[clang-scan-deps] Allow continuation line backslashes followed by whitespace

in the dependency source minimizer

Clang allows continuations that have whitespace between the backslash and the newline.
This patch ensures that the dependency source minimizer can handle the whitespace between
the backslash and the newline when looking for a line continuation.

Differential Revision: https://reviews.llvm.org/D68052

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@373007 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Lex/DependencyDirectivesSourceMinimizer.cpp b/lib/Lex/DependencyDirectivesSourceMinimizer.cpp
index 2a3c88251bc37ef73eee24e58a63b718be02c1da..2ffbcfb7e676899f9c62e3d253d8e5cf14daf1bf 100644 (file)
--- a/lib/Lex/DependencyDirectivesSourceMinimizer.cpp
+++ b/lib/Lex/DependencyDirectivesSourceMinimizer.cpp
@@ -244,14 +244,20 @@ static void skipToNewlineRaw(const char *&First, const char *const End) {
   }
 }
 
-static const char *reverseOverSpaces(const char *First, const char *Last) {
+static const char *findLastNonSpace(const char *First, const char *Last) {
   assert(First <= Last);
-  const char *PrevLast = Last;
-  while (First != Last && isHorizontalWhitespace(Last[-1])) {
-    PrevLast = Last;
+  while (First != Last && isHorizontalWhitespace(Last[-1]))
     --Last;
-  }
-  return PrevLast;
+  return Last;
+}
+
+static const char *findFirstTrailingSpace(const char *First,
+                                          const char *Last) {
+  const char *LastNonSpace = findLastNonSpace(First, Last);
+  if (Last == LastNonSpace)
+    return Last;
+  assert(isHorizontalWhitespace(LastNonSpace[0]));
+  return LastNonSpace + 1;
 }
 
 static void skipLineComment(const char *&First, const char *const End) {
@@ -385,7 +391,7 @@ void Minimizer::printToNewline(const char *&First, const char *const End) {
       }
 
       // Deal with "//..." and "/*...*/".
-      append(First, reverseOverSpaces(First, Last));
+      append(First, findFirstTrailingSpace(First, Last));
       First = Last;
 
       if (Last[1] == '/') {
@@ -400,15 +406,20 @@ void Minimizer::printToNewline(const char *&First, const char *const End) {
     } while (Last != End && !isVerticalWhitespace(*Last));
 
     // Print out the string.
-    if (Last == End || Last == First || Last[-1] != '\\') {
-      append(First, reverseOverSpaces(First, Last));
+    const char *LastBeforeTrailingSpace = findLastNonSpace(First, Last);
+    if (Last == End || LastBeforeTrailingSpace == First ||
+        LastBeforeTrailingSpace[-1] != '\\') {
+      append(First, LastBeforeTrailingSpace);
       First = Last;
       skipNewline(First, End);
       return;
     }
 
-    // Print up to the backslash, backing up over spaces.
-    append(First, reverseOverSpaces(First, Last - 1));
+    // Print up to the backslash, backing up over spaces. Preserve at least one
+    // space, as the space matters when tokens are separated by a line
+    // continuation.
+    append(First, findFirstTrailingSpace(
+                      First, LastBeforeTrailingSpace - 1));
 
     First = Last;
     skipNewline(First, End);

diff --git a/unittests/Lex/DependencyDirectivesSourceMinimizerTest.cpp b/unittests/Lex/DependencyDirectivesSourceMinimizerTest.cpp
index c00c160977e98fafb21b8f7c32cfc91e453f6721..5eb7d256a367aba6f3721c7c50170b4c5acd503c 100644 (file)
--- a/unittests/Lex/DependencyDirectivesSourceMinimizerTest.cpp
+++ b/unittests/Lex/DependencyDirectivesSourceMinimizerTest.cpp
@@ -157,19 +157,19 @@ TEST(MinimizeSourceToDependencyDirectivesTest, DefineHorizontalWhitespace) {
 
   ASSERT_FALSE(minimizeSourceToDependencyDirectives(
       "#define MACRO(\t)\tcon \t tent\t", Out));
-  EXPECT_STREQ("#define MACRO() con \t tent\t\n", Out.data());
+  EXPECT_STREQ("#define MACRO() con \t tent\n", Out.data());
 
   ASSERT_FALSE(minimizeSourceToDependencyDirectives(
       "#define MACRO(\f)\fcon \f tent\f", Out));
-  EXPECT_STREQ("#define MACRO() con \f tent\f\n", Out.data());
+  EXPECT_STREQ("#define MACRO() con \f tent\n", Out.data());
 
   ASSERT_FALSE(minimizeSourceToDependencyDirectives(
       "#define MACRO(\v)\vcon \v tent\v", Out));
-  EXPECT_STREQ("#define MACRO() con \v tent\v\n", Out.data());
+  EXPECT_STREQ("#define MACRO() con \v tent\n", Out.data());
 
   ASSERT_FALSE(minimizeSourceToDependencyDirectives(
       "#define MACRO \t\v\f\v\t con\f\t\vtent\v\f \v", Out));
-  EXPECT_STREQ("#define MACRO con\f\t\vtent\v\n", Out.data());
+  EXPECT_STREQ("#define MACRO con\f\t\vtent\n", Out.data());
 }
 
 TEST(MinimizeSourceToDependencyDirectivesTest, DefineMultilineArgs) {
@@ -476,6 +476,17 @@ TEST(MinimizeSourceToDependencyDirectivesTest, SplitIdentifier) {
   EXPECT_STREQ("#define GUA RD\n", Out.data());
 }
 
+TEST(MinimizeSourceToDependencyDirectivesTest,
+     WhitespaceAfterLineContinuationSlash) {
+  SmallVector<char, 128> Out;
+
+  ASSERT_FALSE(minimizeSourceToDependencyDirectives("#define A 1 + \\  \n"
+                                                    "2 + \\\t\n"
+                                                    "3\n",
+                                                    Out));
+  EXPECT_STREQ("#define A 1 + 2 + 3\n", Out.data());
+}
+
 TEST(MinimizeSourceToDependencyDirectivesTest, PoundWarningAndError) {
   SmallVector<char, 128> Out;