Auto merge of #78684 - devsnek:inline-asm-wasm, r=Amanieu

Add wasm32 support to inline asm

There is some contention around inline asm and wasm, and I really only made this to figure out the process of hacking on rustc, but I figured as long as the code existed, it was worth uploading.

cc `@Amanieu`

compiler/rustc_target/src/asm/mod.rs

@@ -156,6 +156,7 @@ mod mips;
 mod nvptx;
 mod riscv;
 mod spirv;
+mod wasm;
 mod x86;
 
 pub use aarch64::{AArch64InlineAsmReg, AArch64InlineAsmRegClass};
@@ -165,6 +166,7 @@ pub use mips::{MipsInlineAsmReg, MipsInlineAsmRegClass};
 pub use nvptx::{NvptxInlineAsmReg, NvptxInlineAsmRegClass};
 pub use riscv::{RiscVInlineAsmReg, RiscVInlineAsmRegClass};
 pub use spirv::{SpirVInlineAsmReg, SpirVInlineAsmRegClass};
+pub use wasm::{WasmInlineAsmReg, WasmInlineAsmRegClass};
 pub use x86::{X86InlineAsmReg, X86InlineAsmRegClass};
 
 #[derive(Copy, Clone, Encodable, Decodable, Debug, Eq, PartialEq, Hash)]
@@ -180,6 +182,7 @@ pub enum InlineAsmArch {
     Mips,
     Mips64,
     SpirV,
+    Wasm32,
 }
 
 impl FromStr for InlineAsmArch {
@@ -198,6 +201,7 @@ impl FromStr for InlineAsmArch {
             "mips" => Ok(Self::Mips),
             "mips64" => Ok(Self::Mips64),
             "spirv" => Ok(Self::SpirV),
+            "wasm32" => Ok(Self::Wasm32),
             _ => Err(()),
         }
     }
@@ -213,6 +217,7 @@ pub enum InlineAsmReg {
     Hexagon(HexagonInlineAsmReg),
     Mips(MipsInlineAsmReg),
     SpirV(SpirVInlineAsmReg),
+    Wasm(WasmInlineAsmReg),
 }
 
 impl InlineAsmReg {
@@ -272,6 +277,9 @@ impl InlineAsmReg {
             InlineAsmArch::SpirV => {
                 Self::SpirV(SpirVInlineAsmReg::parse(arch, has_feature, target, &name)?)
             }
+            InlineAsmArch::Wasm32 => {
+                Self::Wasm(WasmInlineAsmReg::parse(arch, has_feature, target, &name)?)
+            }
         })
     }
 
@@ -315,6 +323,7 @@ pub enum InlineAsmRegClass {
     Hexagon(HexagonInlineAsmRegClass),
     Mips(MipsInlineAsmRegClass),
     SpirV(SpirVInlineAsmRegClass),
+    Wasm(WasmInlineAsmRegClass),
 }
 
 impl InlineAsmRegClass {
@@ -328,6 +337,7 @@ impl InlineAsmRegClass {
             Self::Hexagon(r) => r.name(),
             Self::Mips(r) => r.name(),
             Self::SpirV(r) => r.name(),
+            Self::Wasm(r) => r.name(),
         }
     }
 
@@ -344,6 +354,7 @@ impl InlineAsmRegClass {
             Self::Hexagon(r) => r.suggest_class(arch, ty).map(InlineAsmRegClass::Hexagon),
             Self::Mips(r) => r.suggest_class(arch, ty).map(InlineAsmRegClass::Mips),
             Self::SpirV(r) => r.suggest_class(arch, ty).map(InlineAsmRegClass::SpirV),
+            Self::Wasm(r) => r.suggest_class(arch, ty).map(InlineAsmRegClass::Wasm),
         }
     }
 
@@ -367,6 +378,7 @@ impl InlineAsmRegClass {
             Self::Hexagon(r) => r.suggest_modifier(arch, ty),
             Self::Mips(r) => r.suggest_modifier(arch, ty),
             Self::SpirV(r) => r.suggest_modifier(arch, ty),
+            Self::Wasm(r) => r.suggest_modifier(arch, ty),
         }
     }
 
@@ -386,6 +398,7 @@ impl InlineAsmRegClass {
             Self::Hexagon(r) => r.default_modifier(arch),
             Self::Mips(r) => r.default_modifier(arch),
             Self::SpirV(r) => r.default_modifier(arch),
+            Self::Wasm(r) => r.default_modifier(arch),
         }
     }
 
@@ -404,6 +417,7 @@ impl InlineAsmRegClass {
             Self::Hexagon(r) => r.supported_types(arch),
             Self::Mips(r) => r.supported_types(arch),
             Self::SpirV(r) => r.supported_types(arch),
+            Self::Wasm(r) => r.supported_types(arch),
         }
     }
 
@@ -429,6 +443,7 @@ impl InlineAsmRegClass {
                     Self::Mips(MipsInlineAsmRegClass::parse(arch, name)?)
                 }
                 InlineAsmArch::SpirV => Self::SpirV(SpirVInlineAsmRegClass::parse(arch, name)?),
+                InlineAsmArch::Wasm32 => Self::Wasm(WasmInlineAsmRegClass::parse(arch, name)?),
             })
         })
     }
@@ -445,6 +460,7 @@ impl InlineAsmRegClass {
             Self::Hexagon(r) => r.valid_modifiers(arch),
             Self::Mips(r) => r.valid_modifiers(arch),
             Self::SpirV(r) => r.valid_modifiers(arch),
+            Self::Wasm(r) => r.valid_modifiers(arch),
         }
     }
 }
@@ -592,5 +608,10 @@ pub fn allocatable_registers(
             spirv::fill_reg_map(arch, has_feature, target, &mut map);
             map
         }
+        InlineAsmArch::Wasm32 => {
+            let mut map = wasm::regclass_map();
+            wasm::fill_reg_map(arch, has_feature, target, &mut map);
+            map
+        }
     }
 }

compiler/rustc_target/src/asm/wasm.rs

@@ -0,0 +1,46 @@
+use super::{InlineAsmArch, InlineAsmType};
+use rustc_macros::HashStable_Generic;
+
+def_reg_class! {
+    Wasm WasmInlineAsmRegClass {
+        local,
+    }
+}
+
+impl WasmInlineAsmRegClass {
+    pub fn valid_modifiers(self, _arch: super::InlineAsmArch) -> &'static [char] {
+        &[]
+    }
+
+    pub fn suggest_class(self, _arch: InlineAsmArch, _ty: InlineAsmType) -> Option<Self> {
+        None
+    }
+
+    pub fn suggest_modifier(
+        self,
+        _arch: InlineAsmArch,
+        _ty: InlineAsmType,
+    ) -> Option<(char, &'static str)> {
+        None
+    }
+
+    pub fn default_modifier(self, _arch: InlineAsmArch) -> Option<(char, &'static str)> {
+        None
+    }
+
+    pub fn supported_types(
+        self,
+        _arch: InlineAsmArch,
+    ) -> &'static [(InlineAsmType, Option<&'static str>)] {
+        match self {
+            Self::local => {
+                types! { _: I8, I16, I32, I64, F32, F64; }
+            }
+        }
+    }
+}
+
+def_regs! {
+    // WebAssembly doesn't have registers.
+    Wasm WasmInlineAsmReg WasmInlineAsmRegClass {}
+}