BPF: misc minor review fixes

compiler/rustc_target/src/spec/bpf_base.rs

@@ -12,6 +12,10 @@ pub fn opts(endian: Endian) -> TargetOptions {
         no_builtins: true,
         panic_strategy: PanicStrategy::Abort,
         position_independent_executables: true,
+        // Disable MergeFunctions since:
+        // - older kernels don't support bpf-to-bpf calls
+        // - on newer kernels, userspace still needs to relocate before calling
+        //   BPF_PROG_LOAD and not all BPF libraries do that yet
         merge_functions: MergeFunctions::Disabled,
         obj_is_bitcode: true,
         requires_lto: false,

src/bootstrap/native.rs

@@ -235,8 +235,8 @@ fn run(self, builder: &Builder<'_>) -> PathBuf {
         let llvm_targets = match &builder.config.llvm_targets {
             Some(s) => s,
             None => {
-                "AArch64;ARM;Hexagon;MSP430;Mips;NVPTX;PowerPC;RISCV;\
-                     Sparc;SystemZ;WebAssembly;X86;BPF"
+                "AArch64;ARM;BPF;Hexagon;MSP430;Mips;NVPTX;PowerPC;RISCV;\
+                     Sparc;SystemZ;WebAssembly;X86"
             }
         };
 

src/doc/unstable-book/src/library-features/asm.md

@@ -571,8 +571,8 @@ Here is the list of currently supported register classes:
 | PowerPC | `reg_nonzero` | | `r[1-31]` | `b` |
 | PowerPC | `freg` | `f[0-31]` | `f` |
 | wasm32 | `local` | None\* | `r` |
-| BPF | `reg` | `r[0-10]` | `r`|
-| BPF | `wreg` | `w[0-10]` | `w`|
+| BPF | `reg` | `r[0-10]` | `r` |
+| BPF | `wreg` | `w[0-10]` | `w` |
 
 > **Note**: On x86 we treat `reg_byte` differently from `reg` because the compiler can allocate `al` and `ah` separately whereas `reg` reserves the whole register.
 >
@@ -619,7 +619,7 @@ Each register class has constraints on which value types they can be used with.
 | PowerPC | `freg` | None | `f32`, `f64` |
 | wasm32 | `local` | None | `i8` `i16` `i32` `i64` `f32` `f64` |
 | BPF | `reg` | None | `i8` `i16` `i32` `i64` |
-| BPF | `wreg` | `alu32` | `i8` `i16` `i32`|
+| BPF | `wreg` | `alu32` | `i8` `i16` `i32` |
 
 > **Note**: For the purposes of the above table pointers, function pointers and `isize`/`usize` are treated as the equivalent integer type (`i16`/`i32`/`i64` depending on the target).
 

src/tools/compiletest/src/runtest.rs

@@ -2311,10 +2311,6 @@ fn compile_test_and_save_assembly(&self) -> (ProcRes, PathBuf) {
                 // No extra flags needed.
             }
 
-            Some("bpf-linker") => {
-                rustc.arg("-Clink-args=--emit=asm");
-            }
-
             Some(_) => self.fatal("unknown 'assembly-output' header"),
             None => self.fatal("missing 'assembly-output' header"),
         }

src/tools/compiletest/src/util.rs

@@ -48,8 +48,8 @@
     ("armv7s", "arm"),
     ("asmjs", "asmjs"),
     ("avr", "avr"),
-    ("bpfeb", "bpfeb"),
-    ("bpfel", "bpfel"),
+    ("bpfeb", "bpf"),
+    ("bpfel", "bpf"),
     ("hexagon", "hexagon"),
     ("i386", "x86"),
     ("i586", "x86"),