Switch USR generation to use file offsets instead of line/columns for anonymous symbols.  Fixes <rdar://problem/8221557>.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@109095 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/test/Index/usrs.m b/test/Index/usrs.m
index 0b56cca..143b067 100644
--- a/test/Index/usrs.m
+++ b/test/Index/usrs.m
@@ -57,19 +57,19 @@
 @implementation CWithExt
 @end
 
-// CHECK: usrs.m c:usrs.m@3:19@F@my_helper Extent=[3:19 - 3:60]
-// CHECK: usrs.m c:usrs.m@3:29@F@my_helper@x Extent=[3:29 - 3:34]
-// CHECK: usrs.m c:usrs.m@3:36@F@my_helper@y Extent=[3:36 - 3:41]
-// CHECK: usrs.m c:usrs.m@5:1@Ea Extent=[5:1 - 8:2]
-// CHECK: usrs.m c:usrs.m@5:1@Ea@ABA Extent=[6:3 - 6:6]
-// CHECK: usrs.m c:usrs.m@5:1@Ea@CADABA Extent=[7:3 - 7:9]
-// CHECK: usrs.m c:usrs.m@10:1@Ea Extent=[10:1 - 13:2]
-// CHECK: usrs.m c:usrs.m@10:1@Ea@FOO Extent=[11:3 - 11:6]
-// CHECK: usrs.m c:usrs.m@10:1@Ea@BAR Extent=[12:3 - 12:6]
+// CHECK: usrs.m c:usrs.m@85@F@my_helper Extent=[3:19 - 3:60]
+// CHECK: usrs.m c:usrs.m@95@F@my_helper@x Extent=[3:29 - 3:34]
+// CHECK: usrs.m c:usrs.m@102@F@my_helper@y Extent=[3:36 - 3:41]
+// CHECK: usrs.m c:usrs.m@128@Ea Extent=[5:1 - 8:2]
+// CHECK: usrs.m c:usrs.m@128@Ea@ABA Extent=[6:3 - 6:6]
+// CHECK: usrs.m c:usrs.m@128@Ea@CADABA Extent=[7:3 - 7:9]
+// CHECK: usrs.m c:usrs.m@155@Ea Extent=[10:1 - 13:2]
+// CHECK: usrs.m c:usrs.m@155@Ea@FOO Extent=[11:3 - 11:6]
+// CHECK: usrs.m c:usrs.m@155@Ea@BAR Extent=[12:3 - 12:6]
 // CHECK: usrs.m c:@SA@MyStruct Extent=[15:9 - 18:2]
 // CHECK: usrs.m c:@SA@MyStruct@FI@wa Extent=[16:7 - 16:9]
 // CHECK: usrs.m c:@SA@MyStruct@FI@moo Extent=[17:7 - 17:10]
-// CHECK: usrs.m c:usrs.m@18:3@T@MyStruct Extent=[18:3 - 18:11]
+// CHECK: usrs.m c:usrs.m@219@T@MyStruct Extent=[18:3 - 18:11]
 // CHECK: usrs.m c:@E@Pizza Extent=[20:1 - 23:2]
 // CHECK: usrs.m c:@E@Pizza@CHEESE Extent=[21:3 - 21:9]
 // CHECK: usrs.m c:@E@Pizza@MUSHROOMS Extent=[22:3 - 22:12]
@@ -81,21 +81,22 @@
 // CHECK: usrs.m c:objc(cs)Foo(cm)kingkong Extent=[30:1 - 30:17]
 // CHECK: usrs.m c:objc(cs)Foo(im)d1 Extent=[31:15 - 31:17]
 // CHECK: usrs.m c:objc(cs)Foo(im)setD1: Extent=[31:15 - 31:17]
-// CHECK: usrs.m c:usrs.m@31:15objc(cs)Foo(im)setD1:@d1 Extent=[31:15 - 31:17]
+// CHECK: usrs.m c:usrs.m@352objc(cs)Foo(im)setD1:@d1 Extent=[31:15 - 31:17]
 // CHECK: usrs.m c:objc(cs)Foo Extent=[34:1 - 45:2]
 // CHECK: usrs.m c:objc(cs)Foo(im)godzilla Extent=[35:1 - 39:2]
-// CHECK: usrs.m c:usrs.m@36:10objc(cs)Foo(im)godzilla@a Extent=[36:10 - 36:19]
+// CHECK: usrs.m c:usrs.m@409objc(cs)Foo(im)godzilla@a Extent=[36:10 - 36:19]
 // CHECK: usrs.m c:objc(cs)Foo(im)godzilla@z Extent=[37:10 - 37:15]
 // CHECK: usrs.m c:objc(cs)Foo(cm)kingkong Extent=[40:1 - 43:2]
-// CHECK: usrs.m c:usrs.m@41:3objc(cs)Foo(cm)kingkong@local_var Extent=[41:3 - 41:16]
+// CHECK: usrs.m c:usrs.m@470objc(cs)Foo(cm)kingkong@local_var Extent=[41:3 - 41:16]
 // CHECK: usrs.m c:objc(cs)Foo@d1 Extent=[44:13 - 44:15]
 // CHECK: usrs.m c:objc(cs)Foo(py)d1 Extent=[44:1 - 44:15]
 // CHECK: usrs.m c:@z Extent=[47:1 - 47:6]
-// CHECK: usrs.m c:usrs.m@49:12@F@local_func Extent=[49:12 - 49:43]
-// CHECK: usrs.m c:usrs.m@49:23@F@local_func@x Extent=[49:23 - 49:28]
+// CHECK: usrs.m c:usrs.m@540@F@local_func Extent=[49:12 - 49:43]
+// CHECK: usrs.m c:usrs.m@551@F@local_func@x Extent=[49:23 - 49:28]
 // CHECK: usrs.m c:objc(cs)CWithExt Extent=[51:1 - 52:5]
 // CHECK: usrs.m c:objc(cy)CWithExt@ Extent=[53:1 - 54:5]
 // CHECK: usrs.m c:objc(cy)CWithExt@ Extent=[55:1 - 56:5]
 // CHECK: usrs.m c:objc(cs)CWithExt Extent=[57:1 - 58:2]
 
 
+
diff --git a/tools/libclang/CIndexUSRs.cpp b/tools/libclang/CIndexUSRs.cpp
index e98fd26..602a0c7 100644
--- a/tools/libclang/CIndexUSRs.cpp
+++ b/tools/libclang/CIndexUSRs.cpp
@@ -368,10 +368,10 @@
     IgnoreResults = true;
     return true;
   }
-  Out << '@'
-      << SM.getLineNumber(Decomposed.first, Decomposed.second) << ':'
-      << SM.getColumnNumber(Decomposed.first, Decomposed.second);
-
+  // Use the offest into the FileID to represent the location.  Using
+  // a line/column can cause us to look back at the original source file,
+  // which is expensive.
+  Out << '@' << Decomposed.second;
   return IgnoreResults;
 }