RE: AIX support - Mailing list pgsql-hackers

+# -blibpath must contain ALL directories where we should look for libraries
+libpath := $(shell echo $(subst -L,:,$(filter -L/%,$(LDFLAGS))) | sed -e's/ //g'):/usr/lib:/lib
+
+# when building with gcc, need to make sure that libgcc can be found
+ifeq ($(GCC), yes)
+libpath := $(libpath):$(dir $(shell gcc -print-libgcc-file-name))
+endif
+
+rpath = -Wl,-blibpath:'$(rpathdir)$(libpath)’

These lines are no longer required, and we have removed it in v12 patch as well. And this is the root cause of GNU tests failing.

The above lines cause the binary’s lib path to be as below:

                        ***Import File Strings***
INDEX  PATH                          BASE                MEMBER              
0      /usr/local/pgsql/lib:/usr/lib:/lib:/opt/freeware/lib/gcc/powerpc-ibm-aix7.2.0.0/13/ 

The GCC compiler on AIX will leave it to the IBM AIX linker to derive the runtime loader path from the compile time library search paths.  

When we run "gcc -print-search-dirs”  it lists all the library paths as below.

In practice, the GCC driver also contributes its own runtime support directory (where libgcc_s lives) to the link search, and the derived runtime path written into the loader section ends up containing those locations without us manually constructing -blibpath.

After removing the lib path and path from Makefile.aix we get the below library search paths which is what we need to run test cases or run binaries,

   ***Import File Strings***
INDEX  PATH                          BASE                MEMBER
0      ../../../src/port:../../../src/common:../../../src/fe_utils:../../../src/interfaces/libpq:/opt/freeware/lib:/opt/freeware/lib/gcc/powerpc-ibm-aix7.3.0.0/13/ppc64:/opt/freeware/lib/gcc/powerpc-ibm-aix7.3.0.0/13/../../../ppc64:/opt/freeware/lib/gcc/powerpc-ibm-aix7.3.0.0/13:/opt/freeware/lib/gcc/powerpc-ibm-aix7.3.0.0/13/../../..:/usr/lib:/lib

We tried it in the same node and were able to run the TAP tests as well successfully without the mentioned above lines in Makefile.aix . Let me know if you have any issues after removing the same. But those lines are no longer needed given we will move to GCC and Clang(IBM openXL)  in AIX for PostgreSQL. 

       We want to remove the blibpath calculation from this patch for reasons mentioned above.

>0003 through 0005 are changes needed on top of that, mostly
>0006 adds some definitions I found necessary to get a warning-free
>0007 arose from comparing the file sets installed by the autoconf

All these patches look good.


>* The meson build, but not the autoconf build, produces
>complaints about
>../src/common/pg_get_line.c: In function 'pg_get_line_append’:
>../src/common/pg_get_line.c:129:27: warning: '({anonymous})' may be used uninitialized [-Wmaybe-uninitialized]
 > 129 |         if (prompt_ctx && sigsetjmp(*((sigjmp_buf *) prompt_ctx->jmpbuf), 1) != 0)
      |                           ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

>I'm not so worried about the warning itself --- buildfarm member
>hake has also been showing this --- but why are the two builds
>different?  Same compiler, pretty much the same switches, although
>I see Meson is injecting -pthread without being asked.  Could that
>be responsible?

This is our understanding so far: when pthread support is enabled, sigsetjmp is

no longer a straightforward function call—it expands into a more complex macro.

The compiler’s warning refers to an “anonymous” value because the macro

expansion likely uses a GCC statement expression of the form ({ ... }). Within

that expansion, GCC creates a temporary variable to capture some intermediate

state or return value. Since the compiler cannot clearly determine that this

internal temporary is always initialized—especially under certain optimization

levels—it raises the -Wmaybe-uninitialized warning, even though the code itself

is correct.