Disable JIT for arm64 when doing macOS universal builds

Our current approach to building universal macOS Qt is to pass 2 -arch
flags to clang, which underneath spawn 2 clang invocations with each
separate arch and lipo-s the result together.
This approah also meanss that we do only one set of config tests for
the main (first) architecture.

Currently Qml doesn't support JITing for macOS on Apple Silicon
(arm64), but if the first architecture is x86_64, the qml_jit feature
will be set to 'true', and cause compilation errors when trying to
build the arm slice of the jit source files.

To circumvent that, and allow skipping compilation of JIT specific
code, we have to apply the same trick we do in qtbase,
which is to set a compile definition that takes the current
architecture into account, and surround all relevant code with an #if
block taking to account both the feature and current architecture.

Additionally, surround the jit source files with #if
QT_CONFIG(qml_jit).

Amends 561a2cec9b95b22783a00b48078b532010357066

Task-number: QTBUG-85447
Change-Id: I28b286d218333076223177c456175f180888a667
Reviewed-by: Ulf Hermann <ulf.hermann@qt.io>
(cherry picked from commit fcbb78808eea5672f12deb3f15c1fcbf9f0fbdaf)
Reviewed-by: Alexandru Croitor <alexandru.croitor@qt.io>

7 files changed, 44 insertions, 3 deletions

diff --git a/src/qml/jit/qv4assemblercommon.cpp b/src/qml/jit/qv4assemblercommon.cpp
index 45ca259925..57682b6ae7 100644
--- a/src/qml/jit/qv4assemblercommon.cpp
+++ b/src/qml/jit/qv4assemblercommon.cpp
@@ -51,6 +51,8 @@
 #include <assembler/LinkBuffer.h>
 #include <WTFStubs.h>
 
+#if QT_CONFIG(qml_jit)
+
 #undef ENABLE_ALL_ASSEMBLERS_FOR_REFACTORING_PURPOSES
 
 QT_BEGIN_NAMESPACE
@@ -370,3 +372,5 @@ void PlatformAssemblerCommon::storeInt32AsValue(int srcInt, Address destAddr)
 } // QV4 namepsace
 
 QT_END_NAMESPACE
+
+#endif // QT_CONFIG(qml_jit)
diff --git a/src/qml/jit/qv4assemblercommon_p.h b/src/qml/jit/qv4assemblercommon_p.h
index 89efc2ec5b..eaef285d6e 100644
--- a/src/qml/jit/qv4assemblercommon_p.h
+++ b/src/qml/jit/qv4assemblercommon_p.h
@@ -58,7 +58,7 @@
 #include <wtf/Vector.h>
 #include <assembler/MacroAssembler.h>
 
-QT_REQUIRE_CONFIG(qml_jit);
+#if QT_CONFIG(qml_jit)
 
 QT_BEGIN_NAMESPACE
 
@@ -740,4 +740,6 @@ private:
 
 QT_END_NAMESPACE
 
+#endif // QT_CONFIG(qml_jit)
+
 #endif // QV4PLATFORMASSEMBLER_P_H
diff --git a/src/qml/jit/qv4baselineassembler.cpp b/src/qml/jit/qv4baselineassembler.cpp
index 078df56a89..fecb3ecec8 100644
--- a/src/qml/jit/qv4baselineassembler.cpp
+++ b/src/qml/jit/qv4baselineassembler.cpp
@@ -55,6 +55,8 @@
 
 #undef ENABLE_ALL_ASSEMBLERS_FOR_REFACTORING_PURPOSES
 
+#if QT_CONFIG(qml_jit)
+
 QT_BEGIN_NAMESPACE
 namespace QV4 {
 namespace JIT {
@@ -1619,3 +1621,5 @@ void BaselineAssembler::ret()
 } // QV4 namepsace
 
 QT_END_NAMESPACE
+
+#endif // QT_CONFIG(qml_jit)
diff --git a/src/qml/jit/qv4baselineassembler_p.h b/src/qml/jit/qv4baselineassembler_p.h
index 9c4f8d00fb..be6938492a 100644
--- a/src/qml/jit/qv4baselineassembler_p.h
+++ b/src/qml/jit/qv4baselineassembler_p.h
@@ -55,7 +55,7 @@
 #include <private/qv4function_p.h>
 #include <QHash>
 
-QT_REQUIRE_CONFIG(qml_jit);
+#if QT_CONFIG(qml_jit)
 
 QT_BEGIN_NAMESPACE
 
@@ -182,4 +182,6 @@ private:
 
 QT_END_NAMESPACE
 
+#endif // QT_CONFIG(qml_jit)
+
 #endif // QV4BASELINEASSEMBLER_P_H
diff --git a/src/qml/jit/qv4baselinejit.cpp b/src/qml/jit/qv4baselinejit.cpp
index 9a1e57e40b..edc0cf8781 100644
--- a/src/qml/jit/qv4baselinejit.cpp
+++ b/src/qml/jit/qv4baselinejit.cpp
@@ -42,6 +42,8 @@
 #include <private/qv4lookup_p.h>
 #include <private/qv4generatorobject_p.h>
 
+#if QT_CONFIG(qml_jit)
+
 QT_USE_NAMESPACE
 using namespace QV4;
 using namespace QV4::JIT;
@@ -930,3 +932,6 @@ void BaselineJIT::endInstruction(Instr::Type instr)
 {
     Q_UNUSED(instr);
 }
+
+#endif // QT_CONFIG(qml_jit)
+
diff --git a/src/qml/jit/qv4baselinejit_p.h b/src/qml/jit/qv4baselinejit_p.h
index 1b9c781d20..7927922645 100644
--- a/src/qml/jit/qv4baselinejit_p.h
+++ b/src/qml/jit/qv4baselinejit_p.h
@@ -56,7 +56,7 @@
 #include <private/qv4instr_moth_p.h>
 #include <private/qv4bytecodehandler_p.h>
 
-QT_REQUIRE_CONFIG(qml_jit);
+#if QT_CONFIG(qml_jit)
 
 QT_BEGIN_NAMESPACE
 
@@ -220,4 +220,6 @@ private:
 
 QT_END_NAMESPACE
 
+#endif // QT_CONFIG(qml_jit)
+
 #endif // QV4JIT_P_H
diff --git a/src/qml/qtqmlglobal_p.h b/src/qml/qtqmlglobal_p.h
index 4e82e9e2b7..8a12f14645 100644
--- a/src/qml/qtqmlglobal_p.h
+++ b/src/qml/qtqmlglobal_p.h
@@ -70,4 +70,26 @@ GHS_KEEP_REFERENCE(qml_register_types_QtQml);
 #  define Q_QML_AUTOTEST_EXPORT
 #endif
 
+// When doing macOS universal builds, JIT needs to be disabled for the ARM slice.
+// Because both arm and x86_64 slices are built in one clang frontend invocation
+// we need this hack to ensure each backend invocation sees the correct value
+// of the feature definition.
+
+// Unset dummy value
+#undef QT_QML_JIT_SUPPORTED_IMPL
+// Compute per-arch value and save in extra define
+#if QT_CONFIG(qml_jit) && !(defined(Q_OS_MACOS) && defined(Q_PROCESSOR_ARM))
+#  define QT_QML_JIT_SUPPORTED_IMPL 1
+#else
+#  define QT_QML_JIT_SUPPORTED_IMPL 0
+#endif
+// Unset original feature value
+#undef QT_FEATURE_qml_jit
+// Set new value based on previous computation
+#if QT_QML_JIT_SUPPORTED_IMPL
+#  define QT_FEATURE_qml_jit 1
+#else
+#  define QT_FEATURE_qml_jit -1
+#endif
+
 #endif // QTQMLGLOBAL_P_H