Without them they can be merged with non unnamed_addr constants during LTO.
The resulting constant is not unnamed_addr and goes in a different section,
which causes ld64 to crash.
A testcase that would crash before:
* file1.mm:
void g(id notification) {
[notification valueForKey:@"name"];
}
* file2.cpp:
extern const char js_name_str[] = "name";
* file3.cpp
extern bool JS_GetProperty(const char *name);
extern const char js_name_str[];
bool js_ReportUncaughtException() { JS_GetProperty(js_name_str); }
run
clang file1.mm -o file1.o -c -w -emit-llvm
clang file2.cpp -o file2.o -c -w -emit-llvm
clang file3.cpp -o file3.o -c -w
ld -dylib -o XUL file1.o file2.o file3.o -undefined dynamic_lookup.
llvm-svn: 199688
CFStrings writable.
The strings (both Unicode and ASCII) should reside in a read-only section. E.g.,
__TEXT,__cstring instead of __DATA,__data. This is done by making the global
variable created for the strings constant despite the value of that flag.
<rdar://problem/10657500>
llvm-svn: 147845
- This is designed to make it obvious that %clang_cc1 is a "test variable"
which is substituted. It is '%clang_cc1' instead of '%clang -cc1' because it
can be useful to redefine what gets run as 'clang -cc1' (for example, to set
a default target).
llvm-svn: 91446
Sunil Srivastava