clang support gnu asm goto.

Syntax: asm [volatile] goto ( AssemblerTemplate : : InputOperands : Clobbers : GotoLabels) https://gcc.gnu.org/onlinedocs/gcc/Extended-Asm.html New llvm IR is "callbr" for inline asm goto instead "call" for inline asm For: asm goto("testl %0, %0; jne %l1;" :: "r"(cond)::label_true, loop); IR: callbr void asm sideeffect "testl $0, $0; jne ${1:l};", "r,X,X,~{dirflag},~{fpsr},~{flags}"(i32 %0, i8* blockaddress(@foo, %label_true), i8* blockaddress(@foo, %loop)) #1 to label %asm.fallthrough [label %label_true, label %loop], !srcloc !3 asm.fallthrough: Compiler need to generate: 1> a dummy constarint 'X' for each label. 2> an unique fallthrough label for each asm goto stmt " asm.fallthrough%number". Diagnostic 1> duplicate asm operand name are used in output, input and label. 2> goto out of scope. llvm-svn: 362045
llvm · May 30, 2019 · 954ec09 · 954ec09
1 parent 192dd7d
commit 954ec09
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Showing 28 changed files with 732 additions and 148 deletions.
diff --git a/clang/include/clang/AST/Stmt.h b/clang/include/clang/AST/Stmt.h
@@ -46,6 +46,7 @@ class Attr;
 class CapturedDecl;
 class Decl;
 class Expr;
+class AddrLabelExpr;
 class LabelDecl;
 class ODRHash;
 class PrinterHelper;
@@ -2816,13 +2817,15 @@ class GCCAsmStmt : public AsmStmt {
   StringLiteral **Constraints = nullptr;
   StringLiteral **Clobbers = nullptr;
   IdentifierInfo **Names = nullptr;
+  unsigned NumLabels = 0;
 
 public:
   GCCAsmStmt(const ASTContext &C, SourceLocation asmloc, bool issimple,
              bool isvolatile, unsigned numoutputs, unsigned numinputs,
              IdentifierInfo **names, StringLiteral **constraints, Expr **exprs,
              StringLiteral *asmstr, unsigned numclobbers,
-             StringLiteral **clobbers, SourceLocation rparenloc);
+             StringLiteral **clobbers, unsigned numlabels,
+             SourceLocation rparenloc);
 
   /// Build an empty inline-assembly statement.
   explicit GCCAsmStmt(EmptyShell Empty) : AsmStmt(GCCAsmStmtClass, Empty) {}
@@ -2947,13 +2950,59 @@ class GCCAsmStmt : public AsmStmt {
     return const_cast<GCCAsmStmt*>(this)->getInputExpr(i);
   }
 
+  //===--- Labels ---===//
+
+  bool isAsmGoto() const {
+    return NumLabels > 0;
+  }
+
+  unsigned getNumLabels() const {
+    return NumLabels;
+  }
+
+  IdentifierInfo *getLabelIdentifier(unsigned i) const {
+    return Names[i + NumInputs];
+  }
+
+  AddrLabelExpr *getLabelExpr(unsigned i) const;
+  StringRef getLabelName(unsigned i) const;
+  using labels_iterator = CastIterator<AddrLabelExpr>;
+  using const_labels_iterator = ConstCastIterator<AddrLabelExpr>;
+  using labels_range = llvm::iterator_range<labels_iterator>;
+  using labels_const_range = llvm::iterator_range<const_labels_iterator>;
+
+  labels_iterator begin_labels() {
+    return &Exprs[0] + NumInputs;
+  }
+
+  labels_iterator end_labels() {
+    return &Exprs[0] + NumInputs + NumLabels;
+  }
+
+  labels_range labels() {
+    return labels_range(begin_labels(), end_labels());
+  }
+
+  const_labels_iterator begin_labels() const {
+    return &Exprs[0] + NumInputs;
+  }
+
+  const_labels_iterator end_labels() const {
+    return &Exprs[0] + NumInputs + NumLabels;
+  }
+
+  labels_const_range labels() const {
+    return labels_const_range(begin_labels(), end_labels());
+  }
+
 private:
   void setOutputsAndInputsAndClobbers(const ASTContext &C,
                                       IdentifierInfo **Names,
                                       StringLiteral **Constraints,
                                       Stmt **Exprs,
                                       unsigned NumOutputs,
                                       unsigned NumInputs,
+                                      unsigned NumLabels,
                                       StringLiteral **Clobbers,
                                       unsigned NumClobbers);
 

diff --git a/clang/include/clang/Basic/DiagnosticParseKinds.td b/clang/include/clang/Basic/DiagnosticParseKinds.td
@@ -27,8 +27,8 @@ def err_msasm_unable_to_create_target : Error<
   "MS-style inline assembly is not available: %0">;
 def err_gnu_inline_asm_disabled : Error<
   "GNU-style inline assembly is disabled">;
-def err_asm_goto_not_supported_yet : Error<
-  "'asm goto' constructs are not supported yet">;
+def err_asm_goto_cannot_have_output : Error<
+  "'asm goto' cannot have output constraints">;
 }
 
 let CategoryName = "Parse Issue" in {

diff --git a/clang/include/clang/Basic/DiagnosticSemaKinds.td b/clang/include/clang/Basic/DiagnosticSemaKinds.td
@@ -5064,12 +5064,12 @@ def warn_cxx98_compat_switch_into_protected_scope : Warning<
 def err_indirect_goto_without_addrlabel : Error<
   "indirect goto in function with no address-of-label expressions">;
 def err_indirect_goto_in_protected_scope : Error<
-  "cannot jump from this indirect goto statement to one of its possible targets">;
+  "cannot jump from this %select{indirect|asm}0 goto statement to one of its possible targets">;
 def warn_cxx98_compat_indirect_goto_in_protected_scope : Warning<
-  "jump from this indirect goto statement to one of its possible targets "
+  "jump from this %select{indirect|asm}0 goto statement to one of its possible targets "
   "is incompatible with C++98">, InGroup<CXX98Compat>, DefaultIgnore;
 def note_indirect_goto_target : Note<
-  "possible target of indirect goto statement">;
+  "possible target of %select{indirect|asm}0 goto statement">;
 def note_protected_by_variable_init : Note<
   "jump bypasses variable initialization">;
 def note_protected_by_variable_nontriv_destructor : Note<
@@ -7497,6 +7497,10 @@ let CategoryName = "Inline Assembly Issue" in {
     "use constraint modifier \"%0\"">;
   def note_asm_input_duplicate_first : Note<
     "constraint '%0' is already present here">;
+ def error_duplicate_asm_operand_name : Error<
+    "duplicate use of asm operand name \"%0\"">;
+ def note_duplicate_asm_operand_name : Note<
+    "asm operand name \"%0\" first referenced here">;
 }
 
   def error_inoutput_conflict_with_clobber : Error<

diff --git a/clang/include/clang/Sema/Sema.h b/clang/include/clang/Sema/Sema.h
@@ -3971,6 +3971,7 @@ class Sema {
                              unsigned NumInputs, IdentifierInfo **Names,
                              MultiExprArg Constraints, MultiExprArg Exprs,
                              Expr *AsmString, MultiExprArg Clobbers,
+                             unsigned NumLabels,
                              SourceLocation RParenLoc);
 
   void FillInlineAsmIdentifierInfo(Expr *Res,

diff --git a/clang/lib/AST/ASTImporter.cpp b/clang/lib/AST/ASTImporter.cpp
@@ -5592,12 +5592,17 @@ ExpectedStmt ASTNodeImporter::VisitGCCAsmStmt(GCCAsmStmt *S) {
       return InputOrErr.takeError();
   }
 
-  SmallVector<Expr *, 4> Exprs(S->getNumOutputs() + S->getNumInputs());
+  SmallVector<Expr *, 4> Exprs(S->getNumOutputs() + S->getNumInputs() +
+                               S->getNumLabels());
   if (Error Err = ImportContainerChecked(S->outputs(), Exprs))
     return std::move(Err);
 
+  if (Error Err =
+          ImportArrayChecked(S->inputs(), Exprs.begin() + S->getNumOutputs()))
+    return std::move(Err);
+
   if (Error Err = ImportArrayChecked(
-      S->inputs(), Exprs.begin() + S->getNumOutputs()))
+          S->labels(), Exprs.begin() + S->getNumOutputs() + S->getNumInputs()))
     return std::move(Err);
 
   ExpectedSLoc AsmLocOrErr = import(S->getAsmLoc());
@@ -5623,6 +5628,7 @@ ExpectedStmt ASTNodeImporter::VisitGCCAsmStmt(GCCAsmStmt *S) {
       *AsmStrOrErr,
       S->getNumClobbers(),
       Clobbers.data(),
+      S->getNumLabels(),
       *RParenLocOrErr);
 }
 

diff --git a/clang/lib/AST/Stmt.cpp b/clang/lib/AST/Stmt.cpp
@@ -444,6 +444,14 @@ void GCCAsmStmt::setInputExpr(unsigned i, Expr *E) {
   Exprs[i + NumOutputs] = E;
 }
 
+AddrLabelExpr *GCCAsmStmt::getLabelExpr(unsigned i) const {
+  return cast<AddrLabelExpr>(Exprs[i + NumInputs]);
+}
+
+StringRef GCCAsmStmt::getLabelName(unsigned i) const {
+  return getLabelExpr(i)->getLabel()->getName();
+}
+
 /// getInputConstraint - Return the specified input constraint.  Unlike output
 /// constraints, these can be empty.
 StringRef GCCAsmStmt::getInputConstraint(unsigned i) const {
@@ -456,13 +464,16 @@ void GCCAsmStmt::setOutputsAndInputsAndClobbers(const ASTContext &C,
                                                 Stmt **Exprs,
                                                 unsigned NumOutputs,
                                                 unsigned NumInputs,
+                                                unsigned NumLabels,
                                                 StringLiteral **Clobbers,
                                                 unsigned NumClobbers) {
   this->NumOutputs = NumOutputs;
   this->NumInputs = NumInputs;
   this->NumClobbers = NumClobbers;
+  this->NumLabels = NumLabels;
+  assert(!(NumOutputs && NumLabels) && "asm goto cannot have outputs");
 
-  unsigned NumExprs = NumOutputs + NumInputs;
+  unsigned NumExprs = NumOutputs + NumInputs + NumLabels;
 
   C.Deallocate(this->Names);
   this->Names = new (C) IdentifierInfo*[NumExprs];
@@ -497,6 +508,10 @@ int GCCAsmStmt::getNamedOperand(StringRef SymbolicName) const {
     if (getInputName(i) == SymbolicName)
       return getNumOutputs() + NumPlusOperands + i;
 
+  for (unsigned i = 0, e = getNumLabels(); i != e; ++i)
+    if (getLabelName(i) == SymbolicName)
+      return i + getNumInputs();
+
   // Not found.
   return -1;
 }
@@ -614,8 +629,8 @@ unsigned GCCAsmStmt::AnalyzeAsmString(SmallVectorImpl<AsmStringPiece>&Pieces,
       while (CurPtr != StrEnd && isDigit(*CurPtr))
         N = N*10 + ((*CurPtr++)-'0');
 
-      unsigned NumOperands =
-        getNumOutputs() + getNumPlusOperands() + getNumInputs();
+      unsigned NumOperands = getNumOutputs() + getNumPlusOperands() +
+                             getNumInputs() + getNumLabels();
       if (N >= NumOperands) {
         DiagOffs = CurPtr-StrStart-1;
         return diag::err_asm_invalid_operand_number;
@@ -728,10 +743,12 @@ GCCAsmStmt::GCCAsmStmt(const ASTContext &C, SourceLocation asmloc,
                        unsigned numinputs, IdentifierInfo **names,
                        StringLiteral **constraints, Expr **exprs,
                        StringLiteral *asmstr, unsigned numclobbers,
-                       StringLiteral **clobbers, SourceLocation rparenloc)
+                       StringLiteral **clobbers, unsigned numlabels,
+                       SourceLocation rparenloc)
     : AsmStmt(GCCAsmStmtClass, asmloc, issimple, isvolatile, numoutputs,
-              numinputs, numclobbers), RParenLoc(rparenloc), AsmStr(asmstr) {
-  unsigned NumExprs = NumOutputs + NumInputs;
+              numinputs, numclobbers),
+              RParenLoc(rparenloc), AsmStr(asmstr), NumLabels(numlabels) {
+  unsigned NumExprs = NumOutputs + NumInputs + NumLabels;
 
   Names = new (C) IdentifierInfo*[NumExprs];
   std::copy(names, names + NumExprs, Names);

diff --git a/clang/lib/AST/StmtPrinter.cpp b/clang/lib/AST/StmtPrinter.cpp
@@ -414,12 +414,15 @@ void StmtPrinter::VisitGCCAsmStmt(GCCAsmStmt *Node) {
   if (Node->isVolatile())
     OS << "volatile ";
 
+  if (Node->isAsmGoto())
+    OS << "goto ";
+
   OS << "(";
   VisitStringLiteral(Node->getAsmString());
 
   // Outputs
   if (Node->getNumOutputs() != 0 || Node->getNumInputs() != 0 ||
-      Node->getNumClobbers() != 0)
+      Node->getNumClobbers() != 0 || Node->getNumLabels() != 0)
     OS << " : ";
 
   for (unsigned i = 0, e = Node->getNumOutputs(); i != e; ++i) {
@@ -439,7 +442,8 @@ void StmtPrinter::VisitGCCAsmStmt(GCCAsmStmt *Node) {
   }
 
   // Inputs
-  if (Node->getNumInputs() != 0 || Node->getNumClobbers() != 0)
+  if (Node->getNumInputs() != 0 || Node->getNumClobbers() != 0 ||
+      Node->getNumLabels() != 0)
     OS << " : ";
 
   for (unsigned i = 0, e = Node->getNumInputs(); i != e; ++i) {
@@ -459,7 +463,7 @@ void StmtPrinter::VisitGCCAsmStmt(GCCAsmStmt *Node) {
   }
 
   // Clobbers
-  if (Node->getNumClobbers() != 0)
+  if (Node->getNumClobbers() != 0 || Node->getNumLabels())
     OS << " : ";
 
   for (unsigned i = 0, e = Node->getNumClobbers(); i != e; ++i) {
@@ -469,6 +473,16 @@ void StmtPrinter::VisitGCCAsmStmt(GCCAsmStmt *Node) {
     VisitStringLiteral(Node->getClobberStringLiteral(i));
   }
 
+  // Labels
+  if (Node->getNumLabels() != 0)
+    OS << " : ";
+
+  for (unsigned i = 0, e = Node->getNumLabels(); i != e; ++i) {
+    if (i != 0)
+      OS << ", ";
+    OS << Node->getLabelName(i);
+  }
+
   OS << ");";
   if (Policy.IncludeNewlines) OS << NL;
 }

diff --git a/clang/lib/AST/StmtProfile.cpp b/clang/lib/AST/StmtProfile.cpp
@@ -321,6 +321,9 @@ void StmtProfiler::VisitGCCAsmStmt(const GCCAsmStmt *S) {
   ID.AddInteger(S->getNumClobbers());
   for (unsigned I = 0, N = S->getNumClobbers(); I != N; ++I)
     VisitStringLiteral(S->getClobberStringLiteral(I));
+  ID.AddInteger(S->getNumLabels());
+  for (auto *L : S->labels())
+    VisitDecl(L->getLabel());
 }
 
 void StmtProfiler::VisitMSAsmStmt(const MSAsmStmt *S) {

diff --git a/clang/lib/Analysis/CFG.cpp b/clang/lib/Analysis/CFG.cpp
@@ -549,6 +549,7 @@ class CFGBuilder {
   CFGBlock *VisitExprWithCleanups(ExprWithCleanups *E, AddStmtChoice asc);
   CFGBlock *VisitForStmt(ForStmt *F);
   CFGBlock *VisitGotoStmt(GotoStmt *G);
+  CFGBlock *VisitGCCAsmStmt(GCCAsmStmt *G, AddStmtChoice asc);
   CFGBlock *VisitIfStmt(IfStmt *I);
   CFGBlock *VisitImplicitCastExpr(ImplicitCastExpr *E, AddStmtChoice asc);
   CFGBlock *VisitConstantExpr(ConstantExpr *E, AddStmtChoice asc);
@@ -1478,22 +1479,38 @@ std::unique_ptr<CFG> CFGBuilder::buildCFG(const Decl *D, Stmt *Statement) {
                                    E = BackpatchBlocks.end(); I != E; ++I ) {
 
     CFGBlock *B = I->block;
-    const GotoStmt *G = cast<GotoStmt>(B->getTerminator());
-    LabelMapTy::iterator LI = LabelMap.find(G->getLabel());
-
-    // If there is no target for the goto, then we are looking at an
-    // incomplete AST.  Handle this by not registering a successor.
-    if (LI == LabelMap.end()) continue;
-
-    JumpTarget JT = LI->second;
-    prependAutomaticObjLifetimeWithTerminator(B, I->scopePosition,
-                                              JT.scopePosition);
-    prependAutomaticObjDtorsWithTerminator(B, I->scopePosition,
-                                           JT.scopePosition);
-    const VarDecl *VD = prependAutomaticObjScopeEndWithTerminator(
-        B, I->scopePosition, JT.scopePosition);
-    appendScopeBegin(JT.block, VD, G);
-    addSuccessor(B, JT.block);
+    if (auto *G = dyn_cast<GotoStmt>(B->getTerminator())) {
+      LabelMapTy::iterator LI = LabelMap.find(G->getLabel());
+      // If there is no target for the goto, then we are looking at an
+      // incomplete AST.  Handle this by not registering a successor.
+      if (LI == LabelMap.end())
+        continue;
+      JumpTarget JT = LI->second;
+      prependAutomaticObjLifetimeWithTerminator(B, I->scopePosition,
+                                                JT.scopePosition);
+      prependAutomaticObjDtorsWithTerminator(B, I->scopePosition,
+                                             JT.scopePosition);
+      const VarDecl *VD = prependAutomaticObjScopeEndWithTerminator(
+          B, I->scopePosition, JT.scopePosition);
+      appendScopeBegin(JT.block, VD, G);
+      addSuccessor(B, JT.block);
+    };
+    if (auto *G = dyn_cast<GCCAsmStmt>(B->getTerminator())) {
+      CFGBlock *Successor  = (I+1)->block;
+      for (auto *L : G->labels()) {
+        LabelMapTy::iterator LI = LabelMap.find(L->getLabel());
+        // If there is no target for the goto, then we are looking at an
+        // incomplete AST.  Handle this by not registering a successor.
+        if (LI == LabelMap.end())
+          continue;
+        JumpTarget JT = LI->second;
+        // Successor has been added, so skip it.
+        if (JT.block == Successor)
+          continue;
+        addSuccessor(B, JT.block);
+      }
+      I++;
+    }
   }
 
   // Add successors to the Indirect Goto Dispatch block (if we have one).
@@ -2142,6 +2159,9 @@ CFGBlock *CFGBuilder::Visit(Stmt * S, AddStmtChoice asc) {
     case Stmt::GotoStmtClass:
       return VisitGotoStmt(cast<GotoStmt>(S));
 
+    case Stmt::GCCAsmStmtClass:
+      return VisitGCCAsmStmt(cast<GCCAsmStmt>(S), asc);
+
     case Stmt::IfStmtClass:
       return VisitIfStmt(cast<IfStmt>(S));
 
@@ -3146,6 +3166,28 @@ CFGBlock *CFGBuilder::VisitGotoStmt(GotoStmt *G) {
   return Block;
 }
 
+CFGBlock *CFGBuilder::VisitGCCAsmStmt(GCCAsmStmt *G, AddStmtChoice asc) {
+  // Goto is a control-flow statement.  Thus we stop processing the current
+  // block and create a new one.
+
+  if (!G->isAsmGoto())
+    return VisitStmt(G, asc);
+
+  if (Block) {
+    Succ = Block;
+    if (badCFG)
+      return nullptr;
+  }
+  Block = createBlock();
+  Block->setTerminator(G);
+  // We will backpatch this block later for all the labels.
+  BackpatchBlocks.push_back(JumpSource(Block, ScopePos));
+  // Save "Succ" in BackpatchBlocks. In the backpatch processing, "Succ" is
+  // used to avoid adding "Succ" again.
+  BackpatchBlocks.push_back(JumpSource(Succ, ScopePos));
+  return Block;
+}
+
 CFGBlock *CFGBuilder::VisitForStmt(ForStmt *F) {
   CFGBlock *LoopSuccessor = nullptr;