From db05b7f61eb95928ffbef98c1a66b978436ab3d8 Mon Sep 17 00:00:00 2001
From: David Blaikie <dblaikie@gmail.com>
Date: Mon, 16 May 2016 23:26:29 +0000
Subject: [PATCH] llvm-dwp: Add error handling for invalid (non-CU) top level
 tag in debug_info.dwo

The diagnostic could be improved a bit to include information about
which input file had the mistake (& which unit (counted, since the name
of the unit won't be accessible) within the input).

llvm-svn: 269723
---
 .../llvm-dwp/Inputs/non_cu_top_level.dwo      | Bin 0 -> 1153 bytes
 test/tools/llvm-dwp/X86/non_cu_top_level.test |   3 +++
 tools/llvm-dwp/llvm-dwp.cpp                   |  22 +++++++++++-------
 3 files changed, 17 insertions(+), 8 deletions(-)
 create mode 100644 test/tools/llvm-dwp/Inputs/non_cu_top_level.dwo
 create mode 100644 test/tools/llvm-dwp/X86/non_cu_top_level.test

diff --git a/test/tools/llvm-dwp/Inputs/non_cu_top_level.dwo b/test/tools/llvm-dwp/Inputs/non_cu_top_level.dwo
new file mode 100644
index 0000000000000000000000000000000000000000..26f276ad05329c1c69b940d72df13e5de72bf572
GIT binary patch
literal 1153
zcmb<-^>JfjWMqH=Mg}_u1P><4zz~5X=l~XWVBlh4XGqO0D5=y-DbHs}&PmKmS13y@
zD$dN$Q!v)E)H6`fC@Ct<%T_Qlvoy0X*HqBR$tla#M~InPYC;W2E+_yS$^|4HfmjrX
zS->J3j0}t{3`|N-r7xY|$p4v9h+%_MlbvdloiHnNlifxqcAzR=AZ7wOhJk^R@i!mH
zrFzAcxh087K)R#|LTA8ODXB@N>G3)F$zWIOLAXFkG;Vx;T3T^xNini;W?ou8GCwgX
zsVKD!StKVjFBQxOx`84f4b+Vk<Z!bb;4D-Ix>_xuG)T+<RT+Z=l<$ou4$}{#ErIed
zHnP%gD2E4G5R2LXEMg!n(?J9fNJ1z$iEdW{PzGHLq<8~}00K|~K?dk*i-3~oVj%TL
zp_&AtG>k%53zBDsNg~nLpzJ0jF%T17KZwtSrUt~l0X1|5RE`r!gAy(WlrMoKj?MlC
rNUp$YA5<$riWx&UL<=)k7lXn9n@d3AP{*Lz$jrcsCIT~`4O1KdT;*JA

literal 0
HcmV?d00001

diff --git a/test/tools/llvm-dwp/X86/non_cu_top_level.test b/test/tools/llvm-dwp/X86/non_cu_top_level.test
new file mode 100644
index 00000000000..60b8742cdc2
--- /dev/null
+++ b/test/tools/llvm-dwp/X86/non_cu_top_level.test
@@ -0,0 +1,3 @@
+RUN: not llvm-dwp %p/../Inputs/non_cu_top_level.dwo -o %t 2>&1 | FileCheck %s
+
+CHECK: error: top level DIE is not a compile unit
diff --git a/tools/llvm-dwp/llvm-dwp.cpp b/tools/llvm-dwp/llvm-dwp.cpp
index 5e83d7c9cac..31b2f63eb0a 100644
--- a/tools/llvm-dwp/llvm-dwp.cpp
+++ b/tools/llvm-dwp/llvm-dwp.cpp
@@ -141,9 +141,10 @@ static const char *getIndexedString(uint32_t Form, DataExtractor InfoData,
   return StrData.getCStr(&StrOffset);
 }
 
-static CompileUnitIdentifiers getCUIdentifiers(StringRef Abbrev, StringRef Info,
-                                               StringRef StrOffsets,
-                                               StringRef Str) {
+static Expected<CompileUnitIdentifiers> getCUIdentifiers(StringRef Abbrev,
+                                                         StringRef Info,
+                                                         StringRef StrOffsets,
+                                                         StringRef Str) {
   uint32_t Offset = 0;
   DataExtractor InfoData(Info, true, 0);
   InfoData.getU32(&Offset); // Length
@@ -156,9 +157,8 @@ static CompileUnitIdentifiers getCUIdentifiers(StringRef Abbrev, StringRef Info,
   DataExtractor AbbrevData(Abbrev, true, 0);
   uint32_t AbbrevOffset = getCUAbbrev(Abbrev, AbbrCode);
   uint64_t Tag = AbbrevData.getULEB128(&AbbrevOffset);
-  (void)Tag;
-  // FIXME: Real error handling
-  assert(Tag == dwarf::DW_TAG_compile_unit);
+  if (Tag != dwarf::DW_TAG_compile_unit)
+    return make_error<DWPError>("top level DIE is not a compile unit");
   // DW_CHILDREN
   AbbrevData.getU8(&AbbrevOffset);
   uint32_t Name;
@@ -506,11 +506,14 @@ static Error write(MCStreamer &Out, ArrayRef<std::string> Inputs) {
           continue;
         auto P =
             IndexEntries.insert(std::make_pair(E.getSignature(), CurEntry));
-        CompileUnitIdentifiers ID = getCUIdentifiers(
+        Expected<CompileUnitIdentifiers> EID = getCUIdentifiers(
             getSubsection(AbbrevSection, E, DW_SECT_ABBREV),
             getSubsection(InfoSection, E, DW_SECT_INFO),
             getSubsection(CurStrOffsetSection, E, DW_SECT_STR_OFFSETS),
             CurStrSection);
+        if (!EID)
+          return EID.takeError();
+        const auto &ID = *EID;
         if (!P.second)
           return make_error<DWPError>(buildDuplicateError(*P.first, ID, Input));
         auto &NewEntry = P.first->second;
@@ -537,8 +540,11 @@ static Error write(MCStreamer &Out, ArrayRef<std::string> Inputs) {
                            ContributionOffsets[DW_SECT_TYPES - DW_SECT_INFO]);
       }
     } else {
-      CompileUnitIdentifiers ID = getCUIdentifiers(
+      Expected<CompileUnitIdentifiers> EID = getCUIdentifiers(
           AbbrevSection, InfoSection, CurStrOffsetSection, CurStrSection);
+      if (!EID)
+        return EID.takeError();
+      const auto &ID = *EID;
       auto P = IndexEntries.insert(std::make_pair(ID.Signature, CurEntry));
       if (!P.second)
         return make_error<DWPError>(buildDuplicateError(*P.first, ID, ""));