[clang] 3895305 - [clang-scan-deps] do not skip empty #if/#elif in the minimizer to avoid missing `__has_include` dependencies
Alex Lorenz via cfe-commits
cfe-commits at lists.llvm.org
Mon Dec 2 18:47:32 PST 2019
Author: Alex Lorenz
Date: 2019-12-02T18:47:22-08:00
New Revision: 389530524be1715e97947810514f3a75dfe73975
URL: https://github.com/llvm/llvm-project/commit/389530524be1715e97947810514f3a75dfe73975
DIFF: https://github.com/llvm/llvm-project/commit/389530524be1715e97947810514f3a75dfe73975.diff
LOG: [clang-scan-deps] do not skip empty #if/#elif in the minimizer to avoid missing `__has_include` dependencies
This patch makes the minimizer more conservative to avoid missing dependency files that are brought in by __has_include
PP expressions that occur in a condition of an #if/#elif that was previously skipped. The __has_include PP expressions
can be used in an #if/#elif either directly, or through macro expansion, so we can't detect them at the time of minimization.
Differential Revision: https://reviews.llvm.org/D70936
Added:
clang/test/ClangScanDeps/Inputs/has_include_if_elif.json
clang/test/ClangScanDeps/has_include_if_elif.cpp
Modified:
clang/lib/Lex/DependencyDirectivesSourceMinimizer.cpp
clang/unittests/Lex/DependencyDirectivesSourceMinimizerTest.cpp
Removed:
################################################################################
diff --git a/clang/lib/Lex/DependencyDirectivesSourceMinimizer.cpp b/clang/lib/Lex/DependencyDirectivesSourceMinimizer.cpp
index f063ed711c44..029bfe1cd600 100644
--- a/clang/lib/Lex/DependencyDirectivesSourceMinimizer.cpp
+++ b/clang/lib/Lex/DependencyDirectivesSourceMinimizer.cpp
@@ -763,12 +763,13 @@ bool Minimizer::lexEndif(const char *&First, const char *const End) {
if (top() == pp_else)
popToken();
- // Strip out "#elif" if they're empty.
- while (top() == pp_elif)
- popToken();
-
- // If "#if" is empty, strip it and skip the "#endif".
- if (top() == pp_if || top() == pp_ifdef || top() == pp_ifndef) {
+ // If "#ifdef" is empty, strip it and skip the "#endif".
+ //
+ // FIXME: Once/if Clang starts disallowing __has_include in macro expansions,
+ // we can skip empty `#if` and `#elif` blocks as well after scanning for a
+ // literal __has_include in the condition. Even without that rule we could
+ // drop the tokens if we scan for identifiers in the condition and find none.
+ if (top() == pp_ifdef || top() == pp_ifndef) {
popToken();
skipLine(First, End);
return false;
diff --git a/clang/test/ClangScanDeps/Inputs/has_include_if_elif.json b/clang/test/ClangScanDeps/Inputs/has_include_if_elif.json
new file mode 100644
index 000000000000..36ca006b0329
--- /dev/null
+++ b/clang/test/ClangScanDeps/Inputs/has_include_if_elif.json
@@ -0,0 +1,7 @@
+[
+{
+ "directory": "DIR",
+ "command": "clang -E DIR/has_include_if_elif2.cpp -IInputs",
+ "file": "DIR/has_include_if_elif2.cpp"
+}
+]
diff --git a/clang/test/ClangScanDeps/has_include_if_elif.cpp b/clang/test/ClangScanDeps/has_include_if_elif.cpp
new file mode 100644
index 000000000000..dd56ecac69db
--- /dev/null
+++ b/clang/test/ClangScanDeps/has_include_if_elif.cpp
@@ -0,0 +1,38 @@
+// RUN: rm -rf %t.dir
+// RUN: rm -rf %t.cdb
+// RUN: mkdir -p %t.dir
+// RUN: cp %s %t.dir/has_include_if_elif2.cpp
+// RUN: mkdir %t.dir/Inputs
+// RUN: cp %S/Inputs/header.h %t.dir/Inputs/header.h
+// RUN: cp %S/Inputs/header.h %t.dir/Inputs/header2.h
+// RUN: cp %S/Inputs/header.h %t.dir/Inputs/header3.h
+// RUN: cp %S/Inputs/header.h %t.dir/Inputs/header4.h
+// RUN: sed -e "s|DIR|%/t.dir|g" %S/Inputs/has_include_if_elif.json > %t.cdb
+//
+// RUN: clang-scan-deps -compilation-database %t.cdb -j 1 -mode preprocess-minimized-sources | \
+// RUN: FileCheck %s
+// RUN: clang-scan-deps -compilation-database %t.cdb -j 1 -mode preprocess | \
+// RUN: FileCheck %s
+
+#if __has_include("header.h")
+#endif
+
+#if 0
+#elif __has_include("header2.h")
+#endif
+
+#define H3 __has_include("header3.h")
+#if H3
+#endif
+
+#define H4 __has_include("header4.h")
+
+#if 0
+#elif H4
+#endif
+
+// CHECK: has_include_if_elif2.cpp
+// CHECK-NEXT: Inputs{{/|\\}}header.h
+// CHECK-NEXT: Inputs{{/|\\}}header2.h
+// CHECK-NEXT: Inputs{{/|\\}}header3.h
+// CHECK-NEXT: Inputs{{/|\\}}header4.h
diff --git a/clang/unittests/Lex/DependencyDirectivesSourceMinimizerTest.cpp b/clang/unittests/Lex/DependencyDirectivesSourceMinimizerTest.cpp
index ed44cd86b3e4..b5bba30db78d 100644
--- a/clang/unittests/Lex/DependencyDirectivesSourceMinimizerTest.cpp
+++ b/clang/unittests/Lex/DependencyDirectivesSourceMinimizerTest.cpp
@@ -328,12 +328,17 @@ TEST(MinimizeSourceToDependencyDirectivesTest, EmptyIfdef) {
SmallVector<char, 128> Out;
ASSERT_FALSE(minimizeSourceToDependencyDirectives("#ifdef A\n"
+ "void skip();\n"
"#elif B\n"
"#elif C\n"
"#else D\n"
"#endif\n",
Out));
- EXPECT_STREQ("", Out.data());
+ EXPECT_STREQ("#ifdef A\n"
+ "#elif B\n"
+ "#elif C\n"
+ "#endif\n",
+ Out.data());
}
TEST(MinimizeSourceToDependencyDirectivesTest, Pragma) {
@@ -507,6 +512,12 @@ TEST(MinimizeSourceToDependencyDirectivesTest, PoundWarningAndError) {
for (auto Source : {
"#warning \\\n#include <t.h>\n",
"#error \\\n#include <t.h>\n",
+ }) {
+ ASSERT_FALSE(minimizeSourceToDependencyDirectives(Source, Out));
+ EXPECT_STREQ("", Out.data());
+ }
+
+ for (auto Source : {
"#if MACRO\n#warning '\n#endif\n",
"#if MACRO\n#warning \"\n#endif\n",
"#if MACRO\n#warning /*\n#endif\n",
@@ -515,7 +526,7 @@ TEST(MinimizeSourceToDependencyDirectivesTest, PoundWarningAndError) {
"#if MACRO\n#error /*\n#endif\n",
}) {
ASSERT_FALSE(minimizeSourceToDependencyDirectives(Source, Out));
- EXPECT_STREQ("", Out.data());
+ EXPECT_STREQ("#if MACRO\n#endif\n", Out.data());
}
}
@@ -543,7 +554,7 @@ TEST(MinimizeSourceToDependencyDirectivesTest, CharacterLiteralPrefixL) {
#include <test.h>
)";
ASSERT_FALSE(minimizeSourceToDependencyDirectives(Source, Out));
- EXPECT_STREQ("#include <test.h>\n", Out.data());
+ EXPECT_STREQ("#if DEBUG\n#endif\n#include <test.h>\n", Out.data());
}
TEST(MinimizeSourceToDependencyDirectivesTest, CharacterLiteralPrefixU) {
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