[inferbo] Add a test case of global constant

Summary: `CONDITION_ALWAYS_**` can be introduced by global constants.

Reviewed By: ezgicicek, mbouaziz

Differential Revision: D9478528

fbshipit-source-id: 7b1a46e7a

infer/tests/codetoanalyze/c/bufferoverrun/global.c

@@ -11,3 +11,13 @@ void compare_global_variable_bad() {
   if (global < 10)
     arr[10] = 1;
 }
+
+const int global_const_zero = 0;
+
+enum { global_const = global_const_zero };
+
+void compare_global_const_enum_bad_FN() {
+  char arr[10];
+  if (global_const < 10)
+    arr[10] = 1;
+}

infer/tests/codetoanalyze/c/bufferoverrun/issues.exp

@@ -23,6 +23,8 @@ codetoanalyze/c/bufferoverrun/function_call.c, call_by_arr_bad, 3, BUFFER_OVERRU
 codetoanalyze/c/bufferoverrun/function_call.c, call_by_ptr_bad, 4, BUFFER_OVERRUN_L1, no_bucket, ERROR, [ArrayDeclaration,Call,Assignment,ArrayAccess: Offset: -1 Size: 10]
 codetoanalyze/c/bufferoverrun/function_call.c, call_by_struct_ptr_bad, 5, BUFFER_OVERRUN_L1, no_bucket, ERROR, [ArrayDeclaration,Call,Assignment,ArrayAccess: Offset: -1 Size: 10]
 codetoanalyze/c/bufferoverrun/function_call.c, function_call, 4, BUFFER_OVERRUN_L1, no_bucket, ERROR, [ArrayDeclaration,Call,Parameter: arr,Assignment,ArrayAccess: Offset: 100 Size: 10 by call to `arr_access` ]
+codetoanalyze/c/bufferoverrun/global.c, compare_global_const_enum_bad_FN, 2, CONDITION_ALWAYS_FALSE, no_bucket, WARNING, []
+codetoanalyze/c/bufferoverrun/global.c, compare_global_const_enum_bad_FN, 2, CONDITION_ALWAYS_TRUE, no_bucket, WARNING, []
 codetoanalyze/c/bufferoverrun/global.c, compare_global_variable_bad, 3, BUFFER_OVERRUN_L1, no_bucket, ERROR, [ArrayDeclaration,ArrayAccess: Offset: 10 Size: 10]
 codetoanalyze/c/bufferoverrun/goto_loop.c, goto_loop, 11, BUFFER_OVERRUN_L1, no_bucket, ERROR, [ArrayDeclaration,Assignment,ArrayAccess: Offset: [10, +oo] Size: 10]
 codetoanalyze/c/bufferoverrun/inf_loop.c, inf_loop, 4, CONDITION_ALWAYS_TRUE, no_bucket, WARNING, []