Rearchitect -Wconversion and -Wsign-compare.  Instead of computing them
"bottom-up" when implicit casts and comparisons are inserted, compute them
"top-down" when the full expression is finished.  Makes it easier to
coordinate warnings and thus implement -Wconversion for signedness
conversions without double-warning with -Wsign-compare.  Also makes it possible
to realize that a signedness conversion is okay because the context is
performing the inverse conversion.  Also simplifies some logic that was
trying to calculate the ultimate comparison/result type and getting it wrong.
Also fixes a problem with the C++ explicit casts which are often "implemented"
in the AST with a series of implicit cast expressions.



git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@103174 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/test/SemaCXX/compare.cpp b/test/SemaCXX/compare.cpp
index cd243e3..4790347 100644
--- a/test/SemaCXX/compare.cpp
+++ b/test/SemaCXX/compare.cpp
@@ -19,8 +19,8 @@
          ((signed char) a == b) +  // expected-warning {{comparison of integers of different signs}}
          ((long) a == (unsigned long) b) +  // expected-warning {{comparison of integers of different signs}}
          ((int) a == (unsigned int) b) +  // expected-warning {{comparison of integers of different signs}}
-         ((short) a == (unsigned short) b) +  // expected-warning {{comparison of integers of different signs}}
-         ((signed char) a == (unsigned char) b) +  // expected-warning {{comparison of integers of different signs}}
+         ((short) a == (unsigned short) b) +
+         ((signed char) a == (unsigned char) b) +
          (a < (unsigned long) b) +  // expected-warning {{comparison of integers of different signs}}
          (a < (unsigned int) b) +
          (a < (unsigned short) b) +
@@ -31,8 +31,8 @@
          ((signed char) a < b) +  // expected-warning {{comparison of integers of different signs}}
          ((long) a < (unsigned long) b) +  // expected-warning {{comparison of integers of different signs}}
          ((int) a < (unsigned int) b) +  // expected-warning {{comparison of integers of different signs}}
-         ((short) a < (unsigned short) b) +  // expected-warning {{comparison of integers of different signs}}
-         ((signed char) a < (unsigned char) b) +  // expected-warning {{comparison of integers of different signs}}
+         ((short) a < (unsigned short) b) +
+         ((signed char) a < (unsigned char) b) +
 
          // (A,b)
          (A == (unsigned long) b) +
@@ -83,8 +83,8 @@
          ((signed char) a < B) +
          ((long) a < (unsigned long) B) +  // expected-warning {{comparison of integers of different signs}}
          ((int) a < (unsigned int) B) +  // expected-warning {{comparison of integers of different signs}}
-         ((short) a < (unsigned short) B) +  // expected-warning {{comparison of integers of different signs}}
-         ((signed char) a < (unsigned char) B) +  // expected-warning {{comparison of integers of different signs}}
+         ((short) a < (unsigned short) B) +
+         ((signed char) a < (unsigned char) B) +
 
          // (C,b)
          (C == (unsigned long) b) +
@@ -135,8 +135,8 @@
          ((signed char) a < C) +
          ((long) a < (unsigned long) C) +  // expected-warning {{comparison of integers of different signs}}
          ((int) a < (unsigned int) C) +  // expected-warning {{comparison of integers of different signs}}
-         ((short) a < (unsigned short) C) +  // expected-warning {{comparison of integers of different signs}}
-         ((signed char) a < (unsigned char) C) +  // expected-warning {{comparison of integers of different signs}}
+         ((short) a < (unsigned short) C) +
+         ((signed char) a < (unsigned char) C) +
 
          // (0x80000,b)
          (0x80000 == (unsigned long) b) +
@@ -187,8 +187,8 @@
          ((signed char) a < 0x80000) +
          ((long) a < (unsigned long) 0x80000) +  // expected-warning {{comparison of integers of different signs}}
          ((int) a < (unsigned int) 0x80000) +  // expected-warning {{comparison of integers of different signs}}
-         ((short) a < (unsigned short) 0x80000) +  // expected-warning {{comparison of integers of different signs}}
-         ((signed char) a < (unsigned char) 0x80000) +  // expected-warning {{comparison of integers of different signs}}
+         ((short) a < (unsigned short) 0x80000) +
+         ((signed char) a < (unsigned char) 0x80000) +
 
          10
     ;