[llvm] bd28bd5 - [clang-cl] /kernel should toggle bit 30 in @feat.00

[David Majnemer via llvm-commits]

Author: David Majnemer
Date: 2022-08-25T14:17:26Z
New Revision: bd28bd59a3693b6abc12231f2140e02760c0ada0

URL: https://github.com/llvm/llvm-project/commit/bd28bd59a3693b6abc12231f2140e02760c0ada0
DIFF: https://github.com/llvm/llvm-project/commit/bd28bd59a3693b6abc12231f2140e02760c0ada0.diff

LOG: [clang-cl] /kernel should toggle bit 30 in @feat.00

The linker is supposed to detect when an object with /kernel is linked
with another object which is not compiled with /kernel. The linker
detects this by checking bit 30 in @feat.00.

Added: 
    

Modified: 
    clang/lib/CodeGen/CodeGenModule.cpp
    clang/test/CodeGen/cfguardtable.c
    llvm/lib/Target/AArch64/AArch64AsmPrinter.cpp
    llvm/lib/Target/X86/X86AsmPrinter.cpp

Removed: 
    


################################################################################
diff  --git a/clang/lib/CodeGen/CodeGenModule.cpp b/clang/lib/CodeGen/CodeGenModule.cpp
index 6238a289978d..9df197056664 100644
--- a/clang/lib/CodeGen/CodeGenModule.cpp
+++ b/clang/lib/CodeGen/CodeGenModule.cpp
@@ -697,6 +697,10 @@ void CodeGenModule::Release() {
     // Function ID tables for EH Continuation Guard.
     getModule().addModuleFlag(llvm::Module::Warning, "ehcontguard", 1);
   }
+  if (Context.getLangOpts().Kernel) {
+    // Note if we are compiling with /kernel.
+    getModule().addModuleFlag(llvm::Module::Warning, "ms-kernel", 1);
+  }
   if (CodeGenOpts.OptimizationLevel > 0 && CodeGenOpts.StrictVTablePointers) {
     // We don't support LTO with 2 with 
diff erent StrictVTablePointers
     // FIXME: we could support it by stripping all the information introduced

diff  --git a/clang/test/CodeGen/cfguardtable.c b/clang/test/CodeGen/cfguardtable.c
index a92e1f6c610c..fe65d2a81c23 100644
--- a/clang/test/CodeGen/cfguardtable.c
+++ b/clang/test/CodeGen/cfguardtable.c
@@ -1,6 +1,7 @@
 // RUN: %clang_cc1 -cfguard-no-checks -emit-llvm %s -o - | FileCheck %s -check-prefix=CFGUARDNOCHECKS
 // RUN: %clang_cc1 -cfguard -emit-llvm %s -o - | FileCheck %s -check-prefix=CFGUARD
 // RUN: %clang_cc1 -ehcontguard -emit-llvm %s -o - | FileCheck %s -check-prefix=EHCONTGUARD
+// RUN: %clang_cc1 -fms-kernel -emit-llvm %s -o - | FileCheck %s -check-prefix=MS-KERNEL
 
 void f(void) {}
 
@@ -8,3 +9,4 @@ void f(void) {}
 // CFGUARDNOCHECKS: !"cfguard", i32 1}
 // CFGUARD: !"cfguard", i32 2}
 // EHCONTGUARD: !"ehcontguard", i32 1}
+// MS-KERNEL: !"ms-kernel", i32 1}

diff  --git a/llvm/lib/Target/AArch64/AArch64AsmPrinter.cpp b/llvm/lib/Target/AArch64/AArch64AsmPrinter.cpp
index 32d2f7945646..df2fce5621ad 100644
--- a/llvm/lib/Target/AArch64/AArch64AsmPrinter.cpp
+++ b/llvm/lib/Target/AArch64/AArch64AsmPrinter.cpp
@@ -219,6 +219,10 @@ void AArch64AsmPrinter::emitStartOfAsmFile(Module &M) {
       Feat00Flags |= 0x4000; // Object also has EHCont.
     }
 
+    if (M.getModuleFlag("ms-kernel")) {
+      Feat00Flags |= 0x40000000; // Object is compiled with /kernel.
+    }
+
     OutStreamer->emitSymbolAttribute(S, MCSA_Global);
     OutStreamer->emitAssignment(
         S, MCConstantExpr::create(Feat00Flags, MMI->getContext()));

diff  --git a/llvm/lib/Target/X86/X86AsmPrinter.cpp b/llvm/lib/Target/X86/X86AsmPrinter.cpp
index 834b626dbb15..3e0f2a41ee74 100644
--- a/llvm/lib/Target/X86/X86AsmPrinter.cpp
+++ b/llvm/lib/Target/X86/X86AsmPrinter.cpp
@@ -818,6 +818,10 @@ void X86AsmPrinter::emitStartOfAsmFile(Module &M) {
       Feat00Flags |= 0x4000; // Object also has EHCont.
     }
 
+    if (M.getModuleFlag("ms-kernel")) {
+      Feat00Flags |= 0x40000000; // Object is compiled with /kernel.
+    }
+
     OutStreamer->emitSymbolAttribute(S, MCSA_Global);
     OutStreamer->emitAssignment(
         S, MCConstantExpr::create(Feat00Flags, MMI->getContext()));