Documentation: document runtime.curg and runtime.frameoff (#2835)

Documentation/cli/README.md

@@ -182,6 +182,8 @@ Set breakpoint condition.
 
 Specifies that the breakpoint, tracepoint or watchpoint should break only if the boolean expression is true.
 
+See Documentation/cli/expr.md for a description of supported expressions.
+
 With the -hitcount option a condition on the breakpoint hit count can be set, the following operators are supported
 
 	condition -hitcount bp > n
@@ -194,6 +196,11 @@ With the -hitcount option a condition on the breakpoint hit count can be set, th
 	
 The '% n' form means we should stop at the breakpoint when the hitcount is a multiple of n.
 
+Examples:
+	cond 2 i == 10				breakpoint 2 will stop when variable i equals 10
+	cond name runtime.curg.goid == 5	breakpoint 'name' will stop only on goroutine 5
+
+
 Aliases: cond
 
 ## config
@@ -489,7 +496,7 @@ Evaluate an expression.
 
 	[goroutine <n>] [frame <m>] print [%format] <expression>
 
-See [Documentation/cli/expr.md](//github.com/go-delve/delve/tree/master/Documentation/cli/expr.md) for a description of supported expressions.
+See Documentation/cli/expr.md for a description of supported expressions.
 
 The optional format argument is a format specifier, like the ones used by the fmt package. For example "print %x v" will print v as an hexadecimal number.
 
@@ -504,7 +511,7 @@ Print contents of CPU registers.
 
 	regs [-a]
 
-Argument -a shows more registers. Individual registers can also be displayed by 'print' and 'display'. See [Documentation/cli/expr.md.](//github.com/go-delve/delve/tree/master/Documentation/cli/expr.md.)
+Argument -a shows more registers. Individual registers can also be displayed by 'print' and 'display'. See Documentation/cli/expr.md.
 
 
 ## restart
@@ -547,7 +554,7 @@ Changes the value of a variable.
 
 	[goroutine <n>] [frame <m>] set <variable> = <value>
 
-See [Documentation/cli/expr.md](//github.com/go-delve/delve/tree/master/Documentation/cli/expr.md) for a description of supported expressions. Only numerical variables and pointers can be changed.
+See Documentation/cli/expr.md for a description of supported expressions. Only numerical variables and pointers can be changed.
 
 
 ## source

Documentation/cli/expr.md

@@ -14,6 +14,13 @@ Delve can evaluate a subset of go expression language, specifically the followin
 - Calls to builtin functions: `cap`, `len`, `complex`, `imag` and `real`
 - Type assertion on interface variables (i.e. `somevar.(concretetype)`)
 
+# Special Variables
+
+Delve defines two special variables:
+
+* `runtime.curg` evaluates to the 'g' struct for the current goroutine, in particular `runtime.curg.goid` is the goroutine id of the current goroutine.
+* `runtime.frameoff` is the offset of the frame's base address from the bottom of the stack.
+
 # Nesting limit
 
 When delve evaluates a memory address it will automatically return the value of nested struct members, array and slice items and dereference pointers.
@@ -129,3 +136,4 @@ Because many architectures have SIMD registers that can be used by the applicati
 * `REGNAME.floatN` returns the register REGNAME as an array fo floatN elements.
 
 In all cases N must be a power of 2.
+

pkg/terminal/command.go

@@ -300,7 +300,7 @@ Specifying -a prints all physical breakpoint, including internal breakpoints.`},
 
 	[goroutine <n>] [frame <m>] print [%format] <expression>
 
-See $GOPATH/src/github.com/go-delve/delve/Documentation/cli/expr.md for a description of supported expressions.
+See Documentation/cli/expr.md for a description of supported expressions.
 
 The optional format argument is a format specifier, like the ones used by the fmt package. For example "print %x v" will print v as an hexadecimal number.`},
 		{aliases: []string{"whatis"}, group: dataCmds, cmdFn: whatisCommand, helpMsg: `Prints type of an expression.
@@ -310,7 +310,7 @@ The optional format argument is a format specifier, like the ones used by the fm
 
 	[goroutine <n>] [frame <m>] set <variable> = <value>
 
-See $GOPATH/src/github.com/go-delve/delve/Documentation/cli/expr.md for a description of supported expressions. Only numerical variables and pointers can be changed.`},
+See Documentation/cli/expr.md for a description of supported expressions. Only numerical variables and pointers can be changed.`},
 		{aliases: []string{"sources"}, cmdFn: sources, helpMsg: `Print list of source files.
 
 	sources [<regex>]
@@ -347,7 +347,7 @@ If regex is specified only package variables with a name matching it will be ret
 
 	regs [-a]
 
-Argument -a shows more registers. Individual registers can also be displayed by 'print' and 'display'. See $GOPATH/src/github.com/go-delve/delve/Documentation/cli/expr.md.`},
+Argument -a shows more registers. Individual registers can also be displayed by 'print' and 'display'. See Documentation/cli/expr.md.`},
 		{aliases: []string{"exit", "quit", "q"}, cmdFn: exitCommand, helpMsg: `Exit the debugger.
 		
 	exit [-c]
@@ -454,6 +454,8 @@ The command 'on x -edit' can be used to edit the list of commands executed when
 
 Specifies that the breakpoint, tracepoint or watchpoint should break only if the boolean expression is true.
 
+See Documentation/cli/expr.md for a description of supported expressions.
+
 With the -hitcount option a condition on the breakpoint hit count can be set, the following operators are supported
 
 	condition -hitcount bp > n
@@ -464,7 +466,12 @@ With the -hitcount option a condition on the breakpoint hit count can be set, th
 	condition -hitcount bp != n
 	condition -hitcount bp % n
 	
-The '% n' form means we should stop at the breakpoint when the hitcount is a multiple of n.`},
+The '% n' form means we should stop at the breakpoint when the hitcount is a multiple of n.
+
+Examples:
+	cond 2 i == 10				breakpoint 2 will stop when variable i equals 10
+	cond name runtime.curg.goid == 5	breakpoint 'name' will stop only on goroutine 5
+`},
 		{aliases: []string{"config"}, cmdFn: configureCmd, helpMsg: `Changes configuration parameters.
 
 	config -list