[llvm] JITLink: Add initial SystemZ Support. (PR #144528)

[Ulrich Weigand via llvm-commits]

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@@ -0,0 +1,958 @@
+//=== systemz.h - Generic JITLink systemz edge kinds, utilities -*- 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
+//
+//===----------------------------------------------------------------------===//
+//
+// Generic utilities for graphs representing systemz objects.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_EXECUTIONENGINE_JITLINK_SYSTEMZ_H
+#define LLVM_EXECUTIONENGINE_JITLINK_SYSTEMZ_H
+
+#include "TableManager.h"
+#include "llvm/ExecutionEngine/JITLink/JITLink.h"
+
+using namespace llvm::support::endian;
+
+namespace llvm {
+namespace jitlink {
+namespace systemz {
+
+/// Represents systemz fixups and other systemz-specific edge kinds.
+enum EdgeKind_systemz : Edge::Kind {
+
+  /// A plain 64-bit pointer value relocation.
+  ///
+  /// Fixup expression:
+  ///   Fixup <- Target + Addend : uint64
+  ///
+  Pointer64 = Edge::FirstRelocation,
+
+  /// A plain 32-bit pointer value relocation.
+  ///
+  /// Fixup expression:
+  ///   Fixup <- Target + Addend : uint32
+  ///
+  /// Errors:
+  ///   - The target must reside in the low 32-bits of the address space,
+  ///     otherwise an out-of-range error will be returned.
+  ///
+  Pointer32,
+
+  /// A plain 20-bit pointer value relocation.
+  ///
+  /// Fixup expression:
+  ///   Fixup <- Target + Addend : uint20
+  ///
+  /// Errors:
+  ///   - The target must reside in the mid 20-bits of the address space,
+  ///     otherwise an out-of-range error will be returned.
+  ///
+  Pointer20,
+
+  /// A plain 16-bit pointer value relocation.
+  ///
+  /// Fixup expression:
+  ///   Fixup <- Target + Addend : uint16
+  ///
+  /// Errors:
+  ///   - The target must reside in the low 16-bits of the address space,
+  ///     otherwise an out-of-range error will be returned.
+  ///
+  Pointer16,
+
+  /// A plain 12-bit pointer value relocation.
+  ///
+  /// Fixup expression:
+  ///   Fixup <- Target + Addend : uint12
+  ///
+  /// Errors:
+  ///   - The target must reside in the low 12-bits of the address space,
+  ///     otherwise an out-of-range error will be returned.
+  ///
+  Pointer12,
+
+  /// A plain 8-bit pointer value relocation.
+  ///
+  /// Fixup expression:
+  ///   Fixup <- Target + Addend : uint8
+  ///
+  /// Errors:
+  ///   - The target must reside in the low 8-bits of the address space,
+  ///     otherwise an out-of-range error will be returned.
+  ///
+  Pointer8,
+
+  /// A 64-bit delta.
+  ///
+  /// Delta from the fixup to the target.
+  ///
+  /// Fixup expression:
+  ///   Fixup <- Target - Fixup + Addend : int64
+  ///
+  Delta64,
+
+  /// A 32-bit delta.
+  ///
+  /// Delta from the fixup to the target.
+  ///
+  /// Fixup expression:
+  ///   Fixup <- Target - Fixup + Addend : int32
+  ///
+  /// Errors:
+  ///   - The result of the fixup expression must fit into an int32, otherwise
+  ///     an out-of-range error will be returned.
+  ///
+  Delta32,
+
+  /// A 16-bit delta.
+  ///
+  /// Delta from the fixup to the target.
+  ///
+  /// Fixup expression:
+  ///   Fixup <- Target - Fixup + Addend : int16
+  ///
+  /// Errors:
+  ///   - The result of the fixup expression must fit into an int16, otherwise
+  ///     an out-of-range error will be returned.
+  ///
+  Delta16,
+
+  /// A 32-bit delta.
+  ///
+  /// Delta from the fixup to the target.
+  ///
+  /// Fixup expression:
+  ///   Fixup <- (Target - Fixup + Addend : int32) >> 1
+  ///
+  /// Errors:
+  ///   - The result of the fixup expression before shifting right by 1 must
+  ///     fit into an int33, otherwise an out-of-range error will be returned.
+  ///   - The result of the fixup expression  before shifting right by 1 must
+  ///     be multiple of 2, otherwise an alignment error will be returned.
+  ///
+  Delta32dbl,
+
+  /// A 24-bit delta.
+  ///
+  /// Delta from the fixup to the target.
+  ///
+  /// Fixup expression:
+  ///   Fixup <- (Target - Fixup + Addend : int24) >> 1
+  ///
+  /// Errors:
+  ///   - The result of the fixup expression before shifting right by 1 must
+  ///     fit into an int25, otherwise an out-of-range error will be returned.
+  ///   - The result of the fixup expression  before shifting right by 1 must
+  ///     be multiple of 2, otherwise an alignment error will be returned.
+  ///
+  Delta24dbl,
+
+  /// A 16-bit delta.
+  ///
+  /// Delta from the fixup to the target.
+  ///
+  /// Fixup expression:
+  ///   Fixup <- (Target - Fixup + Addend : int16) >> 1
+  ///
+  /// Errors:
+  ///   - The result of the fixup expression before shifting right by 1 must
+  ///     fit into an int17, otherwise an out-of-range error will be returned.
+  ///   - The result of the fixup expression  before shifting right by 1 must
+  ///     be multiple of 2, otherwise an alignment error will be returned.
+  ///
+  Delta16dbl,
+
+  /// A 12-bit delta.
+  ///
+  /// Delta from the fixup to the target.
+  ///
+  /// Fixup expression:
+  ///   Fixup <- (Target - Fixup + Addend : int12) >> 1
+  ///
+  /// Errors:
+  ///   - The result of the fixup expression before shifting right by 1 must
+  ///     fit into an int13, otherwise an out-of-range error will be returned.
+  ///   - The result of the fixup expression  before shifting right by 1 must
+  ///     be multiple of 2, otherwise an alignment error will be returned.
+  ///
+  Delta12dbl,
+
+  /// A 64-bit negative delta.
+  ///
+  /// Delta from target back to the fixup.
+  ///
+  /// Fixup expression:
+  ///   Fixup <- Fixup - Target + Addend : int64
+  ///
+  NegDelta64,
+
+  /// A 32-bit negative delta.
+  ///
+  /// Delta from the target back to the fixup.
+  ///
+  /// Fixup expression:
+  ///   Fixup <- Fixup - Target + Addend : int32
+  ///
+  /// Errors:
+  ///   - The result of the fixup expression must fit into an int32, otherwise
+  ///     an out-of-range error will be returned.
+  NegDelta32,
+
+  /// A 64-bit GOT delta.
+  ///
+  /// Delta from the global offset table to the target
+  ///
+  /// Fixup expression:
+  ///   Fixup <- Target - GOTSymbol + Addend : int64
+  ///
+  /// Errors:
+  ///   - *ASSERTION* Failure to a null pointer GOTSymbol, which the GOT section
+  ///     symbol was not been defined.
+  RequestGOTAndTransformToDelta64FromGOT,
+
+  /// A 32-bit GOT delta.
+  ///
+  /// Delta from the global offset table to the target
+  ///
+  /// Fixup expression:
+  ///   Fixup <- Target - GOTSymbol + Addend : int32
+  ///
+  /// Errors:
+  ///   - *ASSERTION* Failure to a null pointer GOTSymbol, which the GOT section
+  ///     symbol was not been defined.
+  ///   - The result of the fixup expression must fit into an int32, otherwise
+  ///     an out-of-range error will be returned.
+  RequestGOTAndTransformToDelta32FromGOT,
+
+  /// A 16-bit GOT delta.
+  ///
+  /// Delta from the global offset table to the target
+  ///
+  /// Fixup expression:
+  ///   Fixup <- Target - GOTSymbol + Addend : int16
+  ///
+  /// Errors:
+  ///   - *ASSERTION* Failure to a null pointer GOTSymbol, which the GOT section
+  ///     symbol was not been defined.
+  ///   - The result of the fixup expression must fit into an int16, otherwise
+  ///     an out-of-range error will be returned.
+  RequestGOTAndTransformToDelta16FromGOT,
+
+  /// A 32-bit PC-relative branch.
+  ///
+  /// Represents a PC-relative call or branch to a target. This can be used to
+  /// identify, record, and/or patch call sites.
----------------
uweigand wrote:

These comments should be updated too.  The important thing to mention is that these will lead to creating of a PLT stub.   They are "PC-relative" just the same as the `Delta...` ones, so they should use the same wording for that.

https://github.com/llvm/llvm-project/pull/144528