[clang] 7cab90a - Fix __attribute__((annotate("")) with non-zero globals AS

[Alex Richardson via cfe-commits]

Author: Alex Richardson
Date: 2021-08-26T10:09:40+01:00
New Revision: 7cab90a7b1c47780bbf7cfbfda4a1cbab24f0e5b

URL: https://github.com/llvm/llvm-project/commit/7cab90a7b1c47780bbf7cfbfda4a1cbab24f0e5b
DIFF: https://github.com/llvm/llvm-project/commit/7cab90a7b1c47780bbf7cfbfda4a1cbab24f0e5b.diff

LOG: Fix __attribute__((annotate("")) with non-zero globals AS

The existing code attempting to bitcast from a value in the default globals AS
to i8 addrspace(0)* was triggering an assertion failure in our downstream fork.
I found this while compiling poppler for CHERI-RISC-V (we use AS200 for all
globals). The test case uses AMDGPU since that is one of the in-tree targets
with a non-zero default globals address space.
The new test previously triggered a "Invalid constantexpr bitcast!" assertion
and now correctly generates code with addrspace(1) pointers.

Reviewed By: rjmccall

Differential Revision: https://reviews.llvm.org/D105972

Added: 
    

Modified: 
    clang/lib/CodeGen/CodeGenModule.cpp
    clang/lib/CodeGen/CodeGenTypeCache.h
    clang/test/CodeGen/annotations-global.c

Removed: 
    


################################################################################
diff  --git a/clang/lib/CodeGen/CodeGenModule.cpp b/clang/lib/CodeGen/CodeGenModule.cpp
index 87a15dbeb1b7f..664acefd1815c 100644
--- a/clang/lib/CodeGen/CodeGenModule.cpp
+++ b/clang/lib/CodeGen/CodeGenModule.cpp
@@ -130,8 +130,9 @@ CodeGenModule::CodeGenModule(ASTContext &C, const HeaderSearchOptions &HSO,
     C.getTargetInfo().getMaxPointerWidth());
   Int8PtrTy = Int8Ty->getPointerTo(0);
   Int8PtrPtrTy = Int8PtrTy->getPointerTo(0);
-  AllocaInt8PtrTy = Int8Ty->getPointerTo(
-      M.getDataLayout().getAllocaAddrSpace());
+  const llvm::DataLayout &DL = M.getDataLayout();
+  AllocaInt8PtrTy = Int8Ty->getPointerTo(DL.getAllocaAddrSpace());
+  GlobalsInt8PtrTy = Int8Ty->getPointerTo(DL.getDefaultGlobalsAddressSpace());
   ASTAllocaAddressSpace = getTargetCodeGenInfo().getASTAllocaAddressSpace();
 
   RuntimeCC = getTargetCodeGenInfo().getABIInfo().getRuntimeCC();
@@ -2532,7 +2533,7 @@ llvm::Constant *CodeGenModule::EmitAnnotationLineNo(SourceLocation L) {
 llvm::Constant *CodeGenModule::EmitAnnotationArgs(const AnnotateAttr *Attr) {
   ArrayRef<Expr *> Exprs = {Attr->args_begin(), Attr->args_size()};
   if (Exprs.empty())
-    return llvm::ConstantPointerNull::get(Int8PtrTy);
+    return llvm::ConstantPointerNull::get(GlobalsInt8PtrTy);
 
   llvm::FoldingSetNodeID ID;
   for (Expr *E : Exprs) {
@@ -2556,7 +2557,7 @@ llvm::Constant *CodeGenModule::EmitAnnotationArgs(const AnnotateAttr *Attr) {
                                       ".args");
   GV->setSection(AnnotationSection);
   GV->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
-  auto *Bitcasted = llvm::ConstantExpr::getBitCast(GV, Int8PtrTy);
+  auto *Bitcasted = llvm::ConstantExpr::getBitCast(GV, GlobalsInt8PtrTy);
 
   Lookup = Bitcasted;
   return Bitcasted;
@@ -2571,17 +2572,19 @@ llvm::Constant *CodeGenModule::EmitAnnotateAttr(llvm::GlobalValue *GV,
                  *LineNoCst = EmitAnnotationLineNo(L),
                  *Args = EmitAnnotationArgs(AA);
 
-  llvm::Constant *ASZeroGV = GV;
-  if (GV->getAddressSpace() != 0) {
-    ASZeroGV = llvm::ConstantExpr::getAddrSpaceCast(
-                   GV, GV->getValueType()->getPointerTo(0));
+  llvm::Constant *GVInGlobalsAS = GV;
+  if (GV->getAddressSpace() !=
+      getDataLayout().getDefaultGlobalsAddressSpace()) {
+    GVInGlobalsAS = llvm::ConstantExpr::getAddrSpaceCast(
+        GV, GV->getValueType()->getPointerTo(
+                getDataLayout().getDefaultGlobalsAddressSpace()));
   }
 
   // Create the ConstantStruct for the global annotation.
   llvm::Constant *Fields[] = {
-      llvm::ConstantExpr::getBitCast(ASZeroGV, Int8PtrTy),
-      llvm::ConstantExpr::getBitCast(AnnoGV, Int8PtrTy),
-      llvm::ConstantExpr::getBitCast(UnitGV, Int8PtrTy),
+      llvm::ConstantExpr::getBitCast(GVInGlobalsAS, GlobalsInt8PtrTy),
+      llvm::ConstantExpr::getBitCast(AnnoGV, GlobalsInt8PtrTy),
+      llvm::ConstantExpr::getBitCast(UnitGV, GlobalsInt8PtrTy),
       LineNoCst,
       Args,
   };

diff  --git a/clang/lib/CodeGen/CodeGenTypeCache.h b/clang/lib/CodeGen/CodeGenTypeCache.h
index f258234fb4d8f..577f88367a3a6 100644
--- a/clang/lib/CodeGen/CodeGenTypeCache.h
+++ b/clang/lib/CodeGen/CodeGenTypeCache.h
@@ -69,6 +69,12 @@ struct CodeGenTypeCache {
     llvm::PointerType *AllocaInt8PtrTy;
   };
 
+  /// void* in default globals address space
+  union {
+    llvm::PointerType *GlobalsVoidPtrTy;
+    llvm::PointerType *GlobalsInt8PtrTy;
+  };
+
   /// The size and alignment of the builtin C type 'int'.  This comes
   /// up enough in various ABI lowering tasks to be worth pre-computing.
   union {

diff  --git a/clang/test/CodeGen/annotations-global.c b/clang/test/CodeGen/annotations-global.c
index 5afec5b4eb72e..2a5c847fd9602 100644
--- a/clang/test/CodeGen/annotations-global.c
+++ b/clang/test/CodeGen/annotations-global.c
@@ -4,6 +4,7 @@
 // RUN: FileCheck --check-prefix=BAR %s < %t1
 // RUN: FileCheck --check-prefix=FOOS %s < %t1
 // RUN: FileCheck --check-prefix=ADDRSPACE %s < %t1
+// RUN: %clang_cc1 %s -triple r600 -emit-llvm -o - | FileCheck %s --check-prefix AS1-GLOBALS
 // END.
 
 static __attribute((annotate("sfoo_0"))) __attribute((annotate("sfoo_1"))) char sfoo;
@@ -45,3 +46,8 @@ __attribute((address_space(1))) __attribute__((annotate("addrspace1_ann"))) char
 
 // ADDRSPACE: target triple
 // ADDRSPACE: @llvm.global.annotations = appending global {{.*}} addrspacecast (i8 addrspace(1)* @addrspace1_var to i8*), {{.*}}
+
+// AS1-GLOBALS: target datalayout = "{{.+}}-A5-G1"
+// AS1-GLOBALS: @llvm.global.annotations = appending addrspace(1) global [11 x { i8 addrspace(1)*, i8 addrspace(1)*, i8 addrspace(1)*, i32, i8 addrspace(1)* }]
+// AS1-GLOBALS-SAME: { i8 addrspace(1)* @a.bar,
+// AS1-GLOBALS-SAME: { i8 addrspace(1)* @addrspace1_var,