[clang] [WebAssembly] Make EH depend on multivalue and reference-types (PR #91299)

Heejin Ahn via cfe-commits cfe-commits at lists.llvm.org
Mon May 6 22:38:54 PDT 2024


https://github.com/aheejin created https://github.com/llvm/llvm-project/pull/91299

This PR turns on multivalue and reference-types features when exception-handling feature is turned on, and errors out when disabling of those dependent features is explicitly requested.

I think doing this would be safe anyway regardless of whether or when we end up turning on reference-types by default.

We currently don't yet have a experimental flag for the Clang and LLVM for the new experimental EH yet. But I think it should be fine to turn those features on even if the LLVM does not yet generate the new EH instructions, for the same reason we tried to turn them on by default and the browsers that support EH also support multivalue and reference-types anyway.

>From 527209b600696885ab926cbf09c88feed8a18544 Mon Sep 17 00:00:00 2001
From: Heejin Ahn <aheejin at gmail.com>
Date: Tue, 7 May 2024 05:31:24 +0000
Subject: [PATCH] [WebAssembly] Make EH depend on multivalue and
 reference-types

This PR turns on multivalue and reference-types features when
exception-handling feature is turned on, and errors out when disabling
of those dependent features is explicitly requested.

I think doing this would be safe anyway regardless of whether or when we
end up turning on reference-types by default.

We currently don't yet have a experimental flag for the Clang and LLVM
for the new experimental EH yet. But I think it should be fine to turn
those features on even if the LLVM does not yet generate the new EH
instructions, for the same reason we tried to turn them on by default
and the browsers that support EH also support multivalue and
reference-types anyway.
---
 clang/lib/Driver/ToolChains/WebAssembly.cpp | 34 ++++++++++++++++++
 clang/test/Driver/wasm-toolchain.c          | 39 +++++++++++++++++----
 2 files changed, 67 insertions(+), 6 deletions(-)

diff --git a/clang/lib/Driver/ToolChains/WebAssembly.cpp b/clang/lib/Driver/ToolChains/WebAssembly.cpp
index b7c6efab83e806..5b763df9b33293 100644
--- a/clang/lib/Driver/ToolChains/WebAssembly.cpp
+++ b/clang/lib/Driver/ToolChains/WebAssembly.cpp
@@ -347,6 +347,23 @@ void WebAssembly::addClangTargetOptions(const ArgList &DriverArgs,
     // Backend needs -wasm-enable-eh to enable Wasm EH
     CC1Args.push_back("-mllvm");
     CC1Args.push_back("-wasm-enable-eh");
+
+    // New Wasm EH spec (adopted in Oct 2023) requires multivalue and
+    // reference-types.
+    if (DriverArgs.hasFlag(options::OPT_mno_multivalue,
+                           options::OPT_mmultivalue, false)) {
+      getDriver().Diag(diag::err_drv_argument_not_allowed_with)
+          << "-fwasm-exceptions" << "-mno-multivalue";
+    }
+    if (DriverArgs.hasFlag(options::OPT_mno_reference_types,
+                           options::OPT_mreference_types, false)) {
+      getDriver().Diag(diag::err_drv_argument_not_allowed_with)
+          << "-fwasm-exceptions" << "-mno-reference-types";
+    }
+    CC1Args.push_back("-target-feature");
+    CC1Args.push_back("+multivalue");
+    CC1Args.push_back("-target-feature");
+    CC1Args.push_back("+reference-types");
   }
 
   for (const Arg *A : DriverArgs.filtered(options::OPT_mllvm)) {
@@ -408,6 +425,23 @@ void WebAssembly::addClangTargetOptions(const ArgList &DriverArgs,
       CC1Args.push_back("+exception-handling");
       // Backend needs '-exception-model=wasm' to use Wasm EH instructions
       CC1Args.push_back("-exception-model=wasm");
+
+      // New Wasm EH spec (adopted in Oct 2023) requires multivalue and
+      // reference-types.
+      if (DriverArgs.hasFlag(options::OPT_mno_multivalue,
+                             options::OPT_mmultivalue, false)) {
+        getDriver().Diag(diag::err_drv_argument_not_allowed_with)
+            << "-mllvm -wasm-enable-sjlj" << "-mno-multivalue";
+      }
+      if (DriverArgs.hasFlag(options::OPT_mno_reference_types,
+                             options::OPT_mreference_types, false)) {
+        getDriver().Diag(diag::err_drv_argument_not_allowed_with)
+            << "-mllvm -wasm-enable-sjlj" << "-mno-reference-types";
+      }
+      CC1Args.push_back("-target-feature");
+      CC1Args.push_back("+multivalue");
+      CC1Args.push_back("-target-feature");
+      CC1Args.push_back("+reference-types");
     }
   }
 }
diff --git a/clang/test/Driver/wasm-toolchain.c b/clang/test/Driver/wasm-toolchain.c
index dabf0ac2433bbb..7c26c2c13c0baf 100644
--- a/clang/test/Driver/wasm-toolchain.c
+++ b/clang/test/Driver/wasm-toolchain.c
@@ -120,11 +120,12 @@
 // RUN:   | FileCheck -check-prefix=EMSCRIPTEN_EH_ALLOWED_WO_ENABLE %s
 // EMSCRIPTEN_EH_ALLOWED_WO_ENABLE: invalid argument '-mllvm -emscripten-cxx-exceptions-allowed' only allowed with '-mllvm -enable-emscripten-cxx-exceptions'
 
-// '-fwasm-exceptions' sets +exception-handling and '-mllvm -wasm-enable-eh'
+// '-fwasm-exceptions' sets +exception-handling, -multivalue, -reference-types
+// and '-mllvm -wasm-enable-eh'
 // RUN: %clang -### --target=wasm32-unknown-unknown \
 // RUN:    --sysroot=/foo %s -fwasm-exceptions 2>&1 \
 // RUN:  | FileCheck -check-prefix=WASM_EXCEPTIONS %s
-// WASM_EXCEPTIONS: "-cc1" {{.*}} "-target-feature" "+exception-handling" "-mllvm" "-wasm-enable-eh"
+// WASM_EXCEPTIONS: "-cc1" {{.*}} "-target-feature" "+exception-handling" "-mllvm" "-wasm-enable-eh" "-target-feature" "+multivalue" "-target-feature" "+reference-types"
 
 // '-fwasm-exceptions' not allowed with '-mno-exception-handling'
 // RUN: not %clang -### --target=wasm32-unknown-unknown \
@@ -132,19 +133,32 @@
 // RUN:   | FileCheck -check-prefix=WASM_EXCEPTIONS_NO_EH %s
 // WASM_EXCEPTIONS_NO_EH: invalid argument '-fwasm-exceptions' not allowed with '-mno-exception-handling'
 
-// '-fwasm-exceptions' not allowed with '-mllvm -enable-emscripten-cxx-exceptions'
+// '-fwasm-exceptions' not allowed with
+// '-mllvm -enable-emscripten-cxx-exceptions'
 // RUN: not %clang -### --target=wasm32-unknown-unknown \
 // RUN:     --sysroot=/foo %s -fwasm-exceptions \
 // RUN:     -mllvm -enable-emscripten-cxx-exceptions 2>&1 \
 // RUN:   | FileCheck -check-prefix=WASM_EXCEPTIONS_EMSCRIPTEN_EH %s
 // WASM_EXCEPTIONS_EMSCRIPTEN_EH: invalid argument '-fwasm-exceptions' not allowed with '-mllvm -enable-emscripten-cxx-exceptions'
 
-// '-mllvm -wasm-enable-sjlj' sets +exception-handling and
-// '-exception-model=wasm'
+// '-fwasm-exceptions' not allowed with '-mno-multivalue'
+// RUN: not %clang -### --target=wasm32-unknown-unknown \
+// RUN:     --sysroot=/foo %s -fwasm-exceptions -mno-multivalue 2>&1 \
+// RUN:   | FileCheck -check-prefix=WASM_EXCEPTIONS_NO_MULTIVALUE %s
+// WASM_EXCEPTIONS_NO_MULTIVALUE: invalid argument '-fwasm-exceptions' not allowed with '-mno-multivalue'
+
+// '-fwasm-exceptions' not allowed with '-mno-reference-types'
+// RUN: not %clang -### --target=wasm32-unknown-unknown \
+// RUN:     --sysroot=/foo %s -fwasm-exceptions -mno-reference-types 2>&1 \
+// RUN:   | FileCheck -check-prefix=WASM_EXCEPTIONS_NO_REFERENCE_TYPES %s
+// WASM_EXCEPTIONS_NO_REFERENCE_TYPES: invalid argument '-fwasm-exceptions' not allowed with '-mno-reference-types'
+
+// '-mllvm -wasm-enable-sjlj' sets +exception-handling, +multivalue,
+// +reference-types  and '-exception-model=wasm'
 // RUN: %clang -### --target=wasm32-unknown-unknown \
 // RUN:    --sysroot=/foo %s -mllvm -wasm-enable-sjlj 2>&1 \
 // RUN:  | FileCheck -check-prefix=WASM_SJLJ %s
-// WASM_SJLJ: "-cc1" {{.*}} "-target-feature" "+exception-handling" "-exception-model=wasm"
+// WASM_SJLJ: "-cc1" {{.*}} "-target-feature" "+exception-handling" "-exception-model=wasm" "-target-feature" "+multivalue" "-target-feature" "+reference-types"
 
 // '-mllvm -wasm-enable-sjlj' not allowed with '-mno-exception-handling'
 // RUN: not %clang -### --target=wasm32-unknown-unknown \
@@ -168,6 +182,19 @@
 // RUN:   | FileCheck -check-prefix=WASM_SJLJ_EMSCRIPTEN_SJLJ %s
 // WASM_SJLJ_EMSCRIPTEN_SJLJ: invalid argument '-mllvm -wasm-enable-sjlj' not allowed with '-mllvm -enable-emscripten-sjlj'
 
+// '-mllvm -wasm-enable-sjlj' not allowed with '-mno-multivalue'
+// RUN: not %clang -### --target=wasm32-unknown-unknown \
+// RUN:     --sysroot=/foo %s -mllvm -wasm-enable-sjlj -mno-multivalue 2>&1 \
+// RUN:   | FileCheck -check-prefix=WASM_SJLJ_NO_MULTIVALUE %s
+// WASM_SJLJ_NO_MULTIVALUE: invalid argument '-mllvm -wasm-enable-sjlj' not allowed with '-mno-multivalue'
+
+// '-mllvm -wasm-enable-sjlj' not allowed with '-mno-reference-types'
+// RUN: not %clang -### --target=wasm32-unknown-unknown \
+// RUN:     --sysroot=/foo %s -mllvm -wasm-enable-sjlj \
+// RUN:     -mno-reference-types 2>&1 \
+// RUN:   | FileCheck -check-prefix=WASM_SJLJ_NO_REFERENCE_TYPES %s
+// WASM_SJLJ_NO_REFERENCE_TYPES: invalid argument '-mllvm -wasm-enable-sjlj' not allowed with '-mno-reference-types'
+
 // RUN: %clang -### %s -fsanitize=address --target=wasm32-unknown-emscripten 2>&1 | FileCheck -check-prefix=CHECK-ASAN-EMSCRIPTEN %s
 // CHECK-ASAN-EMSCRIPTEN: "-fsanitize=address"
 // CHECK-ASAN-EMSCRIPTEN: "-fsanitize-address-globals-dead-stripping"



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