Allow multiple asm! options groups and report an error on duplicate options

src/librustc_builtin_macros/asm.rs

@@ -16,7 +16,7 @@ struct AsmArgs {
     named_args: FxHashMap<Symbol, usize>,
     reg_args: FxHashSet<usize>,
     options: ast::InlineAsmOptions,
-    options_span: Option<Span>,
+    options_spans: Vec<Span>,
 }
 
 fn parse_args<'a>(
@@ -59,7 +59,7 @@ fn parse_args<'a>(
         named_args: FxHashMap::default(),
         reg_args: FxHashSet::default(),
         options: ast::InlineAsmOptions::empty(),
-        options_span: None,
+        options_spans: vec![],
     };
 
     let mut allow_templates = true;
@@ -174,9 +174,9 @@ fn parse_args<'a>(
 
         // Validate the order of named, positional & explicit register operands and options. We do
         // this at the end once we have the full span of the argument available.
-        if let Some(options_span) = args.options_span {
+        if !args.options_spans.is_empty() {
             ecx.struct_span_err(span, "arguments are not allowed after options")
-                .span_label(options_span, "previous options")
+                .span_labels(args.options_spans.clone(), "previous options")
                 .span_label(span, "argument")
                 .emit();
         }
@@ -227,23 +227,23 @@ fn parse_args<'a>(
     if args.options.contains(ast::InlineAsmOptions::NOMEM)
         && args.options.contains(ast::InlineAsmOptions::READONLY)
     {
-        let span = args.options_span.unwrap();
-        ecx.struct_span_err(span, "the `nomem` and `readonly` options are mutually exclusive")
+        let spans = args.options_spans.clone();
+        ecx.struct_span_err(spans, "the `nomem` and `readonly` options are mutually exclusive")
             .emit();
     }
     if args.options.contains(ast::InlineAsmOptions::PURE)
         && args.options.contains(ast::InlineAsmOptions::NORETURN)
     {
-        let span = args.options_span.unwrap();
-        ecx.struct_span_err(span, "the `pure` and `noreturn` options are mutually exclusive")
+        let spans = args.options_spans.clone();
+        ecx.struct_span_err(spans, "the `pure` and `noreturn` options are mutually exclusive")
             .emit();
     }
     if args.options.contains(ast::InlineAsmOptions::PURE)
         && !args.options.intersects(ast::InlineAsmOptions::NOMEM | ast::InlineAsmOptions::READONLY)
     {
-        let span = args.options_span.unwrap();
+        let spans = args.options_spans.clone();
         ecx.struct_span_err(
-            span,
+            spans,
             "the `pure` option must be combined with either `nomem` or `readonly`",
         )
         .emit();
@@ -267,7 +267,7 @@ fn parse_args<'a>(
     }
     if args.options.contains(ast::InlineAsmOptions::PURE) && !have_real_output {
         ecx.struct_span_err(
-            args.options_span.unwrap(),
+            args.options_spans.clone(),
             "asm with `pure` option must have at least one output",
         )
         .emit();
@@ -283,27 +283,71 @@ fn parse_args<'a>(
     Ok(args)
 }
 
+/// Report a duplicate option error.
+///
+/// This function must be called immediately after the option token is parsed.
+/// Otherwise, the suggestion will be incorrect.
+fn err_duplicate_option<'a>(p: &mut Parser<'a>, symbol: Symbol, span: Span) {
+    let mut err = p
+        .sess
+        .span_diagnostic
+        .struct_span_err(span, &format!("the `{}` option was already provided", symbol));
+    err.span_label(span, "this option was already provided");
+
+    // Tool-only output
+    let mut full_span = span;
+    if p.token.kind == token::Comma {
+        full_span = full_span.to(p.token.span);
+    }
+    err.tool_only_span_suggestion(
+        full_span,
+        "remove this option",
+        String::new(),
+        Applicability::MachineApplicable,
+    );
+
+    err.emit();
+}
+
+/// Try to set the provided option in the provided `AsmArgs`.
+/// If it is already set, report a duplicate option error.
+///
+/// This function must be called immediately after the option token is parsed.
+/// Otherwise, the error will not point to the correct spot.
+fn try_set_option<'a>(
+    p: &mut Parser<'a>,
+    args: &mut AsmArgs,
+    symbol: Symbol,
+    option: ast::InlineAsmOptions,
+) {
+    if !args.options.contains(option) {
+        args.options |= option;
+    } else {
+        err_duplicate_option(p, symbol, p.prev_token.span);
+    }
+}
+
 fn parse_options<'a>(p: &mut Parser<'a>, args: &mut AsmArgs) -> Result<(), DiagnosticBuilder<'a>> {
     let span_start = p.prev_token.span;
 
     p.expect(&token::OpenDelim(token::DelimToken::Paren))?;
 
     while !p.eat(&token::CloseDelim(token::DelimToken::Paren)) {
         if p.eat(&token::Ident(sym::pure, false)) {
-            args.options |= ast::InlineAsmOptions::PURE;
+            try_set_option(p, args, sym::pure, ast::InlineAsmOptions::PURE);
         } else if p.eat(&token::Ident(sym::nomem, false)) {
-            args.options |= ast::InlineAsmOptions::NOMEM;
+            try_set_option(p, args, sym::nomem, ast::InlineAsmOptions::NOMEM);
         } else if p.eat(&token::Ident(sym::readonly, false)) {
-            args.options |= ast::InlineAsmOptions::READONLY;
+            try_set_option(p, args, sym::readonly, ast::InlineAsmOptions::READONLY);
         } else if p.eat(&token::Ident(sym::preserves_flags, false)) {
-            args.options |= ast::InlineAsmOptions::PRESERVES_FLAGS;
+            try_set_option(p, args, sym::preserves_flags, ast::InlineAsmOptions::PRESERVES_FLAGS);
         } else if p.eat(&token::Ident(sym::noreturn, false)) {
-            args.options |= ast::InlineAsmOptions::NORETURN;
+            try_set_option(p, args, sym::noreturn, ast::InlineAsmOptions::NORETURN);
         } else if p.eat(&token::Ident(sym::nostack, false)) {
-            args.options |= ast::InlineAsmOptions::NOSTACK;
+            try_set_option(p, args, sym::nostack, ast::InlineAsmOptions::NOSTACK);
         } else {
             p.expect(&token::Ident(sym::att_syntax, false))?;
-            args.options |= ast::InlineAsmOptions::ATT_SYNTAX;
+            try_set_option(p, args, sym::att_syntax, ast::InlineAsmOptions::ATT_SYNTAX);
         }
 
         // Allow trailing commas
@@ -314,14 +358,7 @@ fn parse_options<'a>(p: &mut Parser<'a>, args: &mut AsmArgs) -> Result<(), Diagn
     }
 
     let new_span = span_start.to(p.prev_token.span);
-    if let Some(options_span) = args.options_span {
-        p.struct_span_err(new_span, "asm options cannot be specified multiple times")
-            .span_label(options_span, "previously here")
-            .span_label(new_span, "duplicate options")
-            .emit();
-    } else {
-        args.options_span = Some(new_span);
-    }
+    args.options_spans.push(new_span);
 
     Ok(())
 }

src/test/codegen/asm-multiple-options.rs

@@ -0,0 +1,53 @@
+// compile-flags: -O
+// only-x86_64
+
+#![crate_type = "rlib"]
+#![feature(asm)]
+
+// CHECK-LABEL: @pure
+// CHECK-NOT: asm
+// CHECK: ret void
+#[no_mangle]
+pub unsafe fn pure(x: i32) {
+    let y: i32;
+    asm!("", out("ax") y, in("bx") x, options(pure), options(nomem));
+}
+
+pub static mut VAR: i32 = 0;
+pub static mut DUMMY_OUTPUT: i32 = 0;
+
+// CHECK-LABEL: @readonly
+// CHECK: call i32 asm
+// CHECK: ret i32 1
+#[no_mangle]
+pub unsafe fn readonly() -> i32 {
+    VAR = 1;
+    asm!("", out("ax") DUMMY_OUTPUT, options(pure), options(readonly));
+    VAR
+}
+
+// CHECK-LABEL: @nomem
+// CHECK-NOT: store
+// CHECK: call i32 asm
+// CHECK: store
+// CHECK: ret i32 2
+#[no_mangle]
+pub unsafe fn nomem() -> i32 {
+    VAR = 1;
+    asm!("", out("ax") DUMMY_OUTPUT, options(pure), options(nomem));
+    VAR = 2;
+    VAR
+}
+
+// CHECK-LABEL: @not_nomem
+// CHECK: store
+// CHECK: call i32 asm
+// CHECK: store
+// CHECK: ret i32 2
+#[no_mangle]
+pub unsafe fn not_nomem() -> i32 {
+    VAR = 1;
+    asm!("", out("ax") DUMMY_OUTPUT, options(pure), options(readonly));
+    VAR = 2;
+    VAR
+}

src/test/ui/asm/duplicate-options.fixed

@@ -0,0 +1,26 @@
+// only-x86_64
+// run-rustfix
+
+#![feature(asm)]
+
+fn main() {
+    unsafe {
+        asm!("", options(nomem, ));
+        //~^ ERROR the `nomem` option was already provided
+        asm!("", options(att_syntax, ));
+        //~^ ERROR the `att_syntax` option was already provided
+        asm!("", options(nostack, att_syntax), options());
+        //~^ ERROR the `nostack` option was already provided
+        asm!("", options(nostack, ), options(), options());
+        //~^ ERROR the `nostack` option was already provided
+        //~| ERROR the `nostack` option was already provided
+        //~| ERROR the `nostack` option was already provided
+        asm!(
+            "",
+            options(nomem, noreturn),
+            options(att_syntax, ), //~ ERROR the `noreturn` option was already provided
+            options( nostack), //~ ERROR the `nomem` option was already provided
+            options(), //~ ERROR the `noreturn` option was already provided
+        );
+    }
+}

src/test/ui/asm/duplicate-options.rs

@@ -0,0 +1,26 @@
+// only-x86_64
+// run-rustfix
+
+#![feature(asm)]
+
+fn main() {
+    unsafe {
+        asm!("", options(nomem, nomem));
+        //~^ ERROR the `nomem` option was already provided
+        asm!("", options(att_syntax, att_syntax));
+        //~^ ERROR the `att_syntax` option was already provided
+        asm!("", options(nostack, att_syntax), options(nostack));
+        //~^ ERROR the `nostack` option was already provided
+        asm!("", options(nostack, nostack), options(nostack), options(nostack));
+        //~^ ERROR the `nostack` option was already provided
+        //~| ERROR the `nostack` option was already provided
+        //~| ERROR the `nostack` option was already provided
+        asm!(
+            "",
+            options(nomem, noreturn),
+            options(att_syntax, noreturn), //~ ERROR the `noreturn` option was already provided
+            options(nomem, nostack), //~ ERROR the `nomem` option was already provided
+            options(noreturn), //~ ERROR the `noreturn` option was already provided
+        );
+    }
+}

src/test/ui/asm/duplicate-options.stderr

@@ -0,0 +1,56 @@
+error: the `nomem` option was already provided
+  --> $DIR/duplicate-options.rs:8:33
+   |
+LL |         asm!("", options(nomem, nomem));
+   |                                 ^^^^^ this option was already provided
+
+error: the `att_syntax` option was already provided
+  --> $DIR/duplicate-options.rs:10:38
+   |
+LL |         asm!("", options(att_syntax, att_syntax));
+   |                                      ^^^^^^^^^^ this option was already provided
+
+error: the `nostack` option was already provided
+  --> $DIR/duplicate-options.rs:12:56
+   |
+LL |         asm!("", options(nostack, att_syntax), options(nostack));
+   |                                                        ^^^^^^^ this option was already provided
+
+error: the `nostack` option was already provided
+  --> $DIR/duplicate-options.rs:14:35
+   |
+LL |         asm!("", options(nostack, nostack), options(nostack), options(nostack));
+   |                                   ^^^^^^^ this option was already provided
+
+error: the `nostack` option was already provided
+  --> $DIR/duplicate-options.rs:14:53
+   |
+LL |         asm!("", options(nostack, nostack), options(nostack), options(nostack));
+   |                                                     ^^^^^^^ this option was already provided
+
+error: the `nostack` option was already provided
+  --> $DIR/duplicate-options.rs:14:71
+   |
+LL |         asm!("", options(nostack, nostack), options(nostack), options(nostack));
+   |                                                                       ^^^^^^^ this option was already provided
+
+error: the `noreturn` option was already provided
+  --> $DIR/duplicate-options.rs:21:33
+   |
+LL |             options(att_syntax, noreturn),
+   |                                 ^^^^^^^^ this option was already provided
+
+error: the `nomem` option was already provided
+  --> $DIR/duplicate-options.rs:22:21
+   |
+LL |             options(nomem, nostack),
+   |                     ^^^^^ this option was already provided
+
+error: the `noreturn` option was already provided
+  --> $DIR/duplicate-options.rs:23:21
+   |
+LL |             options(noreturn),
+   |                     ^^^^^^^^ this option was already provided
+
+error: aborting due to 9 previous errors
+

src/test/ui/asm/parse-error.rs

@@ -34,11 +34,6 @@ fn main() {
         //~^ ERROR expected one of
         asm!("", options(nomem, foo));
         //~^ ERROR expected one of
-        asm!("", options(), options());
-        //~^ ERROR asm options cannot be specified multiple times
-        asm!("", options(), options(), options());
-        //~^ ERROR asm options cannot be specified multiple times
-        //~^^ ERROR asm options cannot be specified multiple times
         asm!("{}", options(), const foo);
         //~^ ERROR arguments are not allowed after options
         asm!("{a}", a = const foo, a = const bar);