Re: RFR: 8268327: Upstream: 8268169: The system lookup can not find stdio functions such as printf on Windows 10
On Mon, 7 Jun 2021 13:23:46 GMT, Jorn Vernee wrote: > Hi, > > The documentation of `CLinker::systemLookup` [1] says this: > > > * Obtains a system lookup which is suitable to find symbols in the standard C > libraries. > > > However, currently it is not possible to look up common stdio.h symbols, such > as `printf`, using the system lookup on Windows 10. This is because the > backing library that is loaded, namely `ucrtbase.dll`, does not contain these > symbols, as they are implemented in the standard library as inline functions. > > This patch changes the system lookup implementation on Windows 10 to make > these symbols findable as well, by using a fallback library that forces the > generation of the code for the inline functions, and exposes the missing > symbols as a table of function pointers. > > See also the prior review of this patch for the panama-foreign repo: > https://github.com/openjdk/panama-foreign/pull/547 > > Since the exact set of symbols findable by the system lookup is unspecified, > and since the API in question (`CLinker::systemLookup`) was added only last > week [2], I've elected to not create a CSR for this patch, but please let me > know if one is needed). > > Thanks, > Jorn > > [1] : > https://github.com/openjdk/jdk/blob/master/src/jdk.incubator.foreign/share/classes/jdk/incubator/foreign/CLinker.java#L134-L151 > [2] : > https://github.com/openjdk/jdk/commit/a223189b069a7cfe49511d49b5b09e7107cb3cab LGTM - Marked as reviewed by sundar (Reviewer). PR: https://git.openjdk.java.net/jdk/pull/4390
Re: RFR: 8268327: Upstream: 8268169: The system lookup can not find stdio functions such as printf on Windows 10
On Mon, 7 Jun 2021 13:23:46 GMT, Jorn Vernee wrote: > Hi, > > The documentation of `CLinker::systemLookup` [1] says this: > > > * Obtains a system lookup which is suitable to find symbols in the standard C > libraries. > > > However, currently it is not possible to look up common stdio.h symbols, such > as `printf`, using the system lookup on Windows 10. This is because the > backing library that is loaded, namely `ucrtbase.dll`, does not contain these > symbols, as they are implemented in the standard library as inline functions. > > This patch changes the system lookup implementation on Windows 10 to make > these symbols findable as well, by using a fallback library that forces the > generation of the code for the inline functions, and exposes the missing > symbols as a table of function pointers. > > See also the prior review of this patch for the panama-foreign repo: > https://github.com/openjdk/panama-foreign/pull/547 > > Since the exact set of symbols findable by the system lookup is unspecified, > and since the API in question (`CLinker::systemLookup`) was added only last > week [2], I've elected to not create a CSR for this patch, but please let me > know if one is needed). > > Thanks, > Jorn > > [1] : > https://github.com/openjdk/jdk/blob/master/src/jdk.incubator.foreign/share/classes/jdk/incubator/foreign/CLinker.java#L134-L151 > [2] : > https://github.com/openjdk/jdk/commit/a223189b069a7cfe49511d49b5b09e7107cb3cab Build change looks good. - Marked as reviewed by erikj (Reviewer). PR: https://git.openjdk.java.net/jdk/pull/4390
RFR: 8268327: Upstream: 8268169: The system lookup can not find stdio functions such as printf on Windows 10
Hi, The documentation of `CLinker::systemLookup` [1] says this: * Obtains a system lookup which is suitable to find symbols in the standard C libraries. However, currently it is not possible to look up common stdio.h symbols, such as `printf`, using the system lookup on Windows 10. This is because the backing library that is loaded, namely `ucrtbase.dll`, does not contain these symbols, as they are implemented in the standard library as inline functions. This patch changes the system lookup implementation on Windows 10 to make these symbols findable as well, by using a fallback library that forces the generation of the code for the inline functions, and exposes the missing symbols as a table of function pointers. See also the prior review of this patch for the panama-foreign repo: https://github.com/openjdk/panama-foreign/pull/547 Since the exact set of symbols findable by the system lookup is unspecified, and since the API in question (`CLinker::systemLookup`) was added only last week [2], I've elected to not create a CSR for this patch, but please let me know if one is needed). Thanks, Jorn [1] : https://github.com/openjdk/jdk/blob/master/src/jdk.incubator.foreign/share/classes/jdk/incubator/foreign/CLinker.java#L134-L151 [2] : https://github.com/openjdk/jdk/commit/a223189b069a7cfe49511d49b5b09e7107cb3cab - Commit messages: - Upstream 8268169: The system lookup can not find stdio functions such as printf on Windows 10 Changes: https://git.openjdk.java.net/jdk/pull/4390/files Webrev: https://webrevs.openjdk.java.net/?repo=jdk=4390=00 Issue: https://bugs.openjdk.java.net/browse/JDK-8268327 Stats: 273 lines in 5 files changed: 203 ins; 58 del; 12 mod Patch: https://git.openjdk.java.net/jdk/pull/4390.diff Fetch: git fetch https://git.openjdk.java.net/jdk pull/4390/head:pull/4390 PR: https://git.openjdk.java.net/jdk/pull/4390
