From 428caf988be17a1d3d420318f9018a8f4b11a436 Mon Sep 17 00:00:00 2001 From: Bjorn Pettersson Date: Fri, 15 Jun 2018 13:48:55 +0000 Subject: Re-apply "[DebugInfo] Check size of variable in ConvertDebugDeclareToDebugValue" This is r334704 (which was reverted in r334732) with a fix for types like x86_fp80. We need to use getTypeAllocSizeInBits and not getTypeStoreSizeInBits to avoid dropping debug info for such types. Original commit msg: > Summary: > Do not convert a DbgDeclare to DbgValue if the store > instruction only refer to a fragment of the variable > described by the DbgDeclare. > > Problem was seen when for example having an alloca for an > array or struct, and there were stores to individual elements. > In the past we inserted a DbgValue intrinsics for each store, > just as if the store wrote the whole variable. > > When handling store instructions we insert a DbgValue that > indicates that the variable is "undefined", as we do not know > which part of the variable that is updated by the store. > > When ConvertDebugDeclareToDebugValue is used with a load/phi > instruction we assert that the referenced value is large enough > to cover the whole variable. Afaict this should be true for all > scenarios where those methods are used on trunk. If the assert > blows in the future I guess we could simply skip to insert a > dbg.value instruction. > > In the future I think we should examine which part of the variable > that is accessed, and add a DbgValue instrinsic with an appropriate > DW_OP_LLVM_fragment expression. > > Reviewers: dblaikie, aprantl, rnk > > Reviewed By: aprantl > > Subscribers: JDevlieghere, llvm-commits > > Tags: #debug-info > > Differential Revision: https://reviews.llvm.org/D48024 llvm-svn: 334830 --- llvm/lib/IR/IntrinsicInst.cpp | 7 +++++++ 1 file changed, 7 insertions(+) (limited to 'llvm/lib/IR/IntrinsicInst.cpp') diff --git a/llvm/lib/IR/IntrinsicInst.cpp b/llvm/lib/IR/IntrinsicInst.cpp index 67bd5b69bb0..9ffcae1f8f8 100644 --- a/llvm/lib/IR/IntrinsicInst.cpp +++ b/llvm/lib/IR/IntrinsicInst.cpp @@ -24,6 +24,7 @@ #include "llvm/IR/IntrinsicInst.h" #include "llvm/ADT/StringSwitch.h" #include "llvm/IR/Constants.h" +#include "llvm/IR/DebugInfoMetadata.h" #include "llvm/IR/GlobalVariable.h" #include "llvm/IR/Metadata.h" #include "llvm/IR/Module.h" @@ -48,6 +49,12 @@ Value *DbgInfoIntrinsic::getVariableLocation(bool AllowNullOp) const { return nullptr; } +Optional DbgInfoIntrinsic::getFragmentSizeInBits() const { + if (auto Fragment = getExpression()->getFragmentInfo()) + return Fragment->SizeInBits; + return getVariable()->getSizeInBits(); +} + int llvm::Intrinsic::lookupLLVMIntrinsicByName(ArrayRef NameTable, StringRef Name) { assert(Name.startswith("llvm.")); -- cgit v1.2.3