[compiler-rt] a72dc86 - tsan: tsan_interface.h: make constants static

[Dmitry Vyukov via llvm-commits]

Author: Dmitry Vyukov
Date: 2020-03-10T09:13:41+01:00
New Revision: a72dc86cddd26921f12184032e27abcc3be427cb

URL: https://github.com/llvm/llvm-project/commit/a72dc86cddd26921f12184032e27abcc3be427cb
DIFF: https://github.com/llvm/llvm-project/commit/a72dc86cddd26921f12184032e27abcc3be427cb.diff

LOG: tsan: tsan_interface.h: make constants static

Note that in C++ the static keyword is implicit for const objects.
In C however it is not, and we get clashes at link time after
including the header from more than one C file:

lib.a(bar.o):(.rodata+0x0): multiple definition of `__tsan_mutex_linker_init'
lib.a(foo.o):(.rodata+0x0): first defined here
lib.a(bar.o):(.rodata+0xc): multiple definition of `__tsan_mutex_not_static'
lib.a(foo.o):(.rodata+0xc): first defined here
<snip>
Indeed both foo.o and bar.o define the clashing symbols:

$ nm foo.o
<snip>
0000000000000000 R __tsan_mutex_linker_init
000000000000000c R __tsan_mutex_not_static
<snip>
Fix it by explicitly making the constants static.

Reviewed-in: https://reviews.llvm.org/D75820
Author: cota (Emilio G. Cota)

Added: 
    

Modified: 
    compiler-rt/include/sanitizer/tsan_interface.h

Removed: 
    


################################################################################
diff  --git a/compiler-rt/include/sanitizer/tsan_interface.h b/compiler-rt/include/sanitizer/tsan_interface.h
index 011b23350cac..96b8ad58541c 100644
--- a/compiler-rt/include/sanitizer/tsan_interface.h
+++ b/compiler-rt/include/sanitizer/tsan_interface.h
@@ -38,34 +38,34 @@ void __tsan_release(void *addr);
 
 // Mutex has static storage duration and no-op constructor and destructor.
 // This effectively makes tsan ignore destroy annotation.
-const unsigned __tsan_mutex_linker_init      = 1 << 0;
+static const unsigned __tsan_mutex_linker_init      = 1 << 0;
 // Mutex is write reentrant.
-const unsigned __tsan_mutex_write_reentrant  = 1 << 1;
+static const unsigned __tsan_mutex_write_reentrant  = 1 << 1;
 // Mutex is read reentrant.
-const unsigned __tsan_mutex_read_reentrant   = 1 << 2;
+static const unsigned __tsan_mutex_read_reentrant   = 1 << 2;
 // Mutex does not have static storage duration, and must not be used after
 // its destructor runs.  The opposite of __tsan_mutex_linker_init.
 // If this flag is passed to __tsan_mutex_destroy, then the destruction
 // is ignored unless this flag was previously set on the mutex.
-const unsigned __tsan_mutex_not_static       = 1 << 8;
+static const unsigned __tsan_mutex_not_static       = 1 << 8;
 
 // Mutex operation flags:
 
 // Denotes read lock operation.
-const unsigned __tsan_mutex_read_lock        = 1 << 3;
+static const unsigned __tsan_mutex_read_lock        = 1 << 3;
 // Denotes try lock operation.
-const unsigned __tsan_mutex_try_lock         = 1 << 4;
+static const unsigned __tsan_mutex_try_lock         = 1 << 4;
 // Denotes that a try lock operation has failed to acquire the mutex.
-const unsigned __tsan_mutex_try_lock_failed  = 1 << 5;
+static const unsigned __tsan_mutex_try_lock_failed  = 1 << 5;
 // Denotes that the lock operation acquires multiple recursion levels.
 // Number of levels is passed in recursion parameter.
 // This is useful for annotation of e.g. Java builtin monitors,
 // for which wait operation releases all recursive acquisitions of the mutex.
-const unsigned __tsan_mutex_recursive_lock   = 1 << 6;
+static const unsigned __tsan_mutex_recursive_lock   = 1 << 6;
 // Denotes that the unlock operation releases all recursion levels.
 // Number of released levels is returned and later must be passed to
 // the corresponding __tsan_mutex_post_lock annotation.
-const unsigned __tsan_mutex_recursive_unlock = 1 << 7;
+static const unsigned __tsan_mutex_recursive_unlock = 1 << 7;
 
 // Annotate creation of a mutex.
 // Supported flags: mutex creation flags.
@@ -152,7 +152,7 @@ void __tsan_set_fiber_name(void *fiber, const char *name);
 
 // Flags for __tsan_switch_to_fiber:
 // Do not establish a happens-before relation between fibers
-const unsigned __tsan_switch_to_fiber_no_sync = 1 << 0;
+static const unsigned __tsan_switch_to_fiber_no_sync = 1 << 0;
 
 #ifdef __cplusplus
 }  // extern "C"