search for: weakalias

...copy in the alias's module? I looked at some examples without ThinLTO, and am a little confused. Current (non-ThinLTO) behavior in some cases seems to depend on opt level. Example: $ cat weak12main.c extern void test2(); int main() { test2(); } $ cat weak1.c #include <stdio.h> void weakalias() __attribute__((weak, alias ("f"))); void strongalias() __attribute__((alias ("f"))); void f () __attribute__ ((weak)); void f() { printf("In weak1.c:f\n"); } void test1() { printf("Call f() from weak1.c:\n"); f(); printf("Call weakalias() from...

...o answer your question correctly it is helpful to consider what is going on at the object file level. For your test1.c we conceptually have a .text section containing the body of f, and then three symbols: > > .weak f > f = .text > .globl strongalias > strongalias = .text > .weak weakalias > weakalias = .text > > Note that f, strongalias and weakalias are not related at all, except that they happen to point to the same place. If f is overridden by a symbol in another object file, it does not affect the symbols strongalias and weakalias, so we still need to make them point t...

...your question correctly it is helpful to consider > what is going on at the object file level. For your test1.c we conceptually > have a .text section containing the body of f, and then three symbols: > > .weak f > f = .text > .globl strongalias > strongalias = .text > .weak weakalias > weakalias = .text > > Note that f, strongalias and weakalias are not related at all, except that > they happen to point to the same place. If f is overridden by a symbol in > another object file, it does not affect the symbols strongalias and > weakalias, so we still need to mak...

...orrectly it is helpful to consider what is going on at the object file level. For your test1.c we conceptually have a .text section containing the body of f, and then three symbols: >> >> .weak f >> f = .text >> .globl strongalias >> strongalias = .text >> .weak weakalias >> weakalias = .text >> >> Note that f, strongalias and weakalias are not related at all, except that they happen to point to the same place. If f is overridden by a symbol in another object file, it does not affect the symbols strongalias and weakalias, so we still need to make...

...evel. For your test1.c we conceptually have a .text section containing the body of f, and then three symbols: >>>>> >>>>> .weak f >>>>> f = .text >>>>> .globl strongalias >>>>> strongalias = .text >>>>> .weak weakalias >>>>> weakalias = .text >>>>> >>>>> Note that f, strongalias and weakalias are not related at all, except that they happen to point to the same place. If f is overridden by a symbol in another object file, it does not affect the symbols strongalias and...

...some cases seems to depend on > > opt level. > > > > Example: > > > > $ cat weak12main.c > > extern void test2(); > > int main() { > > test2(); > > } > > > > $ cat weak1.c > > #include <stdio.h> > > > > void weakalias() __attribute__((weak, alias ("f"))); > > void strongalias() __attribute__((alias ("f"))); > > > > void f () __attribute__ ((weak)); > > void f() > > { > > printf("In weak1.c:f\n"); > > } > > void test1() { > >...

...p selectCallee() we > specifically prevent importing of aliases that would result in the aliasee > becoming available_externally. Presumably the resulting IRLinked dest > module looks legit, otherwise we would have later verifier failures. > > > So the source module is: > > @weakalias = weak alias void (...), bitcast (void ()* @globalfunc1 to void > (...)*) > define void @globalfunc1() #0 { > entry: > ret void > } > > But we turn globalfunc1 into available_externally in > renameModuleForThinLTO(), which make the alias invalid. > > We don’t import...

...ToImport set. But in FunctionImport.cpp selectCallee() we specifically prevent importing of aliases that would result in the aliasee becoming available_externally. Presumably the resulting IRLinked dest module looks legit, otherwise we would have later verifier failures. So the source module is: @weakalias = weak alias void (...), bitcast (void ()* @globalfunc1 to void (...)*) define void @globalfunc1() #0 { entry: ret void } But we turn globalfunc1 into available_externally in renameModuleForThinLTO(), which make the alias invalid. We don’t import the IR so the destination module is OK. 36 &gt...

...ToImport set. But in FunctionImport.cpp selectCallee() we specifically prevent importing of aliases that would result in the aliasee becoming available_externally. Presumably the resulting IRLinked dest module looks legit, otherwise we would have later verifier failures. So the source module is: @weakalias = weak alias void (...), bitcast (void ()* @globalfunc1 to void (...)*) define void @globalfunc1() #0 { entry: ret void } But we turn globalfunc1 into available_externally in renameModuleForThinLTO(), which make the alias invalid. We don’t import the IR so the destination module is OK. 36 I...

On Thu, Dec 22, 2016 at 8:55 PM, Mehdi Amini <mehdi.amini at apple.com> wrote: > Hey, > > As I’m playing with Metadata lazy-loading, I added a verifier right before > running the IRLinker in FunctionImport.cpp, and it does not pass (on > current trunk) in a few cases. One that I looked at ended up with aliases > pointing to available_externally functions for instance. >

...FunctionImport.cpp selectCallee() we specifically prevent importing of aliases that would result in the aliasee becoming available_externally. Presumably the resulting IRLinked dest module looks legit, otherwise we would have later verifier failures. > > So the source module is: > > @weakalias = weak alias void (...), bitcast (void ()* @globalfunc1 to void (...)*) > define void @globalfunc1() #0 { > entry: > ret void > } > > But we turn globalfunc1 into available_externally in renameModuleForThinLTO(), which make the alias invalid. > > We don’t import the IR s...

...() we specifically prevent importing of aliases that would result in the aliasee becoming available_externally. Presumably the resulting IRLinked dest module looks legit, otherwise we would have later verifier failures. >>> >>> So the source module is: >>> >>> @weakalias = weak alias void (...), bitcast (void ()* @globalfunc1 to void (...)*) >>> define void @globalfunc1() #0 { >>> entry: >>> ret void >>> } >>> >>> But we turn globalfunc1 into available_externally in renameModuleForThinLTO(), which make the al...