[mips][micromips] Fix overlaping FDEs error

When compiling static executable for micromips, CFI symbols
are incorrectly labeled as MICROMIPS, which cause
".eh_frame_hdr refers to overlapping FDEs." error.

This patch does not label CFI symbols as MICROMIPS, and FDEs do not
overlap anymore. This patch also exposes another bug, which is fixed
here: https://reviews.llvm.org/D52985

Differential Revision: https://reviews.llvm.org/D52987

llvm-svn: 344511
This commit is contained in:
Aleksandar Beserminji 2018-10-15 12:59:17 +00:00
parent 82ba7121e8
commit 10ec5c8c28
3 changed files with 62 additions and 0 deletions

View File

@ -15,6 +15,7 @@
#include "llvm/MC/MCAssembler.h"
#include "llvm/MC/MCCodeEmitter.h"
#include "llvm/MC/MCContext.h"
#include "llvm/MC/MCDwarf.h"
#include "llvm/MC/MCInst.h"
#include "llvm/MC/MCObjectWriter.h"
#include "llvm/MC/MCSymbolELF.h"
@ -53,6 +54,22 @@ void MipsELFStreamer::EmitInstruction(const MCInst &Inst,
createPendingLabelRelocs();
}
void MipsELFStreamer::EmitCFIStartProcImpl(MCDwarfFrameInfo &Frame) {
Frame.Begin = getContext().createTempSymbol();
MCELFStreamer::EmitLabel(Frame.Begin);
}
MCSymbol *MipsELFStreamer::EmitCFILabel() {
MCSymbol *Label = getContext().createTempSymbol("cfi", true);
MCELFStreamer::EmitLabel(Label);
return Label;
}
void MipsELFStreamer::EmitCFIEndProcImpl(MCDwarfFrameInfo &Frame) {
Frame.End = getContext().createTempSymbol();
MCELFStreamer::EmitLabel(Frame.End);
}
void MipsELFStreamer::createPendingLabelRelocs() {
MipsTargetELFStreamer *ELFTargetStreamer =
static_cast<MipsTargetELFStreamer *>(getTargetStreamer());

View File

@ -25,6 +25,7 @@ namespace llvm {
class MCAsmBackend;
class MCCodeEmitter;
class MCContext;
class MCDwarfFrameInfo;
class MCSubtargetInfo;
class MipsELFStreamer : public MCELFStreamer {
@ -60,6 +61,12 @@ public:
void EmitValueImpl(const MCExpr *Value, unsigned Size, SMLoc Loc) override;
void EmitIntValue(uint64_t Value, unsigned Size) override;
// Overriding these functions allows us to avoid recording of these labels
// in EmitLabel and later marking them as microMIPS.
void EmitCFIStartProcImpl(MCDwarfFrameInfo &Frame) override;
void EmitCFIEndProcImpl(MCDwarfFrameInfo &Frame) override;
MCSymbol *EmitCFILabel() override;
/// Emits all the option records stored up until the point it's called.
void EmitMipsOptionRecords();

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@ -0,0 +1,38 @@
; RUN: llc -mtriple mips-unknown-linux-gnu -mattr=+micromips -O3 -filetype=obj -o - %s | llvm-readelf -r | FileCheck %s
; CHECK: .rel.eh_frame
; CHECK: DW.ref.__gxx_personality_v0
; CHECK-NEXT: .text
; CHECK-NEXT: .gcc_except_table
@_ZTIi = external constant i8*
define dso_local i32 @main() local_unnamed_addr personality i8* bitcast (i32 (...)* @__gxx_personality_v0 to i8*) {
entry:
%exception.i = tail call i8* @__cxa_allocate_exception(i32 4) nounwind
%0 = bitcast i8* %exception.i to i32*
store i32 5, i32* %0, align 16
invoke void @__cxa_throw(i8* %exception.i, i8* bitcast (i8** @_ZTIi to i8*), i8* null) noreturn
to label %.noexc unwind label %return
.noexc:
unreachable
return:
%1 = landingpad { i8*, i32 }
catch i8* null
%2 = extractvalue { i8*, i32 } %1, 0
%3 = tail call i8* @__cxa_begin_catch(i8* %2) nounwind
tail call void @__cxa_end_catch()
ret i32 0
}
declare i32 @__gxx_personality_v0(...)
declare i8* @__cxa_begin_catch(i8*) local_unnamed_addr
declare void @__cxa_end_catch() local_unnamed_addr
declare i8* @__cxa_allocate_exception(i32) local_unnamed_addr
declare void @__cxa_throw(i8*, i8*, i8*) local_unnamed_addr