Modernizations and strictness improvements

src/patchelf.cc

@@ -24,6 +24,7 @@
 #include <sstream>
 #include <stdexcept>
 #include <string>
+#include <string_view>
 #include <unordered_map>
 #include <vector>
 #include <optional>
@@ -69,14 +70,18 @@ static int forcedPageSize = -1;
 #define EM_LOONGARCH    258
 #endif
 
-
-static std::vector<std::string> splitColonDelimitedString(const char * s)
+[[nodiscard]] static std::vector<std::string> splitColonDelimitedString(std::string_view s)
 {
-    std::string item;
     std::vector<std::string> parts;
-    std::stringstream ss(s);
-    while (std::getline(ss, item, ':'))
-        parts.push_back(item);
+
+    size_t pos;
+    while ((pos = s.find(':')) != std::string_view::npos) {
+        parts.emplace_back(s.substr(0, pos));
+        s = s.substr(pos + 1);
+    }
+
+    if (!s.empty())
+        parts.emplace_back(s);
 
     return parts;
 }
@@ -104,7 +109,7 @@ static std::string downcase(std::string s)
    why... */
 template<ElfFileParams>
 template<class I>
-I ElfFile<ElfFileParamNames>::rdi(I i) const
+constexpr I ElfFile<ElfFileParamNames>::rdi(I i) const noexcept
 {
     I r = 0;
     if (littleEndian) {
@@ -131,7 +136,7 @@ static void debug(const char * format, ...)
 }
 
 
-void fmt2(std::ostringstream & out)
+static void fmt2([[maybe_unused]] std::ostringstream & out)
 {
 }
 
@@ -191,11 +196,11 @@ static FileContents readFile(const std::string & fileName,
     while ((portion = read(fd, contents->data() + bytesRead, size - bytesRead)) > 0)
         bytesRead += portion;
 
+    close(fd);
+
     if (bytesRead != size)
         throw SysError(fmt("reading '", fileName, "'"));
 
-    close(fd);
-
     return contents;
 }
 
@@ -309,7 +314,7 @@ ElfFile<ElfFileParamNames>::ElfFile(FileContents fContents)
 
 
 template<ElfFileParams>
-unsigned int ElfFile<ElfFileParamNames>::getPageSize() const
+unsigned int ElfFile<ElfFileParamNames>::getPageSize() const noexcept
 {
     if (forcedPageSize > 0)
         return forcedPageSize;
@@ -555,7 +560,7 @@ std::optional<std::reference_wrapper<Elf_Shdr>> ElfFile<ElfFileParamNames>::tryF
 
 
 template<ElfFileParams>
-unsigned int ElfFile<ElfFileParamNames>::getSectionIndex(const SectionName & sectionName)
+unsigned int ElfFile<ElfFileParamNames>::getSectionIndex(const SectionName & sectionName) const
 {
     for (unsigned int i = 1; i < rdi(hdr()->e_shnum); ++i)
         if (getSectionName(shdrs.at(i)) == sectionName) return i;

src/patchelf.h

@@ -1,3 +1,12 @@
+#include <map>
+#include <memory>
+#include <optional>
+#include <set>
+#include <string>
+#include <vector>
+
+#include "elf.h"
+
 using FileContents = std::shared_ptr<std::vector<unsigned char>>;
 
 #define ElfFileParams class Elf_Ehdr, class Elf_Phdr, class Elf_Shdr, class Elf_Addr, class Elf_Off, class Elf_Dyn, class Elf_Sym, class Elf_Verneed, class Elf_Versym
@@ -30,14 +39,14 @@ class ElfFile
 
     /* Align on 4 or 8 bytes boundaries on 32- or 64-bit platforms
        respectively. */
-    size_t sectionAlignment = sizeof(Elf_Off);
+    static constexpr size_t sectionAlignment = sizeof(Elf_Off);
 
     std::vector<SectionName> sectionsByOldIndex;
 
 public:
     explicit ElfFile(FileContents fileContents);
 
-    bool isChanged()
+    [[nodiscard]] bool isChanged() const noexcept
     {
         return changed;
     }
@@ -46,8 +55,8 @@ class ElfFile
 
     struct CompPhdr
     {
-        ElfFile * elfFile;
-        bool operator ()(const Elf_Phdr & x, const Elf_Phdr & y)
+        const ElfFile * elfFile;
+        bool operator ()(const Elf_Phdr & x, const Elf_Phdr & y) const noexcept
         {
             // A PHDR comes before everything else.
             if (elfFile->rdi(y.p_type) == PT_PHDR) return false;
@@ -58,39 +67,35 @@ class ElfFile
         }
     };
 
-    friend struct CompPhdr;
-
     void sortPhdrs();
 
     struct CompShdr
     {
-        ElfFile * elfFile;
-        bool operator ()(const Elf_Shdr & x, const Elf_Shdr & y)
+        const ElfFile * elfFile;
+        bool operator ()(const Elf_Shdr & x, const Elf_Shdr & y) const noexcept
         {
             return elfFile->rdi(x.sh_offset) < elfFile->rdi(y.sh_offset);
         }
     };
 
-    friend struct CompShdr;
-
-    unsigned int getPageSize() const;
+    [[nodiscard]] unsigned int getPageSize() const noexcept;
 
     void sortShdrs();
 
     void shiftFile(unsigned int extraPages, size_t sizeOffset, size_t extraBytes);
 
-    std::string getSectionName(const Elf_Shdr & shdr) const;
+    [[nodiscard]] std::string getSectionName(const Elf_Shdr & shdr) const;
 
     Elf_Shdr & findSectionHeader(const SectionName & sectionName);
 
-    std::optional<std::reference_wrapper<Elf_Shdr>> tryFindSectionHeader(const SectionName & sectionName);
+    [[nodiscard]] std::optional<std::reference_wrapper<Elf_Shdr>> tryFindSectionHeader(const SectionName & sectionName);
 
-    unsigned int getSectionIndex(const SectionName & sectionName);
+    [[nodiscard]] unsigned int getSectionIndex(const SectionName & sectionName) const;
 
     std::string & replaceSection(const SectionName & sectionName,
         unsigned int size);
 
-    bool haveReplacedSection(const SectionName & sectionName) const;
+    [[nodiscard]] bool haveReplacedSection(const SectionName & sectionName) const;
 
     void writeReplacedSections(Elf_Off & curOff,
         Elf_Addr startAddr, Elf_Off startOffset);
@@ -107,7 +112,7 @@ class ElfFile
 
     void rewriteSections(bool force = false);
 
-    std::string getInterpreter();
+    [[nodiscard]] std::string getInterpreter();
 
     typedef enum { printOsAbi, replaceOsAbi } osAbiMode;
 
@@ -149,21 +154,21 @@ class ElfFile
        specified by the ELF header) to this platform's integer
        representation. */
     template<class I>
-    I rdi(I i) const;
+    constexpr I rdi(I i) const noexcept;
 
     /* Convert back to the ELF representation. */
     template<class I>
-    I wri(I & t, unsigned long long i) const
+    constexpr I wri(I & t, unsigned long long i) const
     {
         t = rdi((I) i);
         return i;
     }
 
-    Elf_Ehdr *hdr() {
-      return (Elf_Ehdr *)fileContents->data();
+    [[nodiscard]] Elf_Ehdr *hdr() noexcept {
+      return reinterpret_cast<Elf_Ehdr *>(fileContents->data());
     }
 
-    const Elf_Ehdr *hdr() const {
-      return (const Elf_Ehdr *)fileContents->data();
+    [[nodiscard]] const Elf_Ehdr *hdr() const noexcept {
+      return reinterpret_cast<const Elf_Ehdr *>(fileContents->data());
     }
 };