pm24.git/scripts/kconfig, branch rust-fixes-6.12

kconfig: cache expression values

2024-09-20T00:21:53Z

Cache expression values to avoid recalculating them repeatedly. Signed-off-by: Masahiro Yamada

kconfig: use hash table to reuse expressions

2024-09-20T00:21:52Z

Currently, every expression in Kconfig files produces a new abstract syntax tree (AST), even if it is identical to a previously encountered one. Consider the following code: config FOO bool "FOO" depends on (A || B) && C config BAR bool "BAR" depends on (A || B) && C config BAZ bool "BAZ" depends on A || B The "depends on" lines are similar, but currently a separate AST is allocated for each one. The current data structure looks like this: FOO->dep ==> AND BAR->dep ==> AND BAZ->dep ==> OR / \ / \ / \ OR C OR C A B / \ / \ A B A B This is redundant; FOO->dep and BAR->dep have identical ASTs but different memory instances. We can optimize this; FOO->dep and BAR->dep can share the same AST, and BAZ->dep can reference its sub tree. The optimized data structure looks like this: FOO->dep, BAR->dep ==> AND / \ BAZ->dep ==> OR C / \ A B This commit introduces a hash table to keep track of allocated expressions. If an identical expression is found, it is reused. This does not necessarily result in memory savings, as menu_finalize() transforms expressions without freeing up stale ones. This will be addressed later. One optimization that can be easily implemented is caching the expression's value. Once FOO's dependency, (A || B) && C, is calculated, it can be cached, eliminating the need to recalculate it for BAR. This commit also reverts commit e983b7b17ad1 ("kconfig/menu.c: fix multiple references to expressions in menu_add_prop()"). Signed-off-by: Masahiro Yamada

kconfig: refactor expr_eliminate_dups()

2024-09-20T00:21:52Z

Currently, expr_eliminate_dups() passes two identical pointers down to expr_eliminate_dups1(), which later skips processing identical leaves. This approach is somewhat tricky and, more importantly, it will not work with the refactoring made in the next commit. This commit slightly changes the recursion logic; it deduplicates both the left and right arms, and then passes them to expr_eliminate_dups1(). expr_eliminate_dups() should produce the same result. Signed-off-by: Masahiro Yamada

kconfig: add comments to expression transformations

2024-09-20T00:21:52Z

Provide explanations for complex transformations. Signed-off-by: Masahiro Yamada

kconfig: change some expr_*() functions to bool

2024-09-20T00:21:52Z

This clarifies the behavior of these functions. Signed-off-by: Masahiro Yamada

scripts: move hash function from scripts/kconfig/ to scripts/include/

2024-09-20T00:21:52Z

This function was originally added by commit 8af27e1dc4e4 ("fixdep: use hash table instead of a single array"). Move it to scripts/include/ so that other host programs can use it. Signed-off-by: Masahiro Yamada

kbuild: split x*alloc() functions in kconfig to scripts/include/xalloc.h

2024-09-01T11:34:48Z

These functions will be useful for other host programs. Signed-off-by: Masahiro Yamada

kconfig: remove P_SYMBOL property

2024-09-01T11:34:48Z

P_SYMBOL is a pseudo property that was previously used for data linking purposes. It is no longer used except for debug prints. Remove it. Signed-off-by: Masahiro Yamada

kconfig: stop adding P_SYMBOL property to symbols

2024-09-01T11:34:48Z

I believe its last usage was in the following code: if (prop == NULL) prop = stack->sym->prop; This code was previously used to print the file name and line number of associated symbols in sym_check_print_recursive(), which was removed by commit 9d0d26604657 ("kconfig: recursive checks drop file/lineno"). Signed-off-by: Masahiro Yamada

kconfig: remove dummy assignments to cur_{filename,lineno}

2024-09-01T11:34:47Z

Since commit ca4c74ba306e ("kconfig: remove P_CHOICE property"), menu_finalize() no longer calls menu_add_symbol(). No function references cur_filename or cur_lineno after yyparse(). Signed-off-by: Masahiro Yamada