From 651aa689cc37d5932fac0e096aa8b536f282aa21 Mon Sep 17 00:00:00 2001
From: Daniel Dunbar <daniel@zuster.org>
Date: Tue, 18 Aug 2009 19:26:55 +0000
Subject: [PATCH] Improve Triple to recognize the OS in i386-mingw32.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@79359 91177308-0d34-0410-b5e6-96231b3b80d8
---
 include/llvm/ADT/Triple.h    | 18 ++++++++++++++++--
 lib/Support/Triple.cpp       | 21 +++++++++++++++++++--
 unittests/ADT/TripleTest.cpp | 12 ++++++++++++
 3 files changed, 47 insertions(+), 4 deletions(-)

diff --git a/include/llvm/ADT/Triple.h b/include/llvm/ADT/Triple.h
index a74fde3d6e1..c63d91be99b 100644
--- a/include/llvm/ADT/Triple.h
+++ b/include/llvm/ADT/Triple.h
@@ -29,8 +29,22 @@ class Twine;
 /// behavior for particular targets. This class isolates the mapping
 /// from the components of the target triple to well known IDs.
 ///
-/// See autoconf/config.guess for a glimpse into what they look like
-/// in practice.
+/// At its core the Triple class is designed to be a wrapper for a triple
+/// string; it does not normally change or normalize the triple string, instead
+/// it provides additional APIs to parse normalized parts out of the triple.
+///
+/// One curiosity this implies is that for some odd triples the results of,
+/// e.g., getOSName() can be very different from the result of getOS().  For
+/// example, for 'i386-mingw32', getOS() will return MinGW32, but since
+/// getOSName() is purely based on the string structure that will return the
+/// empty string.
+///
+/// Clients should generally avoid using getOSName() and related APIs unless
+/// they are familiar with the triple format (this is particularly true when
+/// rewriting a triple).
+///
+/// See autoconf/config.guess for a glimpse into what they look like in
+/// practice.
 class Triple {
 public:
   enum ArchType {
diff --git a/lib/Support/Triple.cpp b/lib/Support/Triple.cpp
index c2982ce6615..df28b98b689 100644
--- a/lib/Support/Triple.cpp
+++ b/lib/Support/Triple.cpp
@@ -117,6 +117,9 @@ void Triple::Parse() const {
   assert(!isInitialized() && "Invalid parse call.");
 
   StringRef ArchName = getArchName();
+  StringRef VendorName = getVendorName();
+  StringRef OSName = getOSName();
+
   if (ArchName.size() == 4 && ArchName[0] == 'i' && 
       ArchName[2] == '8' && ArchName[3] == '6' && 
       ArchName[1] - '3' < 6) // i[3-9]86
@@ -156,7 +159,22 @@ void Triple::Parse() const {
   else
     Arch = UnknownArch;
 
-  StringRef VendorName = getVendorName();
+
+  // Handle some exceptional cases where the OS / environment components are
+  // stuck into the vendor field.
+  if (StringRef(getTriple()).count('-') == 1) {
+    StringRef VendorName = getVendorName();
+
+    if (VendorName.startswith("mingw32")) { // 'i386-mingw32', etc.
+      Vendor = PC;
+      OS = MinGW32;
+      return;
+    }
+
+    // arm-elf is another example, but we don't currently parse anything about
+    // the environment.
+  }
+
   if (VendorName == "apple")
     Vendor = Apple;
   else if (VendorName == "pc")
@@ -164,7 +182,6 @@ void Triple::Parse() const {
   else
     Vendor = UnknownVendor;
 
-  StringRef OSName = getOSName();
   if (OSName.startswith("auroraux"))
     OS = AuroraUX;
   else if (OSName.startswith("cygwin"))
diff --git a/unittests/ADT/TripleTest.cpp b/unittests/ADT/TripleTest.cpp
index cbb2ea48f1b..1a9e81a0df7 100644
--- a/unittests/ADT/TripleTest.cpp
+++ b/unittests/ADT/TripleTest.cpp
@@ -92,6 +92,18 @@ TEST(TripleTest, ParsedIDs) {
 
   T = Triple("huh");
   EXPECT_EQ(Triple::UnknownArch, T.getArch());
+
+  // Two exceptional cases.
+
+  T = Triple("i386-mingw32");
+  EXPECT_EQ(Triple::x86, T.getArch());
+  EXPECT_EQ(Triple::PC, T.getVendor());
+  EXPECT_EQ(Triple::MinGW32, T.getOS());
+
+  T = Triple("arm-elf");
+  EXPECT_EQ(Triple::arm, T.getArch());
+  EXPECT_EQ(Triple::UnknownVendor, T.getVendor());
+  EXPECT_EQ(Triple::UnknownOS, T.getOS());
 }
 
 TEST(TripleTest, MutateName) {
-- 
2.34.1