introduce a section kind for common linkage. Use this to slightly

simplify and commonize some of the asmprinter logic for globals.

This also avoids printing the MCSection for .zerofill, which broke
the llvm-gcc build.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@93843 91177308-0d34-0410-b5e6-96231b3b80d8

5 files changed, 99 insertions, 24 deletions

diff --git a/lib/Target/ARM/AsmPrinter/ARMAsmPrinter.cpp b/lib/Target/ARM/AsmPrinter/ARMAsmPrinter.cpp
index 2ba940bb49..9016f5c112 100644
--- a/lib/Target/ARM/AsmPrinter/ARMAsmPrinter.cpp
+++ b/lib/Target/ARM/AsmPrinter/ARMAsmPrinter.cpp
@@ -1197,10 +1197,27 @@ void ARMAsmPrinter::PrintGlobalVariable(const GlobalVariable* GVar) {
     O << "\t.type " << *GVarSym << ",%object\n";
 
   SectionKind GVKind = TargetLoweringObjectFile::getKindForGlobal(GVar, TM);
+
+  // Handle normal common symbols.
+  if (GVKind.isCommon()) {
+    if (Size == 0) Size = 1;   // .comm Foo, 0 is undefined, avoid it.
+    
+    O << ".comm " << *GVarSym << ',' << Size;
+    if (MAI->getCOMMDirectiveTakesAlignment())
+      O << ',' << (MAI->getAlignmentIsInBytes() ? (1 << Align) : Align);
+    
+    if (VerboseAsm) {
+      O << "\t\t" << MAI->getCommentString() << " '";
+      WriteAsOperand(O, GVar, /*PrintType=*/false, GVar->getParent());
+      O << '\'';
+    }
+    O << '\n';
+    return;
+  }
+  
   const MCSection *TheSection =
     getObjFileLowering().SectionForGlobal(GVar, GVKind, Mang, TM);
-  OutStreamer.SwitchSection(TheSection);
-
+  
   // Handle the zerofill directive on darwin, which is a special form of BSS
   // emission.
   if (GVKind.isBSS() && MAI->hasMachoZeroFillDirective()) {
@@ -1215,6 +1232,8 @@ void ARMAsmPrinter::PrintGlobalVariable(const GlobalVariable* GVar) {
     }
   }
   
+  OutStreamer.SwitchSection(TheSection);
+
   // FIXME: get this stuff from section kind flags.
   if (C->isNullValue() && !GVar->hasSection() && !GVar->isThreadLocal() &&
       // Don't put things that should go in the cstring section into "comm".
diff --git a/lib/Target/PowerPC/AsmPrinter/PPCAsmPrinter.cpp b/lib/Target/PowerPC/AsmPrinter/PPCAsmPrinter.cpp
index 28dd193deb..5e19428126 100644
--- a/lib/Target/PowerPC/AsmPrinter/PPCAsmPrinter.cpp
+++ b/lib/Target/PowerPC/AsmPrinter/PPCAsmPrinter.cpp
@@ -714,8 +714,27 @@ void PPCLinuxAsmPrinter::PrintGlobalVariable(const GlobalVariable *GVar) {
   unsigned Size = TD->getTypeAllocSize(Type);
   unsigned Align = TD->getPreferredAlignmentLog(GVar);
 
-  OutStreamer.SwitchSection(getObjFileLowering().SectionForGlobal(GVar, Mang,
-                                                                  TM));
+  SectionKind GVKind = TargetLoweringObjectFile::getKindForGlobal(GVar, TM);
+
+  // Handle normal common symbols.
+  if (GVKind.isCommon()) {
+    if (Size == 0) Size = 1;   // .comm Foo, 0 is undefined, avoid it.
+    
+    O << ".comm " << *GVarSym << ',' << Size;
+    if (MAI->getCOMMDirectiveTakesAlignment())
+      O << ',' << Align;
+    
+    if (VerboseAsm) {
+      O << "\t\t" << MAI->getCommentString() << " '";
+      WriteAsOperand(O, GVar, /*PrintType=*/false, GVar->getParent());
+      O << '\'';
+    }
+    O << '\n';
+    return;
+  }
+  
+  OutStreamer.SwitchSection(getObjFileLowering().
+                            SectionForGlobal(GVar, GVKind, Mang, TM));
 
   if (C->isNullValue() && /* FIXME: Verify correct */
       !GVar->hasSection() &&
@@ -945,10 +964,27 @@ void PPCDarwinAsmPrinter::PrintGlobalVariable(const GlobalVariable *GVar) {
   unsigned Align = TD->getPreferredAlignmentLog(GVar);
 
   SectionKind GVKind = TargetLoweringObjectFile::getKindForGlobal(GVar, TM);
+
+  // Handle normal common symbols.
+  if (GVKind.isCommon()) {
+    if (Size == 0) Size = 1;   // .comm Foo, 0 is undefined, avoid it.
+
+    O << ".comm " << *GVarSym << ',' << Size;
+    if (MAI->getCOMMDirectiveTakesAlignment())
+      O << ',' << (MAI->getAlignmentIsInBytes() ? (1 << Align) : Align);
+    
+    if (VerboseAsm) {
+      O << "\t\t" << MAI->getCommentString() << " '";
+      WriteAsOperand(O, GVar, /*PrintType=*/false, GVar->getParent());
+      O << '\'';
+    }
+    O << '\n';
+    return;
+  }
+  
   const MCSection *TheSection =
     getObjFileLowering().SectionForGlobal(GVar, GVKind, Mang, TM);
-  OutStreamer.SwitchSection(TheSection);
-
+  
   // Handle the zerofill directive on darwin, which is a special form of BSS
   // emission.
   if (GVKind.isBSS() && MAI->hasMachoZeroFillDirective()) {
@@ -963,6 +999,8 @@ void PPCDarwinAsmPrinter::PrintGlobalVariable(const GlobalVariable *GVar) {
     }
   }
   
+  OutStreamer.SwitchSection(TheSection);
+
   /// FIXME: Drive this off the section!
   if (C->isNullValue() && /* FIXME: Verify correct */
       !GVar->hasSection() &&
@@ -974,7 +1012,14 @@ void PPCDarwinAsmPrinter::PrintGlobalVariable(const GlobalVariable *GVar) {
 
     if (GVar->hasLocalLinkage()) {
       O << MAI->getLCOMMDirective() << *GVarSym << ',' << Size << ',' << Align;
-    } else if (!GVar->hasCommonLinkage()) {
+      
+      if (VerboseAsm) {
+        O << "\t\t" << MAI->getCommentString() << " '";
+        WriteAsOperand(O, GVar, /*PrintType=*/false, GVar->getParent());
+        O << "'";
+      }
+      O << '\n';
+    } else {
       O << "\t.globl " << *GVarSym << '\n' << MAI->getWeakDefDirective();
       O << *GVarSym << '\n';
       EmitAlignment(Align, GVar);
@@ -985,19 +1030,7 @@ void PPCDarwinAsmPrinter::PrintGlobalVariable(const GlobalVariable *GVar) {
       }
       O << '\n';
       EmitGlobalConstant(C);
-      return;
-    } else {
-      O << ".comm " << *GVarSym << ',' << Size;
-      // Darwin 9 and above support aligned common data.
-      if (Subtarget.isDarwin9())
-        O << ',' << Align;
     }
-    if (VerboseAsm) {
-      O << "\t\t" << MAI->getCommentString() << " '";
-      WriteAsOperand(O, GVar, /*PrintType=*/false, GVar->getParent());
-      O << "'";
-    }
-    O << '\n';
     return;
   }
 
diff --git a/lib/Target/SystemZ/AsmPrinter/SystemZAsmPrinter.cpp b/lib/Target/SystemZ/AsmPrinter/SystemZAsmPrinter.cpp
index 53d2955b62..0171193f12 100644
--- a/lib/Target/SystemZ/AsmPrinter/SystemZAsmPrinter.cpp
+++ b/lib/Target/SystemZ/AsmPrinter/SystemZAsmPrinter.cpp
@@ -318,7 +318,7 @@ void SystemZAsmPrinter::PrintGlobalVariable(const GlobalVariable* GVar) {
 
   if (C->isNullValue() && !GVar->hasSection() &&
       !GVar->isThreadLocal() &&
-      (GVar->hasLocalLinkage() || GVar->isWeakForLinker())) {
+      (GVar->hasLocalLinkage() || GVar->hasCommonLinkage())) {
 
     if (Size == 0) Size = 1;   // .comm Foo, 0 is undefined, avoid it.
 
diff --git a/lib/Target/TargetLoweringObjectFile.cpp b/lib/Target/TargetLoweringObjectFile.cpp
index 26a181aea0..cd0558025b 100644
--- a/lib/Target/TargetLoweringObjectFile.cpp
+++ b/lib/Target/TargetLoweringObjectFile.cpp
@@ -141,6 +141,10 @@ SectionKind TargetLoweringObjectFile::getKindForGlobal(const GlobalValue *GV,
     return SectionKind::getThreadData();
   }
 
+  // Variables with common linkage always get classified as common.
+  if (GVar->hasCommonLinkage())
+    return SectionKind::getCommon();
+
   // Variable can be easily put to BSS section.
   if (isSuitableForBSS(GVar))
     return SectionKind::getBSS();
@@ -577,7 +581,7 @@ SelectSectionForGlobal(const GlobalValue *GV, SectionKind Kind,
 
   // If this global is linkonce/weak and the target handles this by emitting it
   // into a 'uniqued' section name, create and return the section now.
-  if (GV->isWeakForLinker()) {
+  if (GV->isWeakForLinker() && !Kind.isCommon()) {
     const char *Prefix = getSectionPrefixForUniqueGlobal(Kind);
     SmallString<128> Name;
     Name.append(Prefix, Prefix+strlen(Prefix));
@@ -630,7 +634,7 @@ SelectSectionForGlobal(const GlobalValue *GV, SectionKind Kind,
   if (Kind.isThreadData())           return TLSDataSection;
   if (Kind.isThreadBSS())            return TLSBSSSection;
 
-  if (Kind.isBSS())                  return BSSSection;
+  if (Kind.isBSS() || Kind.isCommon()) return BSSSection;
 
   if (Kind.isDataNoRel())            return DataSection;
   if (Kind.isDataRelLocal())         return DataRelLocalSection;
diff --git a/lib/Target/X86/AsmPrinter/X86AsmPrinter.cpp b/lib/Target/X86/AsmPrinter/X86AsmPrinter.cpp
index 3bf4c4c9af..383bc3180b 100644
--- a/lib/Target/X86/AsmPrinter/X86AsmPrinter.cpp
+++ b/lib/Target/X86/AsmPrinter/X86AsmPrinter.cpp
@@ -676,9 +676,26 @@ void X86AsmPrinter::PrintGlobalVariable(const GlobalVariable* GVar) {
     O << "\t.type\t" << *GVarSym << ",@object\n";
   
   SectionKind GVKind = TargetLoweringObjectFile::getKindForGlobal(GVar, TM);
+
+  // Handle normal common symbols.
+  if (GVKind.isCommon()) {
+    if (Size == 0) Size = 1;   // .comm Foo, 0 is undefined, avoid it.
+    
+    O << ".comm " << *GVarSym << ',' << Size;
+    if (MAI->getCOMMDirectiveTakesAlignment())
+      O << ',' << (MAI->getAlignmentIsInBytes() ? (1 << Align) : Align);
+    
+    if (VerboseAsm) {
+      O << "\t\t" << MAI->getCommentString() << " '";
+      WriteAsOperand(O, GVar, /*PrintType=*/false, GVar->getParent());
+      O << '\'';
+    }
+    O << '\n';
+    return;
+  }
+  
   const MCSection *TheSection =
     getObjFileLowering().SectionForGlobal(GVar, GVKind, Mang, TM);
-  OutStreamer.SwitchSection(TheSection);
 
   // Handle the zerofill directive on darwin, which is a special form of BSS
   // emission.
@@ -693,6 +710,8 @@ void X86AsmPrinter::PrintGlobalVariable(const GlobalVariable* GVar) {
       return;
     }
   }
+
+  OutStreamer.SwitchSection(TheSection);
   
   // FIXME: get this stuff from section kind flags.
   if (C->isNullValue() && !GVar->hasSection() &&
@@ -707,7 +726,7 @@ void X86AsmPrinter::PrintGlobalVariable(const GlobalVariable* GVar) {
         O << LComm << *GVarSym << ',' << Size;
         if (Subtarget->isTargetDarwin())
           O << ',' << Align;
-      } else if (Subtarget->isTargetDarwin() && !GVar->hasCommonLinkage()) {
+      } else if (Subtarget->isTargetDarwin()) {
         OutStreamer.EmitSymbolAttribute(GVarSym, MCStreamer::Global);
         O << MAI->getWeakDefDirective() << *GVarSym << '\n';
         EmitAlignment(Align, GVar);