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authorEugeniu Rosca <erosca@de.adit-jv.com>2018-02-24 16:24:18 +0100
committerMasahiro Yamada <yamada.masahiro@socionext.com>2018-03-26 02:03:58 +0900
commitd9119b5925a03b9a3191fa3e93b4091651d8ad25 (patch)
tree09cd91d85c4662526fb61804f01b4e47ccf8702d /scripts/kconfig/expr.c
parent9a47ceec543bfb703fbe2f8d584850b582caf1a6 (diff)
kconfig: Print reverse dependencies in groups
Surprisingly or not, disabling a CONFIG option (which is assumed to be unneeded) may be not so trivial. Especially it is not trivial, when this CONFIG option is selected by a dozen of other configs. Before the moment commit 1ccb27143360 ("kconfig: make "Selected by:" and "Implied by:" readable") popped up in v4.16-rc1, it was an absolute pain to break down the "Selected by" reverse dependency expression in order to identify all those configs which select (IOW *do not allow disabling*) a certain feature (assumed to be not needed). This patch tries to make one step further by putting at users' fingertips the revdep top level OR sub-expressions grouped/clustered by the tristate value they evaluate to. This should allow the users to directly concentrate on and tackle the _active_ reverse dependencies. To give some numbers and quantify the complexity of certain reverse dependencies, assuming commit 617aebe6a97e ("Merge tag 'usercopy-v4.16-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux"), ARCH=arm64 and vanilla arm64 defconfig, here is the top 10 CONFIG options with the highest amount of top level "||" sub-expressions/tokens that make up the final "Selected by" reverse dependency expression. | Config | All revdep | Active revdep | |-------------------|------------|---------------| | REGMAP_I2C | 212 | 9 | | CRC32 | 167 | 25 | | FW_LOADER | 128 | 5 | | MFD_CORE | 124 | 9 | | FB_CFB_IMAGEBLIT | 114 | 2 | | FB_CFB_COPYAREA | 111 | 2 | | FB_CFB_FILLRECT | 110 | 2 | | SND_PCM | 103 | 2 | | CRYPTO_HASH | 87 | 19 | | WATCHDOG_CORE | 86 | 6 | The story behind the above is that users need to visually review/evaluate 212 expressions which *potentially* select REGMAP_I2C in order to identify the expressions which *actually* select REGMAP_I2C, for a particular ARCH and for a particular defconfig used. To make this experience smoother, change the way reverse dependencies are displayed to the user from [1] to [2]. [1] Old representation of DMA_ENGINE_RAID: Selected by: - AMCC_PPC440SPE_ADMA [=n] && DMADEVICES [=y] && (440SPe || 440SP) - BCM_SBA_RAID [=m] && DMADEVICES [=y] && (ARM64 [=y] || ... - FSL_RAID [=n] && DMADEVICES [=y] && FSL_SOC && ... - INTEL_IOATDMA [=n] && DMADEVICES [=y] && PCI [=y] && X86_64 - MV_XOR [=n] && DMADEVICES [=y] && (PLAT_ORION || ARCH_MVEBU [=y] ... - MV_XOR_V2 [=y] && DMADEVICES [=y] && ARM64 [=y] - XGENE_DMA [=n] && DMADEVICES [=y] && (ARCH_XGENE [=y] || ... - DMATEST [=n] && DMADEVICES [=y] && DMA_ENGINE [=y] [2] New representation of DMA_ENGINE_RAID: Selected by [y]: - MV_XOR_V2 [=y] && DMADEVICES [=y] && ARM64 [=y] Selected by [m]: - BCM_SBA_RAID [=m] && DMADEVICES [=y] && (ARM64 [=y] || ... Selected by [n]: - AMCC_PPC440SPE_ADMA [=n] && DMADEVICES [=y] && (440SPe || ... - FSL_RAID [=n] && DMADEVICES [=y] && FSL_SOC && ... - INTEL_IOATDMA [=n] && DMADEVICES [=y] && PCI [=y] && X86_64 - MV_XOR [=n] && DMADEVICES [=y] && (PLAT_ORION || ARCH_MVEBU [=y] ... - XGENE_DMA [=n] && DMADEVICES [=y] && (ARCH_XGENE [=y] || ... - DMATEST [=n] && DMADEVICES [=y] && DMA_ENGINE [=y] Suggested-by: Masahiro Yamada <yamada.masahiro@socionext.com> Signed-off-by: Eugeniu Rosca <erosca@de.adit-jv.com> Reviewed-by: Petr Vorel <pvorel@suse.cz> Reviewed-by: Ulf Magnusson <ulfalizer@gmail.com> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Diffstat (limited to 'scripts/kconfig/expr.c')
-rw-r--r--scripts/kconfig/expr.c18
1 files changed, 12 insertions, 6 deletions
diff --git a/scripts/kconfig/expr.c b/scripts/kconfig/expr.c
index cd3a8f501f38..49376e12fa30 100644
--- a/scripts/kconfig/expr.c
+++ b/scripts/kconfig/expr.c
@@ -1323,19 +1323,25 @@ void expr_gstr_print(struct expr *e, struct gstr *gs)
*/
static void expr_print_revdep(struct expr *e,
void (*fn)(void *, struct symbol *, const char *),
- void *data)
+ void *data, tristate pr_type, const char **title)
{
if (e->type == E_OR) {
- expr_print_revdep(e->left.expr, fn, data);
- expr_print_revdep(e->right.expr, fn, data);
- } else {
+ expr_print_revdep(e->left.expr, fn, data, pr_type, title);
+ expr_print_revdep(e->right.expr, fn, data, pr_type, title);
+ } else if (expr_calc_value(e) == pr_type) {
+ if (*title) {
+ fn(data, NULL, *title);
+ *title = NULL;
+ }
+
fn(data, NULL, " - ");
expr_print(e, fn, data, E_NONE);
fn(data, NULL, "\n");
}
}
-void expr_gstr_print_revdep(struct expr *e, struct gstr *gs)
+void expr_gstr_print_revdep(struct expr *e, struct gstr *gs,
+ tristate pr_type, const char *title)
{
- expr_print_revdep(e, expr_print_gstr_helper, gs);
+ expr_print_revdep(e, expr_print_gstr_helper, gs, pr_type, &title);
}