Merge pull request #6313 from felipepiovezan/felipe/cherry-pick-recursive-subprogram

[cherry-pick][debug-info][codegen] Prevent creation of self-referential SP node

Author: felipepiovezan

clang/lib/CodeGen/CGDebugInfo.cpp

@@ -4209,10 +4209,10 @@ void CGDebugInfo::EmitFunctionDecl(GlobalDecl GD, SourceLocation Loc,
     SPFlags |= llvm::DISubprogram::SPFlagOptimized;
 
   llvm::DINodeArray Annotations = CollectBTFDeclTagAnnotations(D);
+  llvm::DISubroutineType *STy = getOrCreateFunctionType(D, FnType, Unit);
   llvm::DISubprogram *SP = DBuilder.createFunction(
-      FDContext, Name, LinkageName, Unit, LineNo,
-      getOrCreateFunctionType(D, FnType, Unit), ScopeLine, Flags, SPFlags,
-      TParamsArray.get(), getFunctionDeclaration(D), nullptr, Annotations);
+      FDContext, Name, LinkageName, Unit, LineNo, STy, ScopeLine, Flags,
+      SPFlags, TParamsArray.get(), nullptr, nullptr, Annotations);
 
   if (IsDeclForCallSite)
     Fn->setSubprogram(SP);

llvm/docs/LangRef.rst

@@ -5672,11 +5672,12 @@ retained, even if their IR counterparts are optimized out of the IR. The
 
 .. _DISubprogramDeclaration:
 
-When ``isDefinition: false``, subprograms describe a declaration in the type
-tree as opposed to a definition of a function.  If the scope is a composite
-type with an ODR ``identifier:`` and that does not set ``flags: DIFwdDecl``,
-then the subprogram declaration is uniqued based only on its ``linkageName:``
-and ``scope:``.
+When ``spFlags: DISPFlagDefinition`` is not present, subprograms describe a
+declaration in the type tree as opposed to a definition of a function. In this
+case, the ``declaration`` field must be empty. If the scope is a composite type
+with an ODR ``identifier:`` and that does not set ``flags: DIFwdDecl``, then
+the subprogram declaration is uniqued based only on its ``linkageName:`` and
+``scope:``.
 
 .. code-block:: text
 
@@ -5685,9 +5686,9 @@ and ``scope:``.
     }
 
     !0 = distinct !DISubprogram(name: "foo", linkageName: "_Zfoov", scope: !1,
-                                file: !2, line: 7, type: !3, isLocal: true,
-                                isDefinition: true, scopeLine: 8,
-                                containingType: !4,
+                                file: !2, line: 7, type: !3,
+                                spFlags: DISPFlagDefinition | DISPFlagLocalToUnit,
+                                scopeLine: 8, containingType: !4,
                                 virtuality: DW_VIRTUALITY_pure_virtual,
                                 virtualIndex: 10, flags: DIFlagPrototyped,
                                 isOptimized: true, unit: !5, templateParams: !6,

llvm/lib/IR/Verifier.cpp

@@ -1416,6 +1416,8 @@ void Verifier::visitDISubprogram(const DISubprogram &N) {
   } else {
     // Subprogram declarations (part of the type hierarchy).
     CheckDI(!Unit, "subprogram declarations must not have a compile unit", &N);
+    CheckDI(!N.getRawDeclaration(),
+            "subprogram declaration must not have a declaration field");
   }
 
   if (auto *RawThrownTypes = N.getRawThrownTypes()) {

llvm/test/Verifier/disubprogram_declaration.ll

@@ -0,0 +1,17 @@
+; RUN: llvm-as -disable-output <%s 2>&1| FileCheck %s
+
+declare !dbg !12 i32 @declared_only()
+
+!llvm.module.flags = !{!2}
+!llvm.dbg.cu = !{!5}
+
+!2 = !{i32 2, !"Debug Info Version", i32 3}
+!5 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus_14, file: !6, producer: "clang", emissionKind: FullDebug)
+!6 = !DIFile(filename: "a.cpp", directory: "/")
+!7 = !{}
+!11 = !DISubroutineType(types: !7)
+
+!12 = !DISubprogram(name: "declared_only", scope: !6, file: !6, line: 2, type: !11, spFlags: DISPFlagOptimized, retainedNodes: !7, declaration: !13)
+!13 = !DISubprogram(name: "declared_only", scope: !6, file: !6, line: 2, type: !11, spFlags: DISPFlagOptimized, retainedNodes: !7)
+; CHECK: subprogram declaration must not have a declaration field
+; CHECK: warning: ignoring invalid debug info