diff options
| author | Kartik Agaram <vc@akkartik.com> | 2018-10-02 01:21:01 -0700 |
|---|---|---|
| committer | Kartik Agaram <vc@akkartik.com> | 2018-10-02 01:21:32 -0700 |
| commit | 5a2cb154eb016aa8b84ad939f63eb56dd7a0a90f (patch) | |
| tree | 61701a7d8ec8bba5d9b7d5fc2d2e1496b74c5a0c /html/subx/034compute_segment_address.cc.html | |
| parent | 29ab43973a2e9822d84b564e314b4af5c58c4684 (diff) | |
| download | mu-5a2cb154eb016aa8b84ad939f63eb56dd7a0a90f.tar.gz | |
4649
Diffstat (limited to 'html/subx/034compute_segment_address.cc.html')
| -rw-r--r-- | html/subx/034compute_segment_address.cc.html | 211 |
1 files changed, 139 insertions, 72 deletions
diff --git a/html/subx/034compute_segment_address.cc.html b/html/subx/034compute_segment_address.cc.html index d5111bef..e8820050 100644 --- a/html/subx/034compute_segment_address.cc.html +++ b/html/subx/034compute_segment_address.cc.html @@ -15,11 +15,11 @@ body { font-size: 12pt; font-family: monospace; color: #aaaaaa; background-color a { color:#eeeeee; text-decoration: none; } a:hover { text-decoration: underline; } * { font-size: 12pt; font-size: 1em; } +.cSpecial { color: #008000; } .traceContains { color: #008000; } .LineNr { color: #444444; } .Constant { color: #00a0a0; } .Delimiter { color: #800080; } -.Special { color: #c00000; } .Identifier { color: #c0a020; } .Normal { color: #aaaaaa; background-color: #080808; padding-bottom: 1px; } .Comment { color: #9090ff; } @@ -59,77 +59,144 @@ if ('onhashchange' in window) { </head> <body onload='JumpToLine();'> <pre id='vimCodeElement'> -<span id="L1" class="LineNr"> 1 </span><span class="Comment">//: Start allowing us to not specify precise addresses for the start of each</span> -<span id="L2" class="LineNr"> 2 </span><span class="Comment">//: segment.</span> -<span id="L3" class="LineNr"> 3 </span><span class="Comment">//: This gives up a measure of control in placing code and data.</span> -<span id="L4" class="LineNr"> 4 </span> -<span id="L5" class="LineNr"> 5 </span><span class="Comment">//: segment address computation requires setting Mem_offset in test mode to what it'll be in run mode</span> -<span id="L6" class="LineNr"> 6 </span><span class="Delimiter">:(scenario segment_name)</span> -<span id="L7" class="LineNr"> 7 </span><span class="Special">% Mem_offset = CODE_START;</span> -<span id="L8" class="LineNr"> 8 </span>== <a href='031check_operands.cc.html#L14'>code</a> -<span id="L9" class="LineNr"> 9 </span><span class="PreProc">0</span><span class="Constant">5</span>/add <span class="Constant">0x0d0c0b0a</span>/imm32 <span class="Comment"># add 0x0d0c0b0a to EAX</span> -<span id="L10" class="LineNr">10 </span><span class="Comment"># code starts at 0x08048000 + p_offset, which is 0x54 for a single-segment binary</span> -<span id="L11" class="LineNr">11 </span><span class="traceContains">+load: 0x08048054 -> 05</span> -<span id="L12" class="LineNr">12 </span><span class="traceContains">+load: 0x08048055 -> 0a</span> -<span id="L13" class="LineNr">13 </span><span class="traceContains">+load: 0x08048056 -> 0b</span> -<span id="L14" class="LineNr">14 </span><span class="traceContains">+load: 0x08048057 -> 0c</span> -<span id="L15" class="LineNr">15 </span><span class="traceContains">+load: 0x08048058 -> 0d</span> -<span id="L16" class="LineNr">16 </span><span class="traceContains">+run: add imm32 0x0d0c0b0a to <a href='010---vm.cc.html#L23'>reg</a> <a href='010---vm.cc.html#L13'>EAX</a></span> -<span id="L17" class="LineNr">17 </span><span class="traceContains">+run: storing 0x0d0c0b0a</span> -<span id="L18" class="LineNr">18 </span> -<span id="L19" class="LineNr">19 </span><span class="Delimiter">:(before "End Level-2 Transforms")</span> -<span id="L20" class="LineNr">20 </span><a href='011run.cc.html#L207'>Transform</a><span class="Delimiter">.</span>push_back<span class="Delimiter">(</span><a href='034compute_segment_address.cc.html#L23'>compute_segment_starts</a><span class="Delimiter">);</span> -<span id="L21" class="LineNr">21 </span> -<span id="L22" class="LineNr">22 </span><span class="Delimiter">:(code)</span> -<span id="L23" class="LineNr">23 </span><span class="Normal">void</span> <a href='034compute_segment_address.cc.html#L23'>compute_segment_starts</a><span class="Delimiter">(</span>program& p<span class="Delimiter">)</span> <span class="Delimiter">{</span> -<span id="L24" class="LineNr">24 </span> <a href='003trace.cc.html#L204'>trace</a><span class="Delimiter">(</span><span class="Constant">99</span><span class="Delimiter">,</span> <span class="Constant">"transform"</span><span class="Delimiter">)</span> << <span class="Constant">"-- compute segment addresses"</span> << <a href='003trace.cc.html#L230'>end</a><span class="Delimiter">();</span> -<span id="L25" class="LineNr">25 </span> <span class="Normal">uint32_t</span> p_offset = <span class="Comment">/*</span><span class="Comment">size of ehdr</span><span class="Comment">*/</span><span class="Constant">0x34</span> + <a href='001help.cc.html#L157'>SIZE</a><span class="Delimiter">(</span>p<span class="Delimiter">.</span><a href='011run.cc.html#L100'>segments</a><span class="Delimiter">)</span>*<span class="Constant">0x20</span><span class="Comment">/*</span><span class="Comment">size of each phdr</span><span class="Comment">*/</span><span class="Delimiter">;</span> -<span id="L26" class="LineNr">26 </span> <span class="Normal">for</span> <span class="Delimiter">(</span><span class="Normal">size_t</span> i = <span class="Constant">0</span><span class="Delimiter">;</span> i < p<span class="Delimiter">.</span><a href='011run.cc.html#L100'>segments</a><span class="Delimiter">.</span>size<span class="Delimiter">();</span> ++i<span class="Delimiter">)</span> <span class="Delimiter">{</span> -<span id="L27" class="LineNr">27 </span> segment& curr = p<span class="Delimiter">.</span><a href='011run.cc.html#L100'>segments</a><span class="Delimiter">.</span>at<span class="Delimiter">(</span>i<span class="Delimiter">);</span> -<span id="L28" class="LineNr">28 </span> <span class="Normal">if</span> <span class="Delimiter">(</span>curr<span class="Delimiter">.</span><a href='011run.cc.html#L108'>start</a> == <span class="Constant">0</span><span class="Delimiter">)</span> <span class="Delimiter">{</span> -<span id="L29" class="LineNr">29 </span> curr<span class="Delimiter">.</span><a href='011run.cc.html#L108'>start</a> = <a href='012elf.cc.html#L126'>CODE_START</a> + i*SEGMENT_SIZE + p_offset<span class="Delimiter">;</span> -<span id="L30" class="LineNr">30 </span> <a href='003trace.cc.html#L204'>trace</a><span class="Delimiter">(</span><span class="Constant">99</span><span class="Delimiter">,</span> <span class="Constant">"transform"</span><span class="Delimiter">)</span> << <span class="Constant">"segment "</span> << i << <span class="Constant">" begins at address 0x"</span> << <a href='010---vm.cc.html#L260'>HEXWORD</a> << curr<span class="Delimiter">.</span><a href='011run.cc.html#L108'>start</a> << <a href='003trace.cc.html#L230'>end</a><span class="Delimiter">();</span> -<span id="L31" class="LineNr">31 </span> <span class="Delimiter">}</span> -<span id="L32" class="LineNr">32 </span> p_offset += <a href='034compute_segment_address.cc.html#L37'>size_of</a><span class="Delimiter">(</span>curr<span class="Delimiter">);</span> -<span id="L33" class="LineNr">33 </span> assert<span class="Delimiter">(</span>p_offset < <a href='012elf.cc.html#L127'>SEGMENT_SIZE</a><span class="Delimiter">);</span> <span class="Comment">// for now we get less and less available space in each successive segment</span> -<span id="L34" class="LineNr">34 </span> <span class="Delimiter">}</span> -<span id="L35" class="LineNr">35 </span><span class="Delimiter">}</span> -<span id="L36" class="LineNr">36 </span> -<span id="L37" class="LineNr">37 </span><span class="Normal">uint32_t</span> <a href='034compute_segment_address.cc.html#L37'>size_of</a><span class="Delimiter">(</span><span class="Normal">const</span> segment& s<span class="Delimiter">)</span> <span class="Delimiter">{</span> -<span id="L38" class="LineNr">38 </span> <span class="Normal">uint32_t</span> sum = <span class="Constant">0</span><span class="Delimiter">;</span> -<span id="L39" class="LineNr">39 </span> <span class="Normal">for</span> <span class="Delimiter">(</span><span class="Normal">int</span> i = <span class="Constant">0</span><span class="Delimiter">;</span> i < <a href='001help.cc.html#L157'>SIZE</a><span class="Delimiter">(</span>s<span class="Delimiter">.</span><a href='011run.cc.html#L109'>lines</a><span class="Delimiter">);</span> ++i<span class="Delimiter">)</span> -<span id="L40" class="LineNr">40 </span> sum += <a href='034compute_segment_address.cc.html#L45'>num_bytes</a><span class="Delimiter">(</span>s<span class="Delimiter">.</span><a href='011run.cc.html#L109'>lines</a><span class="Delimiter">.</span>at<span class="Delimiter">(</span>i<span class="Delimiter">));</span> -<span id="L41" class="LineNr">41 </span> <span class="Identifier">return</span> sum<span class="Delimiter">;</span> -<span id="L42" class="LineNr">42 </span><span class="Delimiter">}</span> -<span id="L43" class="LineNr">43 </span> -<span id="L44" class="LineNr">44 </span><span class="Comment">// Assumes all bitfields are packed.</span> -<span id="L45" class="LineNr">45 </span><span class="Normal">uint32_t</span> <a href='034compute_segment_address.cc.html#L45'>num_bytes</a><span class="Delimiter">(</span><span class="Normal">const</span> line& inst<span class="Delimiter">)</span> <span class="Delimiter">{</span> -<span id="L46" class="LineNr">46 </span> <span class="Normal">uint32_t</span> sum = <span class="Constant">0</span><span class="Delimiter">;</span> -<span id="L47" class="LineNr">47 </span> <span class="Normal">for</span> <span class="Delimiter">(</span><span class="Normal">int</span> i = <span class="Constant">0</span><span class="Delimiter">;</span> i < <a href='001help.cc.html#L157'>SIZE</a><span class="Delimiter">(</span>inst<span class="Delimiter">.</span><a href='011run.cc.html#L118'>words</a><span class="Delimiter">);</span> ++i<span class="Delimiter">)</span> <span class="Delimiter">{</span> -<span id="L48" class="LineNr">48 </span> <span class="Normal">const</span> word& curr = inst<span class="Delimiter">.</span><a href='011run.cc.html#L118'>words</a><span class="Delimiter">.</span>at<span class="Delimiter">(</span>i<span class="Delimiter">);</span> -<span id="L49" class="LineNr">49 </span> <span class="Normal">if</span> <span class="Delimiter">(</span>has_operand_metadata<span class="Delimiter">(</span>curr<span class="Delimiter">,</span> <span class="Constant">"disp32"</span><span class="Delimiter">)</span> || has_operand_metadata<span class="Delimiter">(</span>curr<span class="Delimiter">,</span> <span class="Constant">"imm32"</span><span class="Delimiter">))</span> <span class="Comment">// only multi-byte operands</span> -<span id="L50" class="LineNr">50 </span> sum += <span class="Constant">4</span><span class="Delimiter">;</span> -<span id="L51" class="LineNr">51 </span> <span class="Comment">// End num_bytes(curr) Special-cases</span> -<span id="L52" class="LineNr">52 </span> <span class="Normal">else</span> -<span id="L53" class="LineNr">53 </span> sum++<span class="Delimiter">;</span> -<span id="L54" class="LineNr">54 </span> <span class="Delimiter">}</span> -<span id="L55" class="LineNr">55 </span> <span class="Identifier">return</span> sum<span class="Delimiter">;</span> -<span id="L56" class="LineNr">56 </span><span class="Delimiter">}</span> -<span id="L57" class="LineNr">57 </span> -<span id="L58" class="LineNr">58 </span><span class="Comment">//: Dependencies:</span> -<span id="L59" class="LineNr">59 </span><span class="Comment">//: - We'd like to compute segment addresses before setting up global variables,</span> -<span id="L60" class="LineNr">60 </span><span class="Comment">//: because computing addresses for global variables requires knowing where</span> -<span id="L61" class="LineNr">61 </span><span class="Comment">//: the data segment starts.</span> -<span id="L62" class="LineNr">62 </span><span class="Comment">//: - We'd like to finish expanding labels before computing segment addresses,</span> -<span id="L63" class="LineNr">63 </span><span class="Comment">//: because it would make computing the sizes of segments more self-contained</span> -<span id="L64" class="LineNr">64 </span><span class="Comment">//: (num_bytes).</span> -<span id="L65" class="LineNr">65 </span><span class="Comment">//:</span> -<span id="L66" class="LineNr">66 </span><span class="Comment">//: Decision: compute segment addresses before expanding labels, by being</span> -<span id="L67" class="LineNr">67 </span><span class="Comment">//: aware in this layer of certain operand types that will eventually occupy</span> -<span id="L68" class="LineNr">68 </span><span class="Comment">//: multiple bytes.</span> -<span id="L69" class="LineNr">69 </span><span class="Comment">//:</span> -<span id="L70" class="LineNr">70 </span><span class="Comment">//: The layer to expand labels later hooks into num_bytes() to teach this</span> -<span id="L71" class="LineNr">71 </span><span class="Comment">//: layer that labels occupy zero space in the binary.</span> +<span id="L1" class="LineNr"> 1 </span><span class="Comment">//: Start allowing us to not specify precise addresses for the start of each</span> +<span id="L2" class="LineNr"> 2 </span><span class="Comment">//: segment.</span> +<span id="L3" class="LineNr"> 3 </span><span class="Comment">//: This gives up a measure of control in placing code and data.</span> +<span id="L4" class="LineNr"> 4 </span> +<span id="L5" class="LineNr"> 5 </span><span class="Delimiter">:(scenario segment_name)</span> +<span id="L6" class="LineNr"> 6 </span>== <a href='031check_operands.cc.html#L14'>code</a> +<span id="L7" class="LineNr"> 7 </span><span class="PreProc">0</span><span class="Constant">5</span>/add <span class="Constant">0x0d0c0b0a</span>/imm32 <span class="Comment"># add 0x0d0c0b0a to EAX</span> +<span id="L8" class="LineNr"> 8 </span><span class="Comment"># code starts at 0x08048000 + p_offset, which is 0x54 for a single-segment binary</span> +<span id="L9" class="LineNr"> 9 </span><span class="traceContains">+load: 0x08048054 -> 05</span> +<span id="L10" class="LineNr"> 10 </span><span class="traceContains">+load: 0x08048055 -> 0a</span> +<span id="L11" class="LineNr"> 11 </span><span class="traceContains">+load: 0x08048056 -> 0b</span> +<span id="L12" class="LineNr"> 12 </span><span class="traceContains">+load: 0x08048057 -> 0c</span> +<span id="L13" class="LineNr"> 13 </span><span class="traceContains">+load: 0x08048058 -> 0d</span> +<span id="L14" class="LineNr"> 14 </span><span class="traceContains">+run: add imm32 0x0d0c0b0a to <a href='010---vm.cc.html#L23'>reg</a> <a href='010---vm.cc.html#L13'>EAX</a></span> +<span id="L15" class="LineNr"> 15 </span><span class="traceContains">+run: storing 0x0d0c0b0a</span> +<span id="L16" class="LineNr"> 16 </span> +<span id="L17" class="LineNr"> 17 </span><span class="Comment">//: Update the parser to handle non-numeric segment name.</span> +<span id="L18" class="LineNr"> 18 </span><span class="Comment">//:</span> +<span id="L19" class="LineNr"> 19 </span><span class="Comment">//: We'll also support repeated segments with non-numeric names.</span> +<span id="L20" class="LineNr"> 20 </span><span class="Comment">//: When we encounter a new reference to an existing segment we'll *prepend*</span> +<span id="L21" class="LineNr"> 21 </span><span class="Comment">//: the new data to existing data for the segment.</span> +<span id="L22" class="LineNr"> 22 </span> +<span id="L23" class="LineNr"> 23 </span><span class="Delimiter">:(before "End Globals")</span> +<span id="L24" class="LineNr"> 24 </span>map<<span class="Comment">/*</span><span class="Comment"><a href='010---vm.cc.html#L336'>name</a></span><span class="Comment">*/</span>string<span class="Delimiter">,</span> <span class="Normal">int</span>> <a href='034compute_segment_address.cc.html#L24'>Segment_index</a><span class="Delimiter">;</span> +<span id="L25" class="LineNr"> 25 </span><span class="Normal">bool</span> <a href='034compute_segment_address.cc.html#L25'>Currently_parsing_named_segment</a> =<span class="Constant"> false</span><span class="Delimiter">;</span> <span class="Comment">// global to permit cross-layer communication</span> +<span id="L26" class="LineNr"> 26 </span><span class="Normal">int</span> <a href='034compute_segment_address.cc.html#L26'>Currently_parsing_segment_index</a> = -<span class="Constant">1</span><span class="Delimiter">;</span> <span class="Comment">// global to permit cross-layer communication</span> +<span id="L27" class="LineNr"> 27 </span><span class="Delimiter">:(before "End Reset")</span> +<span id="L28" class="LineNr"> 28 </span><a href='034compute_segment_address.cc.html#L24'>Segment_index</a><span class="Delimiter">.</span>clear<span class="Delimiter">();</span> +<span id="L29" class="LineNr"> 29 </span><a href='034compute_segment_address.cc.html#L25'>Currently_parsing_named_segment</a> =<span class="Constant"> false</span><span class="Delimiter">;</span> +<span id="L30" class="LineNr"> 30 </span><a href='034compute_segment_address.cc.html#L26'>Currently_parsing_segment_index</a> = -<span class="Constant">1</span><span class="Delimiter">;</span> +<span id="L31" class="LineNr"> 31 </span> +<span id="L32" class="LineNr"> 32 </span><span class="Delimiter">:(before "End Segment Parsing Special-cases(segment_title)")</span> +<span id="L33" class="LineNr"> 33 </span><span class="Normal">if</span> <span class="Delimiter">(</span>!starts_with<span class="Delimiter">(</span>segment_title<span class="Delimiter">,</span> <span class="Constant">"0x"</span><span class="Delimiter">))</span> <span class="Delimiter">{</span> +<span id="L34" class="LineNr"> 34 </span> <a href='034compute_segment_address.cc.html#L25'>Currently_parsing_named_segment</a> =<span class="Constant"> true</span><span class="Delimiter">;</span> +<span id="L35" class="LineNr"> 35 </span> <span class="Normal">if</span> <span class="Delimiter">(</span>!contains_key<span class="Delimiter">(</span><a href='034compute_segment_address.cc.html#L24'>Segment_index</a><span class="Delimiter">,</span> segment_title<span class="Delimiter">))</span> <span class="Delimiter">{</span> +<span id="L36" class="LineNr"> 36 </span> <a href='003trace.cc.html#L204'>trace</a><span class="Delimiter">(</span><span class="Constant">99</span><span class="Delimiter">,</span> <span class="Constant">"parse"</span><span class="Delimiter">)</span> << <span class="Constant">"new segment '"</span> << segment_title << <span class="Constant">"'"</span> << end<span class="Delimiter">();</span> +<span id="L37" class="LineNr"> 37 </span> <span class="Normal">if</span> <span class="Delimiter">(</span>segment_title == <span class="Constant">"code"</span><span class="Delimiter">)</span> +<span id="L38" class="LineNr"> 38 </span> <a href='001help.cc.html#L243'>put</a><span class="Delimiter">(</span><a href='034compute_segment_address.cc.html#L24'>Segment_index</a><span class="Delimiter">,</span> segment_title<span class="Delimiter">,</span> <span class="Constant">0</span><span class="Delimiter">);</span> +<span id="L39" class="LineNr"> 39 </span> <span class="Normal">else</span> <span class="Normal">if</span> <span class="Delimiter">(</span>segment_title == <span class="Constant">"data"</span><span class="Delimiter">)</span> +<span id="L40" class="LineNr"> 40 </span> <a href='001help.cc.html#L243'>put</a><span class="Delimiter">(</span><a href='034compute_segment_address.cc.html#L24'>Segment_index</a><span class="Delimiter">,</span> segment_title<span class="Delimiter">,</span> <span class="Constant">1</span><span class="Delimiter">);</span> +<span id="L41" class="LineNr"> 41 </span> <span class="Normal">else</span> +<span id="L42" class="LineNr"> 42 </span> <a href='001help.cc.html#L243'>put</a><span class="Delimiter">(</span><a href='034compute_segment_address.cc.html#L24'>Segment_index</a><span class="Delimiter">,</span> segment_title<span class="Delimiter">,</span> max<span class="Delimiter">(</span><span class="Constant">2</span><span class="Delimiter">,</span> <a href='001help.cc.html#L157'>SIZE</a><span class="Delimiter">(</span>out<span class="Delimiter">.</span><a href='011run.cc.html#L100'>segments</a><span class="Delimiter">)));</span> +<span id="L43" class="LineNr"> 43 </span> out<span class="Delimiter">.</span><a href='011run.cc.html#L100'>segments</a><span class="Delimiter">.</span>push_back<span class="Delimiter">(</span>segment<span class="Delimiter">());</span> +<span id="L44" class="LineNr"> 44 </span> <span class="Delimiter">}</span> +<span id="L45" class="LineNr"> 45 </span> <span class="Normal">else</span> <span class="Delimiter">{</span> +<span id="L46" class="LineNr"> 46 </span> <a href='003trace.cc.html#L204'>trace</a><span class="Delimiter">(</span><span class="Constant">99</span><span class="Delimiter">,</span> <span class="Constant">"parse"</span><span class="Delimiter">)</span> << <span class="Constant">"prepending to segment '"</span> << segment_title << <span class="Constant">"'"</span> << end<span class="Delimiter">();</span> +<span id="L47" class="LineNr"> 47 </span> <span class="Delimiter">}</span> +<span id="L48" class="LineNr"> 48 </span> <a href='034compute_segment_address.cc.html#L26'>Currently_parsing_segment_index</a> = get<span class="Delimiter">(</span><a href='034compute_segment_address.cc.html#L24'>Segment_index</a><span class="Delimiter">,</span> segment_title<span class="Delimiter">);</span> +<span id="L49" class="LineNr"> 49 </span><span class="Delimiter">}</span> +<span id="L50" class="LineNr"> 50 </span> +<span id="L51" class="LineNr"> 51 </span><span class="Delimiter">:(before "End flush(p, lines) Special-cases")</span> +<span id="L52" class="LineNr"> 52 </span><span class="Normal">if</span> <span class="Delimiter">(</span><a href='034compute_segment_address.cc.html#L25'>Currently_parsing_named_segment</a><span class="Delimiter">)</span> <span class="Delimiter">{</span> +<span id="L53" class="LineNr"> 53 </span> <span class="Normal">if</span> <span class="Delimiter">(</span>p<span class="Delimiter">.</span><a href='011run.cc.html#L100'>segments</a><span class="Delimiter">.</span>empty<span class="Delimiter">()</span> || <a href='034compute_segment_address.cc.html#L26'>Currently_parsing_segment_index</a> < <span class="Constant">0</span><span class="Delimiter">)</span> <span class="Delimiter">{</span> +<span id="L54" class="LineNr"> 54 </span> <a href='003trace.cc.html#L211'>raise</a> << <span class="Constant">"input does not start with a '==' section header</span><span class="cSpecial">\n</span><span class="Constant">"</span> << end<span class="Delimiter">();</span> +<span id="L55" class="LineNr"> 55 </span> <span class="Identifier">return</span><span class="Delimiter">;</span> +<span id="L56" class="LineNr"> 56 </span> <span class="Delimiter">}</span> +<span id="L57" class="LineNr"> 57 </span> <a href='003trace.cc.html#L204'>trace</a><span class="Delimiter">(</span><span class="Constant">99</span><span class="Delimiter">,</span> <span class="Constant">"parse"</span><span class="Delimiter">)</span> << <span class="Constant">"flushing to segment"</span> << end<span class="Delimiter">();</span> +<span id="L58" class="LineNr"> 58 </span> vector<line>& curr_segment_data = p<span class="Delimiter">.</span><a href='011run.cc.html#L100'>segments</a><span class="Delimiter">.</span>at<span class="Delimiter">(</span><a href='034compute_segment_address.cc.html#L26'>Currently_parsing_segment_index</a><span class="Delimiter">).</span><a href='011run.cc.html#L109'>lines</a><span class="Delimiter">;</span> +<span id="L59" class="LineNr"> 59 </span> curr_segment_data<span class="Delimiter">.</span>insert<span class="Delimiter">(</span>curr_segment_data<span class="Delimiter">.</span>begin<span class="Delimiter">(),</span> <a href='011run.cc.html#L109'>lines</a><span class="Delimiter">.</span>begin<span class="Delimiter">(),</span> <a href='011run.cc.html#L109'>lines</a><span class="Delimiter">.</span>end<span class="Delimiter">());</span> +<span id="L60" class="LineNr"> 60 </span> <a href='011run.cc.html#L109'>lines</a><span class="Delimiter">.</span>clear<span class="Delimiter">();</span> +<span id="L61" class="LineNr"> 61 </span> <a href='034compute_segment_address.cc.html#L25'>Currently_parsing_named_segment</a> =<span class="Constant"> false</span><span class="Delimiter">;</span> +<span id="L62" class="LineNr"> 62 </span> <a href='034compute_segment_address.cc.html#L26'>Currently_parsing_segment_index</a> = -<span class="Constant">1</span><span class="Delimiter">;</span> +<span id="L63" class="LineNr"> 63 </span> <span class="Identifier">return</span><span class="Delimiter">;</span> +<span id="L64" class="LineNr"> 64 </span><span class="Delimiter">}</span> +<span id="L65" class="LineNr"> 65 </span> +<span id="L66" class="LineNr"> 66 </span><span class="Delimiter">:(scenario repeated_segment_merges_data)</span> +<span id="L67" class="LineNr"> 67 </span>== <a href='031check_operands.cc.html#L14'>code</a> +<span id="L68" class="LineNr"> 68 </span><span class="PreProc">0</span><span class="Constant">5</span>/add <span class="Constant">0x0d0c0b0a</span>/imm32 <span class="Comment"># add 0x0d0c0b0a to EAX</span> +<span id="L69" class="LineNr"> 69 </span>== <a href='031check_operands.cc.html#L14'>code</a> +<span id="L70" class="LineNr"> 70 </span>2d/subtract <span class="Constant">0xddccbbaa</span>/imm32 <span class="Comment"># subtract 0xddccbbaa from EAX</span> +<span id="L71" class="LineNr"> 71 </span><span class="traceContains">+parse: new segment 'code'</span> +<span id="L72" class="LineNr"> 72 </span><span class="traceContains">+parse: prepending to segment 'code'</span> +<span id="L73" class="LineNr"> 73 </span><span class="traceContains">+load: 0x08048054 -> 2d</span> +<span id="L74" class="LineNr"> 74 </span><span class="traceContains">+load: 0x08048055 -> aa</span> +<span id="L75" class="LineNr"> 75 </span><span class="traceContains">+load: 0x08048056 -> bb</span> +<span id="L76" class="LineNr"> 76 </span><span class="traceContains">+load: 0x08048057 -> cc</span> +<span id="L77" class="LineNr"> 77 </span><span class="traceContains">+load: 0x08048058 -> dd</span> +<span id="L78" class="LineNr"> 78 </span><span class="traceContains">+load: 0x08048059 -> 05</span> +<span id="L79" class="LineNr"> 79 </span><span class="traceContains">+load: 0x0804805a -> 0a</span> +<span id="L80" class="LineNr"> 80 </span><span class="traceContains">+load: 0x0804805b -> 0b</span> +<span id="L81" class="LineNr"> 81 </span><span class="traceContains">+load: 0x0804805c -> 0c</span> +<span id="L82" class="LineNr"> 82 </span><span class="traceContains">+load: 0x0804805d -> 0d</span> +<span id="L83" class="LineNr"> 83 </span> +<span id="L84" class="LineNr"> 84 </span><span class="Comment">//: compute segment address</span> +<span id="L85" class="LineNr"> 85 </span> +<span id="L86" class="LineNr"> 86 </span><span class="Delimiter">:(before "End Level-2 Transforms")</span> +<span id="L87" class="LineNr"> 87 </span><a href='011run.cc.html#L229'>Transform</a><span class="Delimiter">.</span>push_back<span class="Delimiter">(</span><a href='034compute_segment_address.cc.html#L90'>compute_segment_starts</a><span class="Delimiter">);</span> +<span id="L88" class="LineNr"> 88 </span> +<span id="L89" class="LineNr"> 89 </span><span class="Delimiter">:(code)</span> +<span id="L90" class="LineNr"> 90 </span><span class="Normal">void</span> <a href='034compute_segment_address.cc.html#L90'>compute_segment_starts</a><span class="Delimiter">(</span>program& p<span class="Delimiter">)</span> <span class="Delimiter">{</span> +<span id="L91" class="LineNr"> 91 </span> <a href='003trace.cc.html#L204'>trace</a><span class="Delimiter">(</span><span class="Constant">99</span><span class="Delimiter">,</span> <span class="Constant">"transform"</span><span class="Delimiter">)</span> << <span class="Constant">"-- compute segment addresses"</span> << end<span class="Delimiter">();</span> +<span id="L92" class="LineNr"> 92 </span> <span class="Normal">uint32_t</span> p_offset = <span class="Comment">/*</span><span class="Comment">size of ehdr</span><span class="Comment">*/</span><span class="Constant">0x34</span> + <a href='001help.cc.html#L157'>SIZE</a><span class="Delimiter">(</span>p<span class="Delimiter">.</span><a href='011run.cc.html#L100'>segments</a><span class="Delimiter">)</span>*<span class="Constant">0x20</span><span class="Comment">/*</span><span class="Comment">size of each phdr</span><span class="Comment">*/</span><span class="Delimiter">;</span> +<span id="L93" class="LineNr"> 93 </span> <span class="Normal">for</span> <span class="Delimiter">(</span><span class="Normal">size_t</span> i = <span class="Constant">0</span><span class="Delimiter">;</span> i < p<span class="Delimiter">.</span><a href='011run.cc.html#L100'>segments</a><span class="Delimiter">.</span>size<span class="Delimiter">();</span> ++i<span class="Delimiter">)</span> <span class="Delimiter">{</span> +<span id="L94" class="LineNr"> 94 </span> segment& curr = p<span class="Delimiter">.</span><a href='011run.cc.html#L100'>segments</a><span class="Delimiter">.</span>at<span class="Delimiter">(</span>i<span class="Delimiter">);</span> +<span id="L95" class="LineNr"> 95 </span> <span class="Normal">if</span> <span class="Delimiter">(</span>curr<span class="Delimiter">.</span>start == <span class="Constant">0</span><span class="Delimiter">)</span> <span class="Delimiter">{</span> +<span id="L96" class="LineNr"> 96 </span> curr<span class="Delimiter">.</span>start = <a href='012elf.cc.html#L136'>CODE_START</a> + i*SEGMENT_SIZE + p_offset<span class="Delimiter">;</span> +<span id="L97" class="LineNr"> 97 </span> <a href='003trace.cc.html#L204'>trace</a><span class="Delimiter">(</span><span class="Constant">99</span><span class="Delimiter">,</span> <span class="Constant">"transform"</span><span class="Delimiter">)</span> << <span class="Constant">"segment "</span> << i << <span class="Constant">" begins at address 0x"</span> << <a href='010---vm.cc.html#L368'>HEXWORD</a> << curr<span class="Delimiter">.</span>start << end<span class="Delimiter">();</span> +<span id="L98" class="LineNr"> 98 </span> <span class="Delimiter">}</span> +<span id="L99" class="LineNr"> 99 </span> p_offset += <a href='034compute_segment_address.cc.html#L104'>size_of</a><span class="Delimiter">(</span>curr<span class="Delimiter">);</span> +<span id="L100" class="LineNr">100 </span> assert<span class="Delimiter">(</span>p_offset < <a href='012elf.cc.html#L135'>SEGMENT_SIZE</a><span class="Delimiter">);</span> <span class="Comment">// for now we get less and less available space in each successive segment</span> +<span id="L101" class="LineNr">101 </span> <span class="Delimiter">}</span> +<span id="L102" class="LineNr">102 </span><span class="Delimiter">}</span> +<span id="L103" class="LineNr">103 </span> +<span id="L104" class="LineNr">104 </span><span class="Normal">uint32_t</span> <a href='034compute_segment_address.cc.html#L104'>size_of</a><span class="Delimiter">(</span><span class="Normal">const</span> segment& s<span class="Delimiter">)</span> <span class="Delimiter">{</span> +<span id="L105" class="LineNr">105 </span> <span class="Normal">uint32_t</span> sum = <span class="Constant">0</span><span class="Delimiter">;</span> +<span id="L106" class="LineNr">106 </span> <span class="Normal">for</span> <span class="Delimiter">(</span><span class="Normal">int</span> i = <span class="Constant">0</span><span class="Delimiter">;</span> i < <a href='001help.cc.html#L157'>SIZE</a><span class="Delimiter">(</span>s<span class="Delimiter">.</span><a href='011run.cc.html#L109'>lines</a><span class="Delimiter">);</span> ++i<span class="Delimiter">)</span> +<span id="L107" class="LineNr">107 </span> sum += <a href='034compute_segment_address.cc.html#L112'>num_bytes</a><span class="Delimiter">(</span>s<span class="Delimiter">.</span><a href='011run.cc.html#L109'>lines</a><span class="Delimiter">.</span>at<span class="Delimiter">(</span>i<span class="Delimiter">));</span> +<span id="L108" class="LineNr">108 </span> <span class="Identifier">return</span> sum<span class="Delimiter">;</span> +<span id="L109" class="LineNr">109 </span><span class="Delimiter">}</span> +<span id="L110" class="LineNr">110 </span> +<span id="L111" class="LineNr">111 </span><span class="Comment">// Assumes all bitfields are packed.</span> +<span id="L112" class="LineNr">112 </span><span class="Normal">uint32_t</span> <a href='034compute_segment_address.cc.html#L112'>num_bytes</a><span class="Delimiter">(</span><span class="Normal">const</span> line& inst<span class="Delimiter">)</span> <span class="Delimiter">{</span> +<span id="L113" class="LineNr">113 </span> <span class="Normal">uint32_t</span> sum = <span class="Constant">0</span><span class="Delimiter">;</span> +<span id="L114" class="LineNr">114 </span> <span class="Normal">for</span> <span class="Delimiter">(</span><span class="Normal">int</span> i = <span class="Constant">0</span><span class="Delimiter">;</span> i < <a href='001help.cc.html#L157'>SIZE</a><span class="Delimiter">(</span>inst<span class="Delimiter">.</span><a href='011run.cc.html#L118'>words</a><span class="Delimiter">);</span> ++i<span class="Delimiter">)</span> <span class="Delimiter">{</span> +<span id="L115" class="LineNr">115 </span> <span class="Normal">const</span> word& curr = inst<span class="Delimiter">.</span><a href='011run.cc.html#L118'>words</a><span class="Delimiter">.</span>at<span class="Delimiter">(</span>i<span class="Delimiter">);</span> +<span id="L116" class="LineNr">116 </span> <span class="Normal">if</span> <span class="Delimiter">(</span>has_operand_metadata<span class="Delimiter">(</span>curr<span class="Delimiter">,</span> <span class="Constant">"disp32"</span><span class="Delimiter">)</span> || has_operand_metadata<span class="Delimiter">(</span>curr<span class="Delimiter">,</span> <span class="Constant">"imm32"</span><span class="Delimiter">))</span> <span class="Comment">// only multi-byte operands</span> +<span id="L117" class="LineNr">117 </span> sum += <span class="Constant">4</span><span class="Delimiter">;</span> +<span id="L118" class="LineNr">118 </span> <span class="Comment">// End num_bytes(curr) Special-cases</span> +<span id="L119" class="LineNr">119 </span> <span class="Normal">else</span> +<span id="L120" class="LineNr">120 </span> sum++<span class="Delimiter">;</span> +<span id="L121" class="LineNr">121 </span> <span class="Delimiter">}</span> +<span id="L122" class="LineNr">122 </span> <span class="Identifier">return</span> sum<span class="Delimiter">;</span> +<span id="L123" class="LineNr">123 </span><span class="Delimiter">}</span> +<span id="L124" class="LineNr">124 </span> +<span id="L125" class="LineNr">125 </span><span class="Comment">//: Dependencies:</span> +<span id="L126" class="LineNr">126 </span><span class="Comment">//: - We'd like to compute segment addresses before setting up global variables,</span> +<span id="L127" class="LineNr">127 </span><span class="Comment">//: because computing addresses for global variables requires knowing where</span> +<span id="L128" class="LineNr">128 </span><span class="Comment">//: the data segment starts.</span> +<span id="L129" class="LineNr">129 </span><span class="Comment">//: - We'd like to finish expanding labels before computing segment addresses,</span> +<span id="L130" class="LineNr">130 </span><span class="Comment">//: because it would make computing the sizes of segments more self-contained</span> +<span id="L131" class="LineNr">131 </span><span class="Comment">//: (num_bytes).</span> +<span id="L132" class="LineNr">132 </span><span class="Comment">//:</span> +<span id="L133" class="LineNr">133 </span><span class="Comment">//: Decision: compute segment addresses before expanding labels, by being</span> +<span id="L134" class="LineNr">134 </span><span class="Comment">//: aware in this layer of certain operand types that will eventually occupy</span> +<span id="L135" class="LineNr">135 </span><span class="Comment">//: multiple bytes.</span> +<span id="L136" class="LineNr">136 </span><span class="Comment">//:</span> +<span id="L137" class="LineNr">137 </span><span class="Comment">//: The layer to expand labels later hooks into num_bytes() to teach this</span> +<span id="L138" class="LineNr">138 </span><span class="Comment">//: layer that labels occupy zero space in the binary.</span> </pre> </body> </html> |