[clang] [llvm] [clang][docs] Fix typos concerning wasm __funcref (PR #124365)

[Timothy Herchen via llvm-commits]

https://github.com/anematode updated https://github.com/llvm/llvm-project/pull/124365

>From 2508da6fd7f38101011573460724f13df1c1616d Mon Sep 17 00:00:00 2001
From: Timothy Herchen <timothy.herchen at gmail.com>
Date: Fri, 24 Jan 2025 15:13:30 -0800
Subject: [PATCH 1/2] [clang][docs] Fix typos concerning wasm __funcref

---
 clang/docs/LanguageExtensions.rst | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/clang/docs/LanguageExtensions.rst b/clang/docs/LanguageExtensions.rst
index c42b88015e2695..ddb11cc6efb232 100644
--- a/clang/docs/LanguageExtensions.rst
+++ b/clang/docs/LanguageExtensions.rst
@@ -2632,7 +2632,7 @@ with the current table size.
 .. code-block:: c++
 
   typedef void (*__funcref funcref_t)();
-  static __funcref table[0];
+  static funcref_t table[0];
 
   size_t getSize() {
     return __builtin_wasm_table_size(table);
@@ -2654,10 +2654,10 @@ or -1. It will return -1 if not enough space could be allocated.
 .. code-block:: c++
 
   typedef void (*__funcref funcref_t)();
-  static __funcref table[0];
+  static funcref_t table[0];
 
   // grow returns the new table size or -1 on error.
-  int grow(__funcref fn, int delta) {
+  int grow(funcref_t fn, int delta) {
     int prevSize = __builtin_wasm_table_grow(table, fn, delta);
     if (prevSize == -1)
       return -1;

>From 5721ec3228edebb3170df3a8dc80ef12076f5ea8 Mon Sep 17 00:00:00 2001
From: Timothy Herchen <timothy.herchen at gmail.com>
Date: Sat, 25 Jan 2025 20:19:00 -0800
Subject: [PATCH 2/2] [wasm] disallow tail calls when passing structs on the
 stack

---
 llvm/lib/Target/WebAssembly/WebAssemblyISelLowering.cpp | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/llvm/lib/Target/WebAssembly/WebAssemblyISelLowering.cpp b/llvm/lib/Target/WebAssembly/WebAssemblyISelLowering.cpp
index 02db1b142a22b5..ec745ebabb4f63 100644
--- a/llvm/lib/Target/WebAssembly/WebAssemblyISelLowering.cpp
+++ b/llvm/lib/Target/WebAssembly/WebAssemblyISelLowering.cpp
@@ -1211,6 +1211,15 @@ WebAssemblyTargetLowering::LowerCall(CallLoweringInfo &CLI,
         }
       }
     }
+
+    // If outgoing arguments are passed via the stack, we cannot tail call
+    for (const ISD::OutputArg &Out : CLI.Outs) {
+      if (Out.Flags.isByVal() && Out.Flags.getByValSize() != 0) {
+        NoTail(
+            "WebAssembly does not support tail calling with stack arguments");
+        break;
+      }
+    }
   }
 
   SmallVectorImpl<ISD::InputArg> &Ins = CLI.Ins;