[PowerPC] undef Relocation names in PowerPC*.def

glibc's PowerPC /usr/include/asm/sigcontext.h, has this:

  #ifdef __powerpc64__
  #include <asm/elf.h>
  #endif

and that contains defines of all of the relocation symbols, like this:

  #define R_PPC_NONE              0

and if that file is included prior to including
include/llvm/Support/ELFRelocs/PowerPC*.def, which we cannot in general
prevent, the result will fail.

As it turns out, this happens when compiling
lld/unittests/DriverTests/GnuLdDriverTest.cpp under PPC64/Linux, because:

  lld/include/lld/ReaderWriter/ELFLinkingContext.h includes
  lld/unittests/DriverTests/DriverTest.h which includes
  utils/unittest/googletest/include/gtest/gtest.h which includes
  utils/unittest/googletest/include/gtest/internal/gtest-internal.h which includes
  /usr/include/sys/wait.h which includes
  /usr/include/signal.h which includes
  /usr/include/bits/sigcontext.h which includes
  /usr/include/asm/sigcontext.h which includes
  /usr/include/asm/elf.h

the test could be fixed to include ReaderWriter/ELFLinkingContext.h before
including unittests/DriverTests/DriverTest.h, but dealing with this in the
*.def files is a more-general solution that localizes the fix to the headers
instead of requiring changes to an unbounded number of other source files (both
in-tree and external).

llvm-svn: 248957

include/llvm/Support/ELFRelocs/PowerPC.def

@@ -3,6 +3,68 @@
 #error "ELF_RELOC must be defined"
 #endif
 
+// glibc's PowerPC asm/sigcontext.h, when compiling for PPC64, has the
+// unfortunate behavior of including asm/elf.h, which defines R_PPC_NONE, etc.
+// to their corresponding integer values. As a result, we need to undef them
+// here before continuing.
+
+#undef R_PPC_NONE
+#undef R_PPC_ADDR32
+#undef R_PPC_ADDR24
+#undef R_PPC_ADDR16
+#undef R_PPC_ADDR16_LO
+#undef R_PPC_ADDR16_HI
+#undef R_PPC_ADDR16_HA
+#undef R_PPC_ADDR14
+#undef R_PPC_ADDR14_BRTAKEN
+#undef R_PPC_ADDR14_BRNTAKEN
+#undef R_PPC_REL24
+#undef R_PPC_REL14
+#undef R_PPC_REL14_BRTAKEN
+#undef R_PPC_REL14_BRNTAKEN
+#undef R_PPC_GOT16
+#undef R_PPC_GOT16_LO
+#undef R_PPC_GOT16_HI
+#undef R_PPC_GOT16_HA
+#undef R_PPC_PLTREL24
+#undef R_PPC_JMP_SLOT
+#undef R_PPC_LOCAL24PC
+#undef R_PPC_REL32
+#undef R_PPC_TLS
+#undef R_PPC_DTPMOD32
+#undef R_PPC_TPREL16
+#undef R_PPC_TPREL16_LO
+#undef R_PPC_TPREL16_HI
+#undef R_PPC_TPREL16_HA
+#undef R_PPC_TPREL32
+#undef R_PPC_DTPREL16
+#undef R_PPC_DTPREL16_LO
+#undef R_PPC_DTPREL16_HI
+#undef R_PPC_DTPREL16_HA
+#undef R_PPC_DTPREL32
+#undef R_PPC_GOT_TLSGD16
+#undef R_PPC_GOT_TLSGD16_LO
+#undef R_PPC_GOT_TLSGD16_HI
+#undef R_PPC_GOT_TLSGD16_HA
+#undef R_PPC_GOT_TLSLD16
+#undef R_PPC_GOT_TLSLD16_LO
+#undef R_PPC_GOT_TLSLD16_HI
+#undef R_PPC_GOT_TLSLD16_HA
+#undef R_PPC_GOT_TPREL16
+#undef R_PPC_GOT_TPREL16_LO
+#undef R_PPC_GOT_TPREL16_HI
+#undef R_PPC_GOT_TPREL16_HA
+#undef R_PPC_GOT_DTPREL16
+#undef R_PPC_GOT_DTPREL16_LO
+#undef R_PPC_GOT_DTPREL16_HI
+#undef R_PPC_GOT_DTPREL16_HA
+#undef R_PPC_TLSGD
+#undef R_PPC_TLSLD
+#undef R_PPC_REL16
+#undef R_PPC_REL16_LO
+#undef R_PPC_REL16_HI
+#undef R_PPC_REL16_HA
+
 ELF_RELOC(R_PPC_NONE,                   0)      /* No relocation. */
 ELF_RELOC(R_PPC_ADDR32,                 1)
 ELF_RELOC(R_PPC_ADDR24,                 2)

include/llvm/Support/ELFRelocs/PowerPC64.def

@@ -3,6 +3,95 @@
 #error "ELF_RELOC must be defined"
 #endif
 
+// glibc's PowerPC asm/sigcontext.h, when compiling for PPC64, has the
+// unfortunate behavior of including asm/elf.h, which defines R_PPC_NONE, etc.
+// to their corresponding integer values. As a result, we need to undef them
+// here before continuing.
+
+#undef R_PPC64_NONE
+#undef R_PPC64_ADDR32
+#undef R_PPC64_ADDR24
+#undef R_PPC64_ADDR16
+#undef R_PPC64_ADDR16_LO
+#undef R_PPC64_ADDR16_HI
+#undef R_PPC64_ADDR16_HA
+#undef R_PPC64_ADDR14
+#undef R_PPC64_ADDR14_BRTAKEN
+#undef R_PPC64_ADDR14_BRNTAKEN
+#undef R_PPC64_REL24
+#undef R_PPC64_REL14
+#undef R_PPC64_REL14_BRTAKEN
+#undef R_PPC64_REL14_BRNTAKEN
+#undef R_PPC64_GOT16
+#undef R_PPC64_GOT16_LO
+#undef R_PPC64_GOT16_HI
+#undef R_PPC64_GOT16_HA
+#undef R_PPC64_JMP_SLOT
+#undef R_PPC64_REL32
+#undef R_PPC64_ADDR64
+#undef R_PPC64_ADDR16_HIGHER
+#undef R_PPC64_ADDR16_HIGHERA
+#undef R_PPC64_ADDR16_HIGHEST
+#undef R_PPC64_ADDR16_HIGHESTA
+#undef R_PPC64_REL64
+#undef R_PPC64_TOC16
+#undef R_PPC64_TOC16_LO
+#undef R_PPC64_TOC16_HI
+#undef R_PPC64_TOC16_HA
+#undef R_PPC64_TOC
+#undef R_PPC64_ADDR16_DS
+#undef R_PPC64_ADDR16_LO_DS
+#undef R_PPC64_GOT16_DS
+#undef R_PPC64_GOT16_LO_DS
+#undef R_PPC64_TOC16_DS
+#undef R_PPC64_TOC16_LO_DS
+#undef R_PPC64_TLS
+#undef R_PPC64_DTPMOD64
+#undef R_PPC64_TPREL16
+#undef R_PPC64_TPREL16_LO
+#undef R_PPC64_TPREL16_HI
+#undef R_PPC64_TPREL16_HA
+#undef R_PPC64_TPREL64
+#undef R_PPC64_DTPREL16
+#undef R_PPC64_DTPREL16_LO
+#undef R_PPC64_DTPREL16_HI
+#undef R_PPC64_DTPREL16_HA
+#undef R_PPC64_DTPREL64
+#undef R_PPC64_GOT_TLSGD16
+#undef R_PPC64_GOT_TLSGD16_LO
+#undef R_PPC64_GOT_TLSGD16_HI
+#undef R_PPC64_GOT_TLSGD16_HA
+#undef R_PPC64_GOT_TLSLD16
+#undef R_PPC64_GOT_TLSLD16_LO
+#undef R_PPC64_GOT_TLSLD16_HI
+#undef R_PPC64_GOT_TLSLD16_HA
+#undef R_PPC64_GOT_TPREL16_DS
+#undef R_PPC64_GOT_TPREL16_LO_DS
+#undef R_PPC64_GOT_TPREL16_HI
+#undef R_PPC64_GOT_TPREL16_HA
+#undef R_PPC64_GOT_DTPREL16_DS
+#undef R_PPC64_GOT_DTPREL16_LO_DS
+#undef R_PPC64_GOT_DTPREL16_HI
+#undef R_PPC64_GOT_DTPREL16_HA
+#undef R_PPC64_TPREL16_DS
+#undef R_PPC64_TPREL16_LO_DS
+#undef R_PPC64_TPREL16_HIGHER
+#undef R_PPC64_TPREL16_HIGHERA
+#undef R_PPC64_TPREL16_HIGHEST
+#undef R_PPC64_TPREL16_HIGHESTA
+#undef R_PPC64_DTPREL16_DS
+#undef R_PPC64_DTPREL16_LO_DS
+#undef R_PPC64_DTPREL16_HIGHER
+#undef R_PPC64_DTPREL16_HIGHERA
+#undef R_PPC64_DTPREL16_HIGHEST
+#undef R_PPC64_DTPREL16_HIGHESTA
+#undef R_PPC64_TLSGD
+#undef R_PPC64_TLSLD
+#undef R_PPC64_REL16
+#undef R_PPC64_REL16_LO
+#undef R_PPC64_REL16_HI
+#undef R_PPC64_REL16_HA
+
 ELF_RELOC(R_PPC64_NONE,                 0)
 ELF_RELOC(R_PPC64_ADDR32,               1)
 ELF_RELOC(R_PPC64_ADDR24,               2)