From 6ad82d81cc3061a000799ad8751f018c1301906b Mon Sep 17 00:00:00 2001
From: Stuart Hastings <stuart@apple.com>
Date: Mon, 21 Feb 2011 17:27:17 +0000
Subject: [PATCH] Fix to correctly support attribute((section("__DATA,
 __common"))). Radar 9012638.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@126127 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/CodeGen/TargetLoweringObjectFileImpl.cpp | 11 ++++++++++-
 lib/MC/MCSectionMachO.cpp                    | 15 ++++++++-------
 2 files changed, 18 insertions(+), 8 deletions(-)

diff --git a/lib/CodeGen/TargetLoweringObjectFileImpl.cpp b/lib/CodeGen/TargetLoweringObjectFileImpl.cpp
index 0b7bd98cc69..3b01bfdd694 100644
--- a/lib/CodeGen/TargetLoweringObjectFileImpl.cpp
+++ b/lib/CodeGen/TargetLoweringObjectFileImpl.cpp
@@ -630,7 +630,7 @@ getExplicitSectionGlobal(const GlobalValue *GV, SectionKind Kind,
                          Mangler *Mang, const TargetMachine &TM) const {
   // Parse the section specifier and create it if valid.
   StringRef Segment, Section;
-  unsigned TAA, StubSize;
+  unsigned TAA = (unsigned)MCSectionMachO::SECTION_ATTRIBUTES, StubSize = 0;
   std::string ErrorCode =
     MCSectionMachO::ParseSectionSpecifier(GV->getSection(), Segment, Section,
                                           TAA, StubSize);
@@ -643,10 +643,19 @@ getExplicitSectionGlobal(const GlobalValue *GV, SectionKind Kind,
     return DataSection;
   }
 
+  bool TAAWasSet = (TAA != MCSectionMachO::SECTION_ATTRIBUTES);
+  if (!TAAWasSet)
+    TAA = 0;      // Sensible default if this is a new section.
+    
   // Get the section.
   const MCSectionMachO *S =
     getContext().getMachOSection(Segment, Section, TAA, StubSize, Kind);
 
+  // If TAA wasn't set by ParseSectionSpecifier() above,
+  // use the value returned by getMachOSection() as a default.
+  if (!TAAWasSet)
+    TAA = S->getTypeAndAttributes();
+
   // Okay, now that we got the section, verify that the TAA & StubSize agree.
   // If the user declared multiple globals with different section flags, we need
   // to reject it here.
diff --git a/lib/MC/MCSectionMachO.cpp b/lib/MC/MCSectionMachO.cpp
index b897c0bd685..2cfecb2d8be 100644
--- a/lib/MC/MCSectionMachO.cpp
+++ b/lib/MC/MCSectionMachO.cpp
@@ -101,16 +101,16 @@ void MCSectionMachO::PrintSwitchToSection(const MCAsmInfo &MAI,
     return;
   }
 
-  OS << ',';
-
   unsigned SectionType = TAA & MCSectionMachO::SECTION_TYPE;
   assert(SectionType <= MCSectionMachO::LAST_KNOWN_SECTION_TYPE &&
          "Invalid SectionType specified!");
 
-  if (SectionTypeDescriptors[SectionType].AssemblerName)
+  if (SectionTypeDescriptors[SectionType].AssemblerName) {
+    OS << ',';
     OS << SectionTypeDescriptors[SectionType].AssemblerName;
-  else
-    OS << "<<" << SectionTypeDescriptors[SectionType].EnumName << ">>";
+  } else
+    // If we have no name for the attribute, stop here.
+    return;
 
   // If we don't have any attributes, we're done.
   unsigned SectionAttrs = TAA & MCSectionMachO::SECTION_ATTRIBUTES;
@@ -125,7 +125,9 @@ void MCSectionMachO::PrintSwitchToSection(const MCAsmInfo &MAI,
 
   // Check each attribute to see if we have it.
   char Separator = ',';
-  for (unsigned i = 0; SectionAttrDescriptors[i].AttrFlag; ++i) {
+  for (unsigned i = 0;
+       SectionAttrs != 0 && SectionAttrDescriptors[i].AttrFlag;
+       ++i) {
     // Check to see if we have this attribute.
     if ((SectionAttrDescriptors[i].AttrFlag & SectionAttrs) == 0)
       continue;
@@ -207,7 +209,6 @@ std::string MCSectionMachO::ParseSectionSpecifier(StringRef Spec,        // In.
            "between 1 and 16 characters";
 
   // If there is no comma after the section, we're done.
-  TAA = 0;
   StubSize = 0;
   if (Comma.second.empty())
     return "";
-- 
2.34.1