Fix rust-lang#406, handle LLVM comments in asm filtering

The addition of LLVM comments to the generated
asm has prevented the filtering script from
recognizing some labels. This commit fixes
the missing labels and should keep comments
in the filtered asm.

Author: Will Chandler

ui/src/asm_cleanup.rs

@@ -34,13 +34,13 @@ pub fn filter_asm(block: &str) -> String {
     lazy_static! {
         // Example:    mov rax, rdx
         // Always inlude in results
-        static ref OPCODE_REGEX: Regex = Regex::new(r"^\s*[a-zA-Z]+.*[^:]$").unwrap();
+        static ref OPCODE_REGEX: Regex = Regex::new(r"^\s+[a-zA-Z]+.*[^:]$").unwrap();
     }
     lazy_static! {
         // Example:.Lfunc_end7:
         // Finds label declarations
         // Include in results only if it is referenced by an opcode, or is a function
-        static ref LABEL_DECL_REGEX: Regex = Regex::new(r"([a-zA-Z_.<][a-zA-Z0-9$&_.,<>\[\]{}:' ]*):$").unwrap();
+        static ref LABEL_DECL_REGEX: Regex = Regex::new(r"^([a-zA-Z_.<][a-zA-Z0-9$&_.,<>\[\]{}:' ]*):(\s+#.*)?$").unwrap();
     }
     lazy_static! {
         // Example:    mov lea rdi, [rip + str.0] // str.0 is the referenced label
@@ -51,19 +51,19 @@ pub fn filter_asm(block: &str) -> String {
         // Example:    .string "Hello, world!"
         // Note: this is a type of directive
         // Include in results if it is part of a used label, may contain label references
-        static ref DATA_REGEX: Regex = Regex::new(r"^\s*\.(string|asciz|ascii|[1248]?byte|short|word|long|quad|value|zero)").unwrap();
+        static ref DATA_REGEX: Regex = Regex::new(r"^\s+\.(string|asciz|ascii|[1248]?byte|short|word|long|quad|value|zero)").unwrap();
     }
     lazy_static! {
         // Example:    .type main,@function
         // Note: this is a type of directive
         // Never include in results, but is used to find and include functions
-        static ref FUNCTION_REGEX: Regex = Regex::new(r"^\s*\.type\s*(.*),@function$").unwrap();
+        static ref FUNCTION_REGEX: Regex = Regex::new(r"^\s+\.type\s*(.*),@function$").unwrap();
     }
     lazy_static! {
         // Example:    .p2align 4, 0x90
         // Note: this will also match entries found by DATA_REGEX and FUNCTION_REGEX
         // Never include in results
-        static ref DIRECTIVE_REGEX: Regex = Regex::new(r"^\s*\..*[^:]$").unwrap();
+        static ref DIRECTIVE_REGEX: Regex = Regex::new(r"^\s+\..*[^:]$").unwrap();
     }
     lazy_static! {
         // Never include in results
@@ -188,9 +188,8 @@ mod test {
     #[test]
     fn used_label_kept() {
         assert_eq!(
-            
-            super::filter_asm(".Lcfi0:\ncallq    .Lcfi0\n"),
-            "\n.Lcfi0:\ncallq    .Lcfi0\n");
+            super::filter_asm(".Lcfi0:\n  callq    .Lcfi0\n"),
+            "\n.Lcfi0:\n  callq    .Lcfi0\n");
     }
 
     #[test]
@@ -214,14 +213,14 @@ mod test {
 
     #[test]
     fn blank_lines_removed() {
-        assert_eq!(super::filter_asm("  mov rbp, rsp\n  main:\n  jmp core::fmt::Arguments\n  \n"),
+        assert_eq!(super::filter_asm("  mov rbp, rsp\nmain:\n  jmp core::fmt::Arguments\n  \n"),
         "  mov rbp, rsp\n  jmp core::fmt::Arguments\n")
     }
 
     #[test]
     fn functions_kept() {
-        assert_eq!(super::filter_asm("  .type main,@function\n  main:\n  pushq %rax\n"),
-        "\n  main:\n  pushq %rax\n");
+        assert_eq!(super::filter_asm("  .type main,@function\nmain:\n  pushq %rax\n"),
+        "\nmain:\n  pushq %rax\n");
     }
     #[test]
     fn used_data_ref_label_kept() {
@@ -238,4 +237,14 @@ mod test {
         assert_eq!(super::filter_asm("main:\n  .quad ref.1\n  mov main\nref.1:\n  .quad ref.2\nref.2:\n  .quad 1"),
         "\nmain:\n  .quad ref.1\n  mov main\n\nref.1:\n  .quad ref.2\n\nref.2:\n  .quad 1\n");
     }
+    #[test]
+    fn label_with_comment_recognized() {
+        assert_eq!(super::filter_asm(".LBB6_10:  # =>Comment\n movq %r15, %rsi\n movq %rbx, %rdx\n ja .LBB6_10\n"),
+        "\n.LBB6_10:  # =>Comment\n movq %r15, %rsi\n movq %rbx, %rdx\n ja .LBB6_10\n");
+    }
+    #[test]
+    fn comment_retained() {
+        assert_eq!(super::filter_asm("# %bb.0:\n subq $24, %rsp\n"),
+        "# %bb.0:\n subq $24, %rsp\n")
+    }
 }