Bug 1606630 - For clang-tidy fix checkers `readability-misleading-indentation` and `readability-braces-around-statements`. r=sylvestre

The purpose of this patch is to add support for `if constexpr` statements for the above checkers.
`readability-braces-around-statements` fix has been back-ported from <https://reviews.llvm.org/D71980>
and the fix for `readability-misleading-indentation` uses the same logic as a principle.

Differential Revision: https://phabricator.services.mozilla.com/D58825

--HG--
extra : moz-landing-system : lando

build/build-clang/bug-1606630-if_constexpr.patch

@@ -0,0 +1,33 @@
+diff --git a/clang-tools-extra/clang-tidy/readability/BracesAroundStatementsCheck.cpp b/clang-tools-extra/clang-tidy/readability/BracesAroundStatementsCheck.cpp
+index 117ef36d78f..da0bef32c09 100644
+--- a/clang-tools-extra/clang-tidy/readability/BracesAroundStatementsCheck.cpp
++++ b/clang-tools-extra/clang-tidy/readability/BracesAroundStatementsCheck.cpp
+@@ -123,7 +123,10 @@ void BracesAroundStatementsCheck::storeOptions(
+ }
+
+ void BracesAroundStatementsCheck::registerMatchers(MatchFinder *Finder) {
+-  Finder->addMatcher(ifStmt().bind("if"), this);
++  Finder->addMatcher(
++      ifStmt(unless(allOf(isConstexpr(), isInTemplateInstantiation())))
++          .bind("if"),
++      this);
+   Finder->addMatcher(whileStmt().bind("while"), this);
+   Finder->addMatcher(doStmt().bind("do"), this);
+   Finder->addMatcher(forStmt().bind("for"), this);
+diff --git a/clang-tools-extra/clang-tidy/readability/MisleadingIndentationCheck.cpp b/clang-tools-extra/clang-tidy/readability/MisleadingIndentationCheck.cpp
+index 0fd5c1fc55c..3167d159b74 100644
+--- a/clang-tools-extra/clang-tidy/readability/MisleadingIndentationCheck.cpp
++++ b/clang-tools-extra/clang-tidy/readability/MisleadingIndentationCheck.cpp
+@@ -106,7 +106,11 @@ void MisleadingIndentationCheck::missingBracesCheck(const SourceManager &SM,
+ }
+
+ void MisleadingIndentationCheck::registerMatchers(MatchFinder *Finder) {
+-  Finder->addMatcher(ifStmt(hasElse(stmt())).bind("if"), this);
++  Finder->addMatcher(
++      ifStmt(allOf(hasElse(stmt()),
++                   unless(allOf(isConstexpr(), isInTemplateInstantiation()))))
++          .bind("if"),
++      this);
+   Finder->addMatcher(
+       compoundStmt(has(stmt(anyOf(ifStmt(), forStmt(), whileStmt()))))
+           .bind("compound"),

build/build-clang/clang-tidy-linux64.json

@@ -12,6 +12,7 @@
     "patches": [
         "clang-tidy-ci.patch",
         "clang-tidy-no-errors.patch",
-        "bug-1605181-isConstexpr.patch"
+        "bug-1605181-isConstexpr.patch",
+        "bug-1606630-if_constexpr.patch"
     ]
 }

build/build-clang/clang-tidy-macosx64.json

@@ -18,6 +18,7 @@
       "clang-tidy-ci.patch",
       "clang-tidy-no-errors.patch",
       "compiler-rt-no-codesign.patch",
-      "bug-1605181-isConstexpr.patch"
+      "bug-1605181-isConstexpr.patch",
+      "bug-1606630-if_constexpr.patch"
     ]
 }

build/build-clang/clang-tidy-win64.json

@@ -11,6 +11,7 @@
     "patches": [
         "clang-tidy-ci.patch",
         "clang-tidy-no-errors.patch",
-        "bug-1605181-isConstexpr.patch"
+        "bug-1605181-isConstexpr.patch",
+        "bug-1606630-if_constexpr.patch"
     ]
 }