Rollup merge of rust-lang#53290 - whitequark:fix-35741, r=nagisa

Make LLVM emit assembly comments with -Z asm-comments Fixes rust-lang#35741, and makes `-Z asm-comments` actually do something useful. Before: ``` .section .text.main,"ax",@progbits .globl main .p2align 4, 0x90 .type main,@function main: .cfi_startproc pushq %rax .cfi_def_cfa_offset 16 movslq %edi, %rax leaq _ZN1t4main17he95a7d4f1843730eE(%rip), %rdi movq %rsi, (%rsp) movq %rax, %rsi movq (%rsp), %rdx callq _ZN3std2rt10lang_start17h3121da83b2bc3697E movl %eax, %ecx movl %ecx, %eax popq %rcx .cfi_def_cfa_offset 8 retq .Lfunc_end8: .size main, .Lfunc_end8-main .cfi_endproc ``` After: ``` .section .text.main,"ax",@progbits .globl main # -- Begin function main .p2align 4, 0x90 .type main,@function main: # @main .cfi_startproc pushq %rax .cfi_def_cfa_offset 16 movslq %edi, %rax leaq _ZN1t4main17he95a7d4f1843730eE(%rip), %rdi movq %rsi, (%rsp) # 8-byte Spill movq %rax, %rsi movq (%rsp), %rdx # 8-byte Reload callq _ZN3std2rt10lang_start17h3121da83b2bc3697E movl %eax, %ecx movl %ecx, %eax popq %rcx .cfi_def_cfa_offset 8 retq .Lfunc_end8: .size main, .Lfunc_end8-main .cfi_endproc # -- End function ```
kennytm · Aug 12, 2018 · 16210e8 · 16210e8
2 parents 6dd9bcc + 66fd1eb
commit 16210e8
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Showing 3 changed files with 9 additions and 2 deletions.
diff --git a/src/librustc_codegen_llvm/back/write.rs b/src/librustc_codegen_llvm/back/write.rs
@@ -182,6 +182,8 @@ pub fn target_machine_factory(sess: &Session, find_features: bool)
     let is_pie_binary = !find_features && is_pie_binary(sess);
     let trap_unreachable = sess.target.target.options.trap_unreachable;
 
+    let asm_comments = sess.asm_comments();
+
     Arc::new(move || {
         let tm = unsafe {
             llvm::LLVMRustCreateTargetMachine(
@@ -195,6 +197,7 @@ pub fn target_machine_factory(sess: &Session, find_features: bool)
                 fdata_sections,
                 trap_unreachable,
                 singlethread,
+                asm_comments,
             )
         };
 

diff --git a/src/librustc_codegen_llvm/llvm/ffi.rs b/src/librustc_codegen_llvm/llvm/ffi.rs
@@ -1455,7 +1455,8 @@ extern "C" {
                                        FunctionSections: bool,
                                        DataSections: bool,
                                        TrapUnreachable: bool,
-                                       Singlethread: bool)
+                                       Singlethread: bool,
+                                       AsmComments: bool)
                                        -> Option<&'static mut TargetMachine>;
     pub fn LLVMRustDisposeTargetMachine(T: &'static mut TargetMachine);
     pub fn LLVMRustAddAnalysisPasses(T: &'a TargetMachine, PM: &PassManager<'a>, M: &'a Module);

diff --git a/src/rustllvm/PassWrapper.cpp b/src/rustllvm/PassWrapper.cpp
@@ -366,7 +366,8 @@ extern "C" LLVMTargetMachineRef LLVMRustCreateTargetMachine(
     bool PositionIndependentExecutable, bool FunctionSections,
     bool DataSections,
     bool TrapUnreachable,
-    bool Singlethread) {
+    bool Singlethread,
+    bool AsmComments) {
 
   auto OptLevel = fromRust(RustOptLevel);
   auto RM = fromRust(RustReloc);
@@ -393,6 +394,8 @@ extern "C" LLVMTargetMachineRef LLVMRustCreateTargetMachine(
   }
   Options.DataSections = DataSections;
   Options.FunctionSections = FunctionSections;
+  Options.MCOptions.AsmVerbose = AsmComments;
+  Options.MCOptions.PreserveAsmComments = AsmComments;
 
   if (TrapUnreachable) {
     // Tell LLVM to codegen `unreachable` into an explicit trap instruction.