Initial wasm-split tool (#3359)

Implement an initial version of the wasm-split tool, which splits modules into a
primary module and a secondary module that can be instantiated after the primary
module. Eventually, this tool will be able to not only split modules, but also
instrument modules to collect profiles that will be able to guide later
splitting. In this initial version, however, wasm-split can neither perform
instrumentation nor consume any kind of profile data.

Despite those shortcomings, this initial version of the tool is already able to
perform module splitting according to function lists manually provided by the
user via the command line. Follow-up PRs will implement the stubbed out
instrumentation and profile consumption functionality.

3 files changed, 219 insertions, 0 deletions

diff --git a/test/lit/wasm-split/basic.wast b/test/lit/wasm-split/basic.wast
new file mode 100644
index 000000000..d282b0bd6
--- /dev/null
+++ b/test/lit/wasm-split/basic.wast
@@ -0,0 +1,141 @@
+;; RUN: wasm-split %s --export-prefix='%' -o1 %t.none.1.wasm -o2 %t.none.2.wasm -v 2>&1 \
+;; RUN:     | filecheck %s --check-prefix KEEP-NONE
+;; RUN: wasm-dis %t.none.1.wasm | filecheck %s --check-prefix KEEP-NONE-PRIMARY
+;; RUN: wasm-dis %t.none.2.wasm | filecheck %s --check-prefix KEEP-NONE-SECONDARY
+
+;; RUN: wasm-split %s --export-prefix='%' -o1 %t.foo.1.wasm -o2 %t.foo.2.wasm --keep-funcs=foo -v 2>&1 \
+;; RUN:     | filecheck %s --check-prefix KEEP-FOO
+;; RUN: wasm-dis %t.foo.1.wasm | filecheck %s --check-prefix KEEP-FOO-PRIMARY
+;; RUN: wasm-dis %t.foo.2.wasm | filecheck %s --check-prefix KEEP-FOO-SECONDARY
+
+;; RUN: wasm-split %s --export-prefix='%' -o1 %t.bar.1.wasm -o2 %t.bar.2.wasm --keep-funcs=bar -v 2>&1 \
+;; RUN:     | filecheck %s --check-prefix KEEP-BAR
+;; RUN: wasm-dis %t.bar.1.wasm | filecheck %s --check-prefix KEEP-BAR-PRIMARY
+;; RUN: wasm-dis %t.bar.2.wasm | filecheck %s --check-prefix KEEP-BAR-SECONDARY
+
+;; RUN: wasm-split %s --export-prefix='%' -o1 %t.both.1.wasm -o2 %t.both.2.wasm --keep-funcs=foo,bar -v 2>&1 \
+;; RUN:     | filecheck %s --check-prefix KEEP-BOTH
+;; RUN: wasm-dis %t.both.1.wasm | filecheck %s --check-prefix KEEP-BOTH-PRIMARY
+;; RUN: wasm-dis %t.both.2.wasm | filecheck %s --check-prefix KEEP-BOTH-SECONDARY
+
+(module
+ (table $table 1 1 funcref)
+ (elem (i32.const 0) $foo)
+ (func $foo (param i32) (result i32)
+  (call $bar (i32.const 0))
+ )
+ (func $bar (param i32) (result i32)
+  (call $foo (i32.const 1))
+ )
+)
+
+;; KEEP-NONE: warning: not keeping any functions in the primary module
+
+;; KEEP-NONE-PRIMARY:      (module
+;; KEEP-NONE-PRIMARY-NEXT:  (type $i32_=>_i32 (func (param i32) (result i32)))
+;; KEEP-NONE-PRIMARY-NEXT:  (import "placeholder" "0" (func $fimport$0 (param i32) (result i32)))
+;; KEEP-NONE-PRIMARY-NEXT:  (table $0 1 1 funcref)
+;; KEEP-NONE-PRIMARY-NEXT:  (elem (i32.const 0) $fimport$0)
+;; KEEP-NONE-PRIMARY-NEXT:  (export "%table" (table $0))
+;; KEEP-NONE-PRIMARY-NEXT: )
+
+;; KEEP-NONE-SECONDARY:      (module
+;; KEEP-NONE-SECONDARY-NEXT:  (type $i32_=>_i32 (func (param i32) (result i32)))
+;; KEEP-NONE-SECONDARY-NEXT:  (import "primary" "%table" (table $timport$0 1 1 funcref))
+;; KEEP-NONE-SECONDARY-NEXT:  (elem (i32.const 0) $1)
+;; KEEP-NONE-SECONDARY-NEXT:  (func $0 (param $0 i32) (result i32)
+;; KEEP-NONE-SECONDARY-NEXT:   (call $1
+;; KEEP-NONE-SECONDARY-NEXT:    (i32.const 1)
+;; KEEP-NONE-SECONDARY-NEXT:   )
+;; KEEP-NONE-SECONDARY-NEXT:  )
+;; KEEP-NONE-SECONDARY-NEXT:  (func $1 (param $0 i32) (result i32)
+;; KEEP-NONE-SECONDARY-NEXT:   (call $0
+;; KEEP-NONE-SECONDARY-NEXT:    (i32.const 0)
+;; KEEP-NONE-SECONDARY-NEXT:   )
+;; KEEP-NONE-SECONDARY-NEXT:  )
+;; KEEP-NONE-SECONDARY-NEXT: )
+
+;; KEEP-FOO: Keeping functions: foo{{$}}
+;; KEEP-FOO-NEXT: Splitting out functions: bar{{$}}
+
+;; KEEP-FOO-PRIMARY:      (module
+;; KEEP-FOO-PRIMARY-NEXT:  (type $i32_=>_i32 (func (param i32) (result i32)))
+;; KEEP-FOO-PRIMARY-NEXT:  (import "placeholder" "1" (func $fimport$0 (param i32) (result i32)))
+;; KEEP-FOO-PRIMARY-NEXT:  (table $0 2 2 funcref)
+;; KEEP-FOO-PRIMARY-NEXT:  (elem (i32.const 0) $0 $fimport$0)
+;; KEEP-FOO-PRIMARY-NEXT:  (export "%foo" (func $0))
+;; KEEP-FOO-PRIMARY-NEXT:  (export "%table" (table $0))
+;; KEEP-FOO-PRIMARY-NEXT:  (func $0 (param $0 i32) (result i32)
+;; KEEP-FOO-PRIMARY-NEXT:   (call_indirect (type $i32_=>_i32)
+;; KEEP-FOO-PRIMARY-NEXT:    (i32.const 0)
+;; KEEP-FOO-PRIMARY-NEXT:    (i32.const 1)
+;; KEEP-FOO-PRIMARY-NEXT:   )
+;; KEEP-FOO-PRIMARY-NEXT:  )
+;; KEEP-FOO-PRIMARY-NEXT: )
+
+;; KEEP-FOO-SECONDARY:      (module
+;; KEEP-FOO-SECONDARY-NEXT:  (type $i32_=>_i32 (func (param i32) (result i32)))
+;; KEEP-FOO-SECONDARY-NEXT:  (import "primary" "%table" (table $timport$0 2 2 funcref))
+;; KEEP-FOO-SECONDARY-NEXT:  (elem (i32.const 1) $0)
+;; KEEP-FOO-SECONDARY-NEXT:  (import "primary" "%foo" (func $fimport$0 (param i32) (result i32)))
+;; KEEP-FOO-SECONDARY-NEXT:  (func $0 (param $0 i32) (result i32)
+;; KEEP-FOO-SECONDARY-NEXT:   (call $fimport$0
+;; KEEP-FOO-SECONDARY-NEXT:    (i32.const 1)
+;; KEEP-FOO-SECONDARY-NEXT:   )
+;; KEEP-FOO-SECONDARY-NEXT:  )
+;; KEEP-FOO-SECONDARY-NEXT: )
+
+;; KEEP-BAR: Keeping functions: bar{{$}}
+;; KEEP-BAR-NEXT: Splitting out functions: foo{{$}}
+
+;; KEEP-BAR-PRIMARY:      (module
+;; KEEP-BAR-PRIMARY-NEXT:  (type $i32_=>_i32 (func (param i32) (result i32)))
+;; KEEP-BAR-PRIMARY-NEXT:  (import "placeholder" "0" (func $fimport$0 (param i32) (result i32)))
+;; KEEP-BAR-PRIMARY-NEXT:  (table $0 1 1 funcref)
+;; KEEP-BAR-PRIMARY-NEXT:  (elem (i32.const 0) $fimport$0)
+;; KEEP-BAR-PRIMARY-NEXT:  (export "%bar" (func $0))
+;; KEEP-BAR-PRIMARY-NEXT:  (export "%table" (table $0))
+;; KEEP-BAR-PRIMARY-NEXT:  (func $0 (param $0 i32) (result i32)
+;; KEEP-BAR-PRIMARY-NEXT:   (call_indirect (type $i32_=>_i32)
+;; KEEP-BAR-PRIMARY-NEXT:    (i32.const 1)
+;; KEEP-BAR-PRIMARY-NEXT:    (i32.const 0)
+;; KEEP-BAR-PRIMARY-NEXT:   )
+;; KEEP-BAR-PRIMARY-NEXT:  )
+;; KEEP-BAR-PRIMARY-NEXT: )
+
+;; KEEP-BAR-SECONDARY:      (module
+;; KEEP-BAR-SECONDARY-NEXT:  (type $i32_=>_i32 (func (param i32) (result i32)))
+;; KEEP-BAR-SECONDARY-NEXT:  (import "primary" "%table" (table $timport$0 1 1 funcref))
+;; KEEP-BAR-SECONDARY-NEXT:  (elem (i32.const 0) $0)
+;; KEEP-BAR-SECONDARY-NEXT:  (import "primary" "%bar" (func $fimport$0 (param i32) (result i32)))
+;; KEEP-BAR-SECONDARY-NEXT:  (func $0 (param $0 i32) (result i32)
+;; KEEP-BAR-SECONDARY-NEXT:   (call $fimport$0
+;; KEEP-BAR-SECONDARY-NEXT:    (i32.const 0)
+;; KEEP-BAR-SECONDARY-NEXT:   )
+;; KEEP-BAR-SECONDARY-NEXT:  )
+;; KEEP-BAR-SECONDARY-NEXT: )
+
+;; KEEP-BOTH: warning: not splitting any functions out to the secondary module
+;; KEEP-BOTH-NEXT: Keeping functions: bar, foo{{$}}
+;; KEEP-BOTH-NEXT: Splitting out functions:{{$}}
+
+;; KEEP-BOTH-PRIMARY:      (module
+;; KEEP-BOTH-PRIMARY-NEXT:  (type $i32_=>_i32 (func (param i32) (result i32)))
+;; KEEP-BOTH-PRIMARY-NEXT:  (table $0 1 1 funcref)
+;; KEEP-BOTH-PRIMARY-NEXT:  (elem (i32.const 0) $0)
+;; KEEP-BOTH-PRIMARY-NEXT:  (export "%table" (table $0))
+;; KEEP-BOTH-PRIMARY-NEXT:  (func $0 (param $0 i32) (result i32)
+;; KEEP-BOTH-PRIMARY-NEXT:   (call $1
+;; KEEP-BOTH-PRIMARY-NEXT:    (i32.const 0)
+;; KEEP-BOTH-PRIMARY-NEXT:   )
+;; KEEP-BOTH-PRIMARY-NEXT:  )
+;; KEEP-BOTH-PRIMARY-NEXT:  (func $1 (param $0 i32) (result i32)
+;; KEEP-BOTH-PRIMARY-NEXT:   (call $0
+;; KEEP-BOTH-PRIMARY-NEXT:    (i32.const 1)
+;; KEEP-BOTH-PRIMARY-NEXT:   )
+;; KEEP-BOTH-PRIMARY-NEXT:  )
+;; KEEP-BOTH-PRIMARY-NEXT: )
+
+;; KEEP-BOTH-SECONDARY:      (module
+;; KEEP-BOTH-SECONDARY-NEXT:  (import "primary" "%table" (table $timport$0 1 1 funcref))
+;; KEEP-BOTH-SECONDARY-NEXT: )
diff --git a/test/lit/wasm-split/invalid-options.wast b/test/lit/wasm-split/invalid-options.wast
new file mode 100644
index 000000000..f4ef5b6b8
--- /dev/null
+++ b/test/lit/wasm-split/invalid-options.wast
@@ -0,0 +1,64 @@
+;; Test that invalid command line option combinations are properly rejected with
+;; helpful error messages.
+
+;; --instrument cannot be used with --profile
+;; RUN: not wasm-split %s --instrument --profile %t 2>&1 \
+;; RUN:   | filecheck %s --check-prefix INSTRUMENT-PROFILE
+
+;; --instrument cannot be used with -o1
+;; RUN: not wasm-split %s --instrument -o1 %t 2>&1 \
+;; RUN:   | filecheck %s --check-prefix INSTRUMENT-OUT1
+
+;; --instrument cannot be used with -o2
+;; RUN: not wasm-split %s --instrument -o2 %t 2>&1 \
+;; RUN:   | filecheck %s --check-prefix INSTRUMENT-OUT2
+
+;; --instrument cannot be used with --import-namespace
+;; RUN: not wasm-split %s --instrument --import-namespace=foo 2>&1 \
+;; RUN:   | filecheck %s --check-prefix INSTRUMENT-IMPORT-NS
+
+;; --instrument cannot be used with --placeholder-namespace
+;; RUN: not wasm-split %s --instrument --placeholder-namespace=foo 2>&1 \
+;; RUN:   | filecheck %s --check-prefix INSTRUMENT-PLACEHOLDER-NS
+
+;; --instrument cannot be used with --export-prefix
+;; RUN: not wasm-split %s --instrument --export-prefix=foo 2>&1 \
+;; RUN:   | filecheck %s --check-prefix INSTRUMENT-EXPORT-PREFIX
+
+;; --instrument cannot be used with --keep-funcs
+;; RUN: not wasm-split %s --instrument --keep-funcs=foo 2>&1 \
+;; RUN:   | filecheck %s --check-prefix INSTRUMENT-KEEP-FUNCS
+
+;; --instrument cannot be used with --split-funcs
+;; RUN: not wasm-split %s --instrument --split-funcs=foo 2>&1 \
+;; RUN:   | filecheck %s --check-prefix INSTRUMENT-SPLIT-FUNCS
+
+;; --instrument requires -o1 and -o2 rather than -o
+;; RUN: not wasm-split %s -o %t 2>&1 \
+;; RUN:   | filecheck %s --check-prefix NO-INSTRUMENT-OUT
+
+;; --instrument is required to use --profile-export
+;; RUN: not wasm-split %s --profile-export=foo 2>&1 \
+;; RUN:   | filecheck %s --check-prefix NO-INSTRUMENT-PROFILE-EXPORT
+
+;; INSTRUMENT-PROFILE: error: --profile cannot be used with --instrument
+
+;; INSTRUMENT-OUT1: error: primary output cannot be used with --instrument
+
+;; INSTRUMENT-OUT2: error: secondary output cannot be used with --instrument
+
+;; INSTRUMENT-IMPORT-NS: error: --import-namespace cannot be used with --instrument
+
+;; INSTRUMENT-PLACEHOLDER-NS: error: --placeholder-namespace cannot be used with --instrument
+
+;; INSTRUMENT-EXPORT-PREFIX: error: --export-prefix cannot be used with --instrument
+
+;; INSTRUMENT-KEEP-FUNCS: error: --keep-funcs cannot be used with --instrument
+
+;; INSTRUMENT-SPLIT-FUNCS: error: --split-funcs cannot be used with --instrument
+
+;; NO-INSTRUMENT-OUT: error: must provide separate primary and secondary output with -o1 and -o2
+
+;; NO-INSTRUMENT-PROFILE-EXPORT: error: --profile-export must be used with --instrument
+
+(module)
diff --git a/test/lit/wasm-split/verbose.wast b/test/lit/wasm-split/verbose.wast
new file mode 100644
index 000000000..cdedbfae6
--- /dev/null
+++ b/test/lit/wasm-split/verbose.wast
@@ -0,0 +1,14 @@
+;; Test that --verbose mode correctly prints the kept and split funcs
+
+;; RUN: wasm-split %s --keep-funcs=foo,bar --split-funcs=baz --verbose \
+;; RUN:   -o1 %t1.wasm -o2 %t2.wasm | filecheck %s
+
+;; CHECK: Keeping functions: bar, foo{{$}}
+;; CHECK: Splitting out functions: baz, quux{{$}}
+
+(module
+  (func $foo)
+  (func $bar)
+  (func $baz)
+  (func $quux)
+)