Make it illegal for two Functions to point to the same DISubprogram
As recently discussed on llvm-dev [1], this patch makes it illegal for
two Functions to point to the same DISubprogram and updates
FunctionCloner to also clone the debug info of a function to conform
to the new requirement. To simplify the implementation it also factors
out the creation of inlineAt locations from the Inliner into a
general-purpose utility in DILocation.
[1] http://lists.llvm.org/pipermail/llvm-dev/2017-May/112661.html
<rdar://problem/31926379>
Differential Revision: https://reviews.llvm.org/D32975
This reapplies r302469 with a fix for a bot failure (reparentDebugInfo
now checks for the case the orig and new function are identical).
llvm-svn: 302576
diff --git a/llvm/lib/IR/DebugLoc.cpp b/llvm/lib/IR/DebugLoc.cpp
index f31074a..3168ec6 100644
--- a/llvm/lib/IR/DebugLoc.cpp
+++ b/llvm/lib/IR/DebugLoc.cpp
@@ -8,6 +8,7 @@
//===----------------------------------------------------------------------===//
#include "llvm/IR/DebugLoc.h"
+#include "llvm/IR/IntrinsicInst.h"
#include "LLVMContextImpl.h"
#include "llvm/IR/DebugInfo.h"
using namespace llvm;
@@ -66,6 +67,119 @@
const_cast<MDNode *>(InlinedAt));
}
+DebugLoc DebugLoc::appendInlinedAt(DebugLoc DL, DILocation *InlinedAt,
+ LLVMContext &Ctx,
+ DenseMap<const MDNode *, MDNode *> &Cache,
+ bool ReplaceLast) {
+ SmallVector<DILocation *, 3> InlinedAtLocations;
+ DILocation *Last = InlinedAt;
+ DILocation *CurInlinedAt = DL;
+
+ // Gather all the inlined-at nodes.
+ while (DILocation *IA = CurInlinedAt->getInlinedAt()) {
+ // Skip any we've already built nodes for.
+ if (auto *Found = Cache[IA]) {
+ Last = cast<DILocation>(Found);
+ break;
+ }
+
+ if (ReplaceLast && !IA->getInlinedAt())
+ break;
+ InlinedAtLocations.push_back(IA);
+ CurInlinedAt = IA;
+ }
+
+ // Starting from the top, rebuild the nodes to point to the new inlined-at
+ // location (then rebuilding the rest of the chain behind it) and update the
+ // map of already-constructed inlined-at nodes.
+ for (const DILocation *MD : reverse(InlinedAtLocations))
+ Cache[MD] = Last = DILocation::getDistinct(
+ Ctx, MD->getLine(), MD->getColumn(), MD->getScope(), Last);
+
+ return Last;
+}
+
+/// Reparent \c Scope from \c OrigSP to \c NewSP.
+static DIScope *reparentScope(LLVMContext &Ctx, DIScope *Scope,
+ DISubprogram *OrigSP, DISubprogram *NewSP,
+ DenseMap<const MDNode *, MDNode *> &Cache) {
+ SmallVector<DIScope *, 3> ScopeChain;
+ DIScope *Last = NewSP;
+ DIScope *CurScope = Scope;
+ do {
+ if (auto *SP = dyn_cast<DISubprogram>(CurScope)) {
+ // Don't rewrite this scope chain if it doesn't lead to the replaced SP.
+ if (SP != OrigSP)
+ return Scope;
+ Cache.insert({OrigSP, NewSP});
+ break;
+ }
+ if (auto *Found = Cache[CurScope]) {
+ Last = cast<DIScope>(Found);
+ break;
+ }
+ ScopeChain.push_back(CurScope);
+ } while ((CurScope = CurScope->getScope().resolve()));
+
+ // Starting from the top, rebuild the nodes to point to the new inlined-at
+ // location (then rebuilding the rest of the chain behind it) and update the
+ // map of already-constructed inlined-at nodes.
+ for (const DIScope *MD : reverse(ScopeChain)) {
+ if (auto *LB = dyn_cast<DILexicalBlock>(MD))
+ Cache[MD] = Last = DILexicalBlock::getDistinct(
+ Ctx, Last, LB->getFile(), LB->getLine(), LB->getColumn());
+ else if (auto *LB = dyn_cast<DILexicalBlockFile>(MD))
+ Cache[MD] = Last = DILexicalBlockFile::getDistinct(
+ Ctx, Last, LB->getFile(), LB->getDiscriminator());
+ else
+ llvm_unreachable("illegal parent scope");
+ }
+ return Last;
+}
+
+void DebugLoc::reparentDebugInfo(Instruction &I, DISubprogram *OrigSP,
+ DISubprogram *NewSP,
+ DenseMap<const MDNode *, MDNode *> &Cache) {
+ auto DL = I.getDebugLoc();
+ if (!OrigSP || !NewSP || OrigSP == NewSP || !DL)
+ return;
+
+ // Reparent the debug location.
+ auto &Ctx = I.getContext();
+ DILocation *InlinedAt = DL->getInlinedAt();
+ if (InlinedAt) {
+ while (auto *IA = InlinedAt->getInlinedAt())
+ InlinedAt = IA;
+ auto NewScope =
+ reparentScope(Ctx, InlinedAt->getScope(), OrigSP, NewSP, Cache);
+ InlinedAt =
+ DebugLoc::get(InlinedAt->getLine(), InlinedAt->getColumn(), NewScope);
+ }
+ I.setDebugLoc(
+ DebugLoc::get(DL.getLine(), DL.getCol(),
+ reparentScope(Ctx, DL->getScope(), OrigSP, NewSP, Cache),
+ DebugLoc::appendInlinedAt(DL, InlinedAt, Ctx, Cache,
+ ReplaceLastInlinedAt)));
+
+ // Fix up debug variables to point to NewSP.
+ auto reparentVar = [&](DILocalVariable *Var) {
+ return DILocalVariable::getDistinct(
+ Ctx,
+ cast<DILocalScope>(
+ reparentScope(Ctx, Var->getScope(), OrigSP, NewSP, Cache)),
+ Var->getName(), Var->getFile(), Var->getLine(), Var->getType(),
+ Var->getArg(), Var->getFlags(), Var->getAlignInBits());
+ };
+ if (auto *DbgValue = dyn_cast<DbgValueInst>(&I)) {
+ auto *Var = DbgValue->getVariable();
+ I.setOperand(2, MetadataAsValue::get(Ctx, reparentVar(Var)));
+ } else if (auto *DbgDeclare = dyn_cast<DbgDeclareInst>(&I)) {
+ auto *Var = DbgDeclare->getVariable();
+ I.setOperand(1, MetadataAsValue::get(Ctx, reparentVar(Var)));
+ }
+}
+
+
#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
LLVM_DUMP_METHOD void DebugLoc::dump() const {
if (!Loc)
diff --git a/llvm/lib/IR/Verifier.cpp b/llvm/lib/IR/Verifier.cpp
index 65e1245..3b68d63 100644
--- a/llvm/lib/IR/Verifier.cpp
+++ b/llvm/lib/IR/Verifier.cpp
@@ -267,6 +267,9 @@
/// \brief Keep track of the metadata nodes that have been checked already.
SmallPtrSet<const Metadata *, 32> MDNodes;
+ /// Keep track which DISubprogram is attached to which function.
+ DenseMap<const DISubprogram *, const Function *> DISubprogramAttachments;
+
/// Track all DICompileUnits visited.
SmallPtrSet<const Metadata *, 2> CUVisited;
@@ -386,7 +389,7 @@
verifyCompileUnits();
verifyDeoptimizeCallingConvs();
-
+ DISubprogramAttachments.clear();
return !Broken;
}
@@ -2085,13 +2088,19 @@
switch (I.first) {
default:
break;
- case LLVMContext::MD_dbg:
+ case LLVMContext::MD_dbg: {
++NumDebugAttachments;
AssertDI(NumDebugAttachments == 1,
"function must have a single !dbg attachment", &F, I.second);
AssertDI(isa<DISubprogram>(I.second),
"function !dbg attachment must be a subprogram", &F, I.second);
+ auto *SP = cast<DISubprogram>(I.second);
+ const Function *&AttachedTo = DISubprogramAttachments[SP];
+ AssertDI(!AttachedTo || AttachedTo == &F,
+ "DISubprogram attached to more than one function", SP, &F);
+ AttachedTo = &F;
break;
+ }
case LLVMContext::MD_prof:
++NumProfAttachments;
Assert(NumProfAttachments == 1,