[compiler-rt] Fix broken SymInitialize unittest

[etienneb]

Summary

By adding the initialisation of the symbolisation library (DbgHelp)
we are swapping the order in which both warnings are produced.

We can't use CHECK-NEXT as the dbghelp warning is multiline.

[rnk]

test/asan/TestCases/Windows/report_after_syminitialize.cc

12

Doesn't this fail, though?

[etienneb]

test/asan/TestCases/Windows/report_after_syminitialize.cc

12

No, it's not.

Nothing got called before we reach line 15 (write to invalid location).
Than, the report function is calling the initialized function to load dbghelp.

So, it's not affecting this test.

[rnk]

lgtm

lib/sanitizer_common/sanitizer_win.cc

 }
 
 void BufferedStackTrace::SlowUnwindStackWithContext(uptr pc, void *context,
                                                     u32 max_depth) {
   CONTEXT ctx = *(CONTEXT *)context;
   STACKFRAME64 stack_frame;
   memset(&stack_frame, 0, sizeof(stack_frame));
 
+  InitializeDbgHelpIfNeeded();
+
   size = 0;
 #if defined(_WIN64)
   int machine_type = IMAGE_FILE_MACHINE_AMD64;
   stack_frame.AddrPC.Offset = ctx.Rip;
   stack_frame.AddrFrame.Offset = ctx.Rbp;
   stack_frame.AddrStack.Offset = ctx.Rsp;
 #else
   int machine_type = IMAGE_FILE_MACHINE_I386;

test/asan/TestCases/Windows/report_after_syminitialize.cc

 // RUN: %clangxx_asan -O0 %s -o %t
 // RUN: %env_asan_opts=external_symbolizer_path=asdf not %run %t 2>&1 | FileCheck %s
 
 #include <windows.h>
 #include <dbghelp.h>
 
 int main() {
   // Make sure the RTL recovers from "no options enabled" dbghelp setup.
   SymSetOptions(0);
 
   // Make sure the RTL recovers from "fInvadeProcess=FALSE".
   if (!SymInitialize(GetCurrentProcess(), 0, FALSE))
     return 42;
 
   *(volatile int*)0 = 42;
   // CHECK: ERROR: AddressSanitizer: access-violation on unknown address
   // CHECK: The signal is caused by a WRITE memory access.
   // CHECK: Hint: address points to the zero page.
-  // CHECK-NEXT: {{WARNING: Failed to use and restart external symbolizer}}
-  // CHECK-NEXT: {{WARNING: .*DbgHelp}}
+  // CHECK: {{WARNING: .*DbgHelp}}
+  // CHECK: {{WARNING: Failed to use and restart external symbolizer}}
   // CHECK: {{#0 0x.* in main.*report_after_syminitialize.cc:}}[[@LINE-6]]
   // CHECK: AddressSanitizer can not provide additional info.
 }