base: Rename Section to Segment, and some of its members.

ELF is, in my opinion, the most important object file format gem5
currently understands, and in ELF terminolgy the blob of data that
needs to be loaded into memory to a particular location is called a
segment. A section is a software level view of what's in a region
of memory, and a single segment may contain multiple sections which
happen to follow each other in memory.

Change-Id: Ib810c5050723d5a96bd7550515b08ac695fb1b02
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/21462
Tested-by: kokoro <noreply+kokoro@google.com>
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Maintainer: Gabe Black <gabeblack@google.com>

10 files changed, 90 insertions, 102 deletions

diff --git a/src/base/loader/aout_object.cc b/src/base/loader/aout_object.cc
index b731c9a83..e3f703e1d 100644
--- a/src/base/loader/aout_object.cc
+++ b/src/base/loader/aout_object.cc
@@ -46,9 +46,8 @@ AoutObject::tryFile(const string &fname, size_t len, uint8_t *data)
         // right now this is only used for Alpha PAL code
         return new AoutObject(fname, len, data,
                               ObjectFile::Alpha, ObjectFile::UnknownOpSys);
-    }
-    else {
-        return NULL;
+    } else {
+        return nullptr;
     }
 }
 
@@ -62,21 +61,21 @@ AoutObject::AoutObject(const string &_filename,
 
     entry = execHdr->entry;
 
-    text.baseAddr = N_TXTADDR(*execHdr);
+    text.base = N_TXTADDR(*execHdr);
     text.size = execHdr->tsize;
-    text.fileImage = fileData + N_TXTOFF(*execHdr);
+    text.data = fileData + N_TXTOFF(*execHdr);
 
-    data.baseAddr = N_DATADDR(*execHdr);
+    data.base = N_DATADDR(*execHdr);
     data.size = execHdr->dsize;
-    data.fileImage = fileData + N_DATOFF(*execHdr);
+    data.data = fileData + N_DATOFF(*execHdr);
 
-    bss.baseAddr = N_BSSADDR(*execHdr);
+    bss.base = N_BSSADDR(*execHdr);
     bss.size = execHdr->bsize;
-    bss.fileImage = NULL;
+    bss.data = NULL;
 
     DPRINTFR(Loader, "text: 0x%x %d\ndata: 0x%x %d\nbss: 0x%x %d\n",
-             text.baseAddr, text.size, data.baseAddr, data.size,
-             bss.baseAddr, bss.size);
+             text.base, text.size, data.base, data.size,
+             bss.base, bss.size);
 }
 
 
diff --git a/src/base/loader/dtb_object.cc b/src/base/loader/dtb_object.cc
index fab6a762d..92e305ffa 100644
--- a/src/base/loader/dtb_object.cc
+++ b/src/base/loader/dtb_object.cc
@@ -55,17 +55,17 @@ DtbObject::DtbObject(const std::string &_filename, size_t _len, uint8_t *_data,
                      Arch _arch, OpSys _opSys)
     : ObjectFile(_filename, _len, _data, _arch, _opSys)
 {
-    text.baseAddr = 0;
+    text.base = 0;
     text.size = len;
-    text.fileImage = fileData;
+    text.data = fileData;
 
-    data.baseAddr = 0;
+    data.base = 0;
     data.size = 0;
-    data.fileImage = NULL;
+    data.data = nullptr;
 
-    bss.baseAddr = 0;
+    bss.base = 0;
     bss.size = 0;
-    bss.fileImage = NULL;
+    bss.data = nullptr;
 
     fileDataMmapped = true;
 }
@@ -141,7 +141,7 @@ DtbObject::addBootCmdLine(const char* _args, size_t len)
     }
 
     text.size = newLen;
-    text.fileImage = fdt_buf_w_space;
+    text.data = fdt_buf_w_space;
 
     // clean up old buffer and set to new fdt blob
     munmap(fileData, this->len);
diff --git a/src/base/loader/ecoff_object.cc b/src/base/loader/ecoff_object.cc
index caeab5f8f..76b91dd66 100644
--- a/src/base/loader/ecoff_object.cc
+++ b/src/base/loader/ecoff_object.cc
@@ -73,21 +73,21 @@ EcoffObject::EcoffObject(const string &_filename, size_t _len, uint8_t *_data,
 
     entry = aoutHdr->entry;
 
-    text.baseAddr = aoutHdr->text_start;
+    text.base = aoutHdr->text_start;
     text.size = aoutHdr->tsize;
-    text.fileImage = fileData + ECOFF_TXTOFF(execHdr);
+    text.data = fileData + ECOFF_TXTOFF(execHdr);
 
-    data.baseAddr = aoutHdr->data_start;
+    data.base = aoutHdr->data_start;
     data.size = aoutHdr->dsize;
-    data.fileImage = fileData + ECOFF_DATOFF(execHdr);
+    data.data = fileData + ECOFF_DATOFF(execHdr);
 
-    bss.baseAddr = aoutHdr->bss_start;
+    bss.base = aoutHdr->bss_start;
     bss.size = aoutHdr->bsize;
-    bss.fileImage = NULL;
+    bss.data = nullptr;
 
-    DPRINTFR(Loader, "text: 0x%x %d\ndata: 0x%x %d\nbss: 0x%x %d\n",
-             text.baseAddr, text.size, data.baseAddr, data.size,
-             bss.baseAddr, bss.size);
+    DPRINTFR(Loader, "text: %#x %d\ndata: %#x %d\nbss: %#x %d\n",
+             text.base, text.size, data.base, data.size,
+             bss.base, bss.size);
 }
 
 bool
diff --git a/src/base/loader/elf_object.cc b/src/base/loader/elf_object.cc
index 2a8fb04ea..327919540 100644
--- a/src/base/loader/elf_object.cc
+++ b/src/base/loader/elf_object.cc
@@ -295,7 +295,7 @@ ElfObject::ElfObject(const std::string &_filename, size_t _len,
 
     // initialize segment sizes to 0 in case they're not present
     text.size = data.size = bss.size = 0;
-    text.baseAddr = data.baseAddr = bss.baseAddr = 0;
+    text.base = data.base = bss.base = 0;
 
     int sec_idx = 1;
 
@@ -352,9 +352,9 @@ ElfObject::ElfObject(const std::string &_filename, size_t _len,
         if (phdr.p_paddr <= bss_sec_start &&
             phdr.p_paddr + phdr.p_memsz > bss_sec_start &&
             phdr.p_memsz - phdr.p_filesz > 0) {
-            bss.baseAddr = phdr.p_paddr + phdr.p_filesz;
+            bss.base = phdr.p_paddr + phdr.p_filesz;
             bss.size = phdr.p_memsz - phdr.p_filesz;
-            bss.fileImage = NULL;
+            bss.data = nullptr;
         }
 
         // Check to see if this is the text or data segment
@@ -365,21 +365,21 @@ ElfObject::ElfObject(const std::string &_filename, size_t _len,
             if (phdr.p_vaddr != 0)
                 relocate = false;
 
-            text.baseAddr = phdr.p_paddr;
+            text.base = phdr.p_paddr;
             text.size = phdr.p_filesz;
-            text.fileImage = fileData + phdr.p_offset;
+            text.data = fileData + phdr.p_offset;
         } else if (phdr.p_vaddr <= data_sec_start &&
                    phdr.p_vaddr + phdr.p_filesz > data_sec_start) {
-            data.baseAddr = phdr.p_paddr;
+            data.base = phdr.p_paddr;
             data.size = phdr.p_filesz;
-            data.fileImage = fileData + phdr.p_offset;
+            data.data = fileData + phdr.p_offset;
         } else {
             // If it's none of the above but is loadable,
             // load the filesize worth of data
             Segment extra;
-            extra.baseAddr = phdr.p_paddr;
+            extra.base = phdr.p_paddr;
             extra.size = phdr.p_filesz;
-            extra.fileImage = fileData + phdr.p_offset;
+            extra.data = fileData + phdr.p_offset;
             extraSegments.push_back(extra);
         }
     }
@@ -389,9 +389,9 @@ ElfObject::ElfObject(const std::string &_filename, size_t _len,
             "Empty .text segment in '%s'. ELF file corrupted?\n",
             filename);
 
-    DPRINTFR(Loader, "text: 0x%x %d\ndata: 0x%x %d\nbss: 0x%x %d\n",
-             text.baseAddr, text.size, data.baseAddr, data.size,
-             bss.baseAddr, bss.size);
+    DPRINTFR(Loader, "text: %#x %d\ndata: %#x %d\nbss: %#x %d\n",
+             text.base, text.size, data.base, data.size,
+             bss.base, bss.size);
 
     elf_end(elf);
 
@@ -498,20 +498,20 @@ ElfObject::loadWeakSymbols(SymbolTable *symtab, Addr base, Addr offset,
 }
 
 bool
-ElfObject::loadSections(const PortProxy& mem_proxy, Addr addr_mask,
+ElfObject::loadSegments(const PortProxy& mem_proxy, Addr addr_mask,
                         Addr offset)
 {
-    if (!ObjectFile::loadSections(mem_proxy, addr_mask, offset))
+    if (!ObjectFile::loadSegments(mem_proxy, addr_mask, offset))
         return false;
 
     for (auto seg : extraSegments) {
-        if (!loadSection(&seg, mem_proxy, addr_mask, offset)) {
+        if (!loadSegment(&seg, mem_proxy, addr_mask, offset)) {
             return false;
         }
     }
 
     if (interpreter)
-        interpreter->loadSections(mem_proxy, addr_mask, offset);
+        interpreter->loadSegments(mem_proxy, addr_mask, offset);
 
     return true;
 }
@@ -570,9 +570,9 @@ ElfObject::updateBias(Addr bias_addr)
     entry += bias_addr;
 
     // Patch segments with the bias_addr.
-    text.baseAddr += bias_addr;
-    data.baseAddr += bias_addr;
-    bss.baseAddr  += bias_addr;
+    text.base += bias_addr;
+    data.base += bias_addr;
+    bss.base  += bias_addr;
     for (auto &segment : extraSegments)
-        segment.baseAddr += bias_addr;
+        segment.base += bias_addr;
 }
diff --git a/src/base/loader/elf_object.hh b/src/base/loader/elf_object.hh
index 9585684d4..244b9fc3f 100644
--- a/src/base/loader/elf_object.hh
+++ b/src/base/loader/elf_object.hh
@@ -51,9 +51,6 @@
 class ElfObject : public ObjectFile
 {
   protected:
-    // The global definition of a gem5 "Section" is closest to ELF's segments.
-    typedef ObjectFile::Section Segment;
-
     // These values are provided to a linux process by the kernel, so we
     // need to keep them around.
     Addr _programHeaderTable;
@@ -94,7 +91,7 @@ class ElfObject : public ObjectFile
   public:
     virtual ~ElfObject() {}
 
-    bool loadSections(const PortProxy& mem_proxy, Addr addr_mask = maxAddr,
+    bool loadSegments(const PortProxy& mem_proxy, Addr addr_mask = maxAddr,
                       Addr offset = 0) override;
 
     virtual bool loadAllSymbols(SymbolTable *symtab, Addr base = 0,
diff --git a/src/base/loader/hex_file.cc b/src/base/loader/hex_file.cc
index 32de90588..4c9ffa516 100644
--- a/src/base/loader/hex_file.cc
+++ b/src/base/loader/hex_file.cc
@@ -62,7 +62,7 @@ HexFile::~HexFile()
 }
 
 bool
-HexFile::loadSections(PortProxy& memProxy)
+HexFile::loadSegments(PortProxy& memProxy)
 {
     char Line[64];
     Addr MemAddr;
diff --git a/src/base/loader/hex_file.hh b/src/base/loader/hex_file.hh
index fe34fddf0..befd7f320 100644
--- a/src/base/loader/hex_file.hh
+++ b/src/base/loader/hex_file.hh
@@ -52,7 +52,7 @@ class HexFile
     virtual ~HexFile();
 
     void close();
-    bool loadSections(PortProxy& memProxy);
+    bool loadSegments(PortProxy& memProxy);
 };
 
 #endif // __BASE_LOADER_HEX_FILE_HH__
diff --git a/src/base/loader/object_file.cc b/src/base/loader/object_file.cc
index 0bb897cee..8a6b063de 100644
--- a/src/base/loader/object_file.cc
+++ b/src/base/loader/object_file.cc
@@ -73,17 +73,16 @@ ObjectFile::~ObjectFile()
 
 
 bool
-ObjectFile::loadSection(Section *sec, const PortProxy& mem_proxy,
+ObjectFile::loadSegment(Segment *seg, const PortProxy& mem_proxy,
                         Addr addr_mask, Addr offset)
 {
-    if (sec->size != 0) {
-        Addr addr = (sec->baseAddr & addr_mask) + offset;
-        if (sec->fileImage) {
-            mem_proxy.writeBlob(addr, sec->fileImage, sec->size);
-        }
-        else {
+    if (seg->size != 0) {
+        Addr addr = (seg->base & addr_mask) + offset;
+        if (seg->data) {
+            mem_proxy.writeBlob(addr, seg->data, seg->size);
+        } else {
             // no image: must be bss
-            mem_proxy.memsetBlob(addr, 0, sec->size);
+            mem_proxy.memsetBlob(addr, 0, seg->size);
         }
     }
     return true;
@@ -91,12 +90,12 @@ ObjectFile::loadSection(Section *sec, const PortProxy& mem_proxy,
 
 
 bool
-ObjectFile::loadSections(const PortProxy& mem_proxy, Addr addr_mask,
+ObjectFile::loadSegments(const PortProxy& mem_proxy, Addr addr_mask,
                          Addr offset)
 {
-    return (loadSection(&text, mem_proxy, addr_mask, offset)
-            && loadSection(&data, mem_proxy, addr_mask, offset)
-            && loadSection(&bss, mem_proxy, addr_mask, offset));
+    return (loadSegment(&text, mem_proxy, addr_mask, offset)
+            && loadSegment(&data, mem_proxy, addr_mask, offset)
+            && loadSegment(&bss, mem_proxy, addr_mask, offset));
 }
 
 namespace
diff --git a/src/base/loader/object_file.hh b/src/base/loader/object_file.hh
index 14dee3be0..db995f5d7 100644
--- a/src/base/loader/object_file.hh
+++ b/src/base/loader/object_file.hh
@@ -88,17 +88,17 @@ class ObjectFile
 
     static const Addr maxAddr = std::numeric_limits<Addr>::max();
 
-    virtual bool loadSections(const PortProxy& mem_proxy,
-                              Addr mask = maxAddr, Addr offset = 0);
+    virtual bool loadSegments(const PortProxy &mem_proxy,
+                              Addr mask=maxAddr, Addr offset=0);
 
     virtual bool loadAllSymbols(SymbolTable *symtab, Addr base = 0,
-                                Addr offset = 0, Addr mask = maxAddr) = 0;
+                                Addr offset=0, Addr mask=maxAddr) = 0;
     virtual bool loadGlobalSymbols(SymbolTable *symtab, Addr base = 0,
-                                   Addr offset = 0, Addr mask = maxAddr) = 0;
-    virtual bool loadLocalSymbols(SymbolTable *symtab, Addr base = 0,
-                                  Addr offset = 0, Addr mask = maxAddr) = 0;
-    virtual bool loadWeakSymbols(SymbolTable *symtab, Addr base = 0,
-                                 Addr offset = 0, Addr mask = maxAddr)
+                                   Addr offset=0, Addr mask=maxAddr) = 0;
+    virtual bool loadLocalSymbols(SymbolTable *symtab, Addr base=0,
+                                  Addr offset=0, Addr mask=maxAddr) = 0;
+    virtual bool loadWeakSymbols(SymbolTable *symtab, Addr base=0,
+                                 Addr offset=0, Addr mask=maxAddr)
     { return false; }
 
     virtual ObjectFile *getInterpreter() const { return nullptr; }
@@ -116,27 +116,28 @@ class ObjectFile
 
   protected:
 
-    struct Section {
-        Addr baseAddr;
-        uint8_t *fileImage;
+    struct Segment
+    {
+        Addr base;
+        uint8_t *data;
         size_t size;
     };
 
     Addr entry;
 
-    Section text;
-    Section data;
-    Section bss;
+    Segment text;
+    Segment data;
+    Segment bss;
 
-    bool loadSection(Section *sec, const PortProxy& mem_proxy, Addr mask,
-                     Addr offset = 0);
+    bool loadSegment(Segment *seg, const PortProxy &mem_proxy, Addr mask,
+                     Addr offset=0);
 
   public:
     Addr entryPoint() const { return entry; }
 
-    Addr textBase() const { return text.baseAddr; }
-    Addr dataBase() const { return data.baseAddr; }
-    Addr bssBase() const { return bss.baseAddr; }
+    Addr textBase() const { return text.base; }
+    Addr dataBase() const { return data.base; }
+    Addr bssBase() const { return bss.base; }
 
     size_t textSize() const { return text.size; }
     size_t dataSize() const { return data.size; }
@@ -147,7 +148,7 @@ class ObjectFile
      * blob that doesn't include an object header.
      * @param a address to load the binary/text section at
      */
-    void setTextBase(Addr a) { text.baseAddr = a; }
+    void setTextBase(Addr a) { text.base = a; }
 
     /**
      * Each instance of a Loader subclass will have a chance to try to load
diff --git a/src/base/loader/raw_object.cc b/src/base/loader/raw_object.cc
index 4a04f7dfc..9662d8613 100644
--- a/src/base/loader/raw_object.cc
+++ b/src/base/loader/raw_object.cc
@@ -45,21 +45,21 @@ RawObject::RawObject(const std::string &_filename, size_t _len,
         uint8_t *_data, Arch _arch, OpSys _opSys)
     : ObjectFile(_filename, _len, _data, _arch, _opSys)
 {
-    text.baseAddr = 0;
+    text.base = 0;
     text.size = len;
-    text.fileImage = fileData;
+    text.data = fileData;
 
-    data.baseAddr = 0;
+    data.base = 0;
     data.size = 0;
-    data.fileImage = NULL;
+    data.data = nullptr;
 
-    bss.baseAddr = 0;
+    bss.base = 0;
     bss.size = 0;
-    bss.fileImage = NULL;
+    bss.data = nullptr;
 
-    DPRINTFR(Loader, "text: 0x%x %d\ndata: 0x%x %d\nbss: 0x%x %d\n",
-             text.baseAddr, text.size, data.baseAddr, data.size,
-             bss.baseAddr, bss.size);
+    DPRINTFR(Loader, "text: %#x %d\ndata: %#x %d\nbss: %#x %d\n",
+             text.base, text.size, data.base, data.size,
+             bss.base, bss.size);
 }
 
 bool
@@ -73,10 +73,6 @@ bool
 RawObject::loadGlobalSymbols(SymbolTable *symtab, Addr base, Addr offset,
                              Addr addr_mask)
 {
-/*    int fnameStart = filename.rfind('/',filename.size()) + 1;
-    int extStart = filename.rfind('.',filename.size());
-    symtab->insert(text.baseAddr & addr_mask, filename.substr(fnameStart,
-                extStart-fnameStart) + "_start");*/
     return true;
 }
 
@@ -84,9 +80,5 @@ bool
 RawObject::loadLocalSymbols(SymbolTable *symtab, Addr base, Addr offset,
                             Addr addr_mask)
 {
-/*    int fnameStart = filename.rfind('/',filename.size()) + 1;
-    int extStart = filename.rfind('.',filename.size());
-    symtab->insert(text.baseAddr & addr_mask, filename.substr(fnameStart,
-                extStart-fnameStart) + "_start");*/
     return true;
 }