Avoid undefined behavior in the JIT

We need to add an entry to all the RegisterID enums, so that we can mark
a RegisterID as invalid.

Task-number: QTBUG-94068
Change-Id: I5c13b271eade50fd63327612514ba7ebe33a5c39
Reviewed-by: Fabian Kosmale <fabian.kosmale@qt.io>
Reviewed-by: Andrei Golubev <andrei.golubev@qt.io>
(cherry picked from commit 636481a31110f1819efaf6500b25fbc395854311)
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>

5 files changed, 10 insertions, 6 deletions

diff --git a/src/3rdparty/masm/assembler/ARM64Assembler.h b/src/3rdparty/masm/assembler/ARM64Assembler.h
index a856196fe6..1431df50c8 100644
--- a/src/3rdparty/masm/assembler/ARM64Assembler.h
+++ b/src/3rdparty/masm/assembler/ARM64Assembler.h
@@ -517,6 +517,7 @@ typedef enum {
     x29 = fp,
     x30 = lr,
     zr = 0x3f,
+    none = 0xff,
 } RegisterID;
 
 typedef enum {
diff --git a/src/3rdparty/masm/assembler/ARMv7Assembler.h b/src/3rdparty/masm/assembler/ARMv7Assembler.h
index 03cb9f42f8..330b6c3629 100644
--- a/src/3rdparty/masm/assembler/ARMv7Assembler.h
+++ b/src/3rdparty/masm/assembler/ARMv7Assembler.h
@@ -64,6 +64,7 @@ namespace ARMRegisters {
         r13, sp = r13,
         r14, lr = r14,
         r15, pc = r15,
+        none = 0xff,
     } RegisterID;
 
     typedef enum {
diff --git a/src/3rdparty/masm/assembler/MIPSAssembler.h b/src/3rdparty/masm/assembler/MIPSAssembler.h
index 7f553bb9a1..0419ea0504 100644
--- a/src/3rdparty/masm/assembler/MIPSAssembler.h
+++ b/src/3rdparty/masm/assembler/MIPSAssembler.h
@@ -105,7 +105,8 @@ typedef enum {
     gp = r28,
     sp = r29,
     fp = r30,
-    ra = r31
+    ra = r31,
+    none = 0xff,
 } RegisterID;
 
 typedef enum {
diff --git a/src/3rdparty/masm/assembler/X86Assembler.h b/src/3rdparty/masm/assembler/X86Assembler.h
index e8ae687036..1061021227 100644
--- a/src/3rdparty/masm/assembler/X86Assembler.h
+++ b/src/3rdparty/masm/assembler/X86Assembler.h
@@ -62,6 +62,7 @@ namespace X86Registers {
         r14,
         r15,
 #endif
+        none = 0xff,
     } RegisterID;
 
     typedef enum {
diff --git a/src/qml/jit/qv4assemblercommon_p.h b/src/qml/jit/qv4assemblercommon_p.h
index 63a88f287f..c91a61a0a7 100644
--- a/src/qml/jit/qv4assemblercommon_p.h
+++ b/src/qml/jit/qv4assemblercommon_p.h
@@ -73,7 +73,7 @@ class PlatformAssembler_X86_64_SysV : public JSC::MacroAssembler<JSC::MacroAssem
 public:
     static constexpr int NativeStackAlignment = 16;
 
-    static const RegisterID NoRegister = RegisterID(-1);
+    static const RegisterID NoRegister = RegisterID::none;
 
     static const RegisterID ReturnValueRegister   = RegisterID::eax;
     static const RegisterID ReturnValueRegisterValue = ReturnValueRegister;
@@ -160,7 +160,7 @@ typedef PlatformAssembler_X86_64_SysV PlatformAssemblerBase;
 class PlatformAssembler_Win64 : public JSC::MacroAssembler<JSC::MacroAssemblerX86_64>
 {
 public:
-    static const RegisterID NoRegister = RegisterID(-1);
+    static const RegisterID NoRegister = RegisterID::none;
 
     static const RegisterID ReturnValueRegister   = RegisterID::eax;
     static const RegisterID ReturnValueRegisterValue = ReturnValueRegister;
@@ -250,7 +250,7 @@ typedef PlatformAssembler_Win64 PlatformAssemblerBase;
 class PlatformAssembler_X86_All : public JSC::MacroAssembler<JSC::MacroAssemblerX86>
 {
 public:
-    static const RegisterID NoRegister = RegisterID(-1);
+    static const RegisterID NoRegister = RegisterID::none;
 
     static const RegisterID ReturnValueRegisterValue = RegisterID::eax;
     static const RegisterID ReturnValueRegisterTag   = RegisterID::edx;
@@ -340,7 +340,7 @@ typedef PlatformAssembler_X86_All PlatformAssemblerBase;
 class PlatformAssembler_ARM64 : public JSC::MacroAssembler<JSC::MacroAssemblerARM64>
 {
 public:
-    static const RegisterID NoRegister = RegisterID(-1);
+    static const RegisterID NoRegister = RegisterID::none;
 
     static const RegisterID ReturnValueRegister   = JSC::ARM64Registers::x0;
     static const RegisterID ReturnValueRegisterValue = ReturnValueRegister;
@@ -439,7 +439,7 @@ typedef PlatformAssembler_ARM64 PlatformAssemblerBase;
 class PlatformAssembler_ARM32 : public JSC::MacroAssembler<JSC::MacroAssemblerARMv7>
 {
 public:
-    static const RegisterID NoRegister = RegisterID(-1);
+    static const RegisterID NoRegister = RegisterID::none;
 
     static const RegisterID ReturnValueRegisterValue = JSC::ARMRegisters::r0;
     static const RegisterID ReturnValueRegisterTag   = JSC::ARMRegisters::r1;