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llvm-ar: align the first archive member consistently. 

Before we were aligning the member after the symbol table to 4 but
other members to 8.

llvm-svn: 314010
This commit is contained in:
Rafael Espindola 2017-09-22 18:36:00 +00:00
parent 25eb54f789
commit 0bd982b79f
2 changed files with 14 additions and 4 deletions
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8
llvm/lib/Object/ArchiveWriter.cpp
View File

@ -349,9 +349,11 @@ writeSymbolTable(raw_fd_ostream &Out, object::Archive::Kind Kind,
if (StringTable.size() == 0)
print32(Out, Kind, 0);
// ld64 requires the next member header to start at an offset that is
// 4 bytes aligned.
unsigned Alignment = isBSDLike(Kind) ? 4 : 2;
// ld64 expects the members to be 8-byte aligned for 64-bit content and at
// least 4-byte aligned for 32-bit content. Opt for the larger encoding
// uniformly.
// We do this for all bsd formats because it simplifies aligning members.
unsigned Alignment = isBSDLike(Kind) ? 8 : 2;
unsigned Pad = OffsetToAlignment(Out.tell(), Alignment);
while (Pad--)
Out.write(uint8_t(0));

10
llvm/test/Object/archive-symtab.test
View File

@ -115,7 +115,7 @@ COFF-SHORT-IMPORT-NEXT: _foo in coff-short-import-code
COFF-SHORT-IMPORT-NEXT: __imp__bar in coff-short-import-data
COFF-SHORT-IMPORT-NOT: _bar in coff-short-import-data
Test that we pad the symbol table so that it ends in a multiple of 4 bytes:
Test that we pad the symbol table so that it ends in a multiple of 8 bytes:
8 + 60 + 36 == 104
RUN: rm -f %t.a
RUN: llvm-ar --format=bsd rcsU %t.a %p/Inputs/trivial-object-test.macho-x86-64
@ -123,6 +123,14 @@ RUN: FileCheck --check-prefix=MACHO-SYMTAB-ALIGN %s < %t.a
MACHO-SYMTAB-ALIGN: !<arch>
MACHO-SYMTAB-ALIGN-NEXT: #1/12 {{..........}} 0 0 0 36 `
Test that we pad the symbol table so that it ends in a multiple of 8 bytes:
8 + 60 + 52 == 120
RUN: rm -f %t.a
RUN: llvm-ar --format=bsd rcsD %t.a %p/Inputs/trivial-object-test.macho-x86-64 %p/Inputs/trivial-object-test.macho-x86-64
RUN: FileCheck --check-prefix=MACHO-SYMTAB-ALIGN2 %s < %t.a
MACHO-SYMTAB-ALIGN2: !<arch>
MACHO-SYMTAB-ALIGN2-NEXT: #1/12 0 0 0 0 52 `
With a gnu symbol table we only align to two
8 + 60 + 14 = 82
RUN: rm -f %t.a