Adding upstream version 115.7.0esr.upstream/115.7.0esrupstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 187 insertions, 0 deletions

diff --git a/js/src/wasm/WasmDebug.h b/js/src/wasm/WasmDebug.h
new file mode 100644
index 0000000000..35c8a838ed
--- /dev/null
+++ b/js/src/wasm/WasmDebug.h
@@ -0,0 +1,187 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+ * vim: set ts=8 sts=2 et sw=2 tw=80:
+ *
+ * Copyright 2016 Mozilla Foundation
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef wasm_debug_h
+#define wasm_debug_h
+
+#include "js/HashTable.h"
+#include "wasm/WasmCode.h"
+#include "wasm/WasmCodegenTypes.h"
+#include "wasm/WasmConstants.h"
+#include "wasm/WasmExprType.h"
+#include "wasm/WasmModule.h"
+#include "wasm/WasmTypeDecls.h"
+#include "wasm/WasmValType.h"
+
+namespace js {
+
+class Debugger;
+class WasmBreakpointSite;
+class WasmInstanceObject;
+
+namespace wasm {
+
+struct MetadataTier;
+
+// The generated source location for the AST node/expression. The offset field
+// refers an offset in an binary format file.
+
+struct ExprLoc {
+  uint32_t lineno;
+  uint32_t column;
+  uint32_t offset;
+  ExprLoc() : lineno(0), column(0), offset(0) {}
+  ExprLoc(uint32_t lineno_, uint32_t column_, uint32_t offset_)
+      : lineno(lineno_), column(column_), offset(offset_) {}
+};
+
+using StepperCounters =
+    HashMap<uint32_t, uint32_t, DefaultHasher<uint32_t>, SystemAllocPolicy>;
+using WasmBreakpointSiteMap =
+    HashMap<uint32_t, WasmBreakpointSite*, DefaultHasher<uint32_t>,
+            SystemAllocPolicy>;
+
+/*
+ * [SMDOC] Wasm debug traps
+ *
+ * There is a single debug trap handler for the process, WasmHandleDebugTrap in
+ * WasmBuiltins.cpp.  That function is invoked through the Debug Trap Stub,
+ * generated by GenerateDebugTrapStub in WasmStubs.cpp.  When any function in an
+ * instance needs to trap for any reason (enter frame, leave frame, breakpoint,
+ * or single-stepping) then a pointer to the Debug Trap Stub is installed in the
+ * Instance.  Debug-enabled code will look for this pointer and call it if it is
+ * not null.
+ *
+ * WasmHandleDebugTrap may therefore be called very frequently when any function
+ * in the instance is being debugged, and must filter the trap against the
+ * tables in the DebugState.  It can make use of the return address for the
+ * call, which identifies the site uniquely.
+ *
+ * In order to greatly reduce the frequency of calls to the Debug Trap Stub, an
+ * array of flag bits, one per function, is attached to the instance.  The code
+ * at the breakable point calls a shared stub within the function containing the
+ * breakable point to check whether the bit is set for the function.  If it is
+ * not set, the stub can return to its caller immediately; if the bit is set,
+ * the stub will jump to the installed Debug Trap Stub.
+ */
+
+class DebugState {
+  const SharedCode code_;
+  const SharedModule module_;
+
+  // State maintained when debugging is enabled.
+
+  bool enterFrameTrapsEnabled_;
+  uint32_t enterAndLeaveFrameTrapsCounter_;
+  WasmBreakpointSiteMap breakpointSites_;
+  StepperCounters stepperCounters_;
+
+  void enableDebuggingForFunction(Instance* instance, uint32_t funcIndex);
+  void disableDebuggingForFunction(Instance* instance, uint32_t funcIndex);
+  void enableDebugTrap(Instance* instance);
+  void disableDebugTrap(Instance* instance);
+
+ public:
+  DebugState(const Code& code, const Module& module);
+
+  void trace(JSTracer* trc);
+  void finalize(JS::GCContext* gcx);
+
+  const Bytes& bytecode() const { return module_->debugBytecode(); }
+
+  [[nodiscard]] bool getLineOffsets(size_t lineno, Vector<uint32_t>* offsets);
+  [[nodiscard]] bool getAllColumnOffsets(Vector<ExprLoc>* offsets);
+  [[nodiscard]] bool getOffsetLocation(uint32_t offset, size_t* lineno,
+                                       size_t* column);
+
+  // The Code can track enter/leave frame events. Any such event triggers
+  // debug trap. The enter/leave frame events enabled or disabled across
+  // all functions.
+
+  void adjustEnterAndLeaveFrameTrapsState(JSContext* cx, Instance* instance,
+                                          bool enabled);
+  void ensureEnterFrameTrapsState(JSContext* cx, Instance* instance,
+                                  bool enabled);
+  bool enterFrameTrapsEnabled() const { return enterFrameTrapsEnabled_; }
+
+  // When the Code is debugEnabled, individual breakpoints can be enabled or
+  // disabled at instruction offsets.
+
+  bool hasBreakpointTrapAtOffset(uint32_t offset);
+  void toggleBreakpointTrap(JSRuntime* rt, Instance* instance, uint32_t offset,
+                            bool enabled);
+  WasmBreakpointSite* getBreakpointSite(uint32_t offset) const;
+  WasmBreakpointSite* getOrCreateBreakpointSite(JSContext* cx,
+                                                Instance* instance,
+                                                uint32_t offset);
+  bool hasBreakpointSite(uint32_t offset);
+  void destroyBreakpointSite(JS::GCContext* gcx, Instance* instance,
+                             uint32_t offset);
+  void clearBreakpointsIn(JS::GCContext* gcx, WasmInstanceObject* instance,
+                          js::Debugger* dbg, JSObject* handler);
+
+  // When the Code is debug-enabled, single-stepping mode can be toggled on
+  // the granularity of individual functions.
+
+  bool stepModeEnabled(uint32_t funcIndex) const;
+  [[nodiscard]] bool incrementStepperCount(JSContext* cx, Instance* instance,
+                                           uint32_t funcIndex);
+  void decrementStepperCount(JS::GCContext* gcx, Instance* instance,
+                             uint32_t funcIndex);
+
+  // Stack inspection helpers.
+
+  [[nodiscard]] bool debugGetLocalTypes(uint32_t funcIndex,
+                                        ValTypeVector* locals,
+                                        size_t* argsLength,
+                                        StackResults* stackResults);
+  [[nodiscard]] bool getGlobal(Instance& instance, uint32_t globalIndex,
+                               MutableHandleValue vp);
+
+  // Debug URL helpers.
+
+  [[nodiscard]] bool getSourceMappingURL(JSContext* cx,
+                                         MutableHandleString result) const;
+
+  // Accessors for commonly used elements of linked structures.
+
+  const MetadataTier& metadata(Tier t) const { return code_->metadata(t); }
+  const Metadata& metadata() const { return code_->metadata(); }
+  const CodeRangeVector& codeRanges(Tier t) const {
+    return metadata(t).codeRanges;
+  }
+  const CallSiteVector& callSites(Tier t) const {
+    return metadata(t).callSites;
+  }
+
+  uint32_t funcToCodeRangeIndex(uint32_t funcIndex) const {
+    return metadata(Tier::Debug).funcToCodeRange[funcIndex];
+  }
+
+  // about:memory reporting:
+
+  void addSizeOfMisc(MallocSizeOf mallocSizeOf, Metadata::SeenSet* seenMetadata,
+                     Code::SeenSet* seenCode, size_t* code, size_t* data) const;
+};
+
+using UniqueDebugState = UniquePtr<DebugState>;
+
+}  // namespace wasm
+}  // namespace js
+
+#endif  // wasm_debug_h