[ Mistakenly committed older version of patch. This is the right one. ]

Breakpad Linux client: Simplify VerifyStackReadWithMultipleThreads unit test.

As written, the VerifyStackReadWithMultipleThreads unit test makes
assumptions about the layout of thread_function's stack frame. As a result,
the test will fail when compiled with some compilers, or built with certain
optimization levels.

As an extension to C++, the GNU compilers allow you to request that a
variable be placed in a specific register. Using this, we can have
thread_function put the thread id in place where the test can find it
reliably.

a=jimblandy, r=nealsid


git-svn-id: http://google-breakpad.googlecode.com/svn/trunk@559 4c0a9323-5329-0410-9bdc-e9ce6186880e

1 files changed, 3 insertions, 3 deletions

diff --git a/src/client/linux/minidump_writer/linux_dumper_unittest_helper.cc b/src/client/linux/minidump_writer/linux_dumper_unittest_helper.cc
index 388a6580..e91e9767 100644
--- a/src/client/linux/minidump_writer/linux_dumper_unittest_helper.cc
+++ b/src/client/linux/minidump_writer/linux_dumper_unittest_helper.cc
@@ -48,10 +48,10 @@
 #endif
 
 void *thread_function(void *data) {
-  pid_t thread_id = syscall(SYS_gettid);
-  register pid_t *thread_id_ptr asm(TID_PTR_REGISTER) = &thread_id;
+  volatile pid_t thread_id = syscall(SYS_gettid);
+  register volatile pid_t *thread_id_ptr asm(TID_PTR_REGISTER) = &thread_id;
   while (true)
-    asm("" : : "r" (thread_id_ptr));
+    asm volatile ("" : : "r" (thread_id_ptr));
   return NULL;
 }