On Sun, Feb 4, 2018 at 4:50 PM, Petr Vorel <petr.vorel@xxxxxxxxx> wrote:
> Hi Eugeniu,
>
>> From: Eugeniu Rosca <erosca@xxxxxxxxxxxxxx>
>
>> Commit 1ccb27143360 ("kconfig: make "Selected by:" and "Implied by:"
>> readable") made an incredible improvement in how reverse dependencies
>> are perceived by the user, by breaking down the single (often
>> interminable) expression string into small readable chunks.
>
>> Even so, what happens in practice when reading the reverse
>> dependencies is that 80-90% of the OR sub-expressions simply don't
>> matter, since they evaluate to [=n].
>
>> 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 30 of CONFIG options with
>> the highest amount of OR sub-expressions that make up the final
>> "{Selected,Implied} by" reverse dependency expression.
>
>> | Config | Revdep all | Revdep ![=n] |
>> |-------------------------------|------------|--------------|
>> | 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 |
>> | IRQ_DOMAIN | 75 | 19 |
>> | SERIAL_CORE | 75 | 9 |
>> | PHYLIB | 74 | 16 |
>> | REGMAP_MMIO | 72 | 15 |
>> | GENERIC_PHY | 67 | 20 |
>> | DMA_ENGINE | 66 | 11 |
>> | SERIAL_CORE_CONSOLE | 64 | 9 |
>> | CRYPTO_BLKCIPHER | 64 | 13 |
>> | PINMUX | 60 | 17 |
>> | CRYPTO | 59 | 10 |
>> | MII | 58 | 8 |
>> | GPIOLIB_IRQCHIP | 58 | 9 |
>> | MFD_SYSCON | 58 | 15 |
>> | VIDEOBUF2_DMA_CONTIG | 46 | 4 |
>> | REGMAP_IRQ | 45 | 6 |
>> | REGMAP_SPI | 44 | 2 |
>> | CLKSRC_MMIO | 42 | 5 |
>> | SND_SOC_GENERIC_DMAENGINE_PCM | 41 | 3 |
>> | CRYPTO_SHA1 | 37 | 2 |
>> | REGMAP | 36 | 4 |
>
>> The story behind the above is that we still 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.
>
>> This patch attempts to bring at user's fingertips those reverse
>> dependencies that actually participate in selection of given symbol
>> filtering out the rest of them.
>
>> Signed-off-by: Eugeniu Rosca <erosca@xxxxxxxxxxxxxx>
>> ---
>> scripts/kconfig/expr.c | 24 +++++++++++++++++-------
>> 1 file changed, 17 insertions(+), 7 deletions(-)
>
>> diff --git a/scripts/kconfig/expr.c b/scripts/kconfig/expr.c
>> index 2ba332b3fed7..147b2d8a8f3e 100644
>> --- a/scripts/kconfig/expr.c
>> +++ b/scripts/kconfig/expr.c
>> @@ -1234,14 +1234,24 @@ static void __expr_print(struct expr *e, void (*fn)(void *, struct symbol *, con
>> fn(data, e->right.sym, e->right.sym->name);
>> break;
>> case E_OR:
>> - if (revdep && e->left.expr->type != E_OR)
>> - fn(data, NULL, "\n - ");
>> - __expr_print(e->left.expr, fn, data, E_OR, revdep);
>> - if (revdep)
>> - fn(data, NULL, "\n - ");
>> - else
>> + if (revdep) {
>> + struct expr *left = e->left.expr;
>> + struct expr *right = e->right.expr;
>> +
>> + if (expr_calc_value(left) != no) {
>> + if (left->type != E_OR)
>> + fn(data, NULL, "\n - ");
>> + __expr_print(left, fn, data, E_OR, revdep);
>> + }
>> + if (expr_calc_value(right) != no) {
>> + fn(data, NULL, "\n - ");
>> + __expr_print(right, fn, data, E_OR, revdep);
>> + }
>> + } else {
>> + __expr_print(e->left.expr, fn, data, E_OR, revdep);
>> fn(data, NULL, " || ");
>> - __expr_print(e->right.expr, fn, data, E_OR, revdep);
>> + __expr_print(e->right.expr, fn, data, E_OR, revdep);
>> + }
>> break;
>> case E_AND:
>> expr_print(e->left.expr, fn, data, E_AND);
>
> Thanks for trying to improve my change.
>
> Applying your patch, running
> $ ARCH=arm64 make defconfig && ARCH=arm64 make menuconfig
> and searching for USB prints "Selected by:" with nothing actually selected.
>
> Kind regards,
> Petr
Hello,
I implemented the behavior I had in mind. With this patch, REGMAP_I2C
shows up as follows:
Symbol: REGMAP_I2C [=y]│
Type : tristate│
Defined at drivers/base/regmap/Kconfig:19
Depends on: I2C [=y]
Currently selected by:
- RTC_I2C_AND_SPI [=y] && RTC_CLASS [=y] && I2C [=y]
- USB_HSIC_USB3503 [=y] && USB_SUPPORT [=y] && USB [=y] && I2C [=y]
- SND_SOC [=y] && SOUND [=y] && !UML && SND [=y] && I2C [=y]
- DRM_I2C_ADV7511 [=m] && HAS_IOMEM [=y] && DRM [=m] && DRM_BRIDGE
[=y] && OF [=y]
- REGULATOR_FAN53555 [=y] && REGULATOR [=y] && I2C [=y]
- MFD_SEC_CORE [=y] && HAS_IOMEM [=y] && I2C [=y]=y
- MFD_RK808 [=y] && HAS_IOMEM [=y] && I2C [=y] && OF [=y]
- MFD_MAX77620 [=y] && HAS_IOMEM [=y] && I2C [=y]=y && (OF [=y] ||
COMPILE_TEST [=n])
- SENSORS_INA2XX [=m] && HWMON [=y] && I2C [=y]
All selecting symbols:
- PWM_PCA9685 [=n] && PWM [=y] && I2C [=y]
- SX9500 [=n] && IIO [=y] && I2C [=y]
- ZPA2326_I2C [=n] && IIO [=y]
- HP03 [=n] && IIO [=y] && I2C [=y]
- BMP280_I2C [=n] && IIO [=y] && BMP280 [=n] && I2C [=y]
...
USB shows up as:
Symbol: USB [=y]
Type : tristate
Prompt: Support for Host-side USB
Location:
-> Device Drivers
(1) -> USB support (USB_SUPPORT [=y])
Defined at drivers/usb/Kconfig:38
Depends on: USB_SUPPORT [=y] && USB_ARCH_HAS_HCD [=y]
Selects: USB_COMMON [=y] && NLS [=y]
Currently selected by:
No symbols
All selecting symbols:
- DRM_UDL [=n] && HAS_IOMEM [=y] && DRM [=m] && USB_SUPPORT [=y] &&
USB_ARCH_HAS_HCD [=y]
- IR_TTUSBIR [=n] && RC_DEVICES [=y] && USB_ARCH_HAS_HCD [=y] && RC_CORE [=m]
- IR_IGUANA [=n] && RC_DEVICES [=y] && USB_ARCH_HAS_HCD [=y] && RC_CORE [=m]
- IR_IGORPLUGUSB [=n] && RC_DEVICES [=y] && USB_ARCH_HAS_HCD [=y] &&
RC_CORE [=m]
- IR_STREAMZAP [=n] && RC_DEVICES [=y] && USB_ARCH_HAS_HCD [=y] &&
RC_CORE [=m]
...
What do you think about this behavior? Tell me if you spot any bugs.
While working on the patch, I thought I had a regression where a
reverse dependency of just a single symbol showed up without a leading
" - ", hence the slight overengineering. On a second look, I think
the original patch also did that though. It's arguable whether that's
actually a bug, but now it always prints the " - ".
I don't have access to Mutt at the moment, and GMail's web interface
mangles patches, so I'll attach the patch.
If you go with something similar, you could add a Suggested-by:.
Cheers,
Ulf
From 8d3e34dbf4eb11f492519464031cd610ad866b53 Mon Sep 17 00:00:00 2001
From: Ulf Magnusson <ulfalizer@xxxxxxxxx>
Date: Sun, 4 Feb 2018 18:52:40 +0100
Subject: [PATCH] Readable rev. dep WIP
---
scripts/kconfig/expr.c | 97 +++++++++++++++++++++++++++++++++++++++++---------
scripts/kconfig/expr.h | 1 +
scripts/kconfig/menu.c | 11 +++++-
3 files changed, 92 insertions(+), 17 deletions(-)
diff --git a/scripts/kconfig/expr.c b/scripts/kconfig/expr.c
index 2ba332b3fed7..fd4814cb1a31 100644
--- a/scripts/kconfig/expr.c
+++ b/scripts/kconfig/expr.c
@@ -1179,7 +1179,33 @@ struct expr *expr_simplify_unmet_dep(struct expr *e1, struct expr *e2)
return expr_get_leftmost_symbol(ret);
}
-static void __expr_print(struct expr *e, void (*fn)(void *, struct symbol *, const char *), void *data, int prevtoken, bool revdep)
+enum expr_print_mode {
+ PRINT_NORMAL,
+
+ /* Print reverse dependencies with selects on separate lines */
+ PRINT_ALL_SELECTS,
+
+ /* Like PRINT_ALL_SELECTS, but skip 'n'-valued selects */
+ PRINT_ACTIVE_SELECTS
+};
+
+/* Helper for pretty-printing reverse dependencies with one select per line */
+static void print_select(struct expr *e,
+ void (*fn)(void *, struct symbol *, const char *),
+ void *data,
+ enum expr_print_mode mode)
+{
+ if (mode == PRINT_ALL_SELECTS || expr_calc_value(e) != no) {
+ fn(data, NULL, "\n - ");
+ expr_print(e, fn, data, E_OR);
+ }
+}
+
+static void __expr_print(struct expr *e,
+ void (*fn)(void *, struct symbol *, const char *),
+ void *data,
+ int prevtoken,
+ enum expr_print_mode mode)
{
if (!e) {
fn(data, NULL, "y");
@@ -1190,10 +1216,18 @@ static void __expr_print(struct expr *e, void (*fn)(void *, struct symbol *, con
fn(data, NULL, "(");
switch (e->type) {
case E_SYMBOL:
- if (e->left.sym->name)
- fn(data, e->left.sym, e->left.sym->name);
- else
+ if (e->left.sym->name) {
+ if (mode == PRINT_NORMAL)
+ fn(data, e->left.sym, e->left.sym->name);
+ else
+ /*
+ * PRINT_*_SELECTS, with a final select that
+ * has no condition
+ */
+ print_select(e, fn, data, mode);
+ } else {
fn(data, NULL, "<choice>");
+ }
break;
case E_NOT:
fn(data, NULL, "!");
@@ -1234,19 +1268,42 @@ static void __expr_print(struct expr *e, void (*fn)(void *, struct symbol *, con
fn(data, e->right.sym, e->right.sym->name);
break;
case E_OR:
- if (revdep && e->left.expr->type != E_OR)
- fn(data, NULL, "\n - ");
- __expr_print(e->left.expr, fn, data, E_OR, revdep);
- if (revdep)
- fn(data, NULL, "\n - ");
- else
+ if (mode == PRINT_NORMAL) {
+ expr_print(e->left.expr, fn, data, E_OR);
fn(data, NULL, " || ");
- __expr_print(e->right.expr, fn, data, E_OR, revdep);
+ expr_print(e->right.expr, fn, data, E_OR);
+ } else {
+ /*
+ * PRINT_*_SELECTS
+ *
+ * Support both (OR, <select 1>, (OR, <select 2>)) and
+ * (OR, (OR, <select 1>), <select 2>) format for
+ * selects. I think you always get the second one in
+ * practice as of writing.
+ */
+ if (e->right.expr->type != E_OR) {
+ print_select(e->right.expr, fn, data, mode);
+ /* Move on to next select */
+ __expr_print(e->left.expr, fn, data, E_OR, mode);
+ } else {
+ print_select(e->left.expr, fn, data, mode);
+ /* Move on to next select */
+ __expr_print(e->right.expr, fn, data, E_OR, mode);
+ }
+ }
break;
case E_AND:
- expr_print(e->left.expr, fn, data, E_AND);
- fn(data, NULL, " && ");
- expr_print(e->right.expr, fn, data, E_AND);
+ if (mode == PRINT_NORMAL) {
+ expr_print(e->left.expr, fn, data, E_AND);
+ fn(data, NULL, " && ");
+ expr_print(e->right.expr, fn, data, E_AND);
+ } else {
+ /*
+ * PRINT_*_SELECTS, with a final select that has a
+ * condition
+ */
+ print_select(e, fn, data, mode);
+ }
break;
case E_LIST:
fn(data, e->right.sym, e->right.sym->name);
@@ -1276,7 +1333,7 @@ static void __expr_print(struct expr *e, void (*fn)(void *, struct symbol *, con
void expr_print(struct expr *e, void (*fn)(void *, struct symbol *, const char *), void *data, int prevtoken)
{
- __expr_print(e, fn, data, prevtoken, false);
+ __expr_print(e, fn, data, prevtoken, PRINT_NORMAL);
}
static void expr_print_file_helper(void *data, struct symbol *sym, const char *str)
@@ -1331,5 +1388,13 @@ void expr_gstr_print(struct expr *e, struct gstr *gs)
*/
void expr_gstr_print_revdep(struct expr *e, struct gstr *gs)
{
- __expr_print(e, expr_print_gstr_helper, gs, E_NONE, true);
+ __expr_print(e, expr_print_gstr_helper, gs, E_NONE, PRINT_ALL_SELECTS);
+}
+
+/*
+ * Like expr_gstr_print_revdep(), but do not print 'n'-valued selects
+ */
+void expr_gstr_print_active_revdep(struct expr *e, struct gstr *gs)
+{
+ __expr_print(e, expr_print_gstr_helper, gs, E_NONE, PRINT_ACTIVE_SELECTS);
}
diff --git a/scripts/kconfig/expr.h b/scripts/kconfig/expr.h
index c16e82e302a2..c0274dc23a47 100644
--- a/scripts/kconfig/expr.h
+++ b/scripts/kconfig/expr.h
@@ -311,6 +311,7 @@ void expr_fprint(struct expr *e, FILE *out);
struct gstr; /* forward */
void expr_gstr_print(struct expr *e, struct gstr *gs);
void expr_gstr_print_revdep(struct expr *e, struct gstr *gs);
+void expr_gstr_print_active_revdep(struct expr *e, struct gstr *gs);
static inline int expr_is_yes(struct expr *e)
{
diff --git a/scripts/kconfig/menu.c b/scripts/kconfig/menu.c
index 99222855544c..170a8b421e97 100644
--- a/scripts/kconfig/menu.c
+++ b/scripts/kconfig/menu.c
@@ -827,7 +827,16 @@ static void get_symbol_str(struct gstr *r, struct symbol *sym,
get_symbol_props_str(r, sym, P_SELECT, _(" Selects: "));
if (sym->rev_dep.expr) {
- str_append(r, _(" Selected by: "));
+ str_append(r, _(" Currently selected by:"));
+ if (expr_calc_value(sym->rev_dep.expr) == no) {
+ str_append(r, "\n");
+ str_append(r, _(" No symbols"));
+ } else {
+ expr_gstr_print_active_revdep(sym->rev_dep.expr, r);
+ }
+ str_append(r, "\n");
+
+ str_append(r, _(" All selecting symbols:"));
expr_gstr_print_revdep(sym->rev_dep.expr, r);
str_append(r, "\n");
}
--
2.14.1
