When performing typo correction, look through the set of known

identifiers to determine good typo-correction candidates. Once we've
identified those candidates, we perform name lookup on each of them
and the consider the results. 

This optimization makes typo correction > 2x faster on a benchmark
example using a single typo (NSstring) in a tiny file that includes
Cocoa.h from a precompiled header, since we are deserializing far less
information now during typo correction.

There is a semantic change here, which is interesting. The presence of
a similarly-named entity that is not visible can now affect typo
correction. This is both good (you won't get weird corrections if the
thing you wanted isn't in scope) and bad (you won't get good
corrections if there is a similarly-named-but-completely-unrelated
thing). Time will tell whether it was a good choice or not.

llvm-svn: 116528

3 files changed, 13 insertions, 1 deletions

diff --git a/clang/test/PCH/Inputs/typo.h b/clang/test/PCH/Inputs/typo.h
new file mode 100644
index 00000000000..63b553b9169
--- /dev/null
+++ b/clang/test/PCH/Inputs/typo.h
@@ -0,0 +1,6 @@
+
+
+@interface NSString
++ (id)alloc;
+@end
+
diff --git a/clang/test/PCH/typo.m b/clang/test/PCH/typo.m
new file mode 100644
index 00000000000..c6f0275bc2f
--- /dev/null
+++ b/clang/test/PCH/typo.m
@@ -0,0 +1,6 @@
+// RUN: %clang_cc1 -x objective-c-header -emit-pch -o %t %S/Inputs/typo.h
+// RUN: %clang_cc1 -include-pch %t -verify %s
+// In header: expected-note{{declared here}}
+void f() {
+  [NSstring alloc]; // expected-error{{unknown receiver 'NSstring'; did you mean 'NSString'?}}
+}
diff --git a/clang/test/SemaObjC/synth-provisional-ivars.m b/clang/test/SemaObjC/synth-provisional-ivars.m
index 973c771ad77..8ad2233ba4a 100644
--- a/clang/test/SemaObjC/synth-provisional-ivars.m
+++ b/clang/test/SemaObjC/synth-provisional-ivars.m
@@ -18,7 +18,7 @@ int bar;
 @end
 
 @implementation I
-- (int) Meth { return PROP; }	// expected-note {{'PROP' declared here}}
+- (int) Meth { return PROP; }
 
 @dynamic PROP1;
 - (int) Meth1 { return PROP1; }  // expected-error {{use of undeclared identifier 'PROP1'}}