[CrossTU] Test change only: improve ctu-main.c

[balazske]

Summary

New lines are added to test ctu-main.c to make code execute when a
function with invalid source range is encountered on bug path
with NoStoreFuncVisitor.

[Szelethus]

Hmmm, did this result in an assertion?

[balazske]

The problem is already corrected in clang9 but maybe not in clang8. Something similar is fixed in https://reviews.llvm.org/rC357329.

[balazske]

The mentioned commit has a test that reproduces the same problem, so this revision is not needed (abandon it?).

[martong]

In D64628#1584969, @balazske wrote:

The mentioned commit has a test that reproduces the same problem, so this revision is not needed (abandon it?).

I think we should have this change, because it tests also if we can import the "extern implicit" function properly. Plus the bug visitor is exercised when the AST is merged.
So, even if the mentioned commit has a similar test I think with these changes we can achieve higher coverage and can prevent CTU related regression.

[balazske]

I do not know how the AST import is relevant in this case, the 'implicit' function is not imported here. The test does something similar as the mentioned one, only the reported problem is after the imported function.

test/Analysis/ctu-main.c

 
 // Test reporting error in a macro.
 struct S;
 int g(struct S *);
 void testMacro(void) {
   g(0); // expected-warning@Inputs/ctu-other.c:29 {{Access to field 'a' results in a dereference of a null pointer (loaded from variable 'ctx')}}
 }
 
+void h(int);
+
 // The external function prototype is incomplete.
 // warning:implicit functions are prohibited by c99
 void testImplicit() {
-  int res = identImplicit(6);   // external implicit functions are not inlined
+  int res = identImplicit(6);
   clang_analyzer_eval(res == 6); // expected-warning{{TRUE}}
+
+  // Call something with uninitialized from the same function in which the implicit was called.
+  // This is necessary to reproduce a special bug in NoStoreFuncVisitor.
+  int uninitialized;
+  h(uninitialized); // expected-warning@ctu-main.c:59 {{1st function call argument is an uninitialized value}}
 }
 
 // Tests the import of functions that have a struct parameter
 // defined in its prototype.
 struct DataType {
   int a;
   int b;
 };
 int structInProto(struct DataType *d);
 void testStructDefInArgument() {
   struct DataType d;
   d.a = 1;
   d.b = 0;
   clang_analyzer_eval(structInProto(&d) == 0); // expected-warning{{TRUE}} expected-warning{{FALSE}}
 }