[LLVMbugs] [Bug 11910] New: Storage-class extern inside function body on tentatively static symbols breaks later definitions

[bugzilla-daemon at llvm.org]

http://llvm.org/bugs/show_bug.cgi?id=11910

             Bug #: 11910
           Summary: Storage-class extern inside function body on
                    tentatively static symbols breaks later definitions
           Product: clang
           Version: 3.0
          Platform: Macintosh
        OS/Version: MacOS X
            Status: NEW
          Severity: normal
          Priority: P
         Component: Frontend
        AssignedTo: unassignedclangbugs at nondot.org
        ReportedBy: snaury at gmail.com
                CC: llvmbugs at cs.uiuc.edu
    Classification: Unclassified


When a symbol is tentatively defined static, and later inside a function is is
declared extern, then it later confuses clang about its linkage. For example:


static int var;
int func() {
    extern int var;
    return var;
}
static int var = 0; /* static declaration of 'var' follows non-static
declaration */


The error message is wrong, because var is still tentatively static. Even more:


static int var;
int func() {
    extern int var;
    return var;
}
int var = 0;


The above example compiles, when it should actually give an error "non-static
declaration of 'var' follows static declaration". Compiling with -S shows that
linkage was somehow changed to external. However:


static int var;
int func() {
    extern int var;
    return var;
}


The above example compiles fine, however compiling with -S shows that linkage
of var is kept internal. It looks like extern in function body doesn't change
symbol linkage by itself, but something about previous declarations clearly
becomes changed/forgotten.

-- 
Configure bugmail: http://llvm.org/bugs/userprefs.cgi?tab=email
------- You are receiving this mail because: -------
You are on the CC list for the bug.