Use the argument location instead of the format string location when warning
about argument type mismatch.

This gives a nicer diagnostic in cases like
  printf(fmt,
         i);
where previously the snippet just pointed at 'fmt' (with a note at the
definition of fmt).

It's a wash for cases like
  printf("%f",
         i);
where previously we snippeted the offending portion of the format string,
but didn't indicate which argument was at fault.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@156968 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Sema/SemaChecking.cpp b/lib/Sema/SemaChecking.cpp
index 62f45f5..7697054 100644
--- a/lib/Sema/SemaChecking.cpp
+++ b/lib/Sema/SemaChecking.cpp
@@ -2423,8 +2423,8 @@
         S.PDiag(diag::warn_printf_conversion_argument_type_mismatch)
           << ATR.getRepresentativeTypeName(S.Context) << Ex->getType()
           << Ex->getSourceRange(),
-        getLocationOfByte(CS.getStart()),
-        /*IsStringLocation*/true,
+        Ex->getLocStart(),
+        /*IsStringLocation*/false,
         getSpecifierRange(startSpecifier, specifierLen),
         FixItHint::CreateReplacement(
           getSpecifierRange(startSpecifier, specifierLen),
@@ -2436,8 +2436,8 @@
           << ATR.getRepresentativeTypeName(S.Context) << Ex->getType()
           << getSpecifierRange(startSpecifier, specifierLen)
           << Ex->getSourceRange(),
-        getLocationOfByte(CS.getStart()),
-        true,
+        Ex->getLocStart(),
+        /*IsStringLocation*/false,
         getSpecifierRange(startSpecifier, specifierLen));
     }
   }
@@ -2591,8 +2591,8 @@
         S.PDiag(diag::warn_printf_conversion_argument_type_mismatch)
           << ATR.getRepresentativeTypeName(S.Context) << Ex->getType()
           << Ex->getSourceRange(),
-        getLocationOfByte(CS.getStart()),
-        /*IsStringLocation*/true,
+        Ex->getLocStart(),
+        /*IsStringLocation*/false,
         getSpecifierRange(startSpecifier, specifierLen),
         FixItHint::CreateReplacement(
           getSpecifierRange(startSpecifier, specifierLen),
@@ -2602,8 +2602,8 @@
         S.PDiag(diag::warn_printf_conversion_argument_type_mismatch)
           << ATR.getRepresentativeTypeName(S.Context) << Ex->getType()
           << Ex->getSourceRange(),
-        getLocationOfByte(CS.getStart()),
-        /*IsStringLocation*/true,
+        Ex->getLocStart(),
+        /*IsStringLocation*/false,
         getSpecifierRange(startSpecifier, specifierLen));
     }
   }
diff --git a/test/Sema/format-strings.c b/test/Sema/format-strings.c
index afc9e97..5c30849 100644
--- a/test/Sema/format-strings.c
+++ b/test/Sema/format-strings.c
@@ -502,8 +502,13 @@
   printf("%a", (long double)0); // expected-warning{{format specifies type 'double' but the argument has type 'long double'}}
 
   // Test braced char[] initializers.
-  const char kFormat18[] = { "%lld" }; // expected-note{{format string is defined here}}}
+  const char kFormat18[] = { "%lld" }; // expected-note{{format string is defined here}}
   printf(kFormat18, 0); // expected-warning{{format specifies type}}
+
+  // Make sure we point at the offending argument rather than the format string.
+  const char kFormat19[] = "%d";  // expected-note{{format string is defined here}}
+  printf(kFormat19,
+         0.0); // expected-warning{{format specifies}}
 }
 
 // PR 9466: clang: doesn't know about %Lu, %Ld, and %Lx