Various clang tidy warning fixes (#448)

* Fixed clang-tidy bugprone-reserved-identifier warnings

* Fixed clang-tidy bugprone-assert-side-effect warnings

* Fixed clang-tidy bugprone-copy-constructor-init warning

* Fixed clang-tidy readability-redundant-preprocessor warning

For error_test.c the removed code was already dead, because it was in the else of an `#if H5_USE_16_API` block.

Based on H5Location.h, I think p_get_ref_obj_type was meant to be in `#ifndef DOXYGEN_SHOULD_SKIP_THIS` and an `#endif` was missing.  Similarly, in the header, getObjTypeByIdx is only in H5_NO_DEPRECATED_SYMBOLS, not DOXYGEN_SHOULD_SKIP_THIS.

* Fixed clang-tidy readability-redundant-string-init warnings

* Fixed some clang-tidy performance-type-promotion-in-math-fn warnings

* Fixed clang-tidy performance-unnecessary-value-param warnings

* Reformat source with clang v10.0.1.

Co-authored-by: Larry Knox <lrknox@hdfgroup.org>

8 files changed, 13 insertions, 14 deletions

diff --git a/c++/src/H5Attribute.cpp b/c++/src/H5Attribute.cpp
index d893fec..b74349c 100644
--- a/c++/src/H5Attribute.cpp
+++ b/c++/src/H5Attribute.cpp
@@ -308,7 +308,7 @@ Attribute::getName(char *attr_name, size_t buf_size) const
 H5std_string
 Attribute::getName() const
 {
-    H5std_string attr_name(""); // attribute name to return
+    H5std_string attr_name; // attribute name to return
 
     // Preliminary call to get the size of the attribute name
     ssize_t name_size = H5Aget_name(id, static_cast<size_t>(0), NULL);
diff --git a/c++/src/H5DcreatProp.cpp b/c++/src/H5DcreatProp.cpp
index d670b74..0ffcbf7 100644
--- a/c++/src/H5DcreatProp.cpp
+++ b/c++/src/H5DcreatProp.cpp
@@ -769,8 +769,8 @@ DSetCreatPropList::setVirtual(const DataSpace &vspace, const char *src_fname, co
 // Programmer   Binh-Minh Ribler - Mar, 2017
 //--------------------------------------------------------------------------
 void
-DSetCreatPropList::setVirtual(const DataSpace &vspace, const H5std_string src_fname,
-                              const H5std_string src_dsname, const DataSpace &sspace) const
+DSetCreatPropList::setVirtual(const DataSpace &vspace, const H5std_string &src_fname,
+                              const H5std_string &src_dsname, const DataSpace &sspace) const
 {
     setVirtual(vspace, src_fname.c_str(), src_dsname.c_str(), sspace);
 }
diff --git a/c++/src/H5DcreatProp.h b/c++/src/H5DcreatProp.h
index 3c032ee..820c0d1 100644
--- a/c++/src/H5DcreatProp.h
+++ b/c++/src/H5DcreatProp.h
@@ -123,7 +123,7 @@ class H5_DLLCPP DSetCreatPropList : public ObjCreatPropList {
     // Maps elements of a virtual dataset to elements of the source dataset.
     void setVirtual(const DataSpace &vspace, const char *src_fname, const char *src_dsname,
                     const DataSpace &sspace) const;
-    void setVirtual(const DataSpace &vspace, const H5std_string src_fname, const H5std_string src_dsname,
+    void setVirtual(const DataSpace &vspace, const H5std_string &src_fname, const H5std_string &src_dsname,
                     const DataSpace &sspace) const;
 
     ///\brief Returns this class name.
diff --git a/c++/src/H5DxferProp.cpp b/c++/src/H5DxferProp.cpp
index d9d7884..98e6214 100644
--- a/c++/src/H5DxferProp.cpp
+++ b/c++/src/H5DxferProp.cpp
@@ -306,7 +306,7 @@ DSetMemXferPropList::getDataTransform() const
 {
     // Initialize string to "", so that if there is no expression, the returned
     // string will be empty
-    H5std_string expression("");
+    H5std_string expression;
 
     // Preliminary call to get the expression's length
     ssize_t exp_len = H5Pget_data_transform(id, NULL, (size_t)0);
diff --git a/c++/src/H5Exception.cpp b/c++/src/H5Exception.cpp
index 1aa8ecc..8ea20ff 100644
--- a/c++/src/H5Exception.cpp
+++ b/c++/src/H5Exception.cpp
@@ -25,7 +25,7 @@ const char Exception::DEFAULT_MSG[] = "No detailed information provided";
 ///\brief       Default constructor.
 // Programmer   Binh-Minh Ribler - 2000
 //--------------------------------------------------------------------------
-Exception::Exception() : detail_message(""), func_name("") {}
+Exception::Exception() {}
 
 //--------------------------------------------------------------------------
 // Function:    Exception overloaded constructor
diff --git a/c++/src/H5File.cpp b/c++/src/H5File.cpp
index bbdcd6b..e40cafe 100644
--- a/c++/src/H5File.cpp
+++ b/c++/src/H5File.cpp
@@ -178,7 +178,7 @@ H5File::H5File(hid_t existing_id) : Group()
 ///\param       original - IN: H5File instance to copy
 // December 2000
 //--------------------------------------------------------------------------
-H5File::H5File(const H5File &original) : Group()
+H5File::H5File(const H5File &original) : Group(original)
 {
     id = original.getId();
     incRefCount(); // increment number of references to this id
diff --git a/c++/src/H5Location.cpp b/c++/src/H5Location.cpp
index 2d14bfc..b136faa 100644
--- a/c++/src/H5Location.cpp
+++ b/c++/src/H5Location.cpp
@@ -346,7 +346,7 @@ H5Location::getComment(const char *name, size_t buf_size) const
 {
     // Initialize string to "", so that if there is no comment, the returned
     // string will be empty
-    H5std_string comment("");
+    H5std_string comment;
 
     // Preliminary call to get the comment's length
     ssize_t comment_len = H5Oget_comment_by_name(getId(), name, NULL, (size_t)0, H5P_DEFAULT);
@@ -398,6 +398,7 @@ H5Location::getComment(const H5std_string &name, size_t buf_size) const
 {
     return (getComment(name.c_str(), buf_size));
 }
+
 #ifndef DOXYGEN_SHOULD_SKIP_THIS
 
 //--------------------------------------------------------------------------
@@ -646,6 +647,7 @@ H5Location::p_get_obj_type(void *ref, H5R_type_t ref_type) const
     return (obj_type);
 }
 #endif // DOXYGEN_SHOULD_SKIP_THIS
+
 #endif /* H5_NO_DEPRECATED_SYMBOLS */
 
 //--------------------------------------------------------------------------
@@ -704,6 +706,7 @@ H5Location::p_get_ref_obj_type(void *ref, H5R_type_t ref_type) const
     }
     return (obj_type);
 }
+#endif // DOXYGEN_SHOULD_SKIP_THIS
 
 //--------------------------------------------------------------------------
 // Function:    H5Location::getRegion
@@ -1816,7 +1819,7 @@ H5Location::getLinkval(const char *name, size_t size) const
     H5L_info2_t  linkinfo;
     char *       value_C; // value in C string
     size_t       val_size = size;
-    H5std_string value    = "";
+    H5std_string value;
     herr_t       ret_value;
 
     // if user doesn't provide buffer size, determine it
@@ -2294,7 +2297,6 @@ H5Location::childObjVersion(const H5std_string &objname) const
 }
 
 #ifndef H5_NO_DEPRECATED_SYMBOLS
-#ifndef DOXYGEN_SHOULD_SKIP_THIS
 //--------------------------------------------------------------------------
 // Function:    H5Location::getObjTypeByIdx
 ///\brief       Returns the type of an object in this group, given the
@@ -2372,7 +2374,6 @@ H5Location::getObjTypeByIdx(hsize_t idx, H5std_string &type_name) const
     return (obj_type);
 }
 
-#endif // DOXYGEN_SHOULD_SKIP_THIS
 #endif /* H5_NO_DEPRECATED_SYMBOLS */
 
 //--------------------------------------------------------------------------
@@ -2433,6 +2434,4 @@ f_DataSpace_setId(DataSpace *dspace, hid_t new_id)
 //--------------------------------------------------------------------------
 H5Location::~H5Location() {}
 
-#endif // DOXYGEN_SHOULD_SKIP_THIS
-
 } // namespace H5
diff --git a/c++/src/H5Object.cpp b/c++/src/H5Object.cpp
index 725d1da..c2eba8d 100644
--- a/c++/src/H5Object.cpp
+++ b/c++/src/H5Object.cpp
@@ -477,7 +477,7 @@ H5Object::getObjName(char *obj_name, size_t buf_size) const
 H5std_string
 H5Object::getObjName() const
 {
-    H5std_string obj_name(""); // object name to return
+    H5std_string obj_name; // object name to return
 
     // Preliminary call to get the size of the object name
     ssize_t name_size = H5Iget_name(getId(), NULL, static_cast<size_t>(0));