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authorpatrick <patrick@openbsd.org>2020-08-03 14:33:06 +0000
committerpatrick <patrick@openbsd.org>2020-08-03 14:33:06 +0000
commit061da546b983eb767bad15e67af1174fb0bcf31c (patch)
tree83c78b820819d70aa40c36d90447978b300078c5 /gnu/llvm/lldb/source/Symbol/PostfixExpression.cpp
parentImport LLVM 10.0.0 release including clang, lld and lldb. (diff)
downloadwireguard-openbsd-061da546b983eb767bad15e67af1174fb0bcf31c.tar.xz
wireguard-openbsd-061da546b983eb767bad15e67af1174fb0bcf31c.zip
Import LLVM 10.0.0 release including clang, lld and lldb.
ok hackroom tested by plenty
Diffstat (limited to 'gnu/llvm/lldb/source/Symbol/PostfixExpression.cpp')
-rw-r--r--gnu/llvm/lldb/source/Symbol/PostfixExpression.cpp248
1 files changed, 248 insertions, 0 deletions
diff --git a/gnu/llvm/lldb/source/Symbol/PostfixExpression.cpp b/gnu/llvm/lldb/source/Symbol/PostfixExpression.cpp
new file mode 100644
index 00000000000..8ecd571ed92
--- /dev/null
+++ b/gnu/llvm/lldb/source/Symbol/PostfixExpression.cpp
@@ -0,0 +1,248 @@
+//===-- PostfixExpression.cpp -----------------------------------*- C++ -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+//
+// This file implements support for postfix expressions found in several symbol
+// file formats, and their conversion to DWARF.
+//
+//===----------------------------------------------------------------------===//
+
+#include "lldb/Symbol/PostfixExpression.h"
+#include "lldb/Core/dwarf.h"
+#include "lldb/Utility/Stream.h"
+#include "llvm/ADT/StringExtras.h"
+
+using namespace lldb_private;
+using namespace lldb_private::postfix;
+
+static llvm::Optional<BinaryOpNode::OpType>
+GetBinaryOpType(llvm::StringRef token) {
+ if (token.size() != 1)
+ return llvm::None;
+ switch (token[0]) {
+ case '@':
+ return BinaryOpNode::Align;
+ case '-':
+ return BinaryOpNode::Minus;
+ case '+':
+ return BinaryOpNode::Plus;
+ }
+ return llvm::None;
+}
+
+static llvm::Optional<UnaryOpNode::OpType>
+GetUnaryOpType(llvm::StringRef token) {
+ if (token == "^")
+ return UnaryOpNode::Deref;
+ return llvm::None;
+}
+
+Node *postfix::ParseOneExpression(llvm::StringRef expr,
+ llvm::BumpPtrAllocator &alloc) {
+ llvm::SmallVector<Node *, 4> stack;
+
+ llvm::StringRef token;
+ while (std::tie(token, expr) = getToken(expr), !token.empty()) {
+ if (auto op_type = GetBinaryOpType(token)) {
+ // token is binary operator
+ if (stack.size() < 2)
+ return nullptr;
+
+ Node *right = stack.pop_back_val();
+ Node *left = stack.pop_back_val();
+ stack.push_back(MakeNode<BinaryOpNode>(alloc, *op_type, *left, *right));
+ continue;
+ }
+
+ if (auto op_type = GetUnaryOpType(token)) {
+ // token is unary operator
+ if (stack.empty())
+ return nullptr;
+
+ Node *operand = stack.pop_back_val();
+ stack.push_back(MakeNode<UnaryOpNode>(alloc, *op_type, *operand));
+ continue;
+ }
+
+ int64_t value;
+ if (to_integer(token, value, 10)) {
+ // token is integer literal
+ stack.push_back(MakeNode<IntegerNode>(alloc, value));
+ continue;
+ }
+
+ stack.push_back(MakeNode<SymbolNode>(alloc, token));
+ }
+
+ if (stack.size() != 1)
+ return nullptr;
+
+ return stack.back();
+}
+
+std::vector<std::pair<llvm::StringRef, Node *>>
+postfix::ParseFPOProgram(llvm::StringRef prog, llvm::BumpPtrAllocator &alloc) {
+ llvm::SmallVector<llvm::StringRef, 4> exprs;
+ prog.split(exprs, '=');
+ if (exprs.empty() || !exprs.back().trim().empty())
+ return {};
+ exprs.pop_back();
+
+ std::vector<std::pair<llvm::StringRef, Node *>> result;
+ for (llvm::StringRef expr : exprs) {
+ llvm::StringRef lhs;
+ std::tie(lhs, expr) = getToken(expr);
+ Node *rhs = ParseOneExpression(expr, alloc);
+ if (!rhs)
+ return {};
+ result.emplace_back(lhs, rhs);
+ }
+ return result;
+}
+
+namespace {
+class SymbolResolver : public Visitor<bool> {
+public:
+ SymbolResolver(llvm::function_ref<Node *(SymbolNode &symbol)> replacer)
+ : m_replacer(replacer) {}
+
+ using Visitor<bool>::Dispatch;
+
+private:
+ bool Visit(BinaryOpNode &binary, Node *&) override {
+ return Dispatch(binary.Left()) && Dispatch(binary.Right());
+ }
+
+ bool Visit(InitialValueNode &, Node *&) override { return true; }
+ bool Visit(IntegerNode &, Node *&) override { return true; }
+ bool Visit(RegisterNode &, Node *&) override { return true; }
+
+ bool Visit(SymbolNode &symbol, Node *&ref) override {
+ if (Node *replacement = m_replacer(symbol)) {
+ ref = replacement;
+ if (replacement != &symbol)
+ return Dispatch(ref);
+ return true;
+ }
+ return false;
+ }
+
+ bool Visit(UnaryOpNode &unary, Node *&) override {
+ return Dispatch(unary.Operand());
+ }
+
+ llvm::function_ref<Node *(SymbolNode &symbol)> m_replacer;
+};
+
+class DWARFCodegen : public Visitor<> {
+public:
+ DWARFCodegen(Stream &stream) : m_out_stream(stream) {}
+
+ using Visitor<>::Dispatch;
+
+private:
+ void Visit(BinaryOpNode &binary, Node *&) override;
+
+ void Visit(InitialValueNode &val, Node *&) override;
+
+ void Visit(IntegerNode &integer, Node *&) override {
+ m_out_stream.PutHex8(DW_OP_consts);
+ m_out_stream.PutSLEB128(integer.GetValue());
+ ++m_stack_depth;
+ }
+
+ void Visit(RegisterNode &reg, Node *&) override;
+
+ void Visit(SymbolNode &symbol, Node *&) override {
+ llvm_unreachable("Symbols should have been resolved by now!");
+ }
+
+ void Visit(UnaryOpNode &unary, Node *&) override;
+
+ Stream &m_out_stream;
+
+ /// The number keeping track of the evaluation stack depth at any given
+ /// moment. Used for implementing InitialValueNodes. We start with
+ /// m_stack_depth = 1, assuming that the initial value is already on the
+ /// stack. This initial value will be the value of all InitialValueNodes. If
+ /// the expression does not contain InitialValueNodes, then m_stack_depth is
+ /// not used, and the generated expression will run correctly even without an
+ /// initial value.
+ size_t m_stack_depth = 1;
+};
+} // namespace
+
+void DWARFCodegen::Visit(BinaryOpNode &binary, Node *&) {
+ Dispatch(binary.Left());
+ Dispatch(binary.Right());
+
+ switch (binary.GetOpType()) {
+ case BinaryOpNode::Plus:
+ m_out_stream.PutHex8(DW_OP_plus);
+ // NOTE: can be optimized by using DW_OP_plus_uconst opcpode
+ // if right child node is constant value
+ break;
+ case BinaryOpNode::Minus:
+ m_out_stream.PutHex8(DW_OP_minus);
+ break;
+ case BinaryOpNode::Align:
+ // emit align operator a @ b as
+ // a & ~(b - 1)
+ // NOTE: implicitly assuming that b is power of 2
+ m_out_stream.PutHex8(DW_OP_lit1);
+ m_out_stream.PutHex8(DW_OP_minus);
+ m_out_stream.PutHex8(DW_OP_not);
+
+ m_out_stream.PutHex8(DW_OP_and);
+ break;
+ }
+ --m_stack_depth; // Two pops, one push.
+}
+
+void DWARFCodegen::Visit(InitialValueNode &, Node *&) {
+ // We never go below the initial stack, so we can pick the initial value from
+ // the bottom of the stack at any moment.
+ assert(m_stack_depth >= 1);
+ m_out_stream.PutHex8(DW_OP_pick);
+ m_out_stream.PutHex8(m_stack_depth - 1);
+ ++m_stack_depth;
+}
+
+void DWARFCodegen::Visit(RegisterNode &reg, Node *&) {
+ uint32_t reg_num = reg.GetRegNum();
+ assert(reg_num != LLDB_INVALID_REGNUM);
+
+ if (reg_num > 31) {
+ m_out_stream.PutHex8(DW_OP_bregx);
+ m_out_stream.PutULEB128(reg_num);
+ } else
+ m_out_stream.PutHex8(DW_OP_breg0 + reg_num);
+
+ m_out_stream.PutSLEB128(0);
+ ++m_stack_depth;
+}
+
+void DWARFCodegen::Visit(UnaryOpNode &unary, Node *&) {
+ Dispatch(unary.Operand());
+
+ switch (unary.GetOpType()) {
+ case UnaryOpNode::Deref:
+ m_out_stream.PutHex8(DW_OP_deref);
+ break;
+ }
+ // Stack depth unchanged.
+}
+
+bool postfix::ResolveSymbols(
+ Node *&node, llvm::function_ref<Node *(SymbolNode &)> replacer) {
+ return SymbolResolver(replacer).Dispatch(node);
+}
+
+void postfix::ToDWARF(Node &node, Stream &stream) {
+ Node *ptr = &node;
+ DWARFCodegen(stream).Dispatch(ptr);
+}