Fix debug info for merged global.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123862 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/AsmPrinter/DwarfDebug.cpp b/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
index fdd47f2..5c63ab5 100644
--- a/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
+++ b/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
@@ -16,6 +16,7 @@
#include "DIE.h"
#include "llvm/Constants.h"
#include "llvm/Module.h"
+#include "llvm/Instructions.h"
#include "llvm/CodeGen/MachineFunction.h"
#include "llvm/CodeGen/MachineModuleInfo.h"
#include "llvm/MC/MCAsmInfo.h"
@@ -1922,6 +1923,32 @@
return false;
}
+// Return const exprssion if value is a GEP to access merged global
+// constant. e.g.
+// i8* getelementptr ({ i8, i8, i8, i8 }* @_MergedGlobals, i32 0, i32 0)
+static const ConstantExpr *getMergedGlobalExpr(const Value *V) {
+ const ConstantExpr *CE = dyn_cast_or_null<ConstantExpr>(V);
+ if (!CE || CE->getNumOperands() != 3 ||
+ CE->getOpcode() != Instruction::GetElementPtr)
+ return NULL;
+
+ // First operand points to a global value.
+ if (!isa<GlobalValue>(CE->getOperand(0)))
+ return NULL;
+
+ // Second operand is zero.
+ const ConstantInt *CI =
+ dyn_cast_or_null<ConstantInt>(CE->getOperand(1));
+ if (!CI || !CI->isZero())
+ return NULL;
+
+ // Third operand is offset.
+ if (!isa<ConstantInt>(CE->getOperand(2)))
+ return NULL;
+
+ return CE;
+}
+
/// constructGlobalVariableDIE - Construct global variable DIE.
void DwarfDebug::constructGlobalVariableDIE(const MDNode *N) {
DIGlobalVariable GV(N);
@@ -1991,6 +2018,18 @@
} else if (ConstantInt *CI =
dyn_cast_or_null<ConstantInt>(GV.getConstant()))
addConstantValue(VariableDIE, CI, isUnsignedDIType(GTy));
+ else if (const ConstantExpr *CE = getMergedGlobalExpr(N->getOperand(11))) {
+ // GV is a merged global.
+ DIEBlock *Block = new (DIEValueAllocator) DIEBlock();
+ addUInt(Block, 0, dwarf::DW_FORM_data1, dwarf::DW_OP_addr);
+ addLabel(Block, 0, dwarf::DW_FORM_udata,
+ Asm->Mang->getSymbol(cast<GlobalValue>(CE->getOperand(0))));
+ ConstantInt *CII = cast<ConstantInt>(CE->getOperand(2));
+ addUInt(Block, 0, dwarf::DW_FORM_data1, dwarf::DW_OP_constu);
+ addUInt(Block, 0, dwarf::DW_FORM_udata, CII->getZExtValue());
+ addUInt(Block, 0, dwarf::DW_FORM_data1, dwarf::DW_OP_plus);
+ addBlock(VariableDIE, dwarf::DW_AT_location, 0, Block);
+ }
return;
}