[llvm] r286914 - llvm-strings: support the `-n` option

[Saleem Abdulrasool via llvm-commits]

Author: compnerd
Date: Mon Nov 14 18:43:52 2016
New Revision: 286914

URL: http://llvm.org/viewvc/llvm-project?rev=286914&view=rev
Log:
llvm-strings: support the `-n` option

Permit specifying the match length (the `-n` or `--bytes` option).  The
deprecated `-[length]` form is not supported as an option.  This allows the
strings tool to display only the specified length strings rather than the
hardcoded default length of >= 4.

Added:
    llvm/trunk/test/tools/llvm-strings/length.test
Modified:
    llvm/trunk/tools/llvm-strings/llvm-strings.cpp

Added: llvm/trunk/test/tools/llvm-strings/length.test
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/tools/llvm-strings/length.test?rev=286914&view=auto
==============================================================================
--- llvm/trunk/test/tools/llvm-strings/length.test (added)
+++ llvm/trunk/test/tools/llvm-strings/length.test Mon Nov 14 18:43:52 2016
@@ -0,0 +1,24 @@
+RUN: sed -n 's/^STDIN: //p' %s | llvm-strings | FileCheck --check-prefix CHECK-DEFAULT %s
+RUN: sed -n 's/^STDIN: //p' %s | not llvm-strings -n 0 2>&1 | FileCheck --check-prefix CHECK-0 %s
+RUN: sed -n 's/^STDIN: //p' %s | llvm-strings -n 1 | FileCheck --check-prefix CHECK-1 %s
+RUN: sed -n 's/^STDIN: //p' %s | llvm-strings -n 2 | FileCheck --check-prefix CHECK-2 %s
+
+STDIN: a
+STDIN: ab
+STDIN: abc
+STDIN: abcd
+
+CHECK-DEFAULT: abcd
+
+CHECK-0: invalid minimum string length 0
+
+CHECK-1: a
+CHECK-1: ab
+CHECK-1: abc
+CHECK-1: abcd
+
+CHECK-2-NOT: a
+CHECK-2: ab
+CHECK-2: abc
+CHECK-2: abcd
+

Modified: llvm/trunk/tools/llvm-strings/llvm-strings.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/tools/llvm-strings/llvm-strings.cpp?rev=286914&r1=286913&r2=286914&view=diff
==============================================================================
--- llvm/trunk/tools/llvm-strings/llvm-strings.cpp (original)
+++ llvm/trunk/tools/llvm-strings/llvm-strings.cpp Mon Nov 14 18:43:52 2016
@@ -35,8 +35,15 @@ static cl::opt<bool>
 static cl::alias PrintFileNameShort("f", cl::desc(""),
                                     cl::aliasopt(PrintFileName));
 
+static cl::opt<int>
+    MinLength("bytes", cl::desc("Print sequences of the specified length"),
+              cl::init(4));
+static cl::alias MinLengthShort("n", cl::desc(""), cl::aliasopt(MinLength));
+
 static void strings(raw_ostream &OS, StringRef FileName, StringRef Contents) {
   auto print = [&OS, FileName](StringRef L) {
+    if (L.size() < static_cast<size_t>(MinLength))
+      return;
     if (PrintFileName)
       OS << FileName << ": ";
     OS << L << '\n';
@@ -48,12 +55,11 @@ static void strings(raw_ostream &OS, Str
       if (S == nullptr)
         S = P;
     } else if (S) {
-      if (P - S > 3)
-        print(StringRef(S, P - S));
+      print(StringRef(S, P - S));
       S = nullptr;
     }
   }
-  if (S && E - S > 3)
+  if (S)
     print(StringRef(S, E - S));
 }
 
@@ -62,6 +68,10 @@ int main(int argc, char **argv) {
   PrettyStackTraceProgram X(argc, argv);
 
   cl::ParseCommandLineOptions(argc, argv, "llvm string dumper\n");
+  if (MinLength == 0) {
+    errs() << "invalid minimum string length 0\n";
+    return EXIT_FAILURE;
+  }
 
   if (InputFileNames.empty())
     InputFileNames.push_back("-");