[WebAssembly] Fix EH feature flags when compiling multiple files

 llvm#124042 caused a problem that when invoking `clang` with multiple
files, the static `HasRun` variables were set when processing the first
file so the appropriate feature flags were not added from the second
file. This fixes the problem by making those `HasRun` variables just
normal variables within the enclosing function.

Author: aheejin

clang/lib/Driver/ToolChains/WebAssembly.cpp

@@ -344,12 +344,15 @@ void WebAssembly::addClangTargetOptions(const ArgList &DriverArgs,
     }
   }
 
+  bool HasBannedIncompatibleOptionsForWasmEHSjLj = false;
+  bool HasEnabledFeaturesForWasmEHSjLj = false;
+
   // Bans incompatible options for Wasm EH / SjLj. We don't allow using
   // different modes for EH and SjLj.
   auto BanIncompatibleOptionsForWasmEHSjLj = [&](StringRef CurOption) {
-    static bool HasRun = false;
-    if (HasRun)
+    if (HasBannedIncompatibleOptionsForWasmEHSjLj)
       return;
+    HasBannedIncompatibleOptionsForWasmEHSjLj = true;
     if (DriverArgs.hasFlag(options::OPT_mno_exception_handing,
                            options::OPT_mexception_handing, false))
       getDriver().Diag(diag::err_drv_argument_not_allowed_with)
@@ -373,14 +376,13 @@ void WebAssembly::addClangTargetOptions(const ArgList &DriverArgs,
               << CurOption << Option;
       }
     }
-    HasRun = true;
   };
 
   // Enable necessary features for Wasm EH / SjLj in the backend.
   auto EnableFeaturesForWasmEHSjLj = [&]() {
-    static bool HasRun = false;
-    if (HasRun)
+    if (HasEnabledFeaturesForWasmEHSjLj)
       return;
+    HasEnabledFeaturesForWasmEHSjLj = true;
     CC1Args.push_back("-target-feature");
     CC1Args.push_back("+exception-handling");
     // The standardized Wasm EH spec requires multivalue and reference-types.
@@ -390,7 +392,6 @@ void WebAssembly::addClangTargetOptions(const ArgList &DriverArgs,
     CC1Args.push_back("+reference-types");
     // Backend needs '-exception-model=wasm' to use Wasm EH instructions
     CC1Args.push_back("-exception-model=wasm");
-    HasRun = true;
   };
 
   if (DriverArgs.getLastArg(options::OPT_fwasm_exceptions)) {

clang/test/Driver/wasm-toolchain.c

@@ -224,6 +224,14 @@
 // RUN:   | FileCheck -check-prefix=WASM_LEGACY_EH_NO_EH %s
 // WASM_LEGACY_EH_NO_EH: invalid argument '-wasm-use-legacy-eh' not allowed with '-mno-exception-handling'
 
+// When invoking clang with multiple files in a single command line, target
+// feature flags should be equally added to the multiple clang-cc1 command lines
+// RUN: %clang -### --target=wasm32-unknown-unknown \
+// RUN:    --sysroot=/foo %s %s -mllvm -wasm-enable-sjlj 2>&1 \
+// RUN:  | FileCheck -check-prefix=WASM_SJLJ_MULTI_FILES %s
+// WASM_SJLJ_MULTI_FILES: "-cc1" {{.*}} "-target-feature" "+exception-handling" "-target-feature" "+multivalue" "-target-feature" "+reference-types" "-exception-model=wasm"
+// WASM_SJLJ_MULTI_FILES: "-cc1" {{.*}} "-target-feature" "+exception-handling" "-target-feature" "+multivalue" "-target-feature" "+reference-types" "-exception-model=wasm"
+
 // 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"