[wasm-split] Make option validation declarative (#3916)

In anticipation of adding a third wasm-split mode, merge-profiles, in addition
to the existing split and instrument modes, refactor wasm-split's option
validation to let the valid modes be declared for each option. This approach is
more scalable and robust than the ad-hoc validation we had previously.

2 files changed, 81 insertions, 13 deletions

diff --git a/test/lit/wasm-split/help.test b/test/lit/wasm-split/help.test
new file mode 100644
index 000000000..c473b28a1
--- /dev/null
+++ b/test/lit/wasm-split/help.test
@@ -0,0 +1,68 @@
+;; RUN: wasm-split --help | filecheck %s
+
+CHECK:      wasm-split INFILE
+CHECK-NEXT:
+CHECK-NEXT: Split a module into a primary module and a secondary module, or instrument a
+CHECK-NEXT: module to gather a profile that can inform future splitting, or manage such
+CHECK-NEXT: profiles. Options that are only accepted in particular modes are marked with the
+CHECK-NEXT: accepted "[<modes>]" in their descriptions.
+CHECK-NEXT:
+CHECK-NEXT: Options:
+
+;; Skip standard tool options
+
+CHECK:        --split                              Split an input module into two output
+CHECK-NEXT:                                        modules. The default mode.
+CHECK-NEXT:   --instrument                         Instrument an input module to allow it to
+CHECK-NEXT:                                        generate a profile that can be used to
+CHECK-NEXT:                                        guide splitting.
+CHECK-NEXT:   --profile                            [split] The profile to use to guide
+CHECK-NEXT:                                        splitting.
+CHECK-NEXT:   --keep-funcs                         [split] Comma-separated list of functions
+CHECK-NEXT:                                        to keep in the primary module, regardless
+CHECK-NEXT:                                        of any profile.
+CHECK-NEXT:   --split-funcs                        [split] Comma-separated list of functions
+CHECK-NEXT:                                        to split into the secondary module,
+CHECK-NEXT:                                        regardless of any profile. If there is no
+CHECK-NEXT:                                        profile, then this defaults to all
+CHECK-NEXT:                                        functions defined in the module.
+CHECK-NEXT:   --primary-output,-o1                 [split] Output file for the primary
+CHECK-NEXT:                                        module.
+CHECK-NEXT:   --secondary-output,-o2               [split] Output file for the secondary
+CHECK-NEXT:                                        module.
+CHECK-NEXT:   --symbolmap                          [split] Write a symbol map file for each
+CHECK-NEXT:                                        of the output modules.
+CHECK-NEXT:   --import-namespace                   [split] The namespace from which to
+CHECK-NEXT:                                        import objects from the primary module
+CHECK-NEXT:                                        into the secondary module.
+CHECK-NEXT:   --placeholder-namespace              [split] The namespace from which to
+CHECK-NEXT:                                        import placeholder functions into the
+CHECK-NEXT:                                        primary module.
+CHECK-NEXT:   --export-prefix                      [split] An identifying prefix to prepend
+CHECK-NEXT:                                        to new export names created by module
+CHECK-NEXT:                                        splitting.
+CHECK-NEXT:   --output,-o                          [instrument] Output file.
+CHECK-NEXT:   --profile-export                     [instrument] The export name of the
+CHECK-NEXT:                                        function the embedder calls to write the
+CHECK-NEXT:                                        profile into memory. Defaults to
+CHECK-NEXT:                                        `__write_profile`.
+CHECK-NEXT:   --emit-module-names                  [split, instrument] Emit module names,
+CHECK-NEXT:                                        even if not emitting the rest of the
+CHECK-NEXT:                                        names section. Can help differentiate the
+CHECK-NEXT:                                        modules in stack traces. This option will
+CHECK-NEXT:                                        be removed once simpler ways of naming
+CHECK-NEXT:                                        modules are widely available. See
+CHECK-NEXT:                                        https://bugs.chromium.org/p/v8/issues/detail?id=11808.
+CHECK-NEXT:   --initial-table                      [split, instrument] A hack to ensure the
+CHECK-NEXT:                                        split and instrumented modules have the
+CHECK-NEXT:                                        same table size when using Emscripten's
+CHECK-NEXT:                                        SPLIT_MODULE mode with dynamic linking.
+CHECK-NEXT:                                        TODO: Figure out a more elegant solution
+CHECK-NEXT:                                        for that use case and remove this.
+CHECK-NEXT:   --verbose,-v                         Verbose output mode. Prints the functions
+CHECK-NEXT:                                        that will be kept and split out when
+CHECK-NEXT:                                        splitting a module.
+CHECK-NEXT:   --emit-text,-S                       Emit text instead of binary for the
+CHECK-NEXT:                                        output file or files.
+CHECK-NEXT:   --debuginfo,-g                       Emit names section in wasm binary (or
+CHECK-NEXT:                                        full debuginfo in wast)
diff --git a/test/lit/wasm-split/invalid-options.wast b/test/lit/wasm-split/invalid-options.wast
index 32899b87b..89a68e6aa 100644
--- a/test/lit/wasm-split/invalid-options.wast
+++ b/test/lit/wasm-split/invalid-options.wast
@@ -39,32 +39,32 @@
 
 ;; Split mode requires -o1 and -o2 rather than -o
 ;; RUN: not wasm-split %s -o %t 2>&1 \
-;; RUN:   | filecheck %s --check-prefix NO-INSTRUMENT-OUT
+;; RUN:   | filecheck %s --check-prefix SPLIT-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
+;; RUN:   | filecheck %s --check-prefix SPLIT-PROFILE-EXPORT
 
-;; INSTRUMENT-PROFILE: error: --profile cannot be used with --instrument
+;; INSTRUMENT-PROFILE: error: Option --profile cannot be used in instrument mode.
 
-;; INSTRUMENT-OUT1: error: primary output cannot be used with --instrument
+;; INSTRUMENT-OUT1: error: Option --primary-output cannot be used in instrument mode.
 
-;; INSTRUMENT-OUT2: error: secondary output cannot be used with --instrument
+;; INSTRUMENT-OUT2: error: Option --secondary-output cannot be used in instrument mode.
 
-;; INSTRUMENT-SYMBOLMAP: error: --symbolmap cannot be used with --instrument
+;; INSTRUMENT-SYMBOLMAP: error: Option --symbolmap cannot be used in instrument mode.
 
-;; INSTRUMENT-IMPORT-NS: error: --import-namespace cannot be used with --instrument
+;; INSTRUMENT-IMPORT-NS: error: Option --import-namespace cannot be used in instrument mode.
 
-;; INSTRUMENT-PLACEHOLDER-NS: error: --placeholder-namespace cannot be used with --instrument
+;; INSTRUMENT-PLACEHOLDER-NS: error: Option --placeholder-namespace cannot be used in instrument mode.
 
-;; INSTRUMENT-EXPORT-PREFIX: error: --export-prefix cannot be used with --instrument
+;; INSTRUMENT-EXPORT-PREFIX: error: Option --export-prefix cannot be used in instrument mode.
 
-;; INSTRUMENT-KEEP-FUNCS: error: --keep-funcs cannot be used with --instrument
+;; INSTRUMENT-KEEP-FUNCS: error: Option --keep-funcs cannot be used in instrument mode.
 
-;; INSTRUMENT-SPLIT-FUNCS: error: --split-funcs cannot be used with --instrument
+;; INSTRUMENT-SPLIT-FUNCS: error: Option --split-funcs cannot be used in instrument mode.
 
-;; NO-INSTRUMENT-OUT: error: must provide separate primary and secondary output with -o1 and -o2
+;; SPLIT-OUT: error: Option --output cannot be used in split mode.
 
-;; NO-INSTRUMENT-PROFILE-EXPORT: error: --profile-export must be used with --instrument
+;; SPLIT-PROFILE-EXPORT: error: Option --profile-export cannot be used in split mode.
 
 (module)