Implement PR315: abort, don't warn, when missing external functions encountered
This fixes some critical problems building libstdc++ on cygwin.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@13934 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/ExecutionEngine/JIT/Intercept.cpp b/lib/ExecutionEngine/JIT/Intercept.cpp
index ce93ab1..8ed9447 100644
--- a/lib/ExecutionEngine/JIT/Intercept.cpp
+++ b/lib/ExecutionEngine/JIT/Intercept.cpp
@@ -60,8 +60,13 @@
};
#endif // __linux__
-// NoopFn - Used if we have nothing else to call...
-static void NoopFn() {}
+// __mainFunc - If the program does not have a linked in __main function, allow
+// it to run, but print a warning.
+static void __mainFunc() {
+ fprintf(stderr, "WARNING: Program called __main but was not linked to "
+ "libcrtend.a.\nThis probably won't hurt anything unless the "
+ "program is written in C++.\n");
+}
// jit_exit - Used to intercept the "exit" library call.
static void jit_exit(int Status) {
@@ -86,13 +91,16 @@
if (Name == "exit") return (void*)&jit_exit;
if (Name == "atexit") return (void*)&jit_atexit;
+ // If the program does not have a linked in __main function, allow it to run,
+ // but print a warning.
+ if (Name == "__main") return (void*)&__mainFunc;
+
// If it's an external function, look it up in the process image...
void *Ptr = GetAddressOfSymbol(Name);
- if (Ptr == 0) {
- std::cerr << "WARNING: Cannot resolve fn '" << Name
- << "' using a dummy noop function instead!\n";
- Ptr = (void*)NoopFn;
- }
-
- return Ptr;
+ if (Ptr) return Ptr;
+
+ std::cerr << "ERROR: Program used external function '" << Name
+ << "' which could not be resolved!\n";
+ abort();
+ return 0;
}