For explicit sections, limit unique section ids to when fintegrated-as=true.

[rahmanl]

Summary

This limits the applicability of r367501 to the integrated assembler because the gnu-assembler does not recognize unique section ids.

[dblaikie]

Test case?

[rahmanl]

Added test case.

[dblaikie]

Looks good - thanks! (still seems like if the syntax for no-unique-section-names is only supported by the integrated assembler, then this feature should also be gated by that flag too (or that flag shouldn't exist and be implied by the use of the integrated assembler?))

[dblaikie]

Was this or some other solution committed?

[rahmanl]

The original commit that this revision was trying to fix was reverted in rG885fa02da97a9f4d15f05fd7ec9c1358c47dd125 due to other technical reasons that this revision was not aiming to fix.

lib/CodeGen/TargetLoweringObjectFileImpl.cpp

MCSection *TargetLoweringObjectFileELF::getExplicitSectionGlobal(
   unsigned Flags = getELFSectionFlags(Kind);
   if (const Comdat *C = getELFComdat(GO)) {
     Group = C->getName();
     Flags |= ELF::SHF_GROUP;
   }
 
   bool EmitUniqueSection = false;
 
-  // If we have -ffunction-sections or -fdata-sections then we should emit the
-  // global value to a uniqued section of the same name.
+  if (TM.getMCAsmInfo()->useIntegratedAssembler()) {
+    // If we are using the integrated assembler and we have -ffunction-sections
+    // or -fdata-sections, then we emit the global value into a uniqued section
+    // of the same name.
     if (!(Flags & ELF::SHF_MERGE) && !Kind.isCommon()) {
       if (Kind.isText())
         EmitUniqueSection = TM.getFunctionSections();
       else
         EmitUniqueSection = TM.getDataSections();
     }
     EmitUniqueSection |= GO->hasComdat();
+  }
 
   // A section can have at most one associated section. Put each global with
   // MD_associated in a unique section.
   const MCSymbolELF *AssociatedSymbol = getAssociatedSymbol(GO, TM);
   if (AssociatedSymbol) {
     EmitUniqueSection = true;
     Flags |= ELF::SHF_LINK_ORDER;
   }

test/CodeGen/X86/explicit-elf-sections.ll

 ; RUN: llc < %s -mtriple=x86_64-pc-linux -function-sections=1 -data-sections=1 | FileCheck %s -check-prefix=SECTIONS
+; RUN: llc < %s -mtriple=x86_64-pc-linux -no-integrated-as -function-sections=1 -data-sections=1 | FileCheck %s -check-prefix=NIAS
 ; RUN: llc < %s -mtriple=x86_64-pc-linux -function-sections=0 -data-sections=0 | FileCheck %s -check-prefix=NSECTIONS
 
 define void @f() section "aaa" { ret void }
 define void @g() section "aaa" { ret void }
 
 define void @h() { ret void }
 
 @x = global i32 1, section "aaa"

 ; SECTIONS: .section        .data.z,"aw",@progbits
 ; SECTIONS-NOT: {{\.section|\.text|\.data}}
 ; SECTIONS: z:
 ; SECTIONS: .section  aaa,"aw",@progbits,unique,6
 ; SECTIONS-NOT: {{\.section|\.text|\.data}}
 ; SECTIONS: w:
 
 
+; With -no-integrated-as, function and data sections are only created
+; for implicit sections.
+;
+; NIAS:   .section  aaa,"ax",@progbits
+; NIAS-NOT: {{\.section|\.text|\.data}}
+; NIAS:   f:
+; NIAS-NOT: {{\.section|\.text|\.data}}
+; NIAS:   g:
+; NIAS:   .section        .text.h,"ax",@progbits
+; NIAS-NOT: {{\.section|\.text|\.data}}
+; NIAS:   h:
+; NIAS:   .section  aaa,"ax",@progbits
+; NIAS-NOT: {{\.section|\.text|\.data}}
+; NIAS:   i:
+; NIAS-NOT: {{\.section|\.text|\.data}}
+; NIAS:   x:
+; NIAS-NOT: {{\.section|\.text|\.data}}
+; NIAS:   y:
+; NIAS:   .section        .data.z,"aw",@progbits
+; NIAS-NOT: {{\.section|\.text|\.data}}
+; NIAS:   z:
+; NIAS:   .section  aaa,"ax",@progbits
+; NIAS-NOT: {{\.section|\.text|\.data}}
+; NIAS:   w:
+