From 1d3b431c98ef13e35a06ab6e69005983e6d2a030 Mon Sep 17 00:00:00 2001
From: Joerg Sonnenberger <joerg@bec.de>
Date: Mon, 16 Mar 2015 17:54:54 +0000
Subject: [PATCH] Global inline assembler blocks are merged before parsing, so
 no specific location data is available. If pragma handling wants to look up
 the position, it finds the LLVM buffer and wants to compare it with the
 special built-in buffer, failing badly. Extend to the special handling of the
 built-in buffer to also check for the inline asm buffer. Expect only a single
 asm buffer. Sort it between the built-in buffers and the normal file buffers.

Fixes the assert part of PR 22576.

llvm-svn: 232389
---
 clang/lib/Basic/SourceManager.cpp       | 39 ++++++++++++++++---------
 clang/test/CodeGen/invalid_global_asm.c |  5 ++++
 2 files changed, 30 insertions(+), 14 deletions(-)
 create mode 100644 clang/test/CodeGen/invalid_global_asm.c

diff --git a/clang/lib/Basic/SourceManager.cpp b/clang/lib/Basic/SourceManager.cpp
index 305dcd43960c..118e3f32008b 100644
--- a/clang/lib/Basic/SourceManager.cpp
+++ b/clang/lib/Basic/SourceManager.cpp
@@ -2076,22 +2076,33 @@ bool SourceManager::isBeforeInTranslationUnit(SourceLocation LHS,
     return IsBeforeInTUCache.getCachedResult(LOffs.second, ROffs.second);
   }
 
-  // This can happen if a location is in a built-ins buffer.
-  // But see PR5662.
+  // If we arrived here, the location is either in a built-ins buffer or
+  // associated with global inline asm. PR5662 and PR22576 are examples.
+
   // Clear the lookup cache, it depends on a common location.
   IsBeforeInTUCache.clear();
-  bool LIsBuiltins = strcmp("<built-in>",
-                            getBuffer(LOffs.first)->getBufferIdentifier()) == 0;
-  bool RIsBuiltins = strcmp("<built-in>",
-                            getBuffer(ROffs.first)->getBufferIdentifier()) == 0;
-  // built-in is before non-built-in
-  if (LIsBuiltins != RIsBuiltins)
-    return LIsBuiltins;
-  assert(LIsBuiltins && RIsBuiltins &&
-         "Non-built-in locations must be rooted in the main file");
-  // Both are in built-in buffers, but from different files. We just claim that
-  // lower IDs come first.
-  return LOffs.first < ROffs.first;
+  llvm::MemoryBuffer *LBuf = getBuffer(LOffs.first);
+  llvm::MemoryBuffer *RBuf = getBuffer(ROffs.first);
+  bool LIsBuiltins = strcmp("<built-in>", LBuf->getBufferIdentifier()) == 0;
+  bool RIsBuiltins = strcmp("<built-in>", RBuf->getBufferIdentifier()) == 0;
+  // Sort built-in before non-built-in.
+  if (LIsBuiltins || RIsBuiltins) {
+    if (LIsBuiltins != RIsBuiltins)
+      return LIsBuiltins;
+    // Both are in built-in buffers, but from different files. We just claim that
+    // lower IDs come first.
+    return LOffs.first < ROffs.first;
+  }
+  bool LIsAsm = strcmp("<inline asm>", LBuf->getBufferIdentifier()) == 0;
+  bool RIsAsm = strcmp("<inline asm>", RBuf->getBufferIdentifier()) == 0;
+  // Sort assembler after built-ins, but before the rest.
+  if (LIsAsm || RIsAsm) {
+    if (LIsAsm != RIsAsm)
+      return RIsAsm;
+    assert(LOffs.first == ROffs.first);
+    return false;
+  }
+  llvm_unreachable("Unsortable locations found");
 }
 
 void SourceManager::PrintStats() const {
diff --git a/clang/test/CodeGen/invalid_global_asm.c b/clang/test/CodeGen/invalid_global_asm.c
new file mode 100644
index 000000000000..5b7e8b43d752
--- /dev/null
+++ b/clang/test/CodeGen/invalid_global_asm.c
@@ -0,0 +1,5 @@
+// REQUIRES: arm-registered-target
+// RUN: not %clang_cc1 -emit-obj -triple armv6-unknown-unknown -o %t %s 2>&1 | FileCheck %s
+#pragma clang diagnostic ignored "-Wmissing-noreturn"
+__asm__(".Lfoo: movw r2, #:lower16:.Lbar - .Lfoo");
+// CHECK: <inline asm>:1:8: error: instruction requires: armv6t2