Cherry-pick exc_thrower.cxx changes from c367a2781f99ed22d0f7d64184fb567aacc43f35

This cherry-picks just the changes to
`cppuhelper/source/exc_thrower.cxx` to our
distro/lhm/libreoffice-7-3+backports
branch to simplify backporting of Android-related changes.
(The other WASM-related changes are irrelevant since we
don't use WASM.)

This is a partial cherry-pick of:

commit c367a2781f99ed22d0f7d64184fb567aacc43f35
Author: Thorsten Behrens <thorsten.behrens@allotropia.de>
Date:   Sat Sep 25 18:03:31 2021 +0200

    WASM UNO: add a minimal dummy bridge

    ... and use the same fake exception rethrowing code then the
    mobile platforms.

    Change-Id: Ic90de1cfd1e0092d6064d041a613d60d9f5f76b5
    Reviewed-on: https://gerrit.libreoffice.org/c/core/+/128596
    Tested-by: Jenkins
    Reviewed-by: Jan-Marek Glogowski <glogow@fbihome.de>

Change-Id: Icfb74267c59437eb6467f2f91a5aa1dada3716d4

1 files changed, 12 insertions, 5 deletions

diff --git a/cppuhelper/source/exc_thrower.cxx b/cppuhelper/source/exc_thrower.cxx
index 1bb8bfab13b3..c0d441fcd48b 100644
--- a/cppuhelper/source/exc_thrower.cxx
+++ b/cppuhelper/source/exc_thrower.cxx
@@ -168,9 +168,15 @@ ExceptionThrower::ExceptionThrower()
     uno_Interface::pDispatcher = ExceptionThrower_dispatch;
 }
 
+#if defined(IOS) || (defined(__aarch64__) && defined(ANDROID)) || defined(EMSCRIPTEN)
+#define RETHROW_FAKE_EXCEPTIONS 1
+#else
+#define RETHROW_FAKE_EXCEPTIONS 0
+#endif
+
 class theExceptionThrower : public rtl::Static<ExceptionThrower, theExceptionThrower> {};
 
-#if defined(IOS) || (defined(__aarch64__) && defined(ANDROID))
+#if RETHROW_FAKE_EXCEPTIONS
 // In the native iOS / Android app, where we don't have any Java, Python,
 // BASIC, or other scripting, the only thing that would use the C++/UNO bridge
 // functionality that invokes codeSnippet() was cppu::throwException().
@@ -208,7 +214,7 @@ void lo_mobile_throwException(css::uno::Any const& aException)
 
     assert(false);
 }
-#endif // defined(IOS) || (defined(__aarch64__) && defined(ANDROID))
+#endif // RETHROW_FAKE_EXCEPTIONS
 
 } // anonymous namespace
 
@@ -226,7 +232,7 @@ void SAL_CALL throwException( Any const & exc )
             "(must be derived from com::sun::star::uno::Exception)!" );
     }
 
-#if defined(IOS) || (defined(__aarch64__) && defined(ANDROID))
+#if RETHROW_FAKE_EXCEPTIONS
     lo_mobile_throwException(exc);
 #else
     Mapping uno2cpp(Environment(UNO_LB_UNO), Environment::getCurrent());
@@ -243,13 +249,14 @@ void SAL_CALL throwException( Any const & exc )
         ExceptionThrower::getCppuType() );
     OSL_ASSERT( xThrower.is() );
     xThrower->throwException( exc );
-#endif
+#endif // !RETHROW_FAKE_EXCEPTIONS
 }
 
 
 Any SAL_CALL getCaughtException()
 {
-#if defined(__aarch64__) && defined(ANDROID)
+    // why does this differ from RETHROW_FAKE_EXCEPTIONS?
+#if (defined(__aarch64__) && defined(ANDROID)) || defined(EMSCRIPTEN)
     // FIXME This stuff works on 32bit ARM, let's use the shortcut only for
     // the 64bit ARM.
     return Any();