C.12 Whole program optimization messages

This section lists errors that occur when the compiler is performing whole program optimization.

Fatal: Cannot open whole program optimization feedback file ”arg1”

The compiler cannot open the specified feedback file with whole program optimization information.

Processing whole program optimization information in wpo feedback file ”arg1”

The compiler starts processing whole program optimization information found in the named file.

Finished processing the whole program optimization information in wpo feedback file ”arg1”

The compiler has finished processing the whole program optimization information found in the named file.

Error: Expected section header, but got ”arg2” at line arg1 of wpo feedback file

The compiler expected a section header in the whole program optimization file (starting with %), but did not find it.

Warning: No handler registered for whole program optimization section ”arg2” at line arg1 of wpo feedback file, ignoring

The compiler has no handler to deal with the mentioned whole program optimization information section, and will therefore ignore it and skip to the next section.

Found whole program optimization section ”arg1” with information about ”arg2”

The compiler encountered a section with whole program optimization information, and according to its handler this section contains information usable for the mentioned purpose.

Fatal: The selected whole program optimizations require a previously generated feedback file (use -Fw to specify)

The compiler needs information gathered during a previous compilation run to perform the selected whole program optimizations. You can specify the location of the feedback file containing this information using the -Fw switch.

Error: No collected information necessary to perform ”arg1” whole program optimization found

While you pointed the compiler to a file containing whole program optimization feedback, it did not contain the information necessary to perform the selected optimizations. You most likely have to recompile the program using the appropriate -OWxxx switch.

Fatal: Specify a whole program optimization feedback file to store the generated info in (using -FW)

You have to specify the feedback file in which the compiler has to store the whole program optimization feedback that is generated during the compilation run. This can be done using the -FW switch.

Error: Not generating any whole program optimization information, yet a feedback file was specified (using -FW)

The compiler was instructed to store whole program optimization feedback into a file specified using -FW, but not to actually generated any whole program optimization feedback. The classes of to be generated information can be specified using -OWxxx.

Error: Not performing any whole program optimizations, yet an input feedback file was specified (using -Fw)

The compiler was not instructed to perform any whole program optimizations (no -Owxxx parameters), but nevertheless an input file with such feedback was specified (using -Fwyyy). Since this can indicate that you forgot to specify an -Owxxx parameter, the compiler generates an error in this case.

Skipping whole program optimization section ”arg1”, because not needed by the requested optimizations

The whole program optimization feedback file contains a section with information that is not required by the selected whole program optimizations.

Warning: Overriding previously read information for ”arg1” from feedback input file using information in section ”arg2”

The feedback file contains multiple sections that provide the same class of information (e.g., information about which virtual methods can be devirtualized). In this case, the information in last encountered section is used. Turn on debugging output (-vd) to see which class of information is provided by each section.

Error: Cannot extract symbol liveness information from program when stripping symbols, use -Xs-

Certain symbol liveness collectors extract the symbol information from the linked program. If the symbol information is stripped (option -Xs), this is not possible.

Error: Cannot extract symbol liveness information from program when when not linking

Certain symbol liveness collectors extract the symbol information from the linked program. If the program is not linked by the compiler, this is not possible.

Fatal: Cannot find ”arg1” or ”arg2” to extract symbol liveness information from linked program

Certain symbol liveness collectors need a helper program to extract the symbol information from the linked program. This helper program is normally ’nm’, which is part of the GNU binutils.

Error: Error during reading symbol liveness information produced by ”arg1”

An error occurred during the reading of the symbol liveness file that was generated using the ’nm’ or ’objdump’ program. The reason can be that it was shorter than expected, or that its format was not understood.

Fatal: Error executing ”arg1” (exitcode: arg2) to extract symbol information from linked program

Certain symbol liveness collectors need a helper program to extract the symbol information from the linked program. The helper program produced the reported error code when it was run on the linked program.

Error: Collection of symbol liveness information can only help when using smart linking, use -CX -XX

Whether or not a symbol is live is determined by looking whether it exists in the final linked program. Without smart linking/dead code stripping, all symbols are always included, regardless of whether they are actually used or not. So in that case all symbols will be seen as live, which makes this optimization ineffective.

Error: Cannot create specified whole program optimisation feedback file ”arg1”

The compiler is unable to create the file specified using the -FW parameter to store the whole program optimisation information.