truncated to 20.00 KiB below, full version: https://github.com/llvm/llvm-project/pull/94679.diff
5 Files Affected:
- (modified) lldb/source/Expression/DWARFExpression.cpp (+126-249)
- (modified) llvm/include/llvm/BinaryFormat/Dwarf.def (+182-182)
- (modified) llvm/include/llvm/BinaryFormat/Dwarf.h (+10-1)
- (modified) llvm/include/llvm/ObjectYAML/DWARFYAML.h (+1-1)
- (modified) llvm/lib/BinaryFormat/Dwarf.cpp (+30-4)
``````````diff
diff --git a/lldb/source/Expression/DWARFExpression.cpp b/lldb/source/Expression/DWARFExpression.cpp
index 4681dbafb6f9c..b10c3d4ac5ad9 100644
--- a/lldb/source/Expression/DWARFExpression.cpp
+++ b/lldb/source/Expression/DWARFExpression.cpp
@@ -912,6 +912,14 @@ llvm::Expected<Value> DWARFExpression::Evaluate(
DW_OP_value_to_name(op));
}
+ if (std::optional<unsigned> arity =
+ llvm::dwarf::OperationArity(static_cast<LocationAtom>(op))) {
+ if (stack.size() < *arity)
+ return llvm::createStringError(
+ "%s needs at least %d stack entries (stack has %d entries)",
+ DW_OP_value_to_name(op), *arity, stack.size());
+ }
+
switch (op) {
// The DW_OP_addr operation has a single operand that encodes a machine
// address and whose size is the size of an address on the target machine.
@@ -1280,11 +1288,7 @@ llvm::Expected<Value> DWARFExpression::Evaluate(
// DESCRIPTION: Duplicates the entry currently second in the stack at
// the top of the stack.
case DW_OP_over:
- if (stack.size() < 2) {
- return llvm::createStringError(
- "expression stack needs at least 2 items for DW_OP_over");
- } else
- stack.push_back(stack[stack.size() - 2]);
+ stack.push_back(stack[stack.size() - 2]);
break;
// OPCODE: DW_OP_pick
@@ -1307,14 +1311,9 @@ llvm::Expected<Value> DWARFExpression::Evaluate(
// of the stack becomes the second stack entry, and the second entry
// becomes the top of the stack
case DW_OP_swap:
- if (stack.size() < 2) {
- return llvm::createStringError(
- "expression stack needs at least 2 items for DW_OP_swap");
- } else {
- tmp = stack.back();
- stack.back() = stack[stack.size() - 2];
- stack[stack.size() - 2] = tmp;
- }
+ tmp = stack.back();
+ stack.back() = stack[stack.size() - 2];
+ stack[stack.size() - 2] = tmp;
break;
// OPCODE: DW_OP_rot
@@ -1323,18 +1322,13 @@ llvm::Expected<Value> DWARFExpression::Evaluate(
// the top of the stack becomes the third stack entry, the second entry
// becomes the top of the stack, and the third entry becomes the second
// entry.
- case DW_OP_rot:
- if (stack.size() < 3) {
- return llvm::createStringError(
- "expression stack needs at least 3 items for DW_OP_rot");
- } else {
- size_t last_idx = stack.size() - 1;
- Value old_top = stack[last_idx];
- stack[last_idx] = stack[last_idx - 1];
- stack[last_idx - 1] = stack[last_idx - 2];
- stack[last_idx - 2] = old_top;
- }
- break;
+ case DW_OP_rot: {
+ size_t last_idx = stack.size() - 1;
+ Value old_top = stack[last_idx];
+ stack[last_idx] = stack[last_idx - 1];
+ stack[last_idx - 1] = stack[last_idx - 2];
+ stack[last_idx - 2] = old_top;
+ } break;
// OPCODE: DW_OP_abs
// OPERANDS: none
@@ -1342,10 +1336,7 @@ llvm::Expected<Value> DWARFExpression::Evaluate(
// value and pushes its absolute value. If the absolute value can not be
// represented, the result is undefined.
case DW_OP_abs:
- if (stack.empty()) {
- return llvm::createStringError(
- "expression stack needs at least 1 item for DW_OP_abs");
- } else if (!stack.back().ResolveValue(exe_ctx).AbsoluteValue()) {
+ if (!stack.back().ResolveValue(exe_ctx).AbsoluteValue()) {
return llvm::createStringError(
"failed to take the absolute value of the first stack item");
}
@@ -1356,15 +1347,10 @@ llvm::Expected<Value> DWARFExpression::Evaluate(
// DESCRIPTION: pops the top two stack values, performs a bitwise and
// operation on the two, and pushes the result.
case DW_OP_and:
- if (stack.size() < 2) {
- return llvm::createStringError(
- "expression stack needs at least 2 items for DW_OP_and");
- } else {
- tmp = stack.back();
- stack.pop_back();
- stack.back().ResolveValue(exe_ctx) =
- stack.back().ResolveValue(exe_ctx) & tmp.ResolveValue(exe_ctx);
- }
+ tmp = stack.back();
+ stack.pop_back();
+ stack.back().ResolveValue(exe_ctx) =
+ stack.back().ResolveValue(exe_ctx) & tmp.ResolveValue(exe_ctx);
break;
// OPCODE: DW_OP_div
@@ -1372,42 +1358,32 @@ llvm::Expected<Value> DWARFExpression::Evaluate(
// DESCRIPTION: pops the top two stack values, divides the former second
// entry by the former top of the stack using signed division, and pushes
// the result.
- case DW_OP_div:
- if (stack.size() < 2) {
- return llvm::createStringError(
- "expression stack needs at least 2 items for DW_OP_div");
- } else {
- tmp = stack.back();
- if (tmp.ResolveValue(exe_ctx).IsZero())
- return llvm::createStringError("divide by zero");
-
- stack.pop_back();
- Scalar divisor, dividend;
- divisor = tmp.ResolveValue(exe_ctx);
- dividend = stack.back().ResolveValue(exe_ctx);
- divisor.MakeSigned();
- dividend.MakeSigned();
- stack.back() = dividend / divisor;
-
- if (!stack.back().ResolveValue(exe_ctx).IsValid())
- return llvm::createStringError("divide failed");
- }
- break;
+ case DW_OP_div: {
+ tmp = stack.back();
+ if (tmp.ResolveValue(exe_ctx).IsZero())
+ return llvm::createStringError("divide by zero");
+
+ stack.pop_back();
+ Scalar divisor, dividend;
+ divisor = tmp.ResolveValue(exe_ctx);
+ dividend = stack.back().ResolveValue(exe_ctx);
+ divisor.MakeSigned();
+ dividend.MakeSigned();
+ stack.back() = dividend / divisor;
+
+ if (!stack.back().ResolveValue(exe_ctx).IsValid())
+ return llvm::createStringError("divide failed");
+ } break;
// OPCODE: DW_OP_minus
// OPERANDS: none
// DESCRIPTION: pops the top two stack values, subtracts the former top
// of the stack from the former second entry, and pushes the result.
case DW_OP_minus:
- if (stack.size() < 2) {
- return llvm::createStringError(
- "expression stack needs at least 2 items for DW_OP_minus");
- } else {
- tmp = stack.back();
- stack.pop_back();
- stack.back().ResolveValue(exe_ctx) =
- stack.back().ResolveValue(exe_ctx) - tmp.ResolveValue(exe_ctx);
- }
+ tmp = stack.back();
+ stack.pop_back();
+ stack.back().ResolveValue(exe_ctx) =
+ stack.back().ResolveValue(exe_ctx) - tmp.ResolveValue(exe_ctx);
break;
// OPCODE: DW_OP_mod
@@ -1416,15 +1392,10 @@ llvm::Expected<Value> DWARFExpression::Evaluate(
// the calculation: former second stack entry modulo the former top of the
// stack.
case DW_OP_mod:
- if (stack.size() < 2) {
- return llvm::createStringError(
- "expression stack needs at least 2 items for DW_OP_mod");
- } else {
- tmp = stack.back();
- stack.pop_back();
- stack.back().ResolveValue(exe_ctx) =
- stack.back().ResolveValue(exe_ctx) % tmp.ResolveValue(exe_ctx);
- }
+ tmp = stack.back();
+ stack.pop_back();
+ stack.back().ResolveValue(exe_ctx) =
+ stack.back().ResolveValue(exe_ctx) % tmp.ResolveValue(exe_ctx);
break;
// OPCODE: DW_OP_mul
@@ -1432,28 +1403,18 @@ llvm::Expected<Value> DWARFExpression::Evaluate(
// DESCRIPTION: pops the top two stack entries, multiplies them
// together, and pushes the result.
case DW_OP_mul:
- if (stack.size() < 2) {
- return llvm::createStringError(
- "expression stack needs at least 2 items for DW_OP_mul");
- } else {
- tmp = stack.back();
- stack.pop_back();
- stack.back().ResolveValue(exe_ctx) =
- stack.back().ResolveValue(exe_ctx) * tmp.ResolveValue(exe_ctx);
- }
+ tmp = stack.back();
+ stack.pop_back();
+ stack.back().ResolveValue(exe_ctx) =
+ stack.back().ResolveValue(exe_ctx) * tmp.ResolveValue(exe_ctx);
break;
// OPCODE: DW_OP_neg
// OPERANDS: none
// DESCRIPTION: pops the top stack entry, and pushes its negation.
case DW_OP_neg:
- if (stack.empty()) {
- return llvm::createStringError(
- "expression stack needs at least 1 item for DW_OP_neg");
- } else {
- if (!stack.back().ResolveValue(exe_ctx).UnaryNegate())
- return llvm::createStringError("unary negate failed");
- }
+ if (!stack.back().ResolveValue(exe_ctx).UnaryNegate())
+ return llvm::createStringError("unary negate failed");
break;
// OPCODE: DW_OP_not
@@ -1461,14 +1422,8 @@ llvm::Expected<Value> DWARFExpression::Evaluate(
// DESCRIPTION: pops the top stack entry, and pushes its bitwise
// complement
case DW_OP_not:
- if (stack.empty()) {
- return llvm::createStringError(
- "expression stack needs at least 1 item for DW_OP_not");
- } else {
- if (!stack.back().ResolveValue(exe_ctx).OnesComplement()) {
- return llvm::createStringError("logical NOT failed");
- }
- }
+ if (!stack.back().ResolveValue(exe_ctx).OnesComplement())
+ return llvm::createStringError("logical NOT failed");
break;
// OPCODE: DW_OP_or
@@ -1476,15 +1431,10 @@ llvm::Expected<Value> DWARFExpression::Evaluate(
// DESCRIPTION: pops the top two stack entries, performs a bitwise or
// operation on the two, and pushes the result.
case DW_OP_or:
- if (stack.size() < 2) {
- return llvm::createStringError(
- "expression stack needs at least 2 items for DW_OP_or");
- } else {
- tmp = stack.back();
- stack.pop_back();
- stack.back().ResolveValue(exe_ctx) =
- stack.back().ResolveValue(exe_ctx) | tmp.ResolveValue(exe_ctx);
- }
+ tmp = stack.back();
+ stack.pop_back();
+ stack.back().ResolveValue(exe_ctx) =
+ stack.back().ResolveValue(exe_ctx) | tmp.ResolveValue(exe_ctx);
break;
// OPCODE: DW_OP_plus
@@ -1492,32 +1442,22 @@ llvm::Expected<Value> DWARFExpression::Evaluate(
// DESCRIPTION: pops the top two stack entries, adds them together, and
// pushes the result.
case DW_OP_plus:
- if (stack.size() < 2) {
- return llvm::createStringError(
- "expression stack needs at least 2 items for DW_OP_plus");
- } else {
- tmp = stack.back();
- stack.pop_back();
- stack.back().GetScalar() += tmp.GetScalar();
- }
+ tmp = stack.back();
+ stack.pop_back();
+ stack.back().GetScalar() += tmp.GetScalar();
break;
// OPCODE: DW_OP_plus_uconst
// OPERANDS: none
// DESCRIPTION: pops the top stack entry, adds it to the unsigned LEB128
// constant operand and pushes the result.
- case DW_OP_plus_uconst:
- if (stack.empty()) {
- return llvm::createStringError(
- "expression stack needs at least 1 item for DW_OP_plus_uconst");
- } else {
- const uint64_t uconst_value = opcodes.GetULEB128(&offset);
- // Implicit conversion from a UINT to a Scalar...
- stack.back().GetScalar() += uconst_value;
- if (!stack.back().GetScalar().IsValid())
- return llvm::createStringError("DW_OP_plus_uconst failed");
- }
- break;
+ case DW_OP_plus_uconst: {
+ const uint64_t uconst_value = opcodes.GetULEB128(&offset);
+ // Implicit conversion from a UINT to a Scalar...
+ stack.back().GetScalar() += uconst_value;
+ if (!stack.back().GetScalar().IsValid())
+ return llvm::createStringError("DW_OP_plus_uconst failed");
+ } break;
// OPCODE: DW_OP_shl
// OPERANDS: none
@@ -1525,14 +1465,9 @@ llvm::Expected<Value> DWARFExpression::Evaluate(
// second entry left by the number of bits specified by the former top of
// the stack, and pushes the result.
case DW_OP_shl:
- if (stack.size() < 2) {
- return llvm::createStringError(
- "expression stack needs at least 2 items for DW_OP_shl");
- } else {
- tmp = stack.back();
- stack.pop_back();
- stack.back().ResolveValue(exe_ctx) <<= tmp.ResolveValue(exe_ctx);
- }
+ tmp = stack.back();
+ stack.pop_back();
+ stack.back().ResolveValue(exe_ctx) <<= tmp.ResolveValue(exe_ctx);
break;
// OPCODE: DW_OP_shr
@@ -1541,17 +1476,11 @@ llvm::Expected<Value> DWARFExpression::Evaluate(
// entry right logically (filling with zero bits) by the number of bits
// specified by the former top of the stack, and pushes the result.
case DW_OP_shr:
- if (stack.size() < 2) {
- return llvm::createStringError(
- "expression stack needs at least 2 items for DW_OP_shr");
- } else {
- tmp = stack.back();
- stack.pop_back();
- if (!stack.back().ResolveValue(exe_ctx).ShiftRightLogical(
- tmp.ResolveValue(exe_ctx))) {
- return llvm::createStringError("DW_OP_shr failed");
- }
- }
+ tmp = stack.back();
+ stack.pop_back();
+ if (!stack.back().ResolveValue(exe_ctx).ShiftRightLogical(
+ tmp.ResolveValue(exe_ctx)))
+ return llvm::createStringError("DW_OP_shr failed");
break;
// OPCODE: DW_OP_shra
@@ -1561,14 +1490,9 @@ llvm::Expected<Value> DWARFExpression::Evaluate(
// sign for the result) by the number of bits specified by the former top
// of the stack, and pushes the result.
case DW_OP_shra:
- if (stack.size() < 2) {
- return llvm::createStringError(
- "expression stack needs at least 2 items for DW_OP_shra");
- } else {
- tmp = stack.back();
- stack.pop_back();
- stack.back().ResolveValue(exe_ctx) >>= tmp.ResolveValue(exe_ctx);
- }
+ tmp = stack.back();
+ stack.pop_back();
+ stack.back().ResolveValue(exe_ctx) >>= tmp.ResolveValue(exe_ctx);
break;
// OPCODE: DW_OP_xor
@@ -1576,15 +1500,10 @@ llvm::Expected<Value> DWARFExpression::Evaluate(
// DESCRIPTION: pops the top two stack entries, performs the bitwise
// exclusive-or operation on the two, and pushes the result.
case DW_OP_xor:
- if (stack.size() < 2) {
- return llvm::createStringError(
- "expression stack needs at least 2 items for DW_OP_xor");
- } else {
- tmp = stack.back();
- stack.pop_back();
- stack.back().ResolveValue(exe_ctx) =
- stack.back().ResolveValue(exe_ctx) ^ tmp.ResolveValue(exe_ctx);
- }
+ tmp = stack.back();
+ stack.pop_back();
+ stack.back().ResolveValue(exe_ctx) =
+ stack.back().ResolveValue(exe_ctx) ^ tmp.ResolveValue(exe_ctx);
break;
// OPCODE: DW_OP_skip
@@ -1615,30 +1534,25 @@ llvm::Expected<Value> DWARFExpression::Evaluate(
// value popped is not the constant 0, the 2-byte constant operand is the
// number of bytes of the DWARF expression to skip forward or backward from
// the current operation, beginning after the 2-byte constant.
- case DW_OP_bra:
- if (stack.empty()) {
- return llvm::createStringError(
- "expression stack needs at least 1 item for DW_OP_bra");
- } else {
- tmp = stack.back();
- stack.pop_back();
- int16_t bra_offset = (int16_t)opcodes.GetU16(&offset);
- Scalar zero(0);
- if (tmp.ResolveValue(exe_ctx) != zero) {
- lldb::offset_t new_offset = offset + bra_offset;
- // New offset can point at the end of the data, in this case we should
- // terminate the DWARF expression evaluation (will happen in the loop
- // condition).
- if (new_offset <= opcodes.GetByteSize())
- offset = new_offset;
- else {
- return llvm::createStringError(llvm::formatv(
- "Invalid opcode offset in DW_OP_bra: {0}+({1}) > {2}", offset,
- bra_offset, opcodes.GetByteSize()));
- }
+ case DW_OP_bra: {
+ tmp = stack.back();
+ stack.pop_back();
+ int16_t bra_offset = (int16_t)opcodes.GetU16(&offset);
+ Scalar zero(0);
+ if (tmp.ResolveValue(exe_ctx) != zero) {
+ lldb::offset_t new_offset = offset + bra_offset;
+ // New offset can point at the end of the data, in this case we should
+ // terminate the DWARF expression evaluation (will happen in the loop
+ // condition).
+ if (new_offset <= opcodes.GetByteSize())
+ offset = new_offset;
+ else {
+ return llvm::createStringError(llvm::formatv(
+ "Invalid opcode offset in DW_OP_bra: {0}+({1}) > {2}", offset,
+ bra_offset, opcodes.GetByteSize()));
}
}
- break;
+ } break;
// OPCODE: DW_OP_eq
// OPERANDS: none
@@ -1648,15 +1562,10 @@ llvm::Expected<Value> DWARFExpression::Evaluate(
// of the operation is true or the constant value 0 if the result of the
// operation is false.
case DW_OP_eq:
- if (stack.size() < 2) {
- return llvm::createStringError(
- "expression stack needs at least 2 items for DW_OP_eq");
- } else {
- tmp = stack.back();
- stack.pop_back();
- stack.back().ResolveValue(exe_ctx) =
- stack.back().ResolveValue(exe_ctx) == tmp.ResolveValue(exe_ctx);
- }
+ tmp = stack.back();
+ stack.pop_back();
+ stack.back().ResolveValue(exe_ctx) =
+ stack.back().ResolveValue(exe_ctx) == tmp.ResolveValue(exe_ctx);
break;
// OPCODE: DW_OP_ge
@@ -1667,15 +1576,10 @@ llvm::Expected<Value> DWARFExpression::Evaluate(
// of the operation is true or the constant value 0 if the result of the
// operation is false.
case DW_OP_ge:
- if (stack.size() < 2) {
- return llvm::createStringError(
- "expression stack needs at least 2 items for DW_OP_ge");
- } else {
- tmp = stack.back();
- stack.pop_back();
- stack.back().ResolveValue(exe_ctx) =
- stack.back().ResolveValue(exe_ctx) >= tmp.ResolveValue(exe_ctx);
- }
+ tmp = stack.back();
+ stack.pop_back();
+ stack.back().ResolveValue(exe_ctx) =
+ stack.back().ResolveValue(exe_ctx) >= tmp.ResolveValue(exe_ctx);
break;
// OPCODE: DW_OP_gt
@@ -1686,15 +1590,10 @@ llvm::Expected<Value> DWARFExpression::Evaluate(
// of the operation is true or the constant value 0 if the result of the
// operation is false.
case DW_OP_gt:
- if (stack.size() < 2) {
- return llvm::createStringError(
- "expression stack needs at least 2 items for DW_OP_gt");
- } else {
- tmp = stack.back();
- stack.pop_back();
- stack.back().ResolveValue(exe_ctx) =
- stack.back().ResolveValue(exe_ctx) > tmp.ResolveValue(exe_ctx);
- }
+ tmp = stack.back();
+ stack.pop_back();
+ stack.back().ResolveValue(exe_ctx) =
+ stack.back().ResolveValue(exe_ctx) > tmp.ResolveValue(exe_ctx);
break;
// OPCODE: DW_OP_le
@@ -1705,15 +1604,10 @@ llvm::Expected<Value> DWARFExpression::Evaluate(
// of the operation is true or the constant value 0 if the result of the
// operation is false.
case DW_OP_le:
- if (stack.size() < 2) {
- return llvm::createStringError(
- "expression stack needs at least 2 items for DW_OP_le");
- } else {
- tmp = stack.back();
- stack.pop_back();
- stack.back().ResolveValue(exe_ctx) =
- stack.back().ResolveValue(exe_ctx) <= tmp.ResolveValue(exe_ctx);
- }
+ tmp = stack.back();
+ stack.pop_back();
+ stack.back().ResolveValue(exe_ctx) =
+ stack.back().ResolveValue(exe_ctx) <= tmp.ResolveValue(exe_ctx);
break;
// OPCODE: DW_OP_lt
@@ -1724,15 +1618,10 @@ llvm::Expected<Value> DWARFExpression::Evaluate(
// of the operation is true or the constant value 0 if the result of the
// operation is false.
case DW_OP_lt:
- if (stack.size() < 2) {
- return llvm::createStringError(
- "expression stack needs at least 2 items for DW_OP_lt");
- } else {
- t...
[truncated]
``````````
</details>
https://github.com/llvm/llvm-project/pull/94679
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