[PATCH] D143369: [llvm-profdata] Fix bug llvm-profdata crashes when reading a text sample profile with an empty line with spaces.

[William Junda Huang via Phabricator via llvm-commits]

huangjd created this revision.
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Text editors can introduce spaces aligning the previous line's indentation. This crashes llvm-profdata. Added check to handle this case.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D143369

Files:
  llvm/lib/ProfileData/SampleProfReader.cpp
  llvm/test/tools/llvm-profdata/Inputs/sample-empty-lines.proftext
  llvm/test/tools/llvm-profdata/sample-empty-lines.test


Index: llvm/test/tools/llvm-profdata/sample-empty-lines.test
===================================================================
--- /dev/null
+++ llvm/test/tools/llvm-profdata/sample-empty-lines.test
@@ -0,0 +1,8 @@
+Test llvm-profdata merge can handle empty line with spaces in text format sample profile.
+
+RUN: llvm-profdata merge --sample --text %p/Inputs/sample-empty-lines.proftext | FileCheck %s
+CHECK: main:10:1
+CHECK-NEXT: 2: 3
+CHECK-NEXT: 3: inline1:5
+CHECK-NEXT: 4: 1
+
Index: llvm/test/tools/llvm-profdata/Inputs/sample-empty-lines.proftext
===================================================================
--- /dev/null
+++ llvm/test/tools/llvm-profdata/Inputs/sample-empty-lines.proftext
@@ -0,0 +1,9 @@
+main:10:1
+ 2: 3
+ 
+
+ 3: inline1:5
+  
+  4: 1
+ 
+
Index: llvm/lib/ProfileData/SampleProfReader.cpp
===================================================================
--- llvm/lib/ProfileData/SampleProfReader.cpp
+++ llvm/lib/ProfileData/SampleProfReader.cpp
@@ -328,7 +328,8 @@
   ProfileIsFS = ProfileIsFSDisciminator;
   FunctionSamples::ProfileIsFS = ProfileIsFS;
   for (; !LineIt.is_at_eof(); ++LineIt) {
-    if ((*LineIt)[(*LineIt).find_first_not_of(' ')] == '#')
+    size_t pos = LineIt->find_first_not_of(' ');
+    if (pos == LineIt->npos || (*LineIt)[pos] == '#')
       continue;
     // Read the header of each function.
     //


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