Improvements to vexing-parse warnings. Make the no-parameters case more

accurate by asking the parser whether there was an ambiguity rather than trying
to reverse-engineer it from the DeclSpec. Make the with-parameters case have
better diagnostics by using semantic information to drive the warning,
improving the diagnostics and adding a fixit.

Patch by Nikola Smiljanic. Some minor changes by me to suppress diagnostics for
declarations of the form 'T (*x)(...)', which seem to have a very high false
positive rate, and to reduce indentation in 'warnAboutAmbiguousFunction'.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@160998 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 35 insertions, 16 deletions

diff --git a/test/FixIt/fixit-vexing-parse.cpp b/test/FixIt/fixit-vexing-parse.cpp
index 8450590c67..dd0f87304a 100644
--- a/test/FixIt/fixit-vexing-parse.cpp
+++ b/test/FixIt/fixit-vexing-parse.cpp
@@ -7,6 +7,7 @@ struct S {
 
 struct T {
   T();
+  T(S, S);
   int n;
 };
 
@@ -30,26 +31,44 @@ S F2();
 
 namespace N {
   void test() {
-    // CHECK: fix-it:"{{.*}}":{34:9-34:11}:" = {}"
+    // CHECK: fix-it:"{{.*}}":{35:9-35:11}:" = {}"
     S s1(); // expected-warning {{function declaration}} expected-note {{replace parentheses with an initializer}}
 
-    // CHECK: fix-it:"{{.*}}":{38:9-38:10}:";"
-    // CHECK: fix-it:"{{.*}}":{39:7-39:9}:" = {}"
+    // CHECK: fix-it:"{{.*}}":{39:9-39:10}:";"
+    // CHECK: fix-it:"{{.*}}":{40:7-40:9}:" = {}"
     S s2, // expected-note {{change this ',' to a ';' to call 'F2'}}
     F2(); // expected-warning {{function declaration}} expected-note {{replace parentheses with an initializer}}
 
-    // CHECK: fix-it:"{{.*}}":{43:9-43:11}:""
     // CHECK: fix-it:"{{.*}}":{44:9-44:11}:""
+    // CHECK: fix-it:"{{.*}}":{45:9-45:11}:""
     T t1(), // expected-warning {{function declaration}} expected-note {{remove parentheses}}
       t2(); // expected-warning {{function declaration}} expected-note {{remove parentheses}}
 
-    // CHECK: fix-it:"{{.*}}":{47:8-47:10}:" = {}"
+    // Suggest parentheses only around the first argument.
+    // CHECK: fix-it:"{{.*}}":{50:10-50:10}:"("
+    // CHECK: fix-it:"{{.*}}":{50:13-50:13}:")"
+    T t3(S(), S()); // expected-warning {{disambiguated as a function declaration}} expected-note {{add a pair of parentheses}}
+
+    // Check fixit position for pathological case
+    // CHECK: fix-it:"{{.*}}":{56:11-56:11}:"("
+    // CHECK: fix-it:"{{.*}}":{56:20-56:20}:")"
+    float k[1];
+    int l(int(k[0])); // expected-warning {{disambiguated as a function declaration}} expected-note {{add a pair of parentheses}}
+
+    // Don't emit warning and fixit because this must be a function declaration due to void return type.
+    typedef void VO;
+    VO m(int (*p)[4]);
+
+    // Don't emit warning and fixit because direct initializer is not permitted here.
+    if (int n(int())){} // expected-error {{function type is not allowed here}} expected-error {{condition must have an initializer}}
+
+    // CHECK: fix-it:"{{.*}}":{66:8-66:10}:" = {}"
     U u(); // expected-warning {{function declaration}} expected-note {{replace parentheses with an initializer}}
 
-    // CHECK: fix-it:"{{.*}}":{50:8-50:10}:""
+    // CHECK: fix-it:"{{.*}}":{69:8-69:10}:""
     V v(); // expected-warning {{function declaration}} expected-note {{remove parentheses}}
 
-    // CHECK: fix-it:"{{.*}}":{53:8-53:10}:""
+    // CHECK: fix-it:"{{.*}}":{72:8-72:10}:""
     W w(); // expected-warning {{function declaration}} expected-note {{remove parentheses}}
 
     // TODO: Removing the parens here would not initialize U::n.
@@ -57,33 +76,33 @@ namespace N {
     // Maybe suggest removing the parens anyway?
     X x(); // expected-warning {{function declaration}}
 
-    // CHECK: fix-it:"{{.*}}":{61:11-61:13}:" = 0"
+    // CHECK: fix-it:"{{.*}}":{80:11-80:13}:" = 0"
     int n1(); // expected-warning {{function declaration}} expected-note {{replace parentheses with an initializer}}
 
-    // CHECK: fix-it:"{{.*}}":{65:11-65:12}:";"
-    // CHECK: fix-it:"{{.*}}":{66:7-66:9}:" = 0"
+    // CHECK: fix-it:"{{.*}}":{84:11-84:12}:";"
+    // CHECK: fix-it:"{{.*}}":{85:7-85:9}:" = 0"
     int n2, // expected-note {{change this ',' to a ';' to call 'F1'}}
     F1(); // expected-warning {{function declaration}} expected-note {{replace parentheses with an initializer}}
 
-    // CHECK: fix-it:"{{.*}}":{69:13-69:15}:" = 0.0"
+    // CHECK: fix-it:"{{.*}}":{88:13-88:15}:" = 0.0"
     double d(); // expected-warning {{function declaration}} expected-note {{replace parentheses with an initializer}}
 
     typedef void *Ptr;
 
-    // CHECK: fix-it:"{{.*}}":{74:10-74:12}:" = 0"
+    // CHECK: fix-it:"{{.*}}":{93:10-93:12}:" = 0"
     Ptr p(); // expected-warning {{function declaration}} expected-note {{replace parentheses with an initializer}}
 
 #define NULL 0
-    // CHECK: fix-it:"{{.*}}":{78:10-78:12}:" = NULL"
+    // CHECK: fix-it:"{{.*}}":{97:10-97:12}:" = NULL"
     Ptr p(); // expected-warning {{function declaration}} expected-note {{replace parentheses with an initializer}}
 
-    // CHECK: fix-it:"{{.*}}":{81:11-81:13}:" = false"
+    // CHECK: fix-it:"{{.*}}":{100:11-100:13}:" = false"
     bool b(); // expected-warning {{function declaration}} expected-note {{replace parentheses with an initializer}}
 
-    // CHECK: fix-it:"{{.*}}":{84:11-84:13}:" = '\\0'"
+    // CHECK: fix-it:"{{.*}}":{103:11-103:13}:" = '\\0'"
     char c(); // expected-warning {{function declaration}} expected-note {{replace parentheses with an initializer}}
 
-    // CHECK: fix-it:"{{.*}}":{87:15-87:17}:" = L'\\0'"
+    // CHECK: fix-it:"{{.*}}":{106:15-106:17}:" = L'\\0'"
     wchar_t wc(); // expected-warning {{function declaration}} expected-note {{replace parentheses with an initializer}}
   }
 }