[PATCH] D18699: [ELF] - Teach linkerscript error handler to show full script line + column marker on error.

[George Rimar via llvm-commits]

grimar created this revision.
grimar added reviewers: ruiu, rafael.
grimar added subscribers: llvm-commits, grimar.

When error, this adds the text line of script to the output
and a marks exact incorrect token under it:

```
line 1: <error text here>
UNKNOWN_TAG {
      ^
```

http://reviews.llvm.org/D18699

Files:
  ELF/LinkerScript.cpp
  test/ELF/linkerscript-diagnostic.s

Index: test/ELF/linkerscript-diagnostic.s
===================================================================
--- test/ELF/linkerscript-diagnostic.s
+++ test/ELF/linkerscript-diagnostic.s
@@ -42,3 +42,25 @@
 # RUN: echo ".temp + { *(.temp) } }" >> %t.script
 # RUN: not ld.lld -shared %t -o %t1 --script %t.script 2>&1 | FileCheck -check-prefix=ERR5 %s
 # ERR5: line 6:
+
+## Check that text of lines and pointer to 'bad' token are working ok.
+# RUN: echo "UNKNOWN_TAG {" > %t.script
+# RUN: echo ".text : { *(.text) }" >> %t.script
+# RUN: echo ".keep : { *(.keep) }" >> %t.script
+# RUN: echo ".temp : { *(.temp) } }" >> %t.script
+# RUN: not ld.lld -shared %t -o %t1 --script %t.script > %t.log 2>&1
+# FileCheck -check-prefix=ERR6 %s < %t.log
+# ERR6: line 1:
+# ERR6: UNKNOWN_TAG {
+# ERR6: {{[ ]{5}\^}}
+
+## One more check that text of lines and pointer to 'bad' token are working ok.
+# RUN: echo "SECTIONS {" > %t.script
+# RUN: echo ".text : { *(.text) }" >> %t.script
+# RUN: echo ".keep : { *(.keep) }" >> %t.script
+# RUN: echo "boom .temp : { *(.temp) } }" >> %t.script
+# RUN: not ld.lld -shared %t -o %t1 --script %t.script > %t.log 2>&1
+# FileCheck -check-prefix=ERR7 %s < %t.log
+# ERR7: line 4:
+# ERR7: boom .temp : { *(.temp) }
+# ERR7: {{[ ]{7}\^}}
Index: ELF/LinkerScript.cpp
===================================================================
--- ELF/LinkerScript.cpp
+++ ELF/LinkerScript.cpp
@@ -138,6 +138,7 @@
   void readSectionPatterns(StringRef OutSec, bool Keep);
 
   size_t getPos();
+  std::pair<StringRef, size_t> getLineColumn();
   std::vector<uint8_t> parseHex(StringRef S);
 
   StringSaver Saver;
@@ -172,11 +173,36 @@
   }
 }
 
+std::pair<StringRef, size_t> ScriptParser::getLineColumn() {
+  const char *Begin = Input.data();
+  const char *End = Begin + Input.size();
+
+  if (Pos == 0) {
+    const char *Eol = strchr(Begin, '\n');
+    return {StringRef(Begin, Eol ? (Eol - Begin) : (End - Begin)),
+            Tokens[0].size() / 2};
+  }
+
+  const char *Tok = Tokens[Pos - 1].data();
+  const char *S = Tok;
+  while (S > Begin && *(S - 1) != '\n')
+    --S;
+
+  const char *Eol = strchr(Tok, '\n');
+  return {StringRef(S, Eol ? (Eol - S) : (End - S)),
+          Tok - S + Tokens[Pos - 1].size() / 2};
+}
+
 // We don't want to record cascading errors. Keep only the first one.
 void ScriptParser::setError(const Twine &Msg) {
   if (Error)
     return;
   error("line " + Twine(getPos()) + ": " + Msg);
+  StringRef Line;
+  size_t Col;
+  std::tie(Line, Col) = getLineColumn();
+  error(Line);
+  error(std::string(Col, ' ') + "^");
   Error = true;
 }
 


-------------- next part --------------
A non-text attachment was scrubbed...
Name: D18699.52388.patch
Type: text/x-patch
Size: 2610 bytes
Desc: not available
URL: <http://lists.llvm.org/pipermail/llvm-commits/attachments/20160401/2cf9f9b2/attachment.bin>