Every Option and Flag /swift (1.2) Accepts Ever

alltheflags.md

#Every Single Option Under The Sun

• optimization level options
• automatic crashing options
• debug info options
• swift internal options
• swift debug/development internal options
• linker-specific options
• mode options

Flag	Description
Xcc	Pass to the C/C++/Objective-C compiler
Xfrontend	Pass to the Swift frontend
Xlinker	Specifies an option which should be passed to the linker
Xllvm	Pass to LLVM.
application-extension	Restrict code to those available for App Extensions
assert-config	Specify the assert_configuration replacement. Possible values are Debug, Release, Replacement.
autolink-force-load	Force ld to link against this module even if no symbols are used
color-diagnostics	Print diagnostics in color
debug-assert-after	Force an assertion failure after parsing
debug-assert-immediately	Force an assertion failure immediately
debug-constraints-attempt	Debug the constraint solver at a given attempt
debug-constraints	Debug the constraint-based type checker
debug-crash-after	Force a crash after parsing
debug-crash-immediately	Force a crash immediately
debug-forbid-typecheck	Triggers llvm fatal_error if typechecker tries to typecheck a decl with the provided prefix name
debug-generic-signatures	Debug generic signatures
debug-time-function	Dumps the time it takes to type-check each function body
debugger-support	Process swift code as if running in the debugger
delayed-function-body	Delay function body parsing until the end of all files
deprecated-integrated-repl
disable-access-control	Don't respect access control restrictions
disable-arc-opts	Don't run SIL ARC optimization passes.
disable-diagnostic-passes	Don't run diagnostic passes
disable-func-sig	Disable function signature optimizations
disable-llvm-arc	Don't run LLVM ARC optimization passes.
disable-llvm-optzns	Don't run LLVM optimization passes
disable-llvm-slp	Don't run LLVM SLP vectorizer
disable-llvm-verify	Don't run the LLVM IR verifier.
disable-objc-attr	Disable requiring uses of @objc to require importing the Foundation module
disable-objc-interop	Disable Objective-C interop code generation and config directives
disable-playground-transform	Disable playground transformation
disable-sil-linking	Don't link SIL functions
disable-target-os	Disable checking the target OS of serialized modules
driver-mode=	Set the driver mode to either 'swift' or 'swiftc' or 'swift-update'
driver-print-actions	Dump list of actions to perform
driver-print-bindings	Dump list of bindings
driver-print-jobs	Dump list of jobs to execute
driver-print-output	Dump the contents of the output file map
driver-skip-execution	Skip execution of subtasks when performing compilation
driver-use-frontend	Use the given executable to perform compilations
dump-ast	Parse and type-check input file(s) and dump AST(s)
dump-clang-diagnostics	Dump Clang diagnostics to stderr
dump-parse	Parse input file(s) and dump AST(s)
D	Specifies one or more build configuration options
emit-assembly	Emit assembly file(s) (-S)
emit-bc	Emit LLVM BC file(s)
emit-dependencies-path	Output basic Make-compatible dependencies file to
emit-dependencies	Emit basic Make-compatible dependencies files
emit-executable	Emit a linked executable
emit-ir	Emit LLVM IR file(s)
emit-library	Emit a linked library
emit-module-doc	Output module documentation file
emit-module-doc	Emit a module documentation file based on documentation comments
emit-module-path	emit-module-path
emit-module	Emit an importable module
emit-objc-header-path	Emit an Objective-C header file to <path>
emit-objc-header	Emit an Objective-C header file
emit-object	Emit object file(s) (-c)
emit-reference-dependencies	Output Swift-style dependencies file to
emit-reference-dependencies	Emit a Swift-style dependencies file
emit-silgen	Emit raw SIL file(s)
emit-sil	Emit canonical SIL file(s)
emit-sorted-sil	When printing SIL, print out all sil entities sorted by name to ease diffing
emit-verbose-sil	Emit locations during SIL emission
enable-access-control	Respect access control restrictions
enable-character-literals	Enable legacy character literals
enable-dynamic-value	Enable experimental dynamic generic struct/enum/class type layout
enable-experimental-availability	Enable experimental checking for API availability
enable-experimental-patterns	Enable experimental 'switch' pattern matching features
enable-experimental-unavailable	Enable experimental treat unavailable symbols as optional
enable-guaranteed-self	Enable the passing of self as a guaranteed parameter
enable-objc-attr	Enable requiring uses of @objc to require importing the Foundation module
enable-objc-implicit	Import Objective-C "implicit properties" as properties
enable-objc-interop	Enable Objective-C interop code generation and config directives
enable-private-discriminators	Mangle discriminators into the symbol names for private entities
enable-source-import	Enable importing of Swift source files
enable-target-os	Enable checking the target OS of serialized modules
enable-union-import	Import C unions
external-pass-pipeline	Use the pass pipeline defined by <pass_pipeline_file>
force-single-frontend	framework
F=	Specifies a framework which should be linked against
F	Add directory to framework search path
gline-tables-only	Emit minimal debug info for backtraces only
gnone	Don't emit debug info
g	Emit debug info
help-hidden	Display available options, including hidden options
help	Display available options
import-cf-types	Recognize and import CF types as class types
import-module	Implicitly import the specified module
import-objc-header	Implicitly imports an Objective-C header file
import-underlying-module	Implicitly imports the Objective-C half of a module
incremental	Perform an incremental build if possible
interpret	Immediate mode
I	Add directory to the import search path
j	Number of commands to execute in parallel
link-objc-runtime	Link in additions to the Objective-C runtime
lldb-repl	LLDB-enhanced REPL mode
L=	Add directory to library link search path
L	Specifies a library which should be linked against
module-cache-path	Specifies the Clang module cache path
module-link-name=	Library to link against when using this module
module-name=	Name of the module to build
no-link-objc	Don't link in additions to the Objective-C runtime
nostdimport	Don't search the standard library import path for modules
Onone	Compile without any optimization
Ounchecked	Compile with optimizations and remove runtime safety checks
output-file-map	A file which specifies the location of outputs
O	Compile with optimizations
o	Write output to
parse-as-library	Parse the input file(s) as libraries, not scripts
parse-sil	Parse the input file as SIL code, not Swift source
parse-stdlib	Parse the input file(s) as the Swift standard library
parseable-output	Emit textual output in a parseable format
parse	Parse input file(s)
playground	Apply the playground semantics and transformation
primary-file	Produce output for this file, not the whole module
print-ast	Parse and type-check input file(s) and pretty print AST(s)
print-clang-stats	Print Clang importer statistics
print-inst-counts	Before IRGen, count all the various SIL instructions. Must be used in conjunction with -print-stats.
print-stats	Print various statistics
remove-runtime-asserts	Remove runtime asserts.
repl	REPL mode (the default if there is no input file)
resource-dir	The directory that holds the compiler resource files </usr/lib/swift>
save-temps	Save intermediate compilation results
sdk	Compile against
serialize-debugging-options	Always serialize options for debugging (default: only for apps)
serialize-diagnostics-path	Output serialized diagnostics to
serialize-diagnostics	Serialize diagnostics in a binary format
show-diagnostics-after	Keep emitting subsequent diagnostics after a fatal error
sil-debug-serialization	Do not eliminate functions in Mandatory Inlining/SILCombine dead functions. (for debugging only)
sil-devirt-threshold	Controls the aggressiveness of devirtualization
sil-inline-threshold	Controls the aggressiveness of performance inlining
sil-link-all	Link all SIL functions
sil-opt-pass	Stop optimizing after optimization passes
sil-print-all	Print SIL after each transform
sil-print-pass	Print SIL pass name before each transform
sil-serialize-all	Serialize all generated SIL
sil-time-transforms	Time each SIL transform invocation
sil-verify-all	Verify SIL after each transform
solver-memory-threshold	Set the upper bound for memory consumption, in bytes, by the constraint solver
split-objc-selectors	Split imported Objective-C selectors based on prepositions
target-cpu	Generate code for a particular CPU variant
target=<target triple>	Generate code for the given target
typecheck	Parse and typecheck Swift code
update-code	Update Swift code
use-jit	Register Objective-C classes as if the JIT were in use
use-malloc	Allocate internal data structures using malloc (for memory debugging)
verify-type-layout	Verify compile-time and runtime type layout information for type
verify	Verify diagnostics against expected-{error
version	Print version information and exit
v	Show commands to run and use verbose output
whole-module-optimization	Optimize input files together instead of individually

I wonder how to you generate this from a .td file? refer to https://github.com/apple/swift/blob/master/include/swift/Option/Options.td, this page looks a lot easier to read.

The original was generated by stringsing the Swift binary - this was back when it was all closed-source - and with some sed magic I have long since forgotten.

the swift -help command doesn't show even by far all the list of options. I can name a few that are not even in this list that I have seen. I don't know what they are doing though:
index-system-modules
index-store-path
embed-bitcode-marker
report-errors-to-debugger
enforce-exclusivity=checked
-swift-version 4

@radsimu that is mostly because the flags above are from multiple layers of the build process. some are for swift/swiftc. whilst others are for the drivers, SIL, AST, LVVM IR, etc.