[ADT] Normalize empty triple components

LLVM triple normalization is handling "unknown" and empty components
differently; for example given "x86_64-unknown-linux-gnu" and
"x86_64-linux-gnu" which should be equivalent, triple normalization
returns "x86_64-unknown-linux-gnu" and "x86_64--linux-gnu". autoconf's
config.sub returns "x86_64-unknown-linux-gnu" for both
"x86_64-linux-gnu" and "x86_64-unknown-linux-gnu". This changes the
triple normalization to behave the same way, replacing empty triple
components with "unknown".

This addresses PR37129.

Differential Revision: https://reviews.llvm.org/D50219

llvm-svn: 339294
diff --git a/llvm/unittests/ADT/TripleTest.cpp b/llvm/unittests/ADT/TripleTest.cpp
index b6b470d..fcc71d5 100644
--- a/llvm/unittests/ADT/TripleTest.cpp
+++ b/llvm/unittests/ADT/TripleTest.cpp
@@ -378,22 +378,33 @@
 }
 
 static std::string Join(StringRef A, StringRef B, StringRef C) {
-  std::string Str = A; Str += '-'; Str += B; Str += '-'; Str += C;
+  std::string Str = A;
+  Str += '-';
+  Str += B;
+  Str += '-';
+  Str += C;
   return Str;
 }
 
 static std::string Join(StringRef A, StringRef B, StringRef C, StringRef D) {
-  std::string Str = A; Str += '-'; Str += B; Str += '-'; Str += C; Str += '-';
-  Str += D; return Str;
+  std::string Str = A;
+  Str += '-';
+  Str += B;
+  Str += '-';
+  Str += C;
+  Str += '-';
+  Str += D;
+  return Str;
 }
 
 TEST(TripleTest, Normalization) {
 
-  EXPECT_EQ("", Triple::normalize(""));
-  EXPECT_EQ("-", Triple::normalize("-"));
-  EXPECT_EQ("--", Triple::normalize("--"));
-  EXPECT_EQ("---", Triple::normalize("---"));
-  EXPECT_EQ("----", Triple::normalize("----"));
+  EXPECT_EQ("unknown", Triple::normalize(""));
+  EXPECT_EQ("unknown-unknown", Triple::normalize("-"));
+  EXPECT_EQ("unknown-unknown-unknown", Triple::normalize("--"));
+  EXPECT_EQ("unknown-unknown-unknown-unknown", Triple::normalize("---"));
+  EXPECT_EQ("unknown-unknown-unknown-unknown-unknown",
+            Triple::normalize("----"));
 
   EXPECT_EQ("a", Triple::normalize("a"));
   EXPECT_EQ("a-b", Triple::normalize("a-b"));
@@ -406,24 +417,24 @@
   EXPECT_EQ("i386-a-b-c", Triple::normalize("a-b-c-i386"));
 
   EXPECT_EQ("a-pc-c", Triple::normalize("a-pc-c"));
-  EXPECT_EQ("-pc-b-c", Triple::normalize("pc-b-c"));
+  EXPECT_EQ("unknown-pc-b-c", Triple::normalize("pc-b-c"));
   EXPECT_EQ("a-pc-b", Triple::normalize("a-b-pc"));
   EXPECT_EQ("a-pc-b-c", Triple::normalize("a-b-c-pc"));
 
   EXPECT_EQ("a-b-linux", Triple::normalize("a-b-linux"));
-  EXPECT_EQ("--linux-b-c", Triple::normalize("linux-b-c"));
-  EXPECT_EQ("a--linux-c", Triple::normalize("a-linux-c"));
+  EXPECT_EQ("unknown-unknown-linux-b-c", Triple::normalize("linux-b-c"));
+  EXPECT_EQ("a-unknown-linux-c", Triple::normalize("a-linux-c"));
 
   EXPECT_EQ("i386-pc-a", Triple::normalize("a-pc-i386"));
-  EXPECT_EQ("i386-pc-", Triple::normalize("-pc-i386"));
-  EXPECT_EQ("-pc-linux-c", Triple::normalize("linux-pc-c"));
-  EXPECT_EQ("-pc-linux", Triple::normalize("linux-pc-"));
+  EXPECT_EQ("i386-pc-unknown", Triple::normalize("-pc-i386"));
+  EXPECT_EQ("unknown-pc-linux-c", Triple::normalize("linux-pc-c"));
+  EXPECT_EQ("unknown-pc-linux", Triple::normalize("linux-pc-"));
 
   EXPECT_EQ("i386", Triple::normalize("i386"));
-  EXPECT_EQ("-pc", Triple::normalize("pc"));
-  EXPECT_EQ("--linux", Triple::normalize("linux"));
+  EXPECT_EQ("unknown-pc", Triple::normalize("pc"));
+  EXPECT_EQ("unknown-unknown-linux", Triple::normalize("linux"));
 
-  EXPECT_EQ("x86_64--linux-gnu", Triple::normalize("x86_64-gnu-linux"));
+  EXPECT_EQ("x86_64-unknown-linux-gnu", Triple::normalize("x86_64-gnu-linux"));
 
   // Check that normalizing a permutated set of valid components returns a
   // triple with the unpermuted components.
@@ -499,12 +510,18 @@
 
   // Various real-world funky triples.  The value returned by GCC's config.sub
   // is given in the comment.
-  EXPECT_EQ("i386--windows-gnu", Triple::normalize("i386-mingw32")); // i386-pc-mingw32
-  EXPECT_EQ("x86_64--linux-gnu", Triple::normalize("x86_64-linux-gnu")); // x86_64-pc-linux-gnu
-  EXPECT_EQ("i486--linux-gnu", Triple::normalize("i486-linux-gnu")); // i486-pc-linux-gnu
-  EXPECT_EQ("i386-redhat-linux", Triple::normalize("i386-redhat-linux")); // i386-redhat-linux-gnu
-  EXPECT_EQ("i686--linux", Triple::normalize("i686-linux")); // i686-pc-linux-gnu
-  EXPECT_EQ("arm-none--eabi", Triple::normalize("arm-none-eabi")); // arm-none-eabi
+  EXPECT_EQ("i386-unknown-windows-gnu",
+            Triple::normalize("i386-mingw32")); // i386-pc-mingw32
+  EXPECT_EQ("x86_64-unknown-linux-gnu",
+            Triple::normalize("x86_64-linux-gnu")); // x86_64-pc-linux-gnu
+  EXPECT_EQ("i486-unknown-linux-gnu",
+            Triple::normalize("i486-linux-gnu")); // i486-pc-linux-gnu
+  EXPECT_EQ("i386-redhat-linux",
+            Triple::normalize("i386-redhat-linux")); // i386-redhat-linux-gnu
+  EXPECT_EQ("i686-unknown-linux",
+            Triple::normalize("i686-linux")); // i686-pc-linux-gnu
+  EXPECT_EQ("arm-none-unknown-eabi",
+            Triple::normalize("arm-none-eabi")); // arm-none-eabi
 }
 
 TEST(TripleTest, MutateName) {
@@ -1077,38 +1094,46 @@
 
 TEST(TripleTest, NormalizeWindows) {
   EXPECT_EQ("i686-pc-windows-msvc", Triple::normalize("i686-pc-win32"));
-  EXPECT_EQ("i686--windows-msvc", Triple::normalize("i686-win32"));
+  EXPECT_EQ("i686-unknown-windows-msvc", Triple::normalize("i686-win32"));
   EXPECT_EQ("i686-pc-windows-gnu", Triple::normalize("i686-pc-mingw32"));
-  EXPECT_EQ("i686--windows-gnu", Triple::normalize("i686-mingw32"));
+  EXPECT_EQ("i686-unknown-windows-gnu", Triple::normalize("i686-mingw32"));
   EXPECT_EQ("i686-pc-windows-gnu", Triple::normalize("i686-pc-mingw32-w64"));
-  EXPECT_EQ("i686--windows-gnu", Triple::normalize("i686-mingw32-w64"));
+  EXPECT_EQ("i686-unknown-windows-gnu", Triple::normalize("i686-mingw32-w64"));
   EXPECT_EQ("i686-pc-windows-cygnus", Triple::normalize("i686-pc-cygwin"));
-  EXPECT_EQ("i686--windows-cygnus", Triple::normalize("i686-cygwin"));
+  EXPECT_EQ("i686-unknown-windows-cygnus", Triple::normalize("i686-cygwin"));
 
   EXPECT_EQ("x86_64-pc-windows-msvc", Triple::normalize("x86_64-pc-win32"));
-  EXPECT_EQ("x86_64--windows-msvc", Triple::normalize("x86_64-win32"));
+  EXPECT_EQ("x86_64-unknown-windows-msvc", Triple::normalize("x86_64-win32"));
   EXPECT_EQ("x86_64-pc-windows-gnu", Triple::normalize("x86_64-pc-mingw32"));
-  EXPECT_EQ("x86_64--windows-gnu", Triple::normalize("x86_64-mingw32"));
-  EXPECT_EQ("x86_64-pc-windows-gnu", Triple::normalize("x86_64-pc-mingw32-w64"));
-  EXPECT_EQ("x86_64--windows-gnu", Triple::normalize("x86_64-mingw32-w64"));
+  EXPECT_EQ("x86_64-unknown-windows-gnu", Triple::normalize("x86_64-mingw32"));
+  EXPECT_EQ("x86_64-pc-windows-gnu",
+            Triple::normalize("x86_64-pc-mingw32-w64"));
+  EXPECT_EQ("x86_64-unknown-windows-gnu",
+            Triple::normalize("x86_64-mingw32-w64"));
 
   EXPECT_EQ("i686-pc-windows-elf", Triple::normalize("i686-pc-win32-elf"));
-  EXPECT_EQ("i686--windows-elf", Triple::normalize("i686-win32-elf"));
+  EXPECT_EQ("i686-unknown-windows-elf", Triple::normalize("i686-win32-elf"));
   EXPECT_EQ("i686-pc-windows-macho", Triple::normalize("i686-pc-win32-macho"));
-  EXPECT_EQ("i686--windows-macho", Triple::normalize("i686-win32-macho"));
+  EXPECT_EQ("i686-unknown-windows-macho",
+            Triple::normalize("i686-win32-macho"));
 
   EXPECT_EQ("x86_64-pc-windows-elf", Triple::normalize("x86_64-pc-win32-elf"));
-  EXPECT_EQ("x86_64--windows-elf", Triple::normalize("x86_64-win32-elf"));
-  EXPECT_EQ("x86_64-pc-windows-macho", Triple::normalize("x86_64-pc-win32-macho"));
-  EXPECT_EQ("x86_64--windows-macho", Triple::normalize("x86_64-win32-macho"));
+  EXPECT_EQ("x86_64-unknown-windows-elf",
+            Triple::normalize("x86_64-win32-elf"));
+  EXPECT_EQ("x86_64-pc-windows-macho",
+            Triple::normalize("x86_64-pc-win32-macho"));
+  EXPECT_EQ("x86_64-unknown-windows-macho",
+            Triple::normalize("x86_64-win32-macho"));
 
   EXPECT_EQ("i686-pc-windows-cygnus",
             Triple::normalize("i686-pc-windows-cygnus"));
   EXPECT_EQ("i686-pc-windows-gnu", Triple::normalize("i686-pc-windows-gnu"));
-  EXPECT_EQ("i686-pc-windows-itanium", Triple::normalize("i686-pc-windows-itanium"));
+  EXPECT_EQ("i686-pc-windows-itanium",
+            Triple::normalize("i686-pc-windows-itanium"));
   EXPECT_EQ("i686-pc-windows-msvc", Triple::normalize("i686-pc-windows-msvc"));
 
-  EXPECT_EQ("i686-pc-windows-elf", Triple::normalize("i686-pc-windows-elf-elf"));
+  EXPECT_EQ("i686-pc-windows-elf",
+            Triple::normalize("i686-pc-windows-elf-elf"));
 }
 
 TEST(TripleTest, getARMCPUForArch) {
@@ -1175,14 +1200,22 @@
 }
 
 TEST(TripleTest, NormalizeARM) {
-  EXPECT_EQ("armv6--netbsd-eabi", Triple::normalize("armv6-netbsd-eabi"));
-  EXPECT_EQ("armv7--netbsd-eabi", Triple::normalize("armv7-netbsd-eabi"));
-  EXPECT_EQ("armv6eb--netbsd-eabi", Triple::normalize("armv6eb-netbsd-eabi"));
-  EXPECT_EQ("armv7eb--netbsd-eabi", Triple::normalize("armv7eb-netbsd-eabi"));
-  EXPECT_EQ("armv6--netbsd-eabihf", Triple::normalize("armv6-netbsd-eabihf"));
-  EXPECT_EQ("armv7--netbsd-eabihf", Triple::normalize("armv7-netbsd-eabihf"));
-  EXPECT_EQ("armv6eb--netbsd-eabihf", Triple::normalize("armv6eb-netbsd-eabihf"));
-  EXPECT_EQ("armv7eb--netbsd-eabihf", Triple::normalize("armv7eb-netbsd-eabihf"));
+  EXPECT_EQ("armv6-unknown-netbsd-eabi",
+            Triple::normalize("armv6-netbsd-eabi"));
+  EXPECT_EQ("armv7-unknown-netbsd-eabi",
+            Triple::normalize("armv7-netbsd-eabi"));
+  EXPECT_EQ("armv6eb-unknown-netbsd-eabi",
+            Triple::normalize("armv6eb-netbsd-eabi"));
+  EXPECT_EQ("armv7eb-unknown-netbsd-eabi",
+            Triple::normalize("armv7eb-netbsd-eabi"));
+  EXPECT_EQ("armv6-unknown-netbsd-eabihf",
+            Triple::normalize("armv6-netbsd-eabihf"));
+  EXPECT_EQ("armv7-unknown-netbsd-eabihf",
+            Triple::normalize("armv7-netbsd-eabihf"));
+  EXPECT_EQ("armv6eb-unknown-netbsd-eabihf",
+            Triple::normalize("armv6eb-netbsd-eabihf"));
+  EXPECT_EQ("armv7eb-unknown-netbsd-eabihf",
+            Triple::normalize("armv7eb-netbsd-eabihf"));
 
   EXPECT_EQ("armv7-suse-linux-gnueabihf",
             Triple::normalize("armv7-suse-linux-gnueabi"));