[15] RFR(T) 8242357: [JVMCI] Incorrect use of JVMCI_CHECK_ on return statement

[Vladimir Kozlov]

Thank you, Xin

Vladimir K

On 4/17/20 5:36 PM, Liu, Xin wrote:
> LGTM. I used to backport a similar change (exceptions.hpp) to jdk8u.
> I also use regex to scan the whole source code, I think it’s the only place in hotspot.
> 
> Thanks,
> --lx
> 
> On 4/17/20, 5:02 PM, "hotspot-compiler-dev on behalf of Vladimir Kozlov" <hotspot-compiler-dev-bounces at openjdk.java.net on behalf of vladimir.kozlov at oracle.com> wrote:
> 
>      CAUTION: This email originated from outside of the organization. Do not click links or open attachments unless you can confirm the sender and know the content is safe.
> 
> 
> 
>      https://bugs.openjdk.java.net/browse/JDK-8242357
> 
>      CHECK macros can't be used on a return statement - they expand to include code after the return [2] and so have no affect.
> 
>      Fix:
> 
>      src/hotspot/share/jvmci/jvmciEnv.hpp
>      @@ -262,7 +262,8 @@
>          char* as_utf8_string(JVMCIObject str, char* buf, int buflen);
> 
>          JVMCIObject create_string(Symbol* str, JVMCI_TRAPS) {
>      -    return create_string(str->as_C_string(), JVMCI_CHECK_(JVMCIObject()));
>      +    JVMCIObject s = create_string(str->as_C_string(), JVMCI_CHECK_(JVMCIObject()));
>      +    return s;
>          }
> 
>      I tried to find similar cases but it was the only one.
>      Clang -Wunreachable-code-aggressive does not catch this case.
> 
>      Tested hs-tier1,hs-tier3-graal
> 
>      Thanks,
>      Vladimir
> 
>      [1] http://hg.openjdk.java.net/jdk/jdk/file/90882ba9f488/src/hotspot/share/jvmci/jvmciExceptions.hpp#l48
>