Handle function declaration appearing after definition (fix #399)

Ensure that constrains generated due to a function's declaration are
applied to the variables generated at the definition even when
declaration appears after the definition.

Author: john-h-kastner

clang/lib/3C/ProgramInfo.cpp

@@ -450,8 +450,12 @@ bool ProgramInfo::insertIntoExternalFunctionMap(ExternalFunctionMapType &Map,
           DiagnosticsEngine::Fatal, "duplicate definition for function %0");
       DE.Report(FD->getLocation(), DuplicateDefinitionsID).AddString(FuncName);
       exit(1);
+    } else {
+      // The old constraint has a body, but we've encountered another prototype
+      // for the function.
+      assert(OldC->hasBody() && !NewC->hasBody());
+      NewC->brainTransplant(OldC, *this);
     }
-    // else oldc->hasBody() so we can ignore the newC prototype
   }
   return RetVal;
 }

clang/test/3C/defn_then_decl.c

@@ -0,0 +1,37 @@
+// RUN: 3c -alltypes -addcr %s -- | FileCheck -match-full-lines -check-prefixes="CHECK_ALL","CHECK" %s
+// RUN: 3c -addcr %s -- | FileCheck -match-full-lines -check-prefixes="CHECK_NOALL","CHECK" %s
+// RUN: 3c -alltypes -addcr %s -- | %clang -c -fcheckedc-extension -x c -o /dev/null -
+// RUN: 3c -alltypes -output-postfix=checked %s
+// RUN: 3c -alltypes %S/defn_then_decl.checked.c -- | count 0
+// RUN: rm %S/defn_then_decl.checked.c
+
+// Tests for when a function's declaration appears after the same function's
+// definition. A particular issue that existed in caused constraints added
+// onto the subsequent declaration (for example, because the declaration was in
+// a macro) were not applied to the original definition. 
+
+void test0(int *p) {}
+#define MYDECL void test0(int *p);
+MYDECL
+
+void test1(int *p) {}
+//CHECK: void test1(_Ptr<int> p) _Checked {}
+void test1(int *p);
+//CHECK: void test1(_Ptr<int> p);
+
+void test2(int *p);
+//CHECK: void test2(_Ptr<int> p);
+void test2(int *p) {}
+//CHECK: void test2(_Ptr<int> p) _Checked {}
+void test2(int *p);
+//CHECK: void test2(_Ptr<int> p);
+
+void test3(int *p) { p = 1;}
+//CHECK: void test3(int *p : itype(_Ptr<int>)) { p = 1;}
+void test3(int *p);
+//CHECK: void test3(int *p : itype(_Ptr<int>));
+
+void test4(int *p) {}
+//CHECK: void test4(_Ptr<int> p) _Checked {}
+void test4();
+//CHECK: void test4(_Ptr<int> p);