[ELF] Fix finding the location in messages for undefined hidden symbols.

[ikudrin]

Summary

Currently, the linker prints something like

hidden(undef.s): error: undefined hidden symbol: foo
>>> referenced by undef.s:15

[ruiu]

Common/ErrorHandler.cpp

99 ↗

(On Diff #212508)

Or maybe you can relax this parentheses to \S+.

[MaskRay]

Common/ErrorHandler.cpp

99 ↗

(On Diff #212508)

If you use R"(^undefined (?:internal |hidden |protected |)symbol: .*\n>>> referenced by (\S+):(\d+)\n.*)", this can be merged with undefined symbol above...

[MaskRay]

test/ELF/vs-diagnostics-undefined-hidden.s

2 ↗

(On Diff #212508)

This is generic ELF (OS agnostic) so you can actually use -triple=x86_64..

3 ↗

(On Diff #212508)

%tout -> /dev/null

[ikudrin]

• Combined all the suggestions to improve the regular expression.
• Addressed @MaskRay's comments for the test.

[ruiu]

LGTM

lld/trunk/Common/ErrorHandler.cpp

 
 void lld::checkError(Error e) {
   handleAllErrors(std::move(e),
                   [&](ErrorInfoBase &eib) { error(eib.message()); });
 }
 
 static std::string getLocation(std::string msg, std::string defaultMsg) {
   static std::vector<std::regex> Regexes{
-      std::regex(R"(^undefined symbol:.*\n>>> referenced by (\S+):(\d+)\n.*)"),
+      std::regex(R"(^undefined (?:\S+ )?symbol:.*\n>>> referenced by (\S+):(\d+)\n.*)"),
       std::regex(R"(^undefined symbol:.*\n>>> referenced by (.*):)"),
       std::regex(
           R"(^duplicate symbol: .*\n>>> defined in (\S+)\n>>> defined in.*)"),
       std::regex(
           R"(^duplicate symbol: .*\n>>> defined at (\S+):(\d+).*)"),
       std::regex(
           R"(.*\n>>> defined in .*\n>>> referenced by (\S+):(\d+))"),
-      std::regex(
-          R"(^undefined (internal|hidden|protected) symbol: .*\n>>> referenced by (\S+):(\d+)\n.*)"),
       std::regex(R"((\S+):(\d+): unclosed quote)"),
   };
 
   std::smatch Match;
   for (std::regex &Re : Regexes) {
     if (std::regex_search(msg, Match, Re)) {
       return Match.size() > 2 ? Match.str(1) + "(" + Match.str(2) + ")"
                               : Match.str(1);

lld/trunk/test/ELF/vs-diagnostics-undefined-hidden.s

+// REQUIRES: x86
+// RUN: llvm-mc -filetype=obj -triple=x86_64 %s -o %t.o
+// RUN: not ld.lld --vs-diagnostics -shared %t.o -o /dev/null 2>&1 \
+// RUN:   | FileCheck %s
+
+// CHECK:      undef.s(15): error: undefined hidden symbol: foo
+// CHECK-NEXT: >>> referenced by undef.s:15
+
+// CHECK:      undef.s(27): error: undefined protected symbol: bar
+// CHECK-NEXT: >>> referenced by undef.s:27
+
+.file 1 "undef.s"
+
+.hidden foo
+.protected bar
+.text
+_start:
+.loc 1 15
+  jmp foo
+.loc 1 27
+  jmp bar
+
+.section .debug_abbrev,"",@progbits
+  .byte  1                      # Abbreviation Code
+  .byte 17                      # DW_TAG_compile_unit
+  .byte  0                      # DW_CHILDREN_no
+  .byte 16                      # DW_AT_stmt_list
+  .byte 23                      # DW_FORM_sec_offset
+  .byte  0                      # EOM(1)
+  .byte  0                      # EOM(2)
+  .byte  0                      # EOM(3)
+
+.section .debug_info,"",@progbits
+  .long .Lend0 - .Lbegin0       # Length of Unit
+.Lbegin0:
+  .short 4                      # DWARF version number
+  .long  .debug_abbrev          # Offset Into Abbrev. Section
+  .byte  8                      # Address Size (in bytes)
+  .byte  1                      # Abbrev [1] 0xb:0x1f DW_TAG_compile_unit
+  .long  .debug_line            # DW_AT_stmt_list
+.Lend0:
+  .section .debug_line,"",@progbits