From a9bae4dae94c5e7823e1f3a7488e264b7a13f6c7 Mon Sep 17 00:00:00 2001
From: Quentin MICHAUD <quentin.michaud@thalesgroup.com>
Date: Fri, 12 Dec 2025 15:08:55 +0100
Subject: [PATCH] Updated patch for new Wasm SSP

---
 .../WebAssembly/WebAssemblyAsmPrinter.cpp     |  6 ++++--
 .../WebAssembly/WebAssemblyISelLowering.cpp   |  4 ++++
 .../WebAssembly/WebAssemblyISelLowering.h     |  2 ++
 .../WebAssembly/WebAssemblyInstrInfo.cpp      | 21 ++++++++++++++++++-
 .../Target/WebAssembly/WebAssemblyInstrInfo.h |  3 +++
 5 files changed, 33 insertions(+), 3 deletions(-)

diff --git a/llvm/lib/Target/WebAssembly/WebAssemblyAsmPrinter.cpp b/llvm/lib/Target/WebAssembly/WebAssemblyAsmPrinter.cpp
index 526420bb2b294..19c11244bb6b1 100644
--- a/llvm/lib/Target/WebAssembly/WebAssemblyAsmPrinter.cpp
+++ b/llvm/lib/Target/WebAssembly/WebAssemblyAsmPrinter.cpp
@@ -229,9 +229,11 @@ MCSymbol *WebAssemblyAsmPrinter::getOrCreateWasmSymbol(StringRef Name) {
   // Clang-provided symbols.
   if (Name == "__stack_pointer" || Name == "__tls_base" ||
       Name == "__memory_base" || Name == "__table_base" ||
-      Name == "__tls_size" || Name == "__tls_align") {
+      Name == "__tls_size" || Name == "__tls_align" ||
+      Name == "__stack_chk_guard") {
     bool Mutable =
-        Name == "__stack_pointer" || Name == "__tls_base";
+        Name == "__stack_pointer" || Name == "__tls_base" ||
+        Name == "__stack_chk_guard";
     WasmSym->setType(wasm::WASM_SYMBOL_TYPE_GLOBAL);
     WasmSym->setGlobalType(wasm::WasmGlobalType{
         uint8_t(Subtarget.hasAddr64() ? wasm::WASM_TYPE_I64
diff --git a/llvm/lib/Target/WebAssembly/WebAssemblyISelLowering.cpp b/llvm/lib/Target/WebAssembly/WebAssemblyISelLowering.cpp
index e0c527b9b2581..c13dbac06dc5c 100644
--- a/llvm/lib/Target/WebAssembly/WebAssemblyISelLowering.cpp
+++ b/llvm/lib/Target/WebAssembly/WebAssemblyISelLowering.cpp
@@ -3695,3 +3695,7 @@ WebAssemblyTargetLowering::PerformDAGCombine(SDNode *N,
     return performMulCombine(N, DCI);
   }
 }
+
+bool WebAssemblyTargetLowering::useLoadStackGuardNode(const Module &M) const {
+  return true;
+}
diff --git a/llvm/lib/Target/WebAssembly/WebAssemblyISelLowering.h b/llvm/lib/Target/WebAssembly/WebAssemblyISelLowering.h
index c37970f458e36..9b5056e7b9bea 100644
--- a/llvm/lib/Target/WebAssembly/WebAssemblyISelLowering.h
+++ b/llvm/lib/Target/WebAssembly/WebAssemblyISelLowering.h
@@ -29,6 +29,8 @@ class WebAssemblyTargetLowering final : public TargetLowering {
   MVT getPointerTy(const DataLayout &DL, uint32_t AS = 0) const override;
   MVT getPointerMemTy(const DataLayout &DL, uint32_t AS = 0) const override;
 
+  bool useLoadStackGuardNode(const Module &M) const override;
+
 private:
   /// Keep a pointer to the WebAssemblySubtarget around so that we can make the
   /// right decision when generating code for different targets.
diff --git a/llvm/lib/Target/WebAssembly/WebAssemblyInstrInfo.cpp b/llvm/lib/Target/WebAssembly/WebAssemblyInstrInfo.cpp
index 8b4e4fbbbd1e5..fe49097a64391 100644
--- a/llvm/lib/Target/WebAssembly/WebAssemblyInstrInfo.cpp
+++ b/llvm/lib/Target/WebAssembly/WebAssemblyInstrInfo.cpp
@@ -37,7 +37,7 @@ WebAssemblyInstrInfo::WebAssemblyInstrInfo(const WebAssemblySubtarget &STI)
     : WebAssemblyGenInstrInfo(STI, RI, WebAssembly::ADJCALLSTACKDOWN,
                               WebAssembly::ADJCALLSTACKUP,
                               WebAssembly::CATCHRET),
-      RI(STI.getTargetTriple()) {}
+      Subtarget(STI), RI(STI.getTargetTriple()) {}
 
 bool WebAssemblyInstrInfo::isReMaterializableImpl(
     const MachineInstr &MI) const {
@@ -233,3 +233,22 @@ bool WebAssemblyInstrInfo::isExplicitTargetIndexDef(const MachineInstr &MI,
   }
   return false;
 }
+
+bool WebAssemblyInstrInfo::expandPostRAPseudo(MachineInstr &MI) const {
+  if(MI.getOpcode() == TargetOpcode::LOAD_STACK_GUARD) {
+    MachineFunction *MF = MI.getParent()->getParent();
+    const TargetInstrInfo *TII = MF->getSubtarget().getInstrInfo();
+    const char *BaseName = MF->createExternalSymbolName("__stack_chk_guard");
+
+    MachineInstrBuilder MIB = BuildMI(*MF, MI.getDebugLoc(),
+                                  TII->get(Subtarget.hasAddr64()
+                                       ? WebAssembly::GLOBAL_GET_I64
+                                       : WebAssembly::GLOBAL_GET_I32))
+                                  .addDef(MI.getOperand(0).getReg())
+                                  .addExternalSymbol(BaseName);
+    MI.getParent()->insert(MI.getIterator(), MIB.getInstr());
+    MI.eraseFromParent();
+    return true;
+  }
+  return false;
+}
diff --git a/llvm/lib/Target/WebAssembly/WebAssemblyInstrInfo.h b/llvm/lib/Target/WebAssembly/WebAssemblyInstrInfo.h
index b92f62d7638c1..9507956a2a9be 100644
--- a/llvm/lib/Target/WebAssembly/WebAssemblyInstrInfo.h
+++ b/llvm/lib/Target/WebAssembly/WebAssemblyInstrInfo.h
@@ -30,6 +30,7 @@ namespace llvm {
 class WebAssemblySubtarget;
 
 class WebAssemblyInstrInfo final : public WebAssemblyGenInstrInfo {
+  const WebAssemblySubtarget &Subtarget;
   const WebAssemblyRegisterInfo RI;
 
 public:
@@ -67,6 +68,8 @@ class WebAssemblyInstrInfo final : public WebAssemblyGenInstrInfo {
 
   bool isExplicitTargetIndexDef(const MachineInstr &MI, int &Index,
                                 int64_t &Offset) const override;
+
+  bool expandPostRAPseudo(MachineInstr &MI) const override;
 };
 
 } // end namespace llvm