WASM open links in new browser tabs

I quickly gave up trying to understand what exactly clashes
between the Emscripten macros and OUString templates /
initializers. Not sure it can actually be "fixed".

Also disables the makeshared clang compilerplugin; currently
there is no way to get rid of all the false positive hits
when assigning the std::shared_ptr from a function instead of
a constructor call.

Change-Id: I8b13f179629ea63ff221584030556d2bedadc01b
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/128604
Tested-by: Jenkins
Reviewed-by: Jan-Marek Glogowski <glogow@fbihome.de>

3 files changed, 58 insertions, 0 deletions

diff --git a/shell/Library_syssh.mk b/shell/Library_syssh.mk
index e83a85262dcf..d059d6c5b671 100644
--- a/shell/Library_syssh.mk
+++ b/shell/Library_syssh.mk
@@ -43,6 +43,12 @@ $(eval $(call gb_Library_add_exception_objects,syssh,\
 	shell/source/unix/exec/shellexec \
 ))
 
+ifeq ($(OS),EMSCRIPTEN)
+$(eval $(call gb_Library_add_exception_objects,syssh,\
+    shell/source/unix/exec/shellexec_em \
+))
+endif
+
 endif # OS
 
 # vim: set shiftwidth=4 tabstop=4 noexpandtab:
diff --git a/shell/source/unix/exec/shellexec.cxx b/shell/source/unix/exec/shellexec.cxx
index 5248c934ab16..2e2b2040af1b 100644
--- a/shell/source/unix/exec/shellexec.cxx
+++ b/shell/source/unix/exec/shellexec.cxx
@@ -39,6 +39,11 @@
 #include <sys/stat.h>
 #endif
 
+#ifdef EMSCRIPTEN
+#include <rtl/uri.hxx>
+extern void execute_browser(const char* sUrl);
+#endif
+
 using com::sun::star::system::XSystemShellExecute;
 using com::sun::star::system::SystemShellExecuteException;
 
@@ -47,6 +52,7 @@ using namespace ::com::sun::star::lang;
 using namespace ::com::sun::star::system::SystemShellExecuteFlags;
 using namespace cppu;
 
+#ifndef EMSCRIPTEN
 namespace
 {
     void escapeForShell( OStringBuffer & rBuffer, const OString & rURL)
@@ -63,6 +69,7 @@ namespace
         }
     }
 }
+#endif
 
 ShellExec::ShellExec( const Reference< XComponentContext >& xContext ) :
     m_xContext(xContext)
@@ -71,6 +78,7 @@ ShellExec::ShellExec( const Reference< XComponentContext >& xContext ) :
 
 void SAL_CALL ShellExec::execute( const OUString& aCommand, const OUString& aParameter, sal_Int32 nFlags )
 {
+#ifndef EMSCRIPTEN
     OStringBuffer aBuffer, aLaunchBuffer;
 
     if (comphelper::LibreOfficeKit::isActive())
@@ -228,6 +236,22 @@ void SAL_CALL ShellExec::execute( const OUString& aCommand, const OUString& aPar
     int nerr = errno;
     throw SystemShellExecuteException(OUString::createFromAscii( strerror( nerr ) ),
         static_cast < XSystemShellExecute * > (this), nerr );
+#else // EMSCRIPTEN
+    (void)nFlags;
+
+    css::uno::Reference< css::uri::XUriReference > uri(
+        css::uri::UriReferenceFactory::create(m_xContext)->parse(aCommand));
+    if (!uri.is() || !uri->isAbsolute())
+        throw SystemShellExecuteException("Emscripten can just open absolute URIs.",
+                                          static_cast<XSystemShellExecute*>(this), 42);
+    if (!aParameter.isEmpty())
+        throw SystemShellExecuteException("Emscripten can't process parameters; encode in URI.",
+                                          static_cast<XSystemShellExecute*>(this), 42);
+
+    OUString sEscapedURI(rtl::Uri::encode(aCommand, rtl_UriCharClassUric,
+                                          rtl_UriEncodeIgnoreEscapes, RTL_TEXTENCODING_UTF8));
+    execute_browser(sEscapedURI.toUtf8().getStr());
+#endif
 }
 
 // XServiceInfo
diff --git a/shell/source/unix/exec/shellexec_em.cxx b/shell/source/unix/exec/shellexec_em.cxx
new file mode 100644
index 000000000000..219eac969416
--- /dev/null
+++ b/shell/source/unix/exec/shellexec_em.cxx
@@ -0,0 +1,28 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/*
+ * This file is part of the LibreOffice project.
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+/**
+ * Some of our templating stuff clashes with EM_ASM / MAIN_THREAD_EM_ASM:
+ *
+ *     shellexec.cxx:250:5: error: called object type 'const char *' is not a function or function pointer
+ *     MAIN_THREAD_EM_ASM(
+ *     ^
+ *     git_emsdk/upstream/emscripten/cache/sysroot/include/emscripten/em_asm.h:208:39: note: expanded from macro 'MAIN_THREAD_EM_ASM'
+ *     #define MAIN_THREAD_EM_ASM(code, ...) ((void)emscripten_asm_const_int_sync_on_main_thread(CODE_EXPR(#code) _EM_ASM_PREP_ARGS(__VA_ARGS__)))
+ *                                           ^
+ *     1 error generated.
+ *
+ *  so as a workaround the EM_ASM call is now in an extra file.
+ */
+
+#include <emscripten.h>
+
+void execute_browser(const char* sUrl) { EM_ASM("window.open(UTF8ToString($0));", sUrl); }
+
+/* vim:set shiftwidth=4 softtabstop=4 expandtab: */