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[WebAssembly] Add Wasm SjLj option support for clang 

This adds support for Wasm SjLj in clang. Also this sets the new
`-mllvm -wasm-enable-eh` option for Wasm EH.

Note there is a little unfortunate inconsistency there: Wasm EH is
enabled by a clang option `-fwasm-exceptions`, which sets
`-mllvm -wasm-enable-eh` in the backend options. It also sets
`-exception-model=wasm` but this is done in the common code.

Wasm SjLj doesn't have a clang-level option like `-fwasm-exceptions`.
`-fwasm-exceptions` was added because each exception model has its
corresponding `-f***-exceptions`, but I'm not sure if adding a new
option like `-fwasm-sjlj` or something is a good idea.

So the current plan is Emscripten sets `-mllvm -wasm-enable-sjlj` if
Wasm SJLj is enabled in its settings.js, as it does for Emscripten
EH/SjLj (it sets `-mllvm -enable-emscripten-cxx-exceptions` for
Emscripten EH and `-mllvm -enable-emscripten-sjlj` for Emscripten SjLj).
And setting this enables the exception handling feature, and also sets
`-exception-model=wasm`, but this time this is not done in the common
code so we do it ourselves.

Also note that other exception models have 1-to-1 correspondance with
their `-f***-exceptions` flag and their `-exception-model=***` flag, but
because we use `-exception-model=wasm` also for Wasm SjLj while
`-fwasm-exceptions` still means Wasm EH, there is also a little
inconsistency there, but I think it is manageable.

Also this adds various error checking and tests.

Reviewed By: dschuff

Differential Revision: https://reviews.llvm.org/D108582
This commit is contained in:
Heejin Ahn 2021-08-23 03:55:55 -07:00
parent 6609892a2d
commit a947b40caf
2 changed files with 72 additions and 8 deletions
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41
clang/lib/Driver/ToolChains/WebAssembly.cpp
View File

@ -293,6 +293,9 @@ void WebAssembly::addClangTargetOptions(const ArgList &DriverArgs,
// '-fwasm-exceptions' implies exception-handling feature
CC1Args.push_back("-target-feature");
CC1Args.push_back("+exception-handling");
// Backend needs -wasm-enable-eh to enable Wasm EH
CC1Args.push_back("-mllvm");
CC1Args.push_back("-wasm-enable-eh");
}
for (const Arg *A : DriverArgs.filtered(options::OPT_mllvm)) {
@ -300,14 +303,14 @@ void WebAssembly::addClangTargetOptions(const ArgList &DriverArgs,
if (Opt.startswith("-emscripten-cxx-exceptions-allowed")) {
// '-mllvm -emscripten-cxx-exceptions-allowed' should be used with
// '-mllvm -enable-emscripten-cxx-exceptions'
bool EmExceptionArgExists = false;
bool EmEHArgExists = false;
for (const Arg *A : DriverArgs.filtered(options::OPT_mllvm)) {
if (StringRef(A->getValue(0)) == "-enable-emscripten-cxx-exceptions") {
EmExceptionArgExists = true;
EmEHArgExists = true;
break;
}
}
if (!EmExceptionArgExists)
if (!EmEHArgExists)
getDriver().Diag(diag::err_drv_argument_only_allowed_with)
<< "-mllvm -emscripten-cxx-exceptions-allowed"
<< "-mllvm -enable-emscripten-cxx-exceptions";
@ -323,6 +326,38 @@ void WebAssembly::addClangTargetOptions(const ArgList &DriverArgs,
":noinline"));
}
}
if (Opt.startswith("-wasm-enable-sjlj")) {
// '-mllvm -wasm-enable-sjlj' is not compatible with
// '-mno-exception-handling'
if (DriverArgs.hasFlag(options::OPT_mno_exception_handing,
options::OPT_mexception_handing, false))
getDriver().Diag(diag::err_drv_argument_not_allowed_with)
<< "-mllvm -wasm-enable-sjlj"
<< "-mno-exception-handling";
// '-mllvm -wasm-enable-sjlj' is not compatible with
// '-mllvm -enable-emscripten-cxx-exceptions'
// because we don't allow Emscripten EH + Wasm SjLj
for (const Arg *A : DriverArgs.filtered(options::OPT_mllvm)) {
if (StringRef(A->getValue(0)) == "-enable-emscripten-cxx-exceptions")
getDriver().Diag(diag::err_drv_argument_not_allowed_with)
<< "-mllvm -wasm-enable-sjlj"
<< "-mllvm -enable-emscripten-cxx-exceptions";
}
// '-mllvm -wasm-enable-sjlj' is not compatible with
// '-mllvm -enable-emscripten-sjlj'
for (const Arg *A : DriverArgs.filtered(options::OPT_mllvm)) {
if (StringRef(A->getValue(0)) == "-enable-emscripten-sjlj")
getDriver().Diag(diag::err_drv_argument_not_allowed_with)
<< "-mllvm -wasm-enable-sjlj"
<< "-mllvm -enable-emscripten-sjlj";
}
// '-mllvm -wasm-enable-sjlj' implies exception-handling feature
CC1Args.push_back("-target-feature");
CC1Args.push_back("+exception-handling");
// Backend needs '-exception-model=wasm' to use Wasm EH instructions
CC1Args.push_back("-exception-model=wasm");
}
}
}

39
clang/test/Driver/wasm-toolchain.c
View File

@ -94,11 +94,11 @@
// 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
// '-fwasm-exceptions' sets +exception-handling and '-mllvm -wasm-enable-eh'
// RUN: %clang -### -no-canonical-prefixes -target wasm32-unknown-unknown \
// RUN: --sysroot=/foo %s -fwasm-exceptions 2>&1 \
// RUN: | FileCheck -check-prefix=WASM_EXCEPTIONS %s
// WASM_EXCEPTIONS: clang{{.*}}" "-cc1" {{.*}} "-target-feature" "+exception-handling"
// WASM_EXCEPTIONS: clang{{.*}}" "-cc1" {{.*}} "-target-feature" "+exception-handling" "-mllvm" "-wasm-enable-eh"
// '-fwasm-exceptions' not allowed with '-mno-exception-handling'
// RUN: %clang -### -no-canonical-prefixes -target wasm32-unknown-unknown \
@ -106,13 +106,42 @@
// 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: %clang -### -no-canonical-prefixes -target wasm32-unknown-unknown \
// RUN: --sysroot=/foo %s -fwasm-exceptions -mllvm -enable-emscripten-cxx-exceptions 2>&1 \
// 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'
// RUN: %clang -### -no-canonical-prefixes -target wasm32-unknown-unknown \
// RUN: --sysroot=/foo %s -mllvm -wasm-enable-sjlj 2>&1 \
// RUN: | FileCheck -check-prefix=WASM_SJLJ %s
// WASM_SJLJ: clang{{.*}}" "-cc1" {{.*}} "-target-feature" "+exception-handling" "-exception-model=wasm"
// '-mllvm -wasm-enable-sjlj' not allowed with '-mno-exception-handling'
// RUN: %clang -### -no-canonical-prefixes -target wasm32-unknown-unknown \
// RUN: --sysroot=/foo %s -mllvm -wasm-enable-sjlj -mno-exception-handling \
// RUN: 2>&1 \
// RUN: | FileCheck -check-prefix=WASM_SJLJ_NO_EH %s
// WASM_SJLJ_NO_EH: invalid argument '-mllvm -wasm-enable-sjlj' not allowed with '-mno-exception-handling'
// '-mllvm -wasm-enable-sjlj' not allowed with
// '-mllvm -enable-emscripten-cxx-exceptions'
// RUN: %clang -### -no-canonical-prefixes -target wasm32-unknown-unknown \
// RUN: --sysroot=/foo %s -mllvm -wasm-enable-sjlj \
// RUN: -mllvm -enable-emscripten-cxx-exceptions 2>&1 \
// RUN: | FileCheck -check-prefix=WASM_SJLJ_EMSCRIPTEN_EH %s
// WASM_SJLJ_EMSCRIPTEN_EH: invalid argument '-mllvm -wasm-enable-sjlj' not allowed with '-mllvm -enable-emscripten-cxx-exceptions'
// '-mllvm -wasm-enable-sjlj' not allowed with '-mllvm -enable-emscripten-sjlj'
// RUN: %clang -### -no-canonical-prefixes -target wasm32-unknown-unknown \
// RUN: --sysroot=/foo %s -mllvm -wasm-enable-sjlj \
// RUN: -mllvm -enable-emscripten-sjlj 2>&1 \
// 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'
// 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"