Update readme tagline

Author: cirosantilli

Makefile_many

@@ -117,7 +117,7 @@ set_profile_flags:
 
 test: all
 	@\
-	if [ -x $(TEST)  ]; then \
+	if [ -x $(TEST) ]; then \
 	  ./$(TEST) '$(OUT_EXT)' ;\
 	else\
 	  fail=false ;\

README.md

@@ -2,7 +2,7 @@
 
 [![Build Status](https://travis-ci.org/cirosantilli/cpp-cheat.svg?branch=master)](https://travis-ci.org/cirosantilli/cpp-cheat)
 
-C and C++ information, cheatsheets and mini-projects.
+C and C++ minimal examples. Asserts used wherever possible. Cheatsheet, tutorial and mini-projects.
 
 Relies on [C++ boilerplate](https://github.com/cirosantilli/cpp-boilerplate) to factor code out. See [its documentation](https://github.com/cirosantilli/cpp-boilerplate/blob/master/README.md) for information on how to use this project.
 

cpp/constexpr.cpp

@@ -122,6 +122,11 @@ int main() {
         //i = 1;
     }
 
+    {
+        constexpr int i = 0;
+        &i;
+    }
+
     // WARN: unitialized constexpr
     {
         //constexpr int i;

gcc/asm.c

@@ -18,11 +18,11 @@
     General syntax:
 
         asm (
-            "mov $1, %%eax;"   //commands string
-            : "=X" (y),   //outputs
+            "mov $1, %%eax;"   // commands string
+            : "=X" (y),   // outputs
                 "=X" (z)
-            : "X" (x)    //inputs
-            : "%eax"     //clobbered registers
+            : "X" (x)    // inputs
+            : "%eax"     // clobbered registers
         );
 
     where:
@@ -86,9 +86,9 @@ int main() {
     /*
     # m constraint
 
-        Instructs gcc to store keep value of given expressions into RAM.
+        Instructs GCC to keep value of given expressions into RAM.
 
-        This is the most basic way to get/set values of c variables in assembly code.
+        This is the most basic way to get/set values of C variables in assembly code.
     */
     {
         int in = 1;
@@ -99,7 +99,7 @@ int main() {
             "movl %%eax, %0"
             : "=m" (out)
             : "m" (in)
-            : "%eax"      /* eax will be modified, so we have to list it in the clobber list */
+            : "%eax"
         );
         assert(out == 1);
     }
@@ -130,7 +130,7 @@ int main() {
         assert(out == -1.0);
     }
 
-    /* Input and ouput can be the same memory location. */
+    /* Input and output can be the same memory location. */
     {
         float x = 1.0;
         /*x = -x*/
@@ -145,11 +145,13 @@ int main() {
     }
 
     /*
-    # register constraints
+    # Register constraints
 
-        tell gcc to automatically read memory into registers or write registers into memory
+        https://gcc.gnu.org/onlinedocs/gcc/Simple-Constraints.html
 
-        this is more precise and complicated than using `m`
+        Tell GCC to automatically read memory into registers or write registers into memory
+
+        This is more precise and complicated than using `m`:
 
         - r: gcc chooses any free register
         - a: %eax
@@ -170,7 +172,7 @@ int main() {
         note how we can do an `inc` operation directly on `%1` and `%0`
         so they must both already be inside a registers as expected
 
-        gcc just makes sure they are writen from/to memory before/after the operations
+        GCC just makes sure they are written from/to memory before/after the operations.
     */
     {
         int in = 0;

gdb/commands.md

@@ -242,7 +242,7 @@ Like `si` by for `next`.
 
 Don't enter `call`.
 
-Does enter `int` in 16-bit code. In that case, you can use instead:
+Does enter `int` in 16-bit code. In that case, you can use instead: TODO <http://stackoverflow.com/questions/24491516/how-to-step-over-interrupt-calls-when-debugging-a-bootloader-bios-with-gdb-and-q> If only we could get the size of the current instruction automatically.
 
 ### until
 
@@ -795,6 +795,21 @@ Useful for batch mode scripts that automatically check executables.
 
     printf "rax = %d\n", $rax
 
+### echo
+
+Like `printf`, but:
+
+- does not take `"`
+- does not take format strings
+
+Backslash escapes are considered.
+
+E.g.:
+
+    echo asdf\n
+
+Just use the saner `printf` instead.
+
 ### disas
 
 ### disassemble

gdb/disassemble.py

@@ -1,7 +1,7 @@
 """
 Disassemble some instructions.
 
-https://sourceware.org/gdb/onlinedocs/gdb/Architectures-In-Python.html#Architectures-In-Python
+https://sourceware.org/gdb/onlinedocs/gdb/Architectures-In-Python.html
 """
 
 gdb.execute('file big_function.out', to_string=True)
@@ -13,5 +13,4 @@
 
 pc = gdb.selected_frame().pc()
 
-# 1 instruction.
-print(arch.disassemble(pc)[0]['asm'])
+print(arch.disassemble(pc)[0])