Merge pull request #84939 from DougGregor/sil-asmname-and-section

[SIL] Add asmname attribute to SIL functions and global variables

Author: DougGregor

docs/SIL/FunctionAttributes.md

@@ -228,3 +228,11 @@ Specifies that the optimizer and IRGen must not add runtime calls which
 are not in the function originally. This attribute is set for functions
 with performance constraints or functions which are called from
 functions with performance constraints.
+
+### Naming
+
+```
+sil-function-attribute :: '[' asmname "' identifier '" ']'
+```
+
+Specifies that the SIL function should be lowered to LLVM IR with the given function name.

include/swift/SIL/SILFunction.h

@@ -320,6 +320,11 @@ class SILFunction
   /// The function's remaining set of specialize attributes.
   std::vector<SILSpecializeAttr*> SpecializeAttrSet;
 
+  /// The name that this function should have when it is lowered to LLVM IR.
+  ///
+  /// If empty, use the SIL function's name directly.
+  StringRef AsmName;
+
   /// Name of a section if @_section attribute was used, otherwise empty.
   StringRef Section;
 
@@ -1423,6 +1428,10 @@ class SILFunction
   bool markedAsUsed() const { return MarkedAsUsed; }
   void setMarkedAsUsed(bool value) { MarkedAsUsed = value; }
 
+  /// Return custom assembler name, otherwise empty.
+  StringRef asmName() const { return AsmName; }
+  void setAsmName(StringRef value) { AsmName = value; }
+
   /// Return custom section name if @_section was used, otherwise empty
   StringRef section() const { return Section; }
   void setSection(StringRef value) { Section = value; }

include/swift/SIL/SILGlobalVariable.h

@@ -60,6 +60,13 @@ class SILGlobalVariable
   /// binary.  A pointer into the module's lookup table.
   StringRef Name;
 
+  /// The name that this variable should have when lowered to LLVM IR. If empty,
+  /// the mangled name of the variable will be used instead.
+  StringRef AsmName;
+
+  /// Name of a section if @_section attribute was used, otherwise empty.
+  StringRef Section;
+
   /// The lowered type of the variable.
   SILType LoweredType;
 
@@ -150,7 +157,15 @@ class SILGlobalVariable
   }
 
   StringRef getName() const { return Name; }
-  
+
+  /// Return custom assembler name, otherwise empty.
+  StringRef asmName() const { return AsmName; }
+  void setAsmName(StringRef value) { AsmName = value; }
+
+  /// Return custom section name if @_section was used, otherwise empty
+  StringRef section() const { return Section; }
+  void setSection(StringRef value) { Section = value; }
+
   void setDeclaration(bool isD) { IsDeclaration = isD; }
 
   /// True if this is a definition of the variable.
@@ -232,15 +247,6 @@ class SILGlobalVariable
 
   void setMarkedAsUsed(bool used) { IsUsed = used; }
 
-  /// Returns a SectionAttr if this global variable has `@_section` attribute.
-  SectionAttr *getSectionAttr() const {
-    auto *V = getDecl();
-    if (!V)
-      return nullptr;
-
-    return V->getAttrs().getAttribute<SectionAttr>();
-  }
-
   /// Return whether this variable corresponds to a Clang node.
   bool hasClangNode() const;
 

lib/IRGen/GenDecl.cpp

@@ -2865,8 +2865,8 @@ Address IRGenModule::getAddrOfSILGlobalVariable(SILGlobalVariable *var,
       addUsedGlobal(gvar);
     else if (var->shouldBePreservedForDebugger() && forDefinition) 
       addUsedGlobal(gvar);
-    if (auto *sectionAttr = var->getSectionAttr())
-      gvar->setSection(sectionAttr->Name);
+    if (!var->section().empty())
+      gvar->setSection(var->section());
   }
   if (forDefinition && !gvar->hasInitializer()) {
     if (initVal) {

lib/IRGen/Linking.cpp

@@ -408,6 +408,10 @@ std::string LinkEntity::mangleAsString(ASTContext &Ctx) const {
   }
 
   case Kind::SILFunction: {
+    auto asmName = getSILFunction()->asmName();
+    if (!asmName.empty())
+      return asmName.str();
+
     std::string Result(getSILFunction()->getName());
     if (isDynamicallyReplaceable()) {
       Result.append("TI");
@@ -465,8 +469,13 @@ std::string LinkEntity::mangleAsString(ASTContext &Ctx) const {
     return Result;
   }
 
-  case Kind::SILGlobalVariable:
+  case Kind::SILGlobalVariable: {
+    auto asmName = getSILGlobalVariable()->asmName();
+    if (!asmName.empty())
+      return asmName.str();
+
     return getSILGlobalVariable()->getName().str();
+  }
 
   case Kind::ReadOnlyGlobalObject:
     return getSILGlobalVariable()->getName().str() + "r";

lib/SIL/IR/SILGlobalVariable.cpp

@@ -91,7 +91,7 @@ bool SILGlobalVariable::isPossiblyUsedExternally() const {
   if (markedAsUsed())
     return true;
 
-  if (getSectionAttr())
+  if (!section().empty())
     return true;
 
   SILLinkage linkage = getLinkage();
@@ -151,7 +151,7 @@ SILInstruction *SILGlobalVariable::getStaticInitializerValue() {
 }
 
 bool SILGlobalVariable::mustBeInitializedStatically() const {
-  if (getSectionAttr())
+  if (!section().empty())
     return true;
 
   auto *decl = getDecl();  

lib/SIL/IR/SILPrinter.cpp

@@ -3709,6 +3709,9 @@ void SILFunction::print(SILPrintContext &PrintCtx) const {
   if (!section().empty())
     OS << "[section \"" << section() << "\"] ";
 
+  if (!asmName().empty())
+    OS << "[asmname \"" << asmName() << "\"] ";
+
   // TODO: Handle clang node owners which don't have a name.
   if (hasClangNode() && getClangNodeOwner()->hasName()) {
     OS << "[clang ";
@@ -3777,6 +3780,12 @@ void SILGlobalVariable::print(llvm::raw_ostream &OS, bool Verbose) const {
   if (markedAsUsed())
     OS << "[used] ";
 
+  if (!asmName().empty())
+    OS << "[asmname \"" << asmName() << "\"] ";
+
+  if (!section().empty())
+    OS << "[section \"" << section() << "\"] ";
+
   printName(OS);
   OS << " : " << LoweredType;
 

lib/SIL/Parser/ParseSIL.cpp

@@ -679,7 +679,8 @@ static bool parseDeclSILOptional(
     SILFunction **usedAdHocRequirementWitness, Identifier *objCReplacementFor,
     SILFunction::Purpose *specialPurpose, Inline_t *inlineStrategy,
     OptimizationMode *optimizationMode, PerformanceConstraints *perfConstraints,
-    bool *isPerformanceConstraint, bool *markedAsUsed, StringRef *section,
+    bool *isPerformanceConstraint, bool *markedAsUsed, StringRef *asmName,
+    StringRef *section,
     bool *isLet, bool *isWeakImported, bool *needStackProtection,
     bool *isSpecialized, AvailabilityRange *availability,
     bool *isWithoutActuallyEscapingThunk,
@@ -807,6 +808,20 @@ static bool parseDeclSILOptional(
       }
       *actorIsolation = *optIsolation;
       SP.P.consumeToken(tok::string_literal);
+      SP.P.parseToken(tok::r_square, diag::expected_in_attribute_list);
+      continue;
+    } else if (asmName && SP.P.Tok.getText() == "asmname") {
+      SP.P.consumeToken(tok::identifier);
+      if (SP.P.Tok.getKind() != tok::string_literal) {
+        SP.P.diagnose(SP.P.Tok, diag::expected_in_attribute_list);
+        return true;
+      }
+
+      // Drop the double quotes.
+      StringRef rawString = SP.P.Tok.getText().drop_front().drop_back();
+      *asmName = SP.P.Context.getIdentifier(rawString).str();
+      SP.P.consumeToken(tok::string_literal);
+
       SP.P.parseToken(tok::r_square, diag::expected_in_attribute_list);
       continue;
     } else if (section && SP.P.Tok.getText() == "section") {
@@ -7288,6 +7303,7 @@ bool SILParserState::parseDeclSIL(Parser &P) {
   PerformanceConstraints perfConstr = PerformanceConstraints::None;
   bool isPerformanceConstraint = false;
   bool markedAsUsed = false;
+  StringRef asmName;
   StringRef section;
   SmallVector<std::string, 1> Semantics;
   SmallVector<ParsedSpecAttr, 4> SpecAttrs;
@@ -7306,7 +7322,7 @@ bool SILParserState::parseDeclSIL(Parser &P) {
           &DynamicallyReplacedFunction, &AdHocWitnessFunction,
           &objCReplacementFor, &specialPurpose, &inlineStrategy,
           &optimizationMode, &perfConstr, &isPerformanceConstraint,
-          &markedAsUsed, &section, nullptr, &isWeakImported,
+          &markedAsUsed, &asmName, &section, nullptr, &isWeakImported,
           &needStackProtection, nullptr, &availability,
           &isWithoutActuallyEscapingThunk, &Semantics, &SpecAttrs, &ClangDecl,
           &MRK, &actorIsolation, FunctionState, M) ||
@@ -7363,6 +7379,9 @@ bool SILParserState::parseDeclSIL(Parser &P) {
     FunctionState.F->setPerfConstraints(perfConstr);
     FunctionState.F->setIsPerformanceConstraint(isPerformanceConstraint);
     FunctionState.F->setEffectsKind(MRK);
+    FunctionState.F->setMarkedAsUsed(markedAsUsed);
+    FunctionState.F->setAsmName(asmName);
+    FunctionState.F->setSection(section);
 
     if (ClangDecl)
       FunctionState.F->setClangNodeOwner(ClangDecl);
@@ -7557,17 +7576,19 @@ bool SILParserState::parseSILGlobal(Parser &P) {
   SourceLoc NameLoc;
   SerializedKind_t isSerialized = IsNotSerialized;
   bool isMarkedAsUsed = false;
+  StringRef asmName;
+  StringRef section;
   bool isLet = false;
 
   SILParser State(P);
   if (parseSILLinkage(GlobalLinkage, P) ||
       parseDeclSILOptional(nullptr, &isSerialized, nullptr, nullptr, nullptr,
                            nullptr, nullptr, nullptr, nullptr, nullptr, nullptr,
                            nullptr, nullptr, nullptr, nullptr, nullptr, nullptr,
-                           nullptr, nullptr, nullptr, &isMarkedAsUsed, nullptr,
-                           &isLet, nullptr, nullptr, nullptr, nullptr, nullptr,
-                           nullptr, nullptr, nullptr, nullptr, nullptr, State,
-                           M) ||
+                           nullptr, nullptr, nullptr, &isMarkedAsUsed, &asmName,
+                           &section, &isLet, nullptr, nullptr, nullptr, nullptr,
+                           nullptr, nullptr, nullptr, nullptr, nullptr, nullptr,
+                           State, M) ||
       P.parseToken(tok::at_sign, diag::expected_sil_value_name) ||
       P.parseIdentifier(GlobalName, NameLoc, /*diagnoseDollarPrefix=*/false,
                         diag::expected_sil_value_name) ||
@@ -7594,6 +7615,9 @@ bool SILParserState::parseSILGlobal(Parser &P) {
 
   GV->setLet(isLet);
   GV->setMarkedAsUsed(isMarkedAsUsed);
+  GV->setAsmName(asmName);
+  GV->setSection(section);
+
   // Parse static initializer if exists.
   if (State.P.consumeIf(tok::equal) && State.P.consumeIf(tok::l_brace)) {
     SILBuilder B(GV);
@@ -7621,7 +7645,7 @@ bool SILParserState::parseSILProperty(Parser &P) {
                            nullptr, nullptr, nullptr, nullptr, nullptr, nullptr,
                            nullptr, nullptr, nullptr, nullptr, nullptr, nullptr,
                            nullptr, nullptr, nullptr, nullptr, nullptr, nullptr,
-                           nullptr, nullptr, nullptr, nullptr, SP, M))
+                           nullptr, nullptr, nullptr, nullptr, nullptr, SP, M))
     return true;
 
   ValueDecl *VD;
@@ -7691,7 +7715,8 @@ bool SILParserState::parseSILVTable(Parser &P) {
                            nullptr, nullptr, nullptr, nullptr, nullptr, nullptr,
                            nullptr, nullptr, nullptr, nullptr, nullptr, nullptr,
                            nullptr, nullptr, nullptr, nullptr, nullptr, nullptr,
-                           nullptr, nullptr, nullptr, nullptr, VTableState, M))
+                           nullptr, nullptr, nullptr, nullptr, nullptr,
+                           VTableState, M))
     return true;
 
 
@@ -7814,7 +7839,7 @@ bool SILParserState::parseSILMoveOnlyDeinit(Parser &parser) {
                            nullptr, nullptr, nullptr, nullptr, nullptr, nullptr,
                            nullptr, nullptr, nullptr, nullptr, nullptr, nullptr,
                            nullptr, nullptr, nullptr, nullptr, nullptr, nullptr,
-                           nullptr, nullptr, nullptr, nullptr,
+                           nullptr, nullptr, nullptr, nullptr, nullptr,
                            moveOnlyDeinitTableState, M))
     return true;
 
@@ -8359,8 +8384,9 @@ bool SILParserState::parseSILWitnessTable(Parser &P) {
           nullptr, &isSerialized, nullptr, nullptr, nullptr, nullptr, nullptr,
           nullptr, nullptr, nullptr, nullptr, nullptr, nullptr, nullptr,
           nullptr, nullptr, nullptr, nullptr, nullptr, nullptr, nullptr,
-          nullptr, nullptr, nullptr, nullptr, &isSpecialized, nullptr, nullptr,
-          nullptr, nullptr, nullptr, nullptr, nullptr, WitnessState, M))
+          nullptr, nullptr, nullptr, nullptr, nullptr, &isSpecialized,
+          nullptr, nullptr, nullptr, nullptr, nullptr, nullptr, nullptr,
+          WitnessState, M))
     return true;
 
   // Parse the protocol conformance.

lib/SILGen/SILGenGlobalVariable.cpp

@@ -74,6 +74,9 @@ SILGlobalVariable *SILGenModule::getSILGlobalVariable(VarDecl *gDecl,
       M, silLinkage, IsNotSerialized, mangledName, silTy, std::nullopt, gDecl);
   silGlobal->setDeclaration(!forDef);
 
+  if (auto sectionAttr = gDecl->getAttrs().getAttribute<SectionAttr>())
+    silGlobal->setSection(sectionAttr->Name);
+
   return silGlobal;
 }
 

lib/SILOptimizer/Mandatory/PerformanceDiagnostics.cpp

@@ -730,7 +730,7 @@ class PerformanceDiagnosticsPass : public SILModuleTransform {
             "global inst", &g);
 
         auto *decl = g.getDecl();
-        if (g.getSectionAttr()) {
+        if (!g.section().empty()) {
           module->getASTContext().Diags.diagnose(
             g.getDecl()->getLoc(), diag::bad_attr_on_non_const_global,
             "@_section");