XXX: Add linkage to vars.

trailofbits · Sep 24, 2024 · 6080354 · 6080354
1 parent 6c4f4f1
commit 6080354
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Showing 15 changed files with 123 additions and 70 deletions.
diff --git a/include/vast/Dialect/Core/CoreAttributes.td b/include/vast/Dialect/Core/CoreAttributes.td
@@ -219,23 +219,6 @@ def Core_StorageDuration
   Core_SD_Dynamic
 ] >;
 
-class Core_StorageDurationImpl
-{
-  code storageDurationImpl = [{
-    bool hasLocalStorage();
-
-    bool isLocalVarDecl();
-
-    bool isStaticLocal();
-
-    bool hasExternalStorage();
-
-    bool hasGlobalStorage();
-
-    StorageDuration getStorageDuration();
-  }];
-}
-
 // declaration context kinds
 class Core_DeclContextAttr< string name, int val > : I64EnumAttrCase< name, val > {}
 
@@ -266,31 +249,4 @@ def Core_DeclContextKind
   Core_DC_Namespace
 ] >;
 
-class Core_DeclContextImpl
-{
-  code declContextImpl = [{
-    DeclContextKind getDeclContextKind();
-
-    bool isStaticDataMember();
-
-    bool isInFileContext();
-
-    bool isInFunctionOrMethodContext();
-
-    bool isInRecordContext();
-
-    bool isFileVarDecl();
-  }];
-}
-
-class Core_StorageSpecifiers :
-  Core_StorageDurationImpl,
-  Core_DeclContextImpl
-{
-  code storageSpecifiersImpl =
-    storageDurationImpl #
-    declContextImpl;
-}
-
-
 #endif // VAST_DIALECT_CORE_COREATTRIBUTES
diff --git a/include/vast/Dialect/Core/Func.td b/include/vast/Dialect/Core/Func.td
@@ -10,18 +10,7 @@ include "mlir/Interfaces/FunctionInterfaces.td"
 include "vast/Dialect/Core/Interfaces/SymbolInterface.td"
 
 include "vast/Dialect/Core/CoreTraits.td"
-
-def Core_GlobalLinkageKind : Attr<
-    CPred<"::llvm::isa<::vast::core::GlobalLinkageKindAttr>($_self)">,
-    "global linkage kind"
-> {
-    let storageType = "::vast::core::GlobalLinkageKindAttr";
-    let returnType  = "::vast::core::GlobalLinkageKind";
-    let convertFromStorage = "$_self.getValue()";
-    let constBuilderCall = [{
-        ::vast::core::GlobalLinkageKindAttr::get($_builder.getContext(), $0)
-    }];
-}
+include "vast/Dialect/Core/LinkageHelper.td"
 
 def Core_FunctionType : Type<
     CPred<"::llvm::isa<::vast::core::FunctionType>($_self)">,

diff --git a/include/vast/Dialect/Core/Interfaces/DeclStorageInterface.td b/include/vast/Dialect/Core/Interfaces/DeclStorageInterface.td
@@ -68,7 +68,10 @@ def Core_DeclStorageInterface : Core_OpInterface< "DeclStorageInterface" > {
         InterfaceMethod<"",
             "::vast::core::DeclContextKind", "getDeclContextKind", (ins), [{}],
             /*defaultImplementation=*/[{
-                auto st = core::get_effective_symbol_table_for< core::var_symbol >(this->getOperation())->get_defining_operation();
+                if (auto kind_attr = $_op->template getAttrOfType< core::DeclContextKindAttr >("context")) {
+                    return kind_attr.getValue();
+                }
+                auto st = core::get_effective_symbol_table_for< core::var_symbol >($_op)->get_defining_operation();
                 if (mlir::isa< mlir::FunctionOpInterface >(st))
                     return DeclContextKind::dc_function;
                 if (st->template hasTrait< core::ScopeLikeTrait >())

diff --git a/include/vast/Dialect/Core/Linkage.hpp b/include/vast/Dialect/Core/Linkage.hpp
@@ -6,6 +6,7 @@
 
 VAST_RELAX_WARNINGS
 #include <clang/AST/GlobalDecl.h>
+#include <mlir/Dialect/LLVMIR/LLVMAttrs.h>
 VAST_UNRELAX_WARNINGS
 
 #include "vast/Dialect/HighLevel/HighLevelAttributes.hpp"
@@ -21,4 +22,6 @@ namespace vast::core {
 
     std::optional< core::GlobalLinkageKind > get_function_linkage(clang::GlobalDecl glob);
 
+    mlir::LLVM::Linkage convert_linkage_to_llvm(core::GlobalLinkageKind linkage);
+
 } // namespace vast::core
diff --git a/include/vast/Dialect/Core/LinkageHelper.td b/include/vast/Dialect/Core/LinkageHelper.td
@@ -0,0 +1,19 @@
+// Copyright (c) 2023, Trail of Bits, Inc.
+
+#ifndef VAST_DIALECT_CORE_LINKAGE_HELPER
+#define VAST_DIALECT_CORE_LINKAGE_HELPER
+include "mlir/IR/OpBase.td"
+
+def Core_GlobalLinkageKind : Attr<
+    CPred<"::llvm::isa<::vast::core::GlobalLinkageKindAttr>($_self)">,
+    "global linkage kind"
+> {
+    let storageType = "::vast::core::GlobalLinkageKindAttr";
+    let returnType  = "::vast::core::GlobalLinkageKind";
+    let convertFromStorage = "$_self.getValue()";
+    let constBuilderCall = [{
+        ::vast::core::GlobalLinkageKindAttr::get($_builder.getContext(), $0)
+    }];
+}
+
+#endif // VAST_DIALECT_CORE_LINKAGE_HELPER
diff --git a/include/vast/Dialect/HighLevel/HighLevelVar.td b/include/vast/Dialect/HighLevel/HighLevelVar.td
@@ -6,6 +6,7 @@
 include "vast/Dialect/Core/CoreTraits.td"
 include "vast/Dialect/Core/StorageInfo.td"
 include "vast/Dialect/Core/Interfaces/DeclStorageInterface.td"
+include "vast/Dialect/Core/LinkageHelper.td"
 
 // Variable Operation
 def HighLevel_VarDeclOp
@@ -22,7 +23,8 @@ def HighLevel_VarDeclOp
     SymbolNameAttr:$sym_name,
     TypeAttr:$type,
     Core_StorageClass:$storageClass,
-    Core_ThreadStorage:$threadStorageClass
+    Core_ThreadStorage:$threadStorageClass,
+    OptionalAttr<Core_GlobalLinkageKind>:$linkage
   );
 
   let regions = (region
@@ -36,13 +38,14 @@ def HighLevel_VarDeclOp
       "llvm::StringRef":$sym_name,
       "core::StorageClass":$storageClass,
       "core::TSClass":$threadStorageClass,
+      CArg< "std::optional< core::GlobalLinkageKind >", "std::nullopt">:$linkage,
       CArg< "maybe_builder_callback_ref", "std::nullopt" >:$initBuilder,
       CArg< "maybe_builder_callback_ref", "std::nullopt" >:$allocaBuilder
     )>
   ];
 
   let assemblyFormat = [{
-    $sym_name attr-dict custom< StorageClasses >($storageClass, $threadStorageClass)
+    $sym_name attr-dict ($linkage^)? custom< StorageClasses >($storageClass, $threadStorageClass)
       `:` $type
       (`=` $initializer^)?
       (`allocation_size` $allocation_size^)?

diff --git a/lib/vast/CodeGen/DefaultDeclVisitor.cpp b/lib/vast/CodeGen/DefaultDeclVisitor.cpp
@@ -216,13 +216,24 @@ namespace vast::cg {
                 .freeze();
         };
 
+        auto linkage_builder = [](const clang::VarDecl *decl) {
+            auto gva_linkage = decl->getASTContext().GetGVALinkageForVariable(decl);
+            return core::get_declarator_linkage(
+                decl,
+                gva_linkage,
+                decl->getType().isConstQualified()
+            );
+        };
+
+
         auto var = maybe_declare([&] {
             return bld.compose< hl::VarDeclOp >()
                 .bind(self.location(decl))
                 .bind(visit_as_lvalue_type(self, mctx, decl->getType()))
                 .bind(self.symbol(decl))
                 .bind_always(storage_class(decl))
                 .bind_always(thread_storage_class(decl))
+                .bind_choose(is_global, std::optional(linkage_builder(decl)), std::nullopt)
                 // FIXME: The initializer region is filled later as it might
                 // have references to the VarDecl we are currently
                 // visiting - int *x = malloc(sizeof(*x))

diff --git a/lib/vast/Conversion/ToLLVM/IRsToLLVM.cpp b/lib/vast/Conversion/ToLLVM/IRsToLLVM.cpp
@@ -23,6 +23,7 @@ VAST_UNRELAX_WARNINGS
 
 #include "vast/Dialect/Core/CoreAttributes.hpp"
 #include "vast/Dialect/Core/CoreOps.hpp"
+#include "vast/Dialect/Core/Linkage.hpp"
 
 #include "vast/Dialect/LowLevel/LowLevelOps.hpp"
 
@@ -356,13 +357,25 @@ namespace vast::conv::irstollvm
             auto target_type = this->convert(t.getElementType());
 
             // So we know this is a global, otherwise it would be in `ll:`.
+            auto linkage = op.getLinkage();
+            if (!linkage) {
+                if (op.isStaticLocal()) {
+                    linkage = core::GlobalLinkageKind::InternalLinkage;
+                } else {
+                    VAST_REPORT("Global var without linkage information.");
+                    return mlir::failure();
+                }
+            }
+
             auto gop = rewriter.create< mlir::LLVM::GlobalOp >(
                     op.getLoc(),
                     target_type,
                     // TODO(conv:irstollvm): Constant.
-                    true,
-                    LLVM::Linkage::Internal,
-                    op.getSymbolName(), mlir::Attribute());
+                    false,
+                    core::convert_linkage_to_llvm(linkage.value()),
+                    op.getSymbolName(),
+                    mlir::Attribute()
+            );
 
             // We could probably try to analyze the region to see if it isn't
             // a case where we can just do an attribute, but for now let's
@@ -437,11 +450,13 @@ namespace vast::conv::irstollvm
             //                    want to lower them all.
 
 
-            // TODO(lukas): Linkage?
-            auto linkage = LLVM::Linkage::External;
+            auto linkage = func_op.getLinkage();
+            VAST_CHECK(linkage, "Attempting lower function without set linkage {0}", func_op);
             auto new_func = rewriter.create< llvm_func_op >(
-                func_op.getLoc(), func_op.getName(),
-                target_type, linkage,
+                func_op.getLoc(),
+                func_op.getName(),
+                target_type,
+                core::convert_linkage_to_llvm(linkage.value()),
                 func_op.isVarArg(), LLVM::CConv::C
             );
 

diff --git a/lib/vast/Conversion/ToMem/EvictStaticLocals.cpp b/lib/vast/Conversion/ToMem/EvictStaticLocals.cpp
@@ -38,12 +38,16 @@ namespace vast::conv {
 
                 auto new_decl = rewriter.create< hl::VarDeclOp >(
                         op.getLoc(),
-                        (parent_fn.getName() + "." + op.getSymName()).str(),
                         op.getType(),
+                        (parent_fn.getName() + "." + op.getSymName()).str(),
                         op.getStorageClass(),
-                        op.getThreadStorageClass()
+                        op.getThreadStorageClass(),
+                        std::optional(core::GlobalLinkageKind::InternalLinkage)
                 );
 
+                // Save current context informationinto the op to make sure the information stays valid
+                new_decl->setAttr("context", core::DeclContextKindAttr::get(op.getContext(), op.getDeclContextKind()));
+
                 new_decl.getInitializer().takeBody(op.getInitializer());
                 new_decl.getAllocationSize().takeBody(op.getAllocationSize());
 

diff --git a/lib/vast/Dialect/Core/Linkage.cpp b/lib/vast/Dialect/Core/Linkage.cpp
@@ -276,4 +276,31 @@ namespace vast::core {
         return get_declarator_linkage(decl, linkage, /* is const variable */ false);
     }
 
+    mlir::LLVM::Linkage convert_linkage_to_llvm(core::GlobalLinkageKind linkage) {
+        switch (linkage) {
+            case core::GlobalLinkageKind::ExternalLinkage:
+                return mlir::LLVM::Linkage::External;
+            case core::GlobalLinkageKind::AvailableExternallyLinkage:
+                return mlir::LLVM::Linkage::AvailableExternally;
+            case core::GlobalLinkageKind::LinkOnceAnyLinkage:
+                return mlir::LLVM::Linkage::Linkonce;
+            case core::GlobalLinkageKind::LinkOnceODRLinkage:
+                return mlir::LLVM::Linkage::LinkonceODR;
+            case core::GlobalLinkageKind::WeakAnyLinkage:
+                return mlir::LLVM::Linkage::Weak;
+            case core::GlobalLinkageKind::WeakODRLinkage:
+                return mlir::LLVM::Linkage::WeakODR;
+            case core::GlobalLinkageKind::InternalLinkage:
+                return mlir::LLVM::Linkage::Internal;
+            case core::GlobalLinkageKind::PrivateLinkage:
+                return mlir::LLVM::Linkage::Private;
+            case core::GlobalLinkageKind::ExternalWeakLinkage:
+                return mlir::LLVM::Linkage::ExternWeak;
+            case core::GlobalLinkageKind::CommonLinkage:
+                return mlir::LLVM::Linkage::Common;
+            case core::GlobalLinkageKind::AppendingLinkage:
+                return mlir::LLVM::Linkage::Appending;
+        }
+    }
+
 } // namespace vast::core
diff --git a/lib/vast/Dialect/HighLevel/HighLevelOps.cpp b/lib/vast/Dialect/HighLevel/HighLevelOps.cpp
@@ -344,6 +344,7 @@ namespace vast::hl
         llvm::StringRef name,
         core::StorageClass storage_class,
         core::TSClass thread_storage_class,
+        std::optional< core::GlobalLinkageKind > linkage,
         maybe_builder_callback_ref init,
         maybe_builder_callback_ref alloc
     ) {
@@ -352,6 +353,9 @@ namespace vast::hl
         st.addAttribute("type", mlir::TypeAttr::get(type));
         st.addAttribute("storageClass", core::StorageClassAttr::get(ctx, storage_class));
         st.addAttribute("threadStorageClass", core::TSClassAttr::get(ctx, thread_storage_class));
+        if (linkage) {
+            st.addAttribute("liinkage", core::GlobalLinkageKindAttr::get(ctx, linkage.value()));
+        }
         InsertionGuard guard(bld);
 
         build_region(bld, st, init);

diff --git a/test/lit.cfg.py b/test/lit.cfg.py
@@ -82,6 +82,7 @@
     , "vast-hl-to-ll-geps"
     , "vast-vars-to-cells"
     , "vast-refs-to-ssa"
+    , "vast-evict-static-locals"
     , "vast-strip-param-lvalues"
     , "vast-lower-value-categories"
     , "vast-hl-to-lazy-regions"

diff --git a/test/vast/Conversion/cmake-platform-test.c b/test/vast/Conversion/cmake-platform-test.c
@@ -24,7 +24,7 @@
 
 #define SIZE (sizeof(unsigned short))
 
-// CHECK: constant @info_size() {{.*}} !llvm.array
+// CHECK: @info_size() {{.*}} !llvm.array
 static char info_size[] =  {'I', 'N', 'F', 'O', ':', 's','i','z','e','[',
   ('0' + ((SIZE / 10000)%10)),
   ('0' + ((SIZE / 1000)%10)),

diff --git a/test/vast/Conversion/static-var-a.c b/test/vast/Conversion/static-var-a.c
@@ -0,0 +1,18 @@
+// RUN: %vast-front -vast-emit-mlir=hl -o - %s | %file-check %s -check-prefix=HL
+// RUN: %check-evict-static-locals %s | %file-check %s -check-prefix=EVICTED
+// RUN: %check-core-to-llvm %s | %file-check %s -check-prefix=LLVM
+
+// HL: hl.var @x  sc_static
+// HL: hl.ref @x
+
+// EVICTED: hl.var @foo.x  sc_static
+// EVICTED: ll.func @foo
+// EVICTED: hl.ref @foo.x
+
+// LLVM: llvm.mlir.global internal @foo.x()
+// LLVM: llvm.func @foo
+// LLVM: llvm.mlir.addressof @foo.x
+int foo() {
+    static int x = 5;
+    return x++;
+}
diff --git a/test/vast/Conversion/subscript-b.c b/test/vast/Conversion/subscript-b.c
@@ -9,7 +9,7 @@
 // VAL_CAT:    hl.value.yield {{.*}} : !hl.array<3, si32>
 
 
-// C_LLVM:  llvm.mlir.global internal constant @arr1() {addr_space = 0 : i32} : !llvm.array<3 x i32> {
+// C_LLVM:  llvm.mlir.global internal @arr1() {addr_space = 0 : i32} : !llvm.array<3 x i32> {
 
 int arr1[] = { 0, 2, 4 };