implement --print=all-target-specs-json

compiler/rustc_driver_impl/src/lib.rs

@@ -44,8 +44,10 @@ use rustc_session::{early_error, early_error_no_abort, early_warn};
 use rustc_span::source_map::{FileLoader, FileName};
 use rustc_span::symbol::sym;
 use rustc_target::json::ToJson;
+use rustc_target::spec::{Target, TargetTriple};
 
 use std::cmp::max;
+use std::collections::BTreeMap;
 use std::env;
 use std::ffi::OsString;
 use std::fs;
@@ -648,6 +650,15 @@ fn print_crate_info(
             TargetSpec => {
                 println!("{}", serde_json::to_string_pretty(&sess.target.to_json()).unwrap());
             }
+            AllTargetSpecs => {
+                let mut targets = BTreeMap::new();
+                for name in rustc_target::spec::TARGETS {
+                    let triple = TargetTriple::from_triple(name);
+                    let target = Target::expect_builtin(&triple);
+                    targets.insert(name, target.to_json());
+                }
+                println!("{}", serde_json::to_string_pretty(&targets).unwrap());
+            }
             FileNames | CrateName => {
                 let Some(attrs) = attrs.as_ref() else {
                     // no crate attributes, print out an error and exit

compiler/rustc_session/src/config.rs

@@ -580,6 +580,7 @@ pub enum PrintRequest {
     CodeModels,
     TlsModels,
     TargetSpec,
+    AllTargetSpecs,
     NativeStaticLibs,
     StackProtectorStrategies,
     LinkArgs,
@@ -1439,8 +1440,8 @@ pub fn rustc_short_optgroups() -> Vec<RustcOptGroup> {
             "Compiler information to print on stdout",
             "[crate-name|file-names|sysroot|target-libdir|cfg|calling-conventions|\
              target-list|target-cpus|target-features|relocation-models|code-models|\
-             tls-models|target-spec-json|native-static-libs|stack-protector-strategies|\
+             tls-models|target-spec-json|all-target-specs-json|native-static-libs|\
-             link-args]",
+             stack-protector-strategies|link-args]",
         ),
         opt::flagmulti_s("g", "", "Equivalent to -C debuginfo=2"),
         opt::flagmulti_s("O", "", "Equivalent to -C opt-level=2"),
@@ -1887,6 +1888,7 @@ fn collect_print_requests(
         ("native-static-libs", PrintRequest::NativeStaticLibs),
         ("stack-protector-strategies", PrintRequest::StackProtectorStrategies),
         ("target-spec-json", PrintRequest::TargetSpec),
+        ("all-target-specs-json", PrintRequest::AllTargetSpecs),
         ("link-args", PrintRequest::LinkArgs),
         ("split-debuginfo", PrintRequest::SplitDebuginfo),
     ];
@@ -1904,6 +1906,17 @@ fn collect_print_requests(
                     );
                 }
             }
+            Some((_, PrintRequest::AllTargetSpecs)) => {
+                if unstable_opts.unstable_options {
+                    PrintRequest::AllTargetSpecs
+                } else {
+                    early_error(
+                        error_format,
+                        "the `-Z unstable-options` flag must also be passed to \
+                         enable the all-target-specs-json print option",
+                    );
+                }
+            }
             Some(&(_, print_request)) => print_request,
             None => {
                 let prints =

tests/run-make/valid-print-requests/valid-print-requests.stderr

@@ -1,2 +1,2 @@
-error: unknown print request `uwu`. Valid print requests are: `crate-name`, `file-names`, `sysroot`, `target-libdir`, `cfg`, `calling-conventions`, `target-list`, `target-cpus`, `target-features`, `relocation-models`, `code-models`, `tls-models`, `native-static-libs`, `stack-protector-strategies`, `target-spec-json`, `link-args`, `split-debuginfo`
+error: unknown print request `uwu`. Valid print requests are: `crate-name`, `file-names`, `sysroot`, `target-libdir`, `cfg`, `calling-conventions`, `target-list`, `target-cpus`, `target-features`, `relocation-models`, `code-models`, `tls-models`, `native-static-libs`, `stack-protector-strategies`, `target-spec-json`, `all-target-specs-json`, `link-args`, `split-debuginfo`